Reorganize source tree to use single autotools instance

Change-Id: I7b51f88292e057c6443b12224486f2d0c9f8ae23
Signed-off-by: Damjan Marion <damarion@cisco.com>

48 files changed, 25560 insertions, 0 deletions

diff --git a/src/vnet/fib/fib.c b/src/vnet/fib/fib.c
new file mode 100644
index 00000000000..413f93e893c
--- /dev/null
+++ b/src/vnet/fib/fib.c
@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vnet/fib/fib_entry_src.h>
+#include <vnet/fib/fib_entry.h>
+#include <vnet/fib/fib_path.h>
+#include <vnet/fib/fib_walk.h>
+#include <vnet/fib/fib_path_list.h>
+
+static clib_error_t *
+fib_module_init (vlib_main_t * vm)
+{
+    clib_error_t * error;
+
+    if ((error = vlib_call_init_function (vm, dpo_module_init)))
+	return (error);
+    if ((error = vlib_call_init_function (vm, adj_module_init)))
+	return (error);
+
+    fib_entry_module_init();
+    fib_entry_src_module_init();
+    fib_path_module_init();
+    fib_path_list_module_init();
+    fib_walk_module_init();
+
+    return (NULL);
+}
+
+VLIB_INIT_FUNCTION (fib_module_init);
diff --git a/src/vnet/fib/fib.h b/src/vnet/fib/fib.h
new file mode 100644
index 00000000000..7cf1d136935
--- /dev/null
+++ b/src/vnet/fib/fib.h
@@ -0,0 +1,652 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/**
+ * \brief
+ * A IP v4/6 independent FIB.
+ *
+ * The main functions provided by the FIB are as follows;
+ *
+ *  - source priorities
+ *
+ *   A route can be added to the FIB by more than entity or source. Sources
+ * include, but are not limited to, API, CLI, LISP, MAP, etc (for the full list
+ * see fib_entry.h). Each source provides the forwarding information (FI) that
+ * is has determined as required for that route. Since each source determines the
+ * FI using different best  path and loop prevention algorithms, it is not
+ * correct for the FI of multiple sources to be combined. Instead the FIB must
+ * choose to use the FI from only one source. This choose is based on a static
+ * priority assignment. For example;
+ * IF a prefix is added as a result of interface configuration:
+ *    set interface address 192.168.1.1/24 GigE0
+ * and then it is also added from the CLI
+ *    ip route 192.168.1.1/32 via 2.2.2.2/32
+ * then the 'interface' source will prevail, and the route will remain as
+ * 'local'.
+ * The requirement of the FIB is to always install the FI from the winning
+ * source and thus to maintain the FI added by losing sources so it can be
+ * installed should the winning source be withdrawn.
+ *
+ *  - adj-fib maintenance
+ *
+ *   When ARP or ND discover a neighbour on a link an adjacency forms for the
+ * address of that neighbour. It is also required to insert a route in the
+ * appropriate FIB table, corresponding to the VRF for the link, an entry for
+ * that neighbour. This entry is often referred to as an adj-fib. Adj-fibs
+ * have a dedicated source; 'ADJ'.
+ * The priority of the ADJ source is lower than most. This is so the following
+ * config;
+ *    set interface address 192.168.1.1/32 GigE0
+ *    ip arp 192.168.1.2 GigE0 dead.dead.dead
+ *    ip route add 192.168.1.2 via 10.10.10.10 GigE1
+ * will forward traffic for 192.168.1.2 via GigE1. That is the route added
+ * by the control plane is favoured over the adjacency discovered by ARP.
+ * The control plane, with its associated authentication, is considered the
+ * authoritative source.
+ * To counter the nefarious addition of adj-fib, through the nefarious injection
+ * of adjacencies, the FIB is also required to ensure that only adj-fibs whose
+ * less specific covering prefix is connected are installed in forwarding. This
+ * requires the use of 'cover tracking', where a route maintains a dependency
+ * relationship with the route that is its less specific cover. When this cover
+ * changes (i.e. there is a new covering route) or the forwarding information
+ * of the cover changes, then the covered route is notified.
+ *
+ * Overlapping sub-nets are not supported, so no adj-fib has multiple paths.
+ * The control plane is expected to remove a prefix configured for an interface
+ * before the interface changes VRF.
+ * So while the following config is accepted:
+ *    set interface address 192.168.1.1/32 GigE0
+ *    ip arp 192.168.1.2 GigE0 dead.dead.dead
+ *    set interface ip table GigE0 2
+ * it does not result in the desired behaviour.
+ *
+ *  - attached export.
+ *
+ * Further to adj-fib maintenance above consider the following config:
+ *    set interface address 192.168.1.1/24 GigE0
+ *    ip route add table 2 192.168.1.0/24 GigE0
+ * Traffic destined for 192.168.1.2 in table 2 will generate an ARP request
+ * on GigE0. However, since GigE0 is in table 0, all adj-fibs will be added in
+ * FIB 0. Hence all hosts in the sub-net are unreachable from table 2. To resolve
+ * this, all adj-fib and local prefixes are exported (i.e. copied) from the 
+ * 'export' table 0, to the 'import' table 2. There can be many import tables
+ * for a single export table.
+ *
+ *  - recursive route resolution
+ *
+ *   A recursive route is of the form:
+ *       1.1.1.1/32 via 10.10.10.10
+ * i.e. a route for which no egress interface is provided. In order to forward
+ * traffic to 1.1.1.1/32 the FIB must therefore first determine how to forward
+ * traffic to 10.10.10.10/32. This is recursive resolution.
+ * Recursive resolution, just like normal resolution, proceeds via a longest
+ * prefix match for the 'via-address' 10.10.10.10. Note it is only possible
+ * to add routes via an address (i.e. a /32 or /128) not via a shorter mask
+ * prefix. There is no use case for the latter.
+ * Since recursive resolution proceeds via a longest prefix match, the entry
+ * in the FIB that will resolve the recursive route, termed the via-entry, may
+ * change as other routes are added to the FIB. Consider the recursive
+ * route shown above, and this non-recursive route:
+ *       10.10.10.0/24 via 192.168.16.1 GigE0
+ * The entry for 10.10.10.0/24 is thus the resolving via-entry. If this entry is
+ * modified, to say;
+ *       10.10.10.0/24 via 192.16.1.3 GigE0
+ * Then packet for 1.1.1.1/32 must also be sent to the new next-hop.
+ * Now consider the addition of;
+ *       10.10.10.0/28 via 192.168.16.2 GigE0
+ * The more specific /28 is a better longest prefix match and thus becomes the
+ * via-entry. Removal of the /28 means the resolution will revert to the /24.
+ * The tracking to the changes in recursive resolution is the requirement of
+ * the FIB. When the forwarding information of the via-entry changes a back-walk
+ * is used to update dependent recursive routes. When new routes are added to
+ * the table the cover tracking feature provides the necessary notifications to
+ * the via-entry routes.
+ * The adjacency constructed for 1.1.1.1/32 will be a recursive adjacency
+ * whose next adjacency will be contributed from the via-entry. Maintaining
+ * the validity of this recursive adjacency is a requirement of the FIB.
+ *
+ *  - recursive loop avoidance
+ *
+ * Consider this set of routes:
+ *     1.1.1.1/32 via 2.2.2.2
+ *     2.2.2.2/32 via 3.3.3.3
+ *     3.3.3.3/32 via 1.1.1.1
+ * this is termed a recursion loop - all of the routes in the loop are
+ * unresolved in so far as they do not have a resolving adjacency, but each
+ * is resolved because the via-entry is known. It is important here to note
+ * the distinction between the control-plane objects and the data-plane objects
+ * (more details in the implementation section). The control plane objects must
+ * allow the loop to form (i.e. the graph becomes cyclic), however, the
+ * data-plane absolutely must not allow the loop to form, otherwise the packet
+ * would loop indefinitely and never egress the device - meltdown would follow.
+ * The control plane must allow the loop to form, because when the loop breaks,
+ * all members of the loop need to be updated. Forming the loop allows the
+ * dependencies to be correctly setup to allow this to happen.
+ * There is no limit to the depth of recursion supported by VPP so:
+ *    9.9.9.100/32 via 9.9.9.99
+ *    9.9.9.99/32  via 9.9.9.98
+ *    9.9.9.98/32  via 9.9.9.97
+ *      ... turtles, turtles, turtles ...
+ *    9.9.9.1/32 via 10.10.10.10 Gig0
+ * is supported to as many layers of turtles is desired, however, when
+ * back-walking a graph (in this case from 9.9.9.1/32 up toward 9.9.9.100/32)
+ * a FIB needs to differentiate the case where the recursion is deep versus
+ * the case where the recursion is looped. A simple method, employed by VPP FIB,
+ * is to limit the number of steps. VPP FIB limit is 16. Typical BGP scenarios
+ * in the wild do not exceed 3 (BGP Inter-AS option C).
+ * 
+ * - Fast Convergence
+ * 
+ * After a network topology change, the 'convergence' time, is the time taken
+ * for the router to complete a transition to forward traffic using the new
+ * topology. The convergence time is therefore a summation of the time to;
+ *  - detect the failure.
+ *  - calculate the new 'best path' information
+ *  - download the new best paths to the data-plane.
+ *  - install those best best in data-plane forwarding.
+ * The last two points are of relevance to VPP architecture. The download API is
+ * binary and batch, details are not discussed here. There is no HW component to
+ * programme, installation time is bounded by the memory allocation and table
+ * lookup and insert access times.
+ *
+ * 'Fast' convergence refers to a set of technologies that a FIB can employ to
+ * completely or partially restore forwarding whilst the convergence actions
+ * listed above are ongoing. Fast convergence technologies are further
+ * sub-divided into Prefix Independent Convergence (PIC) and Loop Free
+ * Alternate path Fast re-route (LFA-FRR or sometimes called IP-FRR) which
+ * affect recursive and non-recursive routes respectively.
+ *
+ * LFA-FRR
+ *
+ * Consider the network topology below:
+ *
+ *          C
+ *        /   \
+ *  X -- A --- B - Y
+ *       |     |
+ *       D     F
+ *        \   /
+ *          E
+ *
+ * all links are equal cost, traffic is passing from X to Y. the best path is
+ * X-A-B-Y. There are two alternative paths, one via C and one via E. An
+ * alternate path is considered to be loop free if no other router on that path
+ * would forward the traffic back to the sender. Consider router C, its best
+ * path to Y is via B, so if A were to send traffic destined to Y to C, then C
+ * would forward that traffic to B - this is a loop-free alternate path. In
+ * contrast consider router D. D's shortest path to Y is via A, so if A were to
+ * send traffic destined to Y via D, then D would send it back to A; this is
+ * not a loop-free alternate path. There are several points of note;
+ *   - we are considering the pre-failure routing topology
+ *   - any equal-cost multi-path between A and B is also a LFA path.
+ *   - in order for A to calculate LFA paths it must be aware of the best-path
+ *     to Y from the perspective of D. These calculations are thus limited to
+ *     routing protocols that have a full view of the network topology, i.e.
+ *     link-state DB protocols like OSPF or an SDN controller. LFA protected
+ *     prefixes are thus non-recursive.
+ *
+ * LFA is specified as a 1 to 1 redundancy; a primary path has only one LFA
+ * (a.k.a. backup) path. To my knowledge this limitation is one of complexity
+ * in the calculation of and capacity planning using a 1-n redundancy. 
+ *
+ * In the event that the link A-B fails, the alternate path via C can be used.
+ * In order to provide 'fast' failover in the event of a failure, the control
+ * plane will download both the primary and the backup path to the FIB. It is
+ * then a requirement of the FIB to perform the failover (a.k.a cutover) from
+ * the primary to the backup path as quickly as possible, and particularly
+ * without any other control-plane intervention. The expectation is cutover is
+ * less than 50 milli-seconds - a value allegedly from the VOIP QoS. Note that
+ * cutover time still includes the fault detection time, which in a vitalised
+ * environment could be the dominant factor. Failure detection can be either a
+ * link down, which will affect multiple paths on a multi-access interface, or
+ * via a specific path heartbeat (i.e. BFD). 
+ * At this time VPP does not support LFA, that is it does not support the
+ * installation of a primary and backup path[s] for a route. However, it does
+ * support ECMP, and VPP FIB is designed to quickly remove failed paths from
+ * the ECMP set, however, it does not insert shared objects specific to the
+ * protected resource into the forwarding object graph, since this would incur
+ * a forwarding/performance cost. Failover time is thus route number dependent.
+ * Details are provided in the implementation section below.
+ *
+ * PIC
+ *
+ * PIC refers to the concept that the converge time should be independent of
+ * the number of prefixes/routes that are affected by the failure. PIC is
+ * therefore most appropriate when considering networks with large number of
+ * prefixes, i.e. BGP networks and thus recursive prefixes. There are several
+ * flavours of PIC covering different locations of protection and failure
+ * scenarios. An outline is given below, see the literature for more details:
+ *
+ * Y/16 - CE1 -- PE1---\
+ *                | \   P1---\
+ *                |  \        PE3 -- CE3 - X/16
+ *                |   - P2---/
+ * Y/16 - CE2 -- PE2---/
+ *
+ * CE = customer edge, PE = provider edge. external-BGP runs between customer
+ * and provider, internal-BGP runs between provider and provider.
+ *
+ * 1) iBGP PIC-core: consider traffic from CE1 to X/16 via CE3. On PE1 there is
+ *    are routes;
+ *       X/16 (and hundreds of thousands of others like it)
+ *         via PE3
+ *    and
+ *      PE3/32 (its loopback address)
+ *        via 10.0.0.1 Link0 (this is P1)
+ *        via 10.1.1.1 Link1 (this is P2)
+ * the failure is the loss of link0 or link1
+ * As in all PIC scenarios, in order to provide prefix independent convergence
+ * it must be that the route for X/16 (and all other routes via PE3) do not
+ * need to be updated in the FIB. The FIB therefore needs to update a single
+ * object that is shared by all routes - once this shared object is updated,
+ * then all routes using it will be instantly updated to use the new forwarding
+ * information. In this case the shared object is the resolving route via PE3.
+ * Once the route via PE3 is updated via IGP (OSPF) convergence, then all
+ * recursive routes that resolve through it are also updated. VPP FIB
+ * implements this scenario via a recursive-adjacency. the X/16 and it sibling
+ * routes share a recursive-adjacency that links to/points at/stacks on the
+ * normal adjacency contributed by the route for PE3. Once this shared
+ * recursive adj is re-linked then all routes are switched to using the new
+ * forwarding information. This is shown below;
+ *
+ * pre-failure;
+ *   X/16 --> R-ADJ-1 --> ADJ-1-PE3 (multi-path via P1 and P2)
+ *
+ * post-failure:
+ *   X/16 --> R-ADJ-1 --> ADJ-2-PE3 (single path via P1)
+ *
+ * note that R-ADJ-1 (the recursive adj) remains in the forwarding graph,
+ * therefore X/16 (and all its siblings) is not updated.
+ * X/16 and its siblings share the recursive adj since they share the same
+ * path-list. It is the path-list object that contributes the recursive-adj
+ * (see next section for more details)
+ *
+ *
+ * 2) iBGP PIC-edge; Traffic from CE3 to Y/16. On PE3 there is are routes;
+ *      Y/16  (and hundreds of thousands of others like it)
+ *        via PE1
+ *        via PE2 
+ *  and
+ *     PE1/32 (PE1's loopback address)
+ *       via 10.0.2.2 Link0 (this is P1)
+ *     PE2/32 (PE2's loopback address)
+ *       via 10.0.3.3 Link1 (this is P2)
+ *
+ * the failure is the loss of reachability to PE2. this could be either the
+ * loss of the link P2-PE2 or the loss of the node PE2. This is detected either
+ * by the withdrawal of the PE2's loopback route or by some form of failure
+ * detection (i.e. BFD).
+ * VPP FIB again provides PIC via the use of the shared recursive-adj. Y/16 and
+ * its siblings will again share a path-list for the list {PE1,PE2}, this
+ * path-list will contribute a multi-path-recursive-adj, i.e. a multi-path-adj
+ * with each choice therein being another adj;
+ *
+ *  Y/16 -> RM-ADJ --> ADJ1 (for PE1)
+ *                 --> ADJ2 (for PE2)
+ *
+ * when the route for PE1 is withdrawn then the multi-path-recursive-adjacency
+ * is updated to be;
+ *
+ * Y/16 --> RM-ADJ --> ADJ1 (for PE1)
+ *                 --> ADJ1 (for PE1)
+ *
+ * that is both choices in the ECMP set are the same and thus all traffic is
+ * forwarded to PE1. Eventually the control plane will download a route update
+ * for Y/16 to be via PE1 only. At that time the situation will be:
+ *
+ * Y/16 -> R-ADJ --> ADJ1 (for PE1)
+ *
+ * In the scenario above we assumed that PE1 and PE2 are ECMP for Y/16. eBGP
+ * PIC core is also specified for the case were one PE is primary and the other
+ * backup - VPP FIB does not support that case at this time.
+ *
+ * 3) eBGP PIC Edge; Traffic from CE3 to Y/16. On PE1 there is are routes;
+ *      Y/16 (and hundreds of thousands of others like it)
+ *         via CE1 (primary)
+ *         via PE2 (backup)
+ *   and
+ *     CE1 (this is an adj-fib)
+ *       via 11.0.0.1 Link0 (this is CE1) << this is an adj-fib
+ *     PE2 (PE2's loopback address)
+ *       via 10.0.5.5 Link1 (this is link PE1-PE2)
+ * the failure is the loss of link0 to CE1. The failure can be detected by FIB
+ * either as a link down event or by the control plane withdrawing the connected
+ * prefix on the link0 (say 10.0.5.4/30). The latter works because the resolving
+ * entry is an adj-fib, so removing the connected will withdraw the adj-fib, and
+ * hence the recursive path becomes unresolved. The former is faster,
+ * particularly in the case of Inter-AS option A where there are many VLAN
+ * sub-interfaces on the PE-CE link, one for each VRF, and so the control plane
+ * must remove the connected prefix for each sub-interface to trigger PIC in
+ * each VRF. Note though that total PIC cutover time will depend on VRF scale
+ * with either trigger.
+ * Primary and backup paths in this eBGP PIC-edge scenario are calculated by
+ * BGP. Each peer is configured to always advertise its best external path to
+ * its iBGP peers. Backup paths therefore send traffic from the PE back into the
+ * core to an alternate PE. A PE may have multiple external paths, i.e. multiple
+ * directly connected CEs, it may also have multiple backup PEs, however there
+ * is no correlation between the two, so unlike LFA-FRR, the redundancy model is
+ * N-M; N primary paths are backed-up by M backup paths - only when all primary
+ * paths fail, then the cutover is performed onto the M backup paths. Note that
+ * PE2 must be suitably configured to forward traffic on its external path that
+ * was received from PE1. VPP FIB does not support external-internal-BGP (eiBGP)
+ * load-balancing.
+ *
+ * As with LFA-FRR the use of primary and backup paths is not currently
+ * supported, however, the use of a recursive-multi-path-adj, and a suitably
+ * constrained hashing algorithm to choose from the primary or backup path sets,
+ * would again provide the necessary shared object and hence the prefix scale
+ * independent cutover.
+ *
+ * Astute readers will recognise that both of the eBGP PIC scenarios refer only
+ * to a BGP free core.
+ *
+ * Fast convergence implementation options come in two flavours:
+ *  1) Insert switches into the data-path. The switch represents the protected
+ *     resource. If the switch is 'on' the primary path is taken, otherwise
+ *     the backup path is taken. Testing the switch in the data-path comes with
+ *     an associated performance cost. A given packet may encounter more than
+ *     one protected resource as it is forwarded. This approach minimises
+ *     cutover times as packets will be forwarded on the backup path as soon
+ *     as the protected resource is detected to be down and the single switch
+ *     is tripped. However, it comes at a performance cost, which increases
+ *     with each shared resource a packet encounters in the data-path.
+ *     This approach is thus best suited to LFA-FRR where the protected routes
+ *     are non-recursive (i.e. encounter few shared resources) and the
+ *     expectation on cutover times is more stringent (<50msecs).
+ *  2) Update shared objects. Identify objects in the data-path, that are
+ *     required to be present whether or not fast convergence is required (i.e.
+ *     adjacencies) that can be shared by multiple routes. Create a dependency
+ *     between these objects at the protected resource. When the protected
+ *     resource fails, each of the shared objects is updated in a way that all
+ *     users of it see a consistent change. This approach incurs no performance
+ *     penalty as the data-path structure is unchanged, however, the cutover
+ *     times are longer as more work is required when the resource fails. This
+ *     scheme is thus more appropriate to recursive prefixes (where the packet
+ *     will encounter multiple protected resources) and to fast-convergence
+ *     technologies where the cutover times are less stringent (i.e. PIC).
+ *
+ * Implementation:
+ * ---------------
+ *
+ * Due to the requirements outlined above, not all routes known to FIB
+ * (e.g. adj-fibs) are installed in forwarding. However, should circumstances
+ * change, those routes will need to be added. This adds the requirement that
+ * a FIB maintains two tables per-VRF, per-AF (where a 'table' is indexed by
+ * prefix); the forwarding and non-forwarding tables.
+ *
+ * For DP speed in VPP we want the lookup in the forwarding table to directly 
+ * result in the ADJ. So the two tables; one contains all the routes (a 
+ * lookup therein yields a fib_entry_t), the other contains only the forwarding 
+ * routes (a lookup therein yields an ip_adjacency_t). The latter is used by the
+ * DP. 
+ * This trades memory for forwarding performance. A good trade-off in VPP's
+ * expected operating environments.
+ *
+ * Note these tables are keyed only by the prefix (and since there 2 two
+ * per-VRF, implicitly by the VRF too). The key for an adjacency is the
+ * tuple:{next-hop, address (and it's AF), interface, link/ether-type}.
+ * consider this curious, but allowed, config;
+ *
+ *   set int ip addr 10.0.0.1/24 Gig0
+ *   set ip arp Gig0 10.0.0.2 dead.dead.dead
+ *   # a host in that sub-net is routed via a better next hop (say it avoids a
+ *   # big L2 domain)
+ *   ip route add 10.0.0.2 Gig1 192.168.1.1
+ *   # this recursive should go via Gig1
+ *   ip route add 1.1.1.1/32 via 10.0.0.2
+ *   # this non-recursive should go via Gig0
+ *   ip route add 2.2.2.2/32 via Gig0 10.0.0.2
+ *
+ * for the last route, the lookup for the path (via {Gig0, 10.0.0.2}) in the
+ * prefix table would not yield the correct result. To fix this we need a
+ * separate table for the adjacencies.
+ *
+ *  - FIB data structures;
+ *
+ * fib_entry_t:
+ *   - a representation of a route.
+ *     - has a prefix.
+ *    - it maintains an array of path-lists that have been contributed by the
+ *      different sources
+ *    - install an adjacency in the forwarding table contributed by the best
+ *      source's path-list.
+ *
+ * fib_path_list_t:
+ *   - a list of paths
+ *   - path-lists may be shared between FIB entries. The path-lists are thus
+ *     kept in a DB. The key is the combined description of the paths. We share
+ *     path-lists  when it will aid convergence to do so. Adding path-lists to
+ *     this DB that are never shared, or are not shared by prefixes that are
+ *     not subject to PIC, will increase the size of the DB unnecessarily and
+ *     may lead to increased search times due to hash collisions.
+ *   - the path-list contributes the appropriate adj for the entry in the 
+ *     forwarding table. The adj can be 'normal', multi-path or recursive,
+ *     depending on the number of paths and their types.
+ *   - since path-lists are shared there is only one instance of the multi-path 
+ *     adj that they [may] create. As such multi-path adjacencies do not need a
+ *     separate DB.
+ * The path-list with recursive paths and the recursive adjacency that it
+ * contributes forms the backbone of the fast convergence architecture (as 
+ * described previously). 
+ *
+ * fib_path_t:
+ *   - a description of how to forward the traffic (i.e. via {Gig1, K}).
+ *   - the path describes the intent on how to forward. This differs from how 
+ *     the path resolves. I.e. it might not be resolved at all (since the
+ *     interface is deleted or down).
+ *   - paths have different types, most notably recursive or non-recursive.
+ *   - a fib_path_t will contribute the appropriate adjacency object. It is from
+ *     these contributions that the DP graph/chain for the route is built.
+ *   - if the path is recursive and a recursion loop is detected, then the path
+ *     will contribute the special DROP adjacency. This way, whilst the control
+ *     plane graph is looped, the data-plane graph does not.
+ *
+ * we build a graph of these objects;
+ *
+ *  fib_entry_t -> fib_path_list_t -> fib_path_t -> ...
+ *
+ * for recursive paths:
+ *
+ *   fib_path_t -> fib_entry_t -> ....
+ *
+ * for non-recursive paths
+ *
+ *  fib_path_t -> ip_adjacency_t -> interface
+ *
+ * These objects, which constitute the 'control plane' part of the FIB are used
+ * to represent the resolution of a route. As a whole this is referred to as the
+ * control plane graph. There is a separate DP graph to represent the forwarding
+ * of a packet. In the DP graph each object represents an action that is applied
+ * to a packet as it traverses the graph. For example, a lookup of a IP address
+ * in the forwarding table could result in the following graph:
+ *
+ *    recursive-adj --> multi-path-adj --> interface_A
+ *                                     --> interface_B
+ *
+ * A packet traversing this FIB DP graph would thus also traverse a VPP node
+ * graph of:
+ *
+ *    ipX_recursive --> ipX_rewrite --> interface_A_tx --> etc
+ *
+ * The taxonomy of objects in a FIB graph is as follows, consider;
+ *
+ *   A -->  
+ *   B --> D
+ *   C -->
+ *
+ * Where A,B and C are (for example) routes that resolve through D. 
+ *  parent; D is the parent of A, B, and C.
+ *  children: A, B, and C are children of D. 
+ *  sibling: A, B and C are siblings of one another.
+ *
+ * All shared objects in the FIB are reference counted. Users of these objects
+ * are thus expected to use the add_lock/unlock semantics (as one would
+ * normally use malloc/free).
+ *
+ * WALKS
+ *
+ * It is necessary to walk/traverse the graph forwards (entry to interface) to
+ * perform a collapse or build a recursive adj and backwards (interface
+ * to entry) to perform updates, i.e. when interface state changes or when
+ * recursive route resolution updates occur.
+ * A forward walk follows simply by navigating an object's parent pointer to
+ * access its parent object. For objects with multiple parents (e.g. a 
+ * path-list), each parent is walked in turn.
+ * To support back-walks direct dependencies are maintained between objects,
+ * i.e. in the relationship, {A, B, C} --> D, then object D will maintain a list
+ * of 'pointers' to its children {A, B, C}. Bare C-language pointers are not 
+ * allowed, so a pointer is described in terms of an object type (i.e. entry,
+ * path-list, etc) and index - this allows the object to be retrieved from the
+ * appropriate pool. A list is maintained to achieve fast convergence at scale.
+ * When there are millions or recursive prefixes, it is very inefficient to
+ * blindly walk the tables looking for entries that were affected by a given
+ * topology change. The lowest hanging fruit when optimising is to remove
+ * actions that are not required, so all back-walks only traverse objects that
+ * are directly affected by the change.
+ *
+ * PIC Core and fast-reroute rely on FIB reacting quickly to an interface
+ * state change to update the multi-path-adjacencies that use this interface.
+ * An example graph is shown below:
+ *
+ *    E_a -->
+ *    E_b --> PL_2 --> P_a --> Interface_A
+ *    ...          --> P_c -\
+ *    E_k -->                \
+ *                            Interface_K
+ *                            /
+ *    E_l -->                /
+ *    E_m --> PL_1 --> P_d -/ 
+ *    ...          --> P_f --> Interface_F
+ *    E_z -->
+ *
+ * E  = fib_entry_t
+ * PL = fib_path_list_t
+ * P  = fib_path_t 
+ * The subscripts are arbitrary and serve only to distinguish object instances.
+ * This CP graph result in the following DP graph:
+ *
+ *     M-ADJ-2 --> Interface_A
+ *             \
+ *              -> Interface_K
+ *             / 
+ *     M-ADJ-1 --> Interface_F
+ *
+ * M-ADJ = multi-path-adjacency.
+ *
+ * When interface K goes down a back-walk is started over its dependants in the
+ * control plane graph. This back-walk will reach PL_1 and PL_2 and result in
+ * the calculation of new adjacencies that have interface K removed. The walk
+ * will continue to the entry objects and thus the forwarding table is updated
+ * for each prefix with the new adjacency. The DP graph then becomes:
+ *
+ *    ADJ-3 --> Interface_A
+ *
+ *    ADJ-4 --> Interface_F
+ * 
+ * The eBGP PIC scenarios described above relied on the update of a path-list's
+ * recursive-adjacency to provide the shared point of cutover. This is shown
+ * below
+ *
+ *    E_a -->
+ *    E_b --> PL_2 --> P_a --> E_44 --> PL_a --> P_b --> Interface_A
+ *    ...          --> P_c -\
+ *    E_k -->                \
+ *                            \
+ *                           E_1 --> PL_k -> P_k --> Interface_K
+ *                            /
+ *    E_l -->                /
+ *    E_m --> PL_1 --> P_d -/ 
+ *    ...          --> P_f --> E_55 --> PL_e --> P_e --> Interface_E
+ *    E_z -->
+ *
+ * The failure scenario is the removal of entry E_1 and thus the paths P_c and
+ * P_d become unresolved. To achieve PIC the two shared recursive path-lists,
+ * PL_1 and PL_2 must be updated to remove E_1 from the recursive-multi-path-
+ * adjacencies that they contribute, before any entry E_a to E_z is updated.
+ * This means that as the update propagates backwards (right to left) in the
+ * graph it must do so breadth first not depth first. Note this approach leads
+ * to convergence times that are dependent on the number of path-list and so
+ * the number of combinations of egress PEs - this is desirable as this
+ * scale is considerably lower than the number of prefixes.
+ *
+ * If we consider another section of the graph that is similar to the one
+ * shown above where there is another prefix E_2 in a similar position to E_1
+ * and so also has many dependent children. It is reasonable to expect that a
+ * particular network failure may simultaneously render E_1 and E_2 unreachable.
+ * This means that the update to withdraw E_2 is download immediately after the
+ * update to withdraw E_1. It is a requirement on the FIB to not spend large
+ * amounts of time in a back-walk whilst processing the update for E_1, i.e. the
+ * back-walk must not reach as far as E_a and its siblings. Therefore, after the
+ * back-walk has traversed one generation (breadth first) to update all the
+ * path-lists it should be suspended/back-ground and further updates allowed
+ * to be handled. Once the update queue is empty, the suspended walks can be
+ * resumed. Note that in the case that multiple updates affect the same entry
+ * (say E_1) then this will trigger multiple similar walks, these are merged,
+ * so each child is updated only once.
+ * In the presence of more layers of recursion PIC is still a desirable
+ * feature. Consider an extension to the diagram above, where more recursive
+ * routes (E_100 -> E_200) are added as children of E_a:
+ *
+ * E_100 -->
+ * E_101 --> PL_3 --> P_j-\
+ * ...                     \
+ * E_199 -->               E_a -->
+ *                         E_b --> PL_2 --> P_a --> E_44 --> ...etc..
+ *                         ...          --> P_c -\
+ *                         E_k                    \
+ *                                                E_1 --> ...etc..
+ *                                                 /
+ *                         E_l -->                /
+ *                         E_m --> PL_1 --> P_d -/ 
+ *                         ...          --> P_e --> E_55 --> ...etc..
+ *                         E_z -->
+ *
+ * To achieve PIC for the routes E_100->E_199, PL_3 needs to be updated before
+ * E_b -> E_z, a breadth first traversal at each level would not achieve this.
+ * Instead the walk must proceed intelligently. Children on PL_2 are sorted so
+ * those Entry objects that themselves have children appear first in the list,
+ * those without later. When an entry object is walked that has children, a
+ * walk of its children is pushed to the front background queue. The back
+ * ground queue is a priority queue. As the breadth first traversal proceeds
+ * across the dependent entry object E_a to E_k, when the first entry that does
+ * not have children is reached (E_b), the walk is suspended and placed at the
+ * back of the queue. Following this prioritisation method shared path-list
+ * updates are performed before all non-resolving entry objects.
+ * The CPU/core/thread that handles the updates is the same thread that handles
+ * the back-walks. Handling updates has a higher priority than making walk
+ * progress, so a walk is required to be interruptable/suspendable when new
+ * updates are available.
+ * !!! TODO - this section describes how walks should be not how they are !!!
+ *
+ * In the diagram above E_100 is an IP route, however, VPP has no restrictions
+ * on the type of object that can be a dependent of a FIB entry. Children of
+ * a FIB entry can be (and are) GRE & VXLAN tunnels endpoints, L2VPN LSPs etc.
+ * By including all object types into the graph and extending the back-walk, we
+ * can thus deliver fast convergence to technologies that overlay on an IP
+ * network.
+ *
+ * If having read all the above carefully you are still thinking;  'i don't need
+ * all this %&$* i have a route only I know about and I just need to jam it in',
+ * then fib_table_entry_special_add() is your only friend.
+ */
+
+#ifndef __FIB_H__
+#define __FIB_H__
+
+#include <vnet/fib/fib_table.h>
+#include <vnet/fib/fib_entry.h>
+#include <vnet/fib/ip4_fib.h>
+#include <vnet/fib/ip6_fib.h>
+
+#endif
diff --git a/src/vnet/fib/fib_api.h b/src/vnet/fib/fib_api.h
new file mode 100644
index 00000000000..f82753170db
--- /dev/null
+++ b/src/vnet/fib/fib_api.h
@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __FIB_API_H__
+#define __FIB_API_H__
+
+
+int
+add_del_route_check (fib_protocol_t table_proto,
+		     u32 table_id,
+		     u32 next_hop_sw_if_index,
+		     fib_protocol_t next_hop_table_proto,
+		     u32 next_hop_table_id,
+		     u8 create_missing_tables,
+		     u32 * fib_index, u32 * next_hop_fib_index);
+
+int
+add_del_route_t_handler (u8 is_multipath,
+			 u8 is_add,
+			 u8 is_drop,
+			 u8 is_unreach,
+			 u8 is_prohibit,
+			 u8 is_local,
+			 u8 is_classify,
+			 u32 classify_table_index,
+			 u8 is_resolve_host,
+			 u8 is_resolve_attached,
+			 u32 fib_index,
+			 const fib_prefix_t * prefix,
+			 u8 next_hop_proto_is_ip4,
+			 const ip46_address_t * next_hop,
+			 u32 next_hop_sw_if_index,
+			 u8 next_hop_fib_index,
+			 u32 next_hop_weight,
+			 mpls_label_t next_hop_via_label,
+			 mpls_label_t * next_hop_out_label_stack);
+
+void
+copy_fib_next_hop (fib_route_path_encode_t * api_rpath,
+		   void * fp_arg);
+
+#endif /* __FIB_API_H__ */
diff --git a/src/vnet/fib/fib_attached_export.c b/src/vnet/fib/fib_attached_export.c
new file mode 100644
index 00000000000..c389ea43feb
--- /dev/null
+++ b/src/vnet/fib/fib_attached_export.c
@@ -0,0 +1,572 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vnet/fib/fib_entry.h>
+#include <vnet/fib/fib_table.h>
+
+#include <vnet/fib/fib_attached_export.h>
+#include <vnet/fib/fib_entry_cover.h>
+#include <vnet/fib/fib_entry_src.h>
+#include <vnet/fib/fib_entry_delegate.h>
+
+/**
+ * A description of the need to import routes from the export table
+ */
+typedef struct fib_ae_import_t_
+{
+    /**
+     * The entry in the epxort table that this importer
+     * is importing covereds from
+     */
+    fib_node_index_t faei_export_entry;
+
+    /**
+     * The attached entry in the import table
+     */
+    fib_node_index_t faei_import_entry;
+    /**
+     * the sibling index on the cover
+     */
+    u32 faei_export_sibling;
+
+    /**
+     * The index of the exporter tracker. Not set if the
+     * export entry is not valid for export
+     */
+    fib_node_index_t faei_exporter;
+
+    /**
+     * A vector/list of imported entry indicies
+     */
+    fib_node_index_t *faei_importeds;
+
+    /**
+     * The FIB index and prefix we are tracking
+     */
+    fib_node_index_t faei_export_fib;
+    fib_prefix_t faei_prefix;
+
+    /**
+     * The FIB index we are importing into
+     */
+    fib_node_index_t faei_import_fib;
+} fib_ae_import_t;
+
+/**
+ * A description of the need to export routes to one or more export tables
+ */
+typedef struct fib_ae_export_t_ {
+    /**
+     * The vector/list of import tracker indicies
+     */
+    fib_node_index_t *faee_importers;
+
+    /**
+     * THe connected entry this export is acting on behalf of
+     */
+    fib_node_index_t faee_ei;
+
+    /**
+     * Reference counting locks
+     */
+    u32 faee_locks;
+} fib_ae_export_t;
+
+/*
+ * memory pools for the importers and exportes
+ */
+static fib_ae_import_t *fib_ae_import_pool;
+static fib_ae_export_t *fib_ae_export_pool;
+
+static fib_ae_export_t *
+fib_entry_ae_add_or_lock (fib_node_index_t connected)
+{
+    fib_entry_delegate_t *fed;
+    fib_ae_export_t *export;
+    fib_entry_t *entry;
+
+    entry = fib_entry_get(connected);
+    fed = fib_entry_delegate_get(entry,
+                                 FIB_ENTRY_DELEGATE_ATTACHED_EXPORT);
+
+    if (NULL == fed)
+    {
+        fed = fib_entry_delegate_find_or_add(entry,
+                                             FIB_ENTRY_DELEGATE_ATTACHED_EXPORT);
+	pool_get(fib_ae_export_pool, export);
+	memset(export, 0, sizeof(*export));
+
+	fed->fd_index = (export - fib_ae_export_pool);
+	export->faee_ei = connected;
+    }
+    else
+    {
+	export = pool_elt_at_index(fib_ae_export_pool, fed->fd_index);
+    }
+
+    export->faee_locks++;
+
+    return (export);
+}
+
+static void
+fib_entry_import_remove (fib_ae_import_t *import,
+			 fib_node_index_t entry_index)
+{
+    fib_prefix_t prefix;
+    u32 index;
+
+    /*
+     * find the index in the vector of the entry we are removing
+     */
+    index = vec_search(import->faei_importeds, entry_index);
+
+    if (index < vec_len(import->faei_importeds))
+    {
+	/*
+	 * this is an entry that was previsouly imported
+	 */
+	fib_entry_get_prefix(entry_index, &prefix);
+
+	fib_table_entry_special_remove(import->faei_import_fib,
+				       &prefix,
+				       FIB_SOURCE_AE);
+
+	fib_entry_unlock(entry_index);
+	vec_del1(import->faei_importeds, index);
+    }
+}
+
+static void
+fib_entry_import_add (fib_ae_import_t *import,
+		      fib_node_index_t entry_index)
+{
+    fib_node_index_t *existing;
+    fib_prefix_t prefix;
+
+    /*
+     * ensure we only add the exported entry once, since
+     * sourcing prefixes in the table is reference counted
+     */
+    vec_foreach(existing, import->faei_importeds)
+    {
+	if (*existing == entry_index)
+	{
+	    return;
+	}
+    }
+
+    /*
+     * this is the first time this export entry has been imported
+     * Add it to the import FIB and to the list of importeds
+     */
+    fib_entry_get_prefix(entry_index, &prefix);
+
+    /*
+     * don't import entries that have the same prefix the import entry
+     */
+    if (0 != fib_prefix_cmp(&prefix,
+			    &import->faei_prefix))
+    {
+        const dpo_id_t *dpo;
+
+        dpo = fib_entry_contribute_ip_forwarding(entry_index);
+
+        if (dpo_id_is_valid(dpo))
+        {
+            fib_table_entry_special_dpo_add(import->faei_import_fib,
+                                            &prefix,
+                                            FIB_SOURCE_AE,
+                                            (fib_entry_get_flags(entry_index) |
+                                             FIB_ENTRY_FLAG_EXCLUSIVE),
+                                            load_balance_get_bucket(dpo->dpoi_index, 0));
+
+            fib_entry_lock(entry_index);
+            vec_add1(import->faei_importeds, entry_index);
+        }
+        /*
+         * else
+         *   the entry currently has no valid forwarding. when it
+         * does it will export itself
+         */
+    }
+}
+
+/**
+ * Call back when walking a connected prefix's covered prefixes for import
+ */
+static int
+fib_entry_covered_walk_import (fib_entry_t *cover,
+			       fib_node_index_t covered,
+			       void *ctx)
+{
+    fib_ae_import_t *import = ctx;
+
+    fib_entry_import_add(import, covered);
+
+    return (0);
+}
+
+/*
+ * fib_entry_ae_import_add
+ *
+ * Add an importer to a connected entry
+ */
+static void
+fib_ae_export_import_add (fib_ae_export_t *export,
+			  fib_ae_import_t *import)
+{
+    fib_entry_t *entry;
+
+    import->faei_exporter = (export - fib_ae_export_pool);
+    entry = fib_entry_get(export->faee_ei);
+
+    fib_entry_cover_walk(entry,
+			 fib_entry_covered_walk_import,
+			 import);
+}
+
+void
+fib_attached_export_import (fib_entry_t *fib_entry,
+			    fib_node_index_t export_fib)
+{
+    fib_entry_delegate_t *fed;
+    fib_ae_import_t *import;
+
+    pool_get(fib_ae_import_pool, import);
+
+    import->faei_import_fib = fib_entry->fe_fib_index;
+    import->faei_export_fib = export_fib;
+    import->faei_prefix = fib_entry->fe_prefix;
+    import->faei_import_entry = fib_entry_get_index(fib_entry);
+    import->faei_export_sibling = ~0;
+
+    /*
+     * do an exact match in the export table
+     */
+    import->faei_export_entry =
+	fib_table_lookup_exact_match(import->faei_export_fib,
+				     &import->faei_prefix);
+
+    if (FIB_NODE_INDEX_INVALID == import->faei_export_entry)
+    {
+	/*
+	 * no exact matching entry in the export table. can't be good.
+	 * track the next best thing
+	 */
+	import->faei_export_entry =
+	    fib_table_lookup(import->faei_export_fib,
+			     &import->faei_prefix);
+	import->faei_exporter = FIB_NODE_INDEX_INVALID;
+    }
+    else
+    {
+	/*
+	 * found the entry in the export table. import the
+	 * the prefixes that it covers.
+	 * only if the prefix found in the export FIB really is
+	 * attached do we want to import its covered
+	 */
+	if (FIB_ENTRY_FLAG_ATTACHED &
+	    fib_entry_get_flags_i(fib_entry_get(import->faei_export_entry)))
+	{
+	    fib_ae_export_t *export;
+
+	    export = fib_entry_ae_add_or_lock(import->faei_export_entry);
+	    vec_add1(export->faee_importers, (import - fib_ae_import_pool));
+	    fib_ae_export_import_add(export, import);
+	}
+    }
+
+    /*
+     * track the entry in the export table so we can update appropriately
+     * when it changes
+     */
+    import->faei_export_sibling =
+	fib_entry_cover_track(fib_entry_get(import->faei_export_entry),
+			      fib_entry_get_index(fib_entry));
+
+    fed = fib_entry_delegate_find_or_add(fib_entry,
+                                         FIB_ENTRY_DELEGATE_ATTACHED_IMPORT);
+    fed->fd_index = (import - fib_ae_import_pool);
+}
+
+/**
+ * \brief All the imported entries need to be pruged
+ */
+void
+fib_attached_export_purge (fib_entry_t *fib_entry)
+{
+    fib_entry_delegate_t *fed;
+
+    fed = fib_entry_delegate_get(fib_entry,
+                                 FIB_ENTRY_DELEGATE_ATTACHED_IMPORT);
+
+    if (NULL != fed)
+    {
+ 	fib_node_index_t *import_index;
+	fib_entry_t *export_entry;
+	fib_ae_import_t *import;
+	fib_ae_export_t *export;
+
+	import = pool_elt_at_index(fib_ae_import_pool, fed->fd_index);
+
+	/*
+	 * remove each imported entry
+	 */
+	vec_foreach(import_index, import->faei_importeds)
+	{
+	    fib_prefix_t prefix;
+
+	    fib_entry_get_prefix(*import_index, &prefix);
+
+	    fib_table_entry_delete(import->faei_import_fib,
+				   &prefix,
+				   FIB_SOURCE_AE);
+	    fib_entry_unlock(*import_index);
+	}
+	vec_free(import->faei_importeds);
+
+	/*
+	 * stop tracking the export entry
+	 */
+	if (~0 != import->faei_export_sibling)
+	{
+	    fib_entry_cover_untrack(fib_entry_get(import->faei_export_entry),
+				    import->faei_export_sibling);
+	}
+	import->faei_export_sibling = ~0;
+
+	/*
+	 * remove this import tracker from the export's list,
+	 * if it is attached to one. It won't be in the case the tracked
+	 * export entry is not an attached exact match.
+	 */
+	if (FIB_NODE_INDEX_INVALID != import->faei_exporter)
+	{
+            fib_entry_delegate_t *fed;
+
+	    export_entry = fib_entry_get(import->faei_export_entry);
+
+            fed = fib_entry_delegate_get(export_entry,
+                                         FIB_ENTRY_DELEGATE_ATTACHED_EXPORT);
+            ASSERT(NULL != fed);
+
+	    export = pool_elt_at_index(fib_ae_export_pool, fed->fd_index);
+
+	    u32 index = vec_search(export->faee_importers,
+				   (import - fib_ae_import_pool));
+
+	    ASSERT(index < vec_len(export->faee_importers));
+	    vec_del1(export->faee_importers, index);
+
+	    /*
+	     * free the exporter if there are no longer importers
+	     */
+	    if (0 == --export->faee_locks)
+	    {
+		pool_put(fib_ae_export_pool, export);
+                fib_entry_delegate_remove(export_entry,
+                                          FIB_ENTRY_DELEGATE_ATTACHED_EXPORT);
+	    }
+	}
+
+	/*
+	 * free the import tracker
+	 */
+	pool_put(fib_ae_import_pool, import);
+        fib_entry_delegate_remove(fib_entry,
+                                  FIB_ENTRY_DELEGATE_ATTACHED_IMPORT);
+    }	
+}
+
+void
+fib_attached_export_covered_added (fib_entry_t *cover,
+				   fib_node_index_t covered)
+{
+    fib_entry_delegate_t *fed;
+
+    fed = fib_entry_delegate_get(cover,
+                                 FIB_ENTRY_DELEGATE_ATTACHED_EXPORT);
+
+    if (NULL != fed)
+    {
+	/*
+	 * the covering prefix is exporting to other tables
+	 */
+ 	fib_node_index_t *import_index;
+	fib_ae_import_t *import;
+	fib_ae_export_t *export;
+
+	export = pool_elt_at_index(fib_ae_export_pool, fed->fd_index);
+
+	/*
+	 * export the covered entry to each of the importers
+	 */
+	vec_foreach(import_index, export->faee_importers)
+	{
+	    import = pool_elt_at_index(fib_ae_import_pool, *import_index);
+
+	    fib_entry_import_add(import, covered);
+	}
+    }
+}
+
+void
+fib_attached_export_covered_removed (fib_entry_t *cover,
+				     fib_node_index_t covered)
+{
+    fib_entry_delegate_t *fed;
+
+    fed = fib_entry_delegate_get(cover,
+                                 FIB_ENTRY_DELEGATE_ATTACHED_EXPORT);
+
+    if (NULL != fed)
+    {
+	/*
+	 * the covering prefix is exporting to other tables
+	 */
+ 	fib_node_index_t *import_index;
+	fib_ae_import_t *import;
+	fib_ae_export_t *export;
+
+	export = pool_elt_at_index(fib_ae_export_pool, fed->fd_index);
+
+	/*
+	 * remove the covered entry from each of the importers
+	 */
+	vec_foreach(import_index, export->faee_importers)
+	{
+	    import = pool_elt_at_index(fib_ae_import_pool, *import_index);
+
+	    fib_entry_import_remove(import, covered);
+	}
+    }
+}
+
+static void
+fib_attached_export_cover_modified_i (fib_entry_t *fib_entry)
+{
+    fib_entry_delegate_t *fed;
+
+    fed = fib_entry_delegate_get(fib_entry,
+                                 FIB_ENTRY_DELEGATE_ATTACHED_IMPORT);
+
+    if (NULL != fed)
+    {
+	fib_ae_import_t *import;
+	u32 export_fib;
+
+	/*
+	 * safe the temporaries we need from the existing import
+	 * since it will be toast after the purge.
+	 */
+	import = pool_elt_at_index(fib_ae_import_pool, fed->fd_index);
+	export_fib = import->faei_export_fib;
+
+	/*
+	 * keep it simple. purge anything that was previously imported.
+	 * then re-evaluate the need to import.
+	 */
+	fib_attached_export_purge(fib_entry);
+	fib_attached_export_import(fib_entry, export_fib);
+    }
+}
+
+/**
+ * \brief If this entry is tracking a cover (in another table)
+ *        then that cover has changed. re-evaluate import.
+ */
+void
+fib_attached_export_cover_change (fib_entry_t *fib_entry)
+{
+    fib_attached_export_cover_modified_i(fib_entry);
+}
+
+/**
+ * \brief If this entry is tracking a cover (in another table)
+ *        then that cover has been updated. re-evaluate import.
+ */
+void
+fib_attached_export_cover_update (fib_entry_t *fib_entry)
+{
+    fib_attached_export_cover_modified_i(fib_entry);
+}
+
+u8*
+fib_ae_import_format (fib_entry_t *fib_entry,
+		      u8* s)
+{
+    fib_entry_delegate_t *fed;
+
+    fed = fib_entry_delegate_get(fib_entry,
+                                 FIB_ENTRY_DELEGATE_ATTACHED_IMPORT);
+
+    if (NULL != fed)
+    {
+	fib_node_index_t *index;
+	fib_ae_import_t *import;
+
+	import = pool_elt_at_index(fib_ae_import_pool, fed->fd_index);
+
+	s = format(s, "\n  Attached-Import:%d:[", (import - fib_ae_import_pool));
+	s = format(s, "export-prefix:%U ", format_fib_prefix, &import->faei_prefix);
+	s = format(s, "export-entry:%d ", import->faei_export_entry);
+	s = format(s, "export-sibling:%d ", import->faei_export_sibling);
+	s = format(s, "exporter:%d ", import->faei_exporter);
+	s = format(s, "export-fib:%d ", import->faei_export_fib);
+
+	s = format(s, "import-entry:%d ", import->faei_import_entry);
+	s = format(s, "import-fib:%d ", import->faei_import_fib);
+
+	s = format(s, "importeds:[");
+	vec_foreach(index, import->faei_importeds)
+	{
+	    s = format(s, "%d, ", *index);
+	}
+	    s = format(s, "]]");
+    }
+
+    return (s);
+}
+
+u8*
+fib_ae_export_format (fib_entry_t *fib_entry,
+		      u8* s)
+{
+    fib_entry_delegate_t *fed;
+
+    fed = fib_entry_delegate_get(fib_entry,
+                                 FIB_ENTRY_DELEGATE_ATTACHED_EXPORT);
+
+    if (NULL != fed)
+    {
+        fib_node_index_t *index;
+	fib_ae_export_t *export;
+
+	export = pool_elt_at_index(fib_ae_export_pool, fed->fd_list);
+    
+	s = format(s, "\n  Attached-Export:%d:[", (export - fib_ae_export_pool));
+	s = format(s, "export-entry:%d ", export->faee_ei);
+
+	s = format(s, "importers:[");
+	vec_foreach(index, export->faee_importers)
+	{
+	    s = format(s, "%d, ", *index);
+	}
+	s = format(s, "]]");
+    }
+    return (s);
+}
diff --git a/src/vnet/fib/fib_attached_export.h b/src/vnet/fib/fib_attached_export.h
new file mode 100644
index 00000000000..fa28a6e13b8
--- /dev/null
+++ b/src/vnet/fib/fib_attached_export.h
@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/**
+ * FIB attached export
+ *
+ * what's it all about?
+ * say one does this:
+ *    set int ip table Gig0 2
+ *    set int ip addr  Gig0 10.0.0.1/24
+ * Ggi0 is in table 2 with a connected address.
+ * Now we add a routing matching said connected in a different table
+ *    ip route add table 3 10.0.0.0/24 via Gig0
+ * How do we expect traffic in table 3 to be forwarded? Clearly out of
+ * Ggi0. It's an attached route, hence we are saying that we can ARP for
+ * hosts in the attached subnet. and we can. but any ARP entries we send
+ * we be received on Gig0, but since Gig0 is in table 2, it will install
+ * the adj-fins in table 2. So traffic in table 3 will never hit an adj-fib
+ * and hence always the glean, and so thus be effectively dropped.
+ * How do we fix this? Attached Export !! All more specfiic entries in table 2
+ * that track and are covered by the connected are automatically exported into
+ * table 3. Now table 3 also has adj-fibs (and the local) so traffic to hosts
+ * is restored.
+ */
+
+#ifndef __FIB_ATTACHED_EXPORT_H__
+#define __FIB_ATTACHED_EXPORT_H__
+
+#include <vnet/fib/fib_types.h>
+
+extern void fib_attached_export_import(fib_entry_t *fib_entry,
+				       fib_node_index_t export_fib);
+				       
+extern void fib_attached_export_purge(fib_entry_t *fib_entry);
+
+extern void fib_attached_export_covered_added(fib_entry_t *cover,
+					      fib_node_index_t covered);
+extern void fib_attached_export_covered_removed(fib_entry_t *cover,
+						fib_node_index_t covered);
+extern void fib_attached_export_cover_change(fib_entry_t *fib_entry);
+extern void fib_attached_export_cover_update(fib_entry_t *fib_entry);
+
+extern u8* fib_ae_import_format(fib_entry_t *fib_entry, u8*s);
+extern u8* fib_ae_export_format(fib_entry_t *fib_entry, u8*s);
+
+#endif
diff --git a/src/vnet/fib/fib_entry.c b/src/vnet/fib/fib_entry.c
new file mode 100644
index 00000000000..24b506379ac
--- /dev/null
+++ b/src/vnet/fib/fib_entry.c
@@ -0,0 +1,1503 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vlib/vlib.h>
+#include <vnet/ip/format.h>
+#include <vnet/ip/lookup.h>
+#include <vnet/adj/adj.h>
+#include <vnet/dpo/load_balance.h>
+#include <vnet/dpo/drop_dpo.h>
+
+#include <vnet/fib/fib_entry.h>
+#include <vnet/fib/fib_walk.h>
+#include <vnet/fib/fib_entry_src.h>
+#include <vnet/fib/fib_entry_cover.h>
+#include <vnet/fib/fib_table.h>
+#include <vnet/fib/fib_internal.h>
+#include <vnet/fib/fib_attached_export.h>
+#include <vnet/fib/fib_path_ext.h>
+
+/*
+ * Array of strings/names for the FIB sources
+ */
+static const char *fib_source_names[] = FIB_SOURCES;
+static const char *fib_attribute_names[] = FIB_ENTRY_ATTRIBUTES;
+
+/*
+ * Pool for all fib_entries
+ */
+static fib_entry_t *fib_entry_pool;
+
+fib_entry_t *
+fib_entry_get (fib_node_index_t index)
+{
+    return (pool_elt_at_index(fib_entry_pool, index));
+}
+
+static fib_node_t *
+fib_entry_get_node (fib_node_index_t index)
+{
+    return ((fib_node_t*)fib_entry_get(index));
+}
+
+fib_node_index_t
+fib_entry_get_index (const fib_entry_t * fib_entry)
+{
+    return (fib_entry - fib_entry_pool);
+}
+
+static fib_protocol_t
+fib_entry_get_proto (const fib_entry_t * fib_entry)
+{
+    return (fib_entry->fe_prefix.fp_proto);
+}
+
+fib_forward_chain_type_t
+fib_entry_get_default_chain_type (const fib_entry_t *fib_entry)
+{
+    switch (fib_entry->fe_prefix.fp_proto)
+    {
+    case FIB_PROTOCOL_IP4:
+	return (FIB_FORW_CHAIN_TYPE_UNICAST_IP4);
+    case FIB_PROTOCOL_IP6:
+	return (FIB_FORW_CHAIN_TYPE_UNICAST_IP6);
+    case FIB_PROTOCOL_MPLS:
+	if (MPLS_EOS == fib_entry->fe_prefix.fp_eos)
+	    /*
+	     * If the entry being asked is a eos-MPLS label entry,
+	     * then use the payload-protocol field, that we stashed there
+	     * for just this purpose
+	     */
+	    return (fib_forw_chain_type_from_dpo_proto(
+			fib_entry->fe_prefix.fp_payload_proto));
+	else
+	    return (FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS);
+    }
+
+    return (FIB_FORW_CHAIN_TYPE_UNICAST_IP4);
+}
+
+u8 *
+format_fib_entry (u8 * s, va_list * args)
+{
+    fib_forward_chain_type_t fct;
+    fib_entry_attribute_t attr;
+    fib_path_ext_t *path_ext;
+    fib_entry_t *fib_entry;
+    fib_entry_src_t *src;
+    fib_node_index_t fei;
+    fib_source_t source;
+    u32 n_covered;
+    int level;
+
+    fei = va_arg (*args, fib_node_index_t);
+    level = va_arg (*args, int);
+    fib_entry = fib_entry_get(fei);
+
+    s = format (s, "%U", format_fib_prefix, &fib_entry->fe_prefix);
+
+    if (level >= FIB_ENTRY_FORMAT_DETAIL)
+    {
+	s = format (s, " fib:%d", fib_entry->fe_fib_index);
+	s = format (s, " index:%d", fib_entry_get_index(fib_entry));
+	s = format (s, " locks:%d", fib_entry->fe_node.fn_locks);
+
+	FOR_EACH_SRC_ADDED(fib_entry, src, source,
+        ({
+	    s = format (s, "\n  src:%s ",
+			fib_source_names[source]);
+	    s = fib_entry_src_format(fib_entry, source, s);
+	    s = format (s, " refs:%d ", src->fes_ref_count);
+	    if (FIB_ENTRY_FLAG_NONE != src->fes_entry_flags) {
+		s = format(s, "flags:");
+		FOR_EACH_FIB_ATTRIBUTE(attr) {
+		    if ((1<<attr) & src->fes_entry_flags) {
+			s = format (s, "%s,", fib_attribute_names[attr]);
+		    }
+		}
+	    }
+	    s = format (s, "\n");
+	    if (FIB_NODE_INDEX_INVALID != src->fes_pl)
+	    {
+		s = fib_path_list_format(src->fes_pl, s);
+	    }
+	    if (NULL != src->fes_path_exts)
+	    {
+		s = format(s, "    Extensions:");
+		vec_foreach(path_ext, src->fes_path_exts)
+		{
+		    s = format(s, "\n     %U", format_fib_path_ext, path_ext);
+		}
+	    }
+	}));
+    
+	n_covered = fib_entry_cover_get_size(fib_entry);
+	if (n_covered > 0) {
+	    s = format(s, "\n tracking %d covered: ", n_covered);
+	    s = fib_entry_cover_list_format(fib_entry, s);
+	}
+	s = fib_ae_import_format(fib_entry, s);
+	s = fib_ae_export_format(fib_entry, s);
+
+	s = format (s, "\n forwarding: ");
+    }
+    else
+    {
+	s = format (s, "\n");
+    }
+
+    fct = fib_entry_get_default_chain_type(fib_entry);
+
+    if (!dpo_id_is_valid(&fib_entry->fe_lb))
+    {
+	s = format (s, "  UNRESOLVED\n");
+	return (s);
+    }
+    else
+    {
+        s = format(s, "  %U-chain\n  %U",
+                   format_fib_forw_chain_type, fct,
+                   format_dpo_id,
+                   &fib_entry->fe_lb,
+                   2);
+        s = format(s, "\n");
+
+        if (level >= FIB_ENTRY_FORMAT_DETAIL2)
+        {
+            fib_entry_delegate_type_t fdt;
+            fib_entry_delegate_t *fed;
+
+            FOR_EACH_DELEGATE_CHAIN(fib_entry, fdt, fed,
+            {
+                s = format(s, "  %U-chain\n  %U",
+                           format_fib_forw_chain_type,
+                           fib_entry_delegate_type_to_chain_type(fdt),
+                           format_dpo_id, &fed->fd_dpo, 2);
+                s = format(s, "\n");
+            });
+        }
+    }
+
+    if (level >= FIB_ENTRY_FORMAT_DETAIL2)
+    {
+        s = format(s, "\nchildren:");
+        s = fib_node_children_format(fib_entry->fe_node.fn_children, s);
+    }
+
+    return (s);
+}
+
+static fib_entry_t*
+fib_entry_from_fib_node (fib_node_t *node)
+{
+#if CLIB_DEBUG > 0
+    ASSERT(FIB_NODE_TYPE_ENTRY == node->fn_type);
+#endif
+    return ((fib_entry_t*)node);
+}
+
+static void
+fib_entry_last_lock_gone (fib_node_t *node)
+{
+    fib_entry_delegate_type_t fdt;
+    fib_entry_delegate_t *fed;
+    fib_entry_t *fib_entry;
+
+    fib_entry = fib_entry_from_fib_node(node);
+
+    FOR_EACH_DELEGATE_CHAIN(fib_entry, fdt, fed,
+    {
+	dpo_reset(&fed->fd_dpo);
+        fib_entry_delegate_remove(fib_entry, fdt);
+    });
+
+    FIB_ENTRY_DBG(fib_entry, "last-lock");
+
+    fib_node_deinit(&fib_entry->fe_node);
+    // FIXME -RR Backwalk
+
+    ASSERT(0 == vec_len(fib_entry->fe_delegates));
+    vec_free(fib_entry->fe_delegates);
+    pool_put(fib_entry_pool, fib_entry);
+}
+
+static fib_entry_src_t*
+fib_entry_get_best_src_i (const fib_entry_t *fib_entry)
+{
+    fib_entry_src_t *bsrc;
+
+    /*
+     * the enum of sources is deliberately arranged in priority order
+     */
+    if (0 == vec_len(fib_entry->fe_srcs))
+    {
+	bsrc = NULL;
+    }
+    else
+    {
+	bsrc = vec_elt_at_index(fib_entry->fe_srcs, 0);
+    }
+
+    return (bsrc);
+}
+
+static fib_source_t
+fib_entry_src_get_source (const fib_entry_src_t *esrc)
+{
+    if (NULL != esrc)
+    {
+	return (esrc->fes_src);
+    }
+    return (FIB_SOURCE_MAX);
+}
+
+static fib_entry_flag_t
+fib_entry_src_get_flags (const fib_entry_src_t *esrc)
+{
+    if (NULL != esrc)
+    {
+	return (esrc->fes_entry_flags);
+    }
+    return (FIB_ENTRY_FLAG_NONE);
+}
+
+fib_entry_flag_t
+fib_entry_get_flags (fib_node_index_t fib_entry_index)
+{
+    return (fib_entry_get_flags_i(fib_entry_get(fib_entry_index)));
+}
+
+/*
+ * fib_entry_back_walk_notify
+ *
+ * A back walk has reach this entry.
+ */
+static fib_node_back_walk_rc_t
+fib_entry_back_walk_notify (fib_node_t *node,
+			    fib_node_back_walk_ctx_t *ctx)
+{
+    fib_entry_t *fib_entry;
+
+    fib_entry = fib_entry_from_fib_node(node);
+
+    if (FIB_NODE_BW_REASON_FLAG_EVALUATE & ctx->fnbw_reason        ||
+        FIB_NODE_BW_REASON_FLAG_ADJ_UPDATE & ctx->fnbw_reason      ||
+        FIB_NODE_BW_REASON_FLAG_ADJ_DOWN & ctx->fnbw_reason        ||
+	FIB_NODE_BW_REASON_FLAG_INTERFACE_UP & ctx->fnbw_reason    ||
+	FIB_NODE_BW_REASON_FLAG_INTERFACE_DOWN & ctx->fnbw_reason  ||
+	FIB_NODE_BW_REASON_FLAG_INTERFACE_DELETE & ctx->fnbw_reason)
+    {
+	fib_entry_src_action_reactivate(fib_entry,
+                                        fib_entry_get_best_source(
+                                            fib_entry_get_index(fib_entry)));
+    }
+
+    /*
+     * all other walk types can be reclassifed to a re-evaluate to
+     * all recursive dependents.
+     * By reclassifying we ensure that should any of these walk types meet
+     * they can be merged.
+     */
+    ctx->fnbw_reason = FIB_NODE_BW_REASON_FLAG_EVALUATE;
+
+    /*
+     * ... and nothing is forced sync from now on.
+     */
+    ctx->fnbw_flags &= ~FIB_NODE_BW_FLAG_FORCE_SYNC;
+
+    /*
+     * propagate the backwalk further if we haven't already reached the
+     * maximum depth.
+     */
+    fib_walk_sync(FIB_NODE_TYPE_ENTRY,
+		  fib_entry_get_index(fib_entry),
+		  ctx);
+
+    return (FIB_NODE_BACK_WALK_CONTINUE);
+}
+
+static void
+fib_entry_show_memory (void)
+{
+    u32 n_srcs = 0, n_exts = 0;
+    fib_entry_src_t *esrc;
+    fib_entry_t *entry;
+
+    fib_show_memory_usage("Entry",
+			  pool_elts(fib_entry_pool),
+			  pool_len(fib_entry_pool),
+			  sizeof(fib_entry_t));
+
+    pool_foreach(entry, fib_entry_pool,
+    ({
+	n_srcs += vec_len(entry->fe_srcs);
+	vec_foreach(esrc, entry->fe_srcs)
+	{
+	    n_exts += vec_len(esrc->fes_path_exts);
+	}
+    }));
+
+    fib_show_memory_usage("Entry Source",
+			  n_srcs, n_srcs, sizeof(fib_entry_src_t));
+    fib_show_memory_usage("Entry Path-Extensions",
+			  n_exts, n_exts,
+			  sizeof(fib_path_ext_t));
+}
+
+/*
+ * The FIB path-list's graph node virtual function table
+ */
+static const fib_node_vft_t fib_entry_vft = {
+    .fnv_get = fib_entry_get_node,
+    .fnv_last_lock = fib_entry_last_lock_gone,
+    .fnv_back_walk = fib_entry_back_walk_notify,
+    .fnv_mem_show = fib_entry_show_memory,
+};
+
+/**
+ * @brief Contribute the set of Adjacencies that this entry forwards with
+ * to build the uRPF list of its children
+ */
+void
+fib_entry_contribute_urpf (fib_node_index_t entry_index,
+			   index_t urpf)
+{
+    fib_entry_t *fib_entry;
+
+    fib_entry = fib_entry_get(entry_index);
+
+    return (fib_path_list_contribute_urpf(fib_entry->fe_parent, urpf));
+}
+
+/*
+ * fib_entry_contribute_forwarding
+ *
+ * Get an lock the forwarding information (DPO) contributed by the FIB entry.
+ */
+void
+fib_entry_contribute_forwarding (fib_node_index_t fib_entry_index,
+				 fib_forward_chain_type_t fct,
+				 dpo_id_t *dpo)
+{
+    fib_entry_delegate_t *fed;
+    fib_entry_t *fib_entry;
+
+    fib_entry = fib_entry_get(fib_entry_index);
+
+    if (fct == fib_entry_get_default_chain_type(fib_entry))
+    {
+        dpo_copy(dpo, &fib_entry->fe_lb);
+    }
+    else
+    {
+        fed = fib_entry_delegate_get(fib_entry,
+                                     fib_entry_chain_type_to_delegate_type(fct));
+
+        if (NULL == fed)
+        {
+            fed = fib_entry_delegate_find_or_add(
+                      fib_entry,
+                      fib_entry_chain_type_to_delegate_type(fct));
+            /*
+             * on-demand create eos/non-eos.
+             * There is no on-demand delete because:
+             *   - memory versus complexity & reliability:
+             *      leaving unrequired [n]eos LB arounds wastes memory, cleaning
+             *      then up on the right trigger is more code. i favour the latter.
+             */
+            fib_entry_src_mk_lb(fib_entry,
+                                fib_entry_get_best_src_i(fib_entry),
+                                fct,
+                                &fed->fd_dpo);
+        }
+
+        dpo_copy(dpo, &fed->fd_dpo);
+    }
+}
+
+const dpo_id_t *
+fib_entry_contribute_ip_forwarding (fib_node_index_t fib_entry_index)
+{
+    fib_forward_chain_type_t fct;
+    fib_entry_t *fib_entry;
+
+    fib_entry = fib_entry_get(fib_entry_index);
+    fct = fib_entry_get_default_chain_type(fib_entry);
+
+    ASSERT((fct == FIB_FORW_CHAIN_TYPE_UNICAST_IP4 ||
+            fct == FIB_FORW_CHAIN_TYPE_UNICAST_IP6));
+
+    return (&fib_entry->fe_lb);
+}
+
+adj_index_t
+fib_entry_get_adj (fib_node_index_t fib_entry_index)
+{
+    const dpo_id_t *dpo;
+
+    dpo = fib_entry_contribute_ip_forwarding(fib_entry_index);
+    dpo = load_balance_get_bucket(dpo->dpoi_index, 0);
+
+    if (dpo_is_adj(dpo))
+    {
+	return (dpo->dpoi_index);
+    }
+    return (ADJ_INDEX_INVALID);
+}
+
+fib_node_index_t
+fib_entry_get_path_list (fib_node_index_t fib_entry_index)
+{
+    fib_entry_t *fib_entry;
+
+    fib_entry = fib_entry_get(fib_entry_index);
+
+    return (fib_entry->fe_parent);
+}
+
+u32
+fib_entry_child_add (fib_node_index_t fib_entry_index,
+		     fib_node_type_t child_type,
+		     fib_node_index_t child_index)
+{
+    return (fib_node_child_add(FIB_NODE_TYPE_ENTRY,
+                               fib_entry_index,
+                               child_type,
+                               child_index));
+};
+
+void
+fib_entry_child_remove (fib_node_index_t fib_entry_index,
+			u32 sibling_index)
+{
+    fib_node_child_remove(FIB_NODE_TYPE_ENTRY,
+                          fib_entry_index,
+                          sibling_index);
+
+    if (0 == fib_node_get_n_children(FIB_NODE_TYPE_ENTRY,
+                                     fib_entry_index))
+    {
+        /*
+         * if there are no children left then there is no reason to keep
+         * the non-default forwarding chains. those chains are built only
+         * because the children want them.
+         */
+        fib_entry_delegate_type_t fdt;
+        fib_entry_delegate_t *fed;
+        fib_entry_t *fib_entry;
+
+        fib_entry = fib_entry_get(fib_entry_index);
+
+        FOR_EACH_DELEGATE_CHAIN(fib_entry, fdt, fed,
+        {
+            dpo_reset(&fed->fd_dpo);
+            fib_entry_delegate_remove(fib_entry, fdt);
+        });
+    }
+}
+
+static fib_entry_t *
+fib_entry_alloc (u32 fib_index,
+		 const fib_prefix_t *prefix,
+		 fib_node_index_t *fib_entry_index)
+{
+    fib_entry_t *fib_entry;
+    fib_prefix_t *fep;
+
+    pool_get(fib_entry_pool, fib_entry);
+    memset(fib_entry, 0, sizeof(*fib_entry));
+
+    fib_node_init(&fib_entry->fe_node,
+		  FIB_NODE_TYPE_ENTRY);
+
+    fib_entry->fe_fib_index = fib_index;
+
+    /*
+     * the one time we need to update the const prefix is when
+     * the entry is first created
+     */
+    fep = (fib_prefix_t*)&(fib_entry->fe_prefix);
+    *fep = *prefix;
+
+    if (FIB_PROTOCOL_MPLS == fib_entry->fe_prefix.fp_proto)
+    {
+	fep->fp_len = 21;
+	if (MPLS_NON_EOS == fep->fp_eos)
+	{
+	    fep->fp_payload_proto = DPO_PROTO_MPLS;
+	}
+    	ASSERT(DPO_PROTO_NONE != fib_entry->fe_prefix.fp_payload_proto);
+    }
+
+    dpo_reset(&fib_entry->fe_lb);
+
+    *fib_entry_index = fib_entry_get_index(fib_entry);
+
+    FIB_ENTRY_DBG(fib_entry, "alloc");
+
+    return (fib_entry);
+}
+
+static void
+fib_entry_post_flag_update_actions (fib_entry_t *fib_entry,
+				    fib_source_t source,
+				    fib_entry_flag_t old_flags)
+{
+    /*
+     * handle changes to attached export for import entries
+     */
+    int is_import  = (FIB_ENTRY_FLAG_IMPORT & fib_entry_get_flags_i(fib_entry));
+    int was_import = (FIB_ENTRY_FLAG_IMPORT & old_flags);
+
+    if (!was_import && is_import)
+    {
+	/*
+	 * transition from not exported to exported
+	 */
+
+	/*
+	 * there is an assumption here that the entry resolves via only
+	 * one interface and that it is the cross VRF interface.
+	 */
+	u32 sw_if_index = fib_path_list_get_resolving_interface(fib_entry->fe_parent);
+
+	fib_attached_export_import(fib_entry,
+				   fib_table_get_index_for_sw_if_index(
+				       fib_entry_get_proto(fib_entry),
+                                       sw_if_index));
+    }
+    else if (was_import && !is_import)
+    {
+	/*
+	 * transition from exported to not exported
+	 */
+	fib_attached_export_purge(fib_entry);
+    }
+    /*
+     * else
+     *   no change. nothing to do.
+     */
+
+    /*
+     * handle changes to attached export for export entries
+     */
+    int is_attached  = (FIB_ENTRY_FLAG_ATTACHED & fib_entry_get_flags_i(fib_entry));
+    int was_attached = (FIB_ENTRY_FLAG_ATTACHED & old_flags);
+
+    if (!was_attached && is_attached)
+    {
+	/*
+	 * transition to attached. time to export
+	 */
+	// FIXME
+    }
+    // else FIXME
+}
+
+static void
+fib_entry_post_install_actions (fib_entry_t *fib_entry,
+				fib_source_t source,
+				fib_entry_flag_t old_flags)
+{
+    fib_entry_post_flag_update_actions(fib_entry, source, old_flags);
+    fib_entry_src_action_installed(fib_entry, source);
+}
+
+fib_node_index_t
+fib_entry_create (u32 fib_index,
+		  const fib_prefix_t *prefix,
+		  fib_source_t source,
+		  fib_entry_flag_t flags,
+		  const fib_route_path_t *paths)
+{
+    fib_node_index_t fib_entry_index;
+    fib_entry_t *fib_entry;
+
+    ASSERT(0 < vec_len(paths));
+
+    fib_entry = fib_entry_alloc(fib_index, prefix, &fib_entry_index);
+
+    /*
+     * since this is a new entry create, we don't need to check for winning
+     * sources - there is only one.
+     */
+    fib_entry = fib_entry_src_action_add(fib_entry, source, flags,
+                                         drop_dpo_get(
+                                             fib_proto_to_dpo(
+                                                 fib_entry_get_proto(fib_entry))));
+    fib_entry_src_action_path_swap(fib_entry,
+				   source,
+				   flags,
+				   paths);
+    /*
+     * handle possible realloc's by refetching the pointer
+     */
+    fib_entry = fib_entry_get(fib_entry_index);
+    fib_entry_src_action_activate(fib_entry, source);
+
+    fib_entry_post_install_actions(fib_entry, source, FIB_ENTRY_FLAG_NONE);
+
+    return (fib_entry_index);
+}
+
+fib_node_index_t
+fib_entry_create_special (u32 fib_index,
+			  const fib_prefix_t *prefix,
+			  fib_source_t source,
+			  fib_entry_flag_t flags,
+			  const dpo_id_t *dpo)
+{
+    fib_node_index_t fib_entry_index;
+    fib_entry_t *fib_entry;
+
+    /*
+     * create and initiliase the new enty
+     */
+    fib_entry = fib_entry_alloc(fib_index, prefix, &fib_entry_index);
+
+    /*
+     * create the path-list
+     */
+    fib_entry = fib_entry_src_action_add(fib_entry, source, flags, dpo);
+    fib_entry_src_action_activate(fib_entry, source);
+
+    fib_entry_post_install_actions(fib_entry, source, FIB_ENTRY_FLAG_NONE);
+
+    return (fib_entry_index);
+}
+
+static void
+fib_entry_post_update_actions (fib_entry_t *fib_entry,
+			       fib_source_t source,
+			       fib_entry_flag_t old_flags)
+{
+    /*
+     * backwalk to children to inform then of the change to forwarding.
+     */
+    fib_node_back_walk_ctx_t bw_ctx = {
+	.fnbw_reason = FIB_NODE_BW_REASON_FLAG_EVALUATE,
+    };
+
+    fib_walk_sync(FIB_NODE_TYPE_ENTRY, fib_entry_get_index(fib_entry), &bw_ctx);
+
+    /*
+     * then inform any covered prefixes
+     */
+    fib_entry_cover_update_notify(fib_entry);
+
+    fib_entry_post_install_actions(fib_entry, source, old_flags);
+}
+
+static void
+fib_entry_source_change (fib_entry_t *fib_entry,
+			 fib_source_t best_source,
+			 fib_source_t new_source,
+			 fib_entry_flag_t old_flags)
+{
+    /*
+     * if the path list for the source passed is invalid,
+     * then we need to create a new one. else we are updating
+     * an existing.
+     */
+    if (new_source < best_source)
+    {
+	/*
+	 * we have a new winning source.
+	 */
+	fib_entry_src_action_deactivate(fib_entry, best_source);
+	fib_entry_src_action_activate(fib_entry, new_source);
+    }
+    else if (new_source > best_source)
+    {
+	/*
+	 * the new source loses. nothing to do here.
+	 * the data from the source is saved in the path-list created
+	 */
+	return;
+    }
+    else
+    {
+	/*
+	 * the new source is one this entry already has.
+	 * But the path-list was updated, which will contribute new forwarding,
+	 * so install it.
+	 */
+	fib_entry_src_action_deactivate(fib_entry, new_source);
+	fib_entry_src_action_activate(fib_entry, new_source);
+    }
+
+    fib_entry_post_update_actions(fib_entry, new_source, old_flags);
+}
+
+void
+fib_entry_special_add (fib_node_index_t fib_entry_index,
+		       fib_source_t source,
+		       fib_entry_flag_t flags,
+		       const dpo_id_t *dpo)
+{
+    fib_source_t best_source;
+    fib_entry_flag_t bflags;
+    fib_entry_t *fib_entry;
+    fib_entry_src_t *bsrc;
+
+    fib_entry = fib_entry_get(fib_entry_index);
+
+    bsrc = fib_entry_get_best_src_i(fib_entry);
+    best_source = fib_entry_src_get_source(bsrc);
+    bflags = fib_entry_src_get_flags(bsrc);
+
+    fib_entry = fib_entry_src_action_add(fib_entry, source, flags, dpo);
+    fib_entry_source_change(fib_entry, best_source, source, bflags);
+}
+
+void
+fib_entry_special_update (fib_node_index_t fib_entry_index,
+			  fib_source_t source,
+			  fib_entry_flag_t flags,
+			  const dpo_id_t *dpo)
+{
+    fib_source_t best_source;
+    fib_entry_flag_t bflags;
+    fib_entry_t *fib_entry;
+    fib_entry_src_t *bsrc;
+
+    fib_entry = fib_entry_get(fib_entry_index);
+
+    bsrc = fib_entry_get_best_src_i(fib_entry);
+    best_source = fib_entry_src_get_source(bsrc);
+    bflags = fib_entry_src_get_flags(bsrc);
+
+    fib_entry = fib_entry_src_action_update(fib_entry, source, flags, dpo);
+    fib_entry_source_change(fib_entry, best_source, source, bflags);
+}
+
+
+void
+fib_entry_path_add (fib_node_index_t fib_entry_index,
+		    fib_source_t source,
+		    fib_entry_flag_t flags,
+		    const fib_route_path_t *rpath)
+{
+    fib_source_t best_source;
+    fib_entry_flag_t bflags;
+    fib_entry_t *fib_entry;
+    fib_entry_src_t *bsrc;
+
+    ASSERT(1 == vec_len(rpath));
+
+    fib_entry = fib_entry_get(fib_entry_index);
+    ASSERT(NULL != fib_entry);
+
+    bsrc = fib_entry_get_best_src_i(fib_entry);
+    best_source = fib_entry_src_get_source(bsrc);
+    bflags = fib_entry_src_get_flags(bsrc);
+    
+    fib_entry = fib_entry_src_action_path_add(fib_entry, source, flags, rpath);
+
+    /*
+     * if the path list for the source passed is invalid,
+     * then we need to create a new one. else we are updating
+     * an existing.
+     */
+    if (source < best_source)
+    {
+	/*
+	 * we have a new winning source.
+	 */
+	fib_entry_src_action_deactivate(fib_entry, best_source);
+	fib_entry_src_action_activate(fib_entry, source);
+    }
+    else if (source > best_source)
+    {
+	/*
+	 * the new source loses. nothing to do here.
+	 * the data from the source is saved in the path-list created
+	 */
+	return;
+    }
+    else
+    {
+	/*
+	 * the new source is one this entry already has.
+	 * But the path-list was updated, which will contribute new forwarding,
+	 * so install it.
+	 */
+	fib_entry_src_action_deactivate(fib_entry, source);
+	fib_entry_src_action_activate(fib_entry, source);
+    }
+
+    fib_entry_post_update_actions(fib_entry, source, bflags);
+}
+
+/*
+ * fib_entry_path_remove
+ *
+ * remove a path from the entry.
+ * return the fib_entry's index if it is still present, INVALID otherwise.
+ */
+fib_entry_src_flag_t
+fib_entry_path_remove (fib_node_index_t fib_entry_index,
+		       fib_source_t source,
+		       const fib_route_path_t *rpath)
+{
+    fib_entry_src_flag_t sflag;
+    fib_source_t best_source;
+    fib_entry_flag_t bflags;
+    fib_entry_t *fib_entry;
+    fib_entry_src_t *bsrc;
+
+    ASSERT(1 == vec_len(rpath));
+
+    fib_entry = fib_entry_get(fib_entry_index);
+    ASSERT(NULL != fib_entry);
+
+    bsrc = fib_entry_get_best_src_i(fib_entry);
+    best_source = fib_entry_src_get_source(bsrc);
+    bflags = fib_entry_src_get_flags(bsrc);
+
+    sflag = fib_entry_src_action_path_remove(fib_entry, source, rpath);
+
+    /*
+     * if the path list for the source passed is invalid,
+     * then we need to create a new one. else we are updating
+     * an existing.
+     */
+    if (source < best_source )
+    {
+	/*
+	 * Que! removing a path from a source that is better than the
+	 * one this entry is using.
+	 */
+	ASSERT(0);
+    }
+    else if (source > best_source )
+    {
+	/*
+	 * the source is not the best. nothing to do.
+	 */
+	return (FIB_ENTRY_SRC_FLAG_ADDED);
+    }
+    else
+    {
+	/*
+	 * removing a path from the path-list we were using.
+	 */
+	if (!(FIB_ENTRY_SRC_FLAG_ADDED & sflag))
+	{
+	    /*
+	     * the last path from the source was removed.
+	     * fallback to lower source
+	     */
+	    bsrc = fib_entry_get_best_src_i(fib_entry);
+	    best_source = fib_entry_src_get_source(bsrc);
+
+	    if (FIB_SOURCE_MAX == best_source) {
+		/*
+		 * no more sources left. this entry is toast.
+		 */
+		fib_entry_src_action_uninstall(fib_entry);
+		fib_entry_post_flag_update_actions(fib_entry, source, bflags);
+
+		return (FIB_ENTRY_SRC_FLAG_NONE);
+	    }
+	    else
+	    {
+		fib_entry_src_action_activate(fib_entry, best_source);
+		source = best_source;
+	    }
+	}
+	else
+	{
+	    /*
+	     * re-install the new forwarding information
+	     */
+	    fib_entry_src_action_deactivate(fib_entry, source);
+	    fib_entry_src_action_activate(fib_entry, source);
+	}
+    }
+
+    fib_entry_post_update_actions(fib_entry, source, bflags);
+
+    /*
+     * still have sources
+     */
+    return (FIB_ENTRY_SRC_FLAG_ADDED);
+}
+
+/*
+ * fib_entry_special_remove
+ *
+ * remove a special source from the entry.
+ * return the fib_entry's index if it is still present, INVALID otherwise.
+ */
+fib_entry_src_flag_t
+fib_entry_special_remove (fib_node_index_t fib_entry_index,
+			  fib_source_t source)
+{
+    fib_entry_src_flag_t sflag;
+    fib_source_t best_source;
+    fib_entry_flag_t bflags;
+    fib_entry_t *fib_entry;
+    fib_entry_src_t *bsrc;
+
+    fib_entry = fib_entry_get(fib_entry_index);
+    ASSERT(NULL != fib_entry);
+
+    bsrc = fib_entry_get_best_src_i(fib_entry);
+    best_source = fib_entry_src_get_source(bsrc);
+    bflags = fib_entry_src_get_flags(bsrc);
+
+    sflag = fib_entry_src_action_remove(fib_entry, source);
+
+    /*
+     * if the path list for the source passed is invalid,
+     * then we need to create a new one. else we are updating
+     * an existing.
+     */
+    if (source < best_source )
+    {
+	/*
+	 * Que! removing a path from a source that is better than the
+	 * one this entry is using. This can only mean it is a source
+         * this prefix does not have.
+	 */
+        return (FIB_ENTRY_SRC_FLAG_ADDED);
+    }
+    else if (source > best_source ) {
+	/*
+	 * the source is not the best. nothing to do.
+	 */
+	return (FIB_ENTRY_SRC_FLAG_ADDED);
+    }
+    else
+    {
+	if (!(FIB_ENTRY_SRC_FLAG_ADDED & sflag))
+	{
+	    /*
+	     * the source was removed. use the next best.
+	     */
+	    bsrc = fib_entry_get_best_src_i(fib_entry);
+	    best_source = fib_entry_src_get_source(bsrc);
+
+	    if (FIB_SOURCE_MAX == best_source) {
+		/*
+		 * no more sources left. this entry is toast.
+		 */
+		fib_entry_src_action_uninstall(fib_entry);
+		fib_entry_post_flag_update_actions(fib_entry, source, bflags);
+
+		return (FIB_ENTRY_SRC_FLAG_NONE);
+	    }
+	    else
+	    {
+		fib_entry_src_action_activate(fib_entry, best_source);
+		source = best_source;
+	    }
+	}
+	else
+	{
+	    /*
+	     * re-install the new forwarding information
+	     */
+	    fib_entry_src_action_reactivate(fib_entry, source);
+	}
+    }
+
+    fib_entry_post_update_actions(fib_entry, source, bflags);
+
+    /*
+     * still have sources
+     */
+    return (FIB_ENTRY_SRC_FLAG_ADDED);
+}
+
+/**
+ * fib_entry_delete
+ *
+ * The source is withdrawing all the paths it provided
+ */
+fib_entry_src_flag_t
+fib_entry_delete (fib_node_index_t fib_entry_index,
+		  fib_source_t source)
+{
+    return (fib_entry_special_remove(fib_entry_index, source));
+}
+
+/**
+ * fib_entry_update
+ *
+ * The source has provided a new set of paths that will replace the old.
+ */
+void
+fib_entry_update (fib_node_index_t fib_entry_index,
+		  fib_source_t source,
+		  fib_entry_flag_t flags,
+		  const fib_route_path_t *paths)
+{
+    fib_source_t best_source;
+    fib_entry_flag_t bflags;
+    fib_entry_t *fib_entry;
+    fib_entry_src_t *bsrc;
+
+    fib_entry = fib_entry_get(fib_entry_index);
+    ASSERT(NULL != fib_entry);
+
+    bsrc = fib_entry_get_best_src_i(fib_entry);
+    best_source = fib_entry_src_get_source(bsrc);
+    bflags = fib_entry_src_get_flags(bsrc);
+
+    fib_entry_src_action_path_swap(fib_entry,
+				   source,
+				   flags,
+				   paths);
+    /*
+     * handle possible realloc's by refetching the pointer
+     */
+    fib_entry = fib_entry_get(fib_entry_index);
+
+    /*
+     * if the path list for the source passed is invalid,
+     * then we need to create a new one. else we are updating
+     * an existing.
+     */
+    if (source < best_source)
+    {
+	/*
+	 * we have a new winning source.
+	 */
+	fib_entry_src_action_deactivate(fib_entry, best_source);
+	fib_entry_src_action_activate(fib_entry, source);
+    }
+    else if (source > best_source) {
+	/*
+	 * the new source loses. nothing to do here.
+	 * the data from the source is saved in the path-list created
+	 */
+	return;
+    }
+    else
+    {
+	/*
+	 * the new source is one this entry already has.
+	 * But the path-list was updated, which will contribute new forwarding,
+	 * so install it.
+	 */
+	fib_entry_src_action_deactivate(fib_entry, source);
+	fib_entry_src_action_activate(fib_entry, source);
+    }
+
+    fib_entry_post_update_actions(fib_entry, source, bflags);
+}
+
+
+/*
+ * fib_entry_cover_changed
+ *
+ * this entry is tracking its cover and that cover has changed.
+ */
+void
+fib_entry_cover_changed (fib_node_index_t fib_entry_index)
+{
+    fib_entry_src_cover_res_t res = {
+	.install = !0,
+	.bw_reason = FIB_NODE_BW_REASON_FLAG_NONE,
+    };
+    fib_source_t source, best_source;
+    fib_entry_flag_t bflags;
+    fib_entry_t *fib_entry;
+    fib_entry_src_t *esrc;
+    u32 index;
+
+    bflags = FIB_ENTRY_FLAG_NONE;
+    best_source = FIB_SOURCE_FIRST;
+    fib_entry = fib_entry_get(fib_entry_index);
+
+    fib_attached_export_cover_change(fib_entry);
+
+    /*
+     * propagate the notificuation to each of the added sources
+     */
+    index = 0;
+    FOR_EACH_SRC_ADDED(fib_entry, esrc, source,
+    ({
+	if (0 == index)
+	{
+	    /*
+	     * only the best source gets to set the back walk flags
+	     */
+	    res = fib_entry_src_action_cover_change(fib_entry, source);
+            bflags = fib_entry_src_get_flags(esrc);
+            best_source = fib_entry_src_get_source(esrc);
+	}
+	else
+	{
+	    fib_entry_src_action_cover_change(fib_entry, source);
+	}
+	index++;
+    }));
+
+    if (res.install)
+    {
+	fib_entry_src_action_reactivate(fib_entry,
+					fib_entry_src_get_source(
+					    fib_entry_get_best_src_i(fib_entry)));
+        fib_entry_post_install_actions(fib_entry, best_source, bflags);
+    }
+    else
+    {
+	fib_entry_src_action_uninstall(fib_entry);
+    }
+
+    if (FIB_NODE_BW_REASON_FLAG_NONE != res.bw_reason)
+    {
+	/*
+	 * time for walkies fido.
+	 */
+	fib_node_back_walk_ctx_t bw_ctx = {
+	    .fnbw_reason = res.bw_reason,
+        };
+
+	fib_walk_sync(FIB_NODE_TYPE_ENTRY, fib_entry_index, &bw_ctx);
+    }
+}
+
+/*
+ * fib_entry_cover_updated
+ *
+ * this entry is tracking its cover and that cover has been updated
+ * (i.e. its forwarding information has changed).
+ */
+void
+fib_entry_cover_updated (fib_node_index_t fib_entry_index)
+{
+    fib_entry_src_cover_res_t res = {
+	.install = !0,
+	.bw_reason = FIB_NODE_BW_REASON_FLAG_NONE,
+    };
+    fib_source_t source, best_source;
+    fib_entry_flag_t bflags;
+    fib_entry_t *fib_entry;
+    fib_entry_src_t *esrc;
+    u32 index;
+
+    bflags = FIB_ENTRY_FLAG_NONE;
+    best_source = FIB_SOURCE_FIRST;
+    fib_entry = fib_entry_get(fib_entry_index);
+
+    fib_attached_export_cover_update(fib_entry);
+
+    /*
+     * propagate the notificuation to each of the added sources
+     */
+    index = 0;
+    FOR_EACH_SRC_ADDED(fib_entry, esrc, source,
+    ({
+	if (0 == index)
+	{
+	    /*
+	     * only the best source gets to set the back walk flags
+	     */
+	    res = fib_entry_src_action_cover_update(fib_entry, source);
+            bflags = fib_entry_src_get_flags(esrc);
+            best_source = fib_entry_src_get_source(esrc);
+	}
+	else
+	{
+	    fib_entry_src_action_cover_update(fib_entry, source);
+	}
+	index++;
+    }));
+
+    if (res.install)
+    {
+	fib_entry_src_action_reactivate(fib_entry,
+					fib_entry_src_get_source(
+					    fib_entry_get_best_src_i(fib_entry)));
+        fib_entry_post_install_actions(fib_entry, best_source, bflags);
+    }
+    else
+    {
+	fib_entry_src_action_uninstall(fib_entry);
+    }
+
+    if (FIB_NODE_BW_REASON_FLAG_NONE != res.bw_reason)
+    {
+	/*
+	 * time for walkies fido.
+	 */
+	fib_node_back_walk_ctx_t bw_ctx = {
+	    .fnbw_reason = res.bw_reason,
+        };
+
+	fib_walk_sync(FIB_NODE_TYPE_ENTRY, fib_entry_index, &bw_ctx);
+    }
+}
+
+int
+fib_entry_recursive_loop_detect (fib_node_index_t entry_index,
+				 fib_node_index_t **entry_indicies)
+{
+    fib_entry_t *fib_entry;
+    int was_looped, is_looped;
+
+    fib_entry = fib_entry_get(entry_index);
+
+    if (FIB_NODE_INDEX_INVALID != fib_entry->fe_parent)
+    {
+	fib_node_index_t *entries = *entry_indicies;
+
+	vec_add1(entries, entry_index);
+	was_looped = fib_path_list_is_looped(fib_entry->fe_parent);
+	is_looped = fib_path_list_recursive_loop_detect(fib_entry->fe_parent,
+							&entries);
+
+	*entry_indicies = entries;
+
+	if (!!was_looped != !!is_looped)
+	{
+	    /*
+	     * re-evaluate all the entry's forwarding
+	     * NOTE: this is an inplace modify
+	     */
+            fib_entry_delegate_type_t fdt;
+            fib_entry_delegate_t *fed;
+
+            FOR_EACH_DELEGATE_CHAIN(fib_entry, fdt, fed,
+            {
+                fib_entry_src_mk_lb(fib_entry,
+                                    fib_entry_get_best_src_i(fib_entry),
+                                    fib_entry_delegate_type_to_chain_type(fdt),
+                                    &fed->fd_dpo);
+	    });
+	}
+    }
+    else
+    {
+	/*
+	 * the entry is currently not linked to a path-list. this happens
+	 * when it is this entry that is re-linking path-lists and has thus
+	 * broken the loop
+	 */
+	is_looped = 0;
+    }
+
+    return (is_looped);
+}
+
+u32
+fib_entry_get_resolving_interface (fib_node_index_t entry_index)
+{
+    fib_entry_t *fib_entry;
+
+    fib_entry = fib_entry_get(entry_index);
+
+    return (fib_path_list_get_resolving_interface(fib_entry->fe_parent));
+}
+
+fib_source_t
+fib_entry_get_best_source (fib_node_index_t entry_index)
+{
+    fib_entry_t *fib_entry;
+    fib_entry_src_t *bsrc;
+
+    fib_entry = fib_entry_get(entry_index);
+
+    bsrc = fib_entry_get_best_src_i(fib_entry);
+    return (fib_entry_src_get_source(bsrc));
+}
+
+static int
+fib_ip4_address_compare (const ip4_address_t * a1,
+                         const ip4_address_t * a2)
+{
+    /*
+     * IP addresses are unsiged ints. the return value here needs to be signed
+     * a simple subtraction won't cut it.
+     * If the addresses are the same, the sort order is undefiend, so phoey.
+     */
+    return ((clib_net_to_host_u32(a1->data_u32) >
+	     clib_net_to_host_u32(a2->data_u32) ) ?
+	    1 : -1);
+}
+
+static int
+fib_ip6_address_compare (const ip6_address_t * a1,
+                         const ip6_address_t * a2)
+{
+  int i;
+  for (i = 0; i < ARRAY_LEN (a1->as_u16); i++)
+  {
+      int cmp = (clib_net_to_host_u16 (a1->as_u16[i]) -
+		 clib_net_to_host_u16 (a2->as_u16[i]));
+      if (cmp != 0)
+	  return cmp;
+  }
+  return 0;
+}
+
+static int
+fib_entry_cmp (fib_node_index_t fib_entry_index1,
+	       fib_node_index_t fib_entry_index2)
+{
+    fib_entry_t *fib_entry1, *fib_entry2;
+    int cmp = 0;
+
+    fib_entry1 = fib_entry_get(fib_entry_index1);
+    fib_entry2 = fib_entry_get(fib_entry_index2);
+
+    switch (fib_entry1->fe_prefix.fp_proto)
+    {
+    case FIB_PROTOCOL_IP4:
+        cmp = fib_ip4_address_compare(&fib_entry1->fe_prefix.fp_addr.ip4,
+                                      &fib_entry2->fe_prefix.fp_addr.ip4);
+        break;
+    case FIB_PROTOCOL_IP6:
+        cmp = fib_ip6_address_compare(&fib_entry1->fe_prefix.fp_addr.ip6,
+                                      &fib_entry2->fe_prefix.fp_addr.ip6);
+        break;
+    case FIB_PROTOCOL_MPLS:
+	cmp = (fib_entry1->fe_prefix.fp_label - fib_entry2->fe_prefix.fp_label);
+
+	if (0 == cmp)
+	{
+	    cmp = (fib_entry1->fe_prefix.fp_eos - fib_entry2->fe_prefix.fp_eos);
+	}
+        break;
+    }
+
+    if (0 == cmp) {
+	cmp = (fib_entry1->fe_prefix.fp_len - fib_entry2->fe_prefix.fp_len);
+    }
+    return (cmp);   
+}
+
+int
+fib_entry_cmp_for_sort (void *i1, void *i2)
+{
+    fib_node_index_t *fib_entry_index1 = i1, *fib_entry_index2 = i2;
+
+    return (fib_entry_cmp(*fib_entry_index1,
+			  *fib_entry_index2));
+}
+
+void
+fib_entry_lock (fib_node_index_t fib_entry_index)
+{
+    fib_entry_t *fib_entry;
+
+    fib_entry = fib_entry_get(fib_entry_index);
+
+    fib_node_lock(&fib_entry->fe_node);
+}
+
+void
+fib_entry_unlock (fib_node_index_t fib_entry_index)
+{
+    fib_entry_t *fib_entry;
+
+    fib_entry = fib_entry_get(fib_entry_index);
+
+    fib_node_unlock(&fib_entry->fe_node);
+}
+
+void
+fib_entry_module_init (void)
+{
+    fib_node_register_type (FIB_NODE_TYPE_ENTRY, &fib_entry_vft);
+}
+
+void
+fib_entry_encode (fib_node_index_t fib_entry_index,
+		  fib_route_path_encode_t **api_rpaths)
+{
+    fib_entry_t *fib_entry;
+
+    fib_entry = fib_entry_get(fib_entry_index);
+    fib_path_list_walk(fib_entry->fe_parent, fib_path_encode, api_rpaths);
+}
+
+void
+fib_entry_get_prefix (fib_node_index_t fib_entry_index,
+		      fib_prefix_t *pfx)
+{
+    fib_entry_t *fib_entry;
+
+    fib_entry = fib_entry_get(fib_entry_index);
+    *pfx = fib_entry->fe_prefix;
+}
+
+u32
+fib_entry_get_fib_index (fib_node_index_t fib_entry_index)
+{
+    fib_entry_t *fib_entry;
+
+    fib_entry = fib_entry_get(fib_entry_index);
+
+    return (fib_entry->fe_fib_index);
+}
+
+u32
+fib_entry_pool_size (void)
+{
+    return (pool_elts(fib_entry_pool));
+}
+
+static clib_error_t *
+show_fib_entry_command (vlib_main_t * vm,
+			unformat_input_t * input,
+			vlib_cli_command_t * cmd)
+{
+    fib_node_index_t fei;
+
+    if (unformat (input, "%d", &fei))
+    {
+	/*
+	 * show one in detail
+	 */
+	if (!pool_is_free_index(fib_entry_pool, fei))
+	{
+	    vlib_cli_output (vm, "%d@%U",
+			     fei,
+			     format_fib_entry, fei,
+			     FIB_ENTRY_FORMAT_DETAIL2);
+	}
+	else
+	{
+	    vlib_cli_output (vm, "entry %d invalid", fei);
+	}
+    }
+    else
+    {
+	/*
+	 * show all
+	 */
+	vlib_cli_output (vm, "FIB Entries:");
+	pool_foreach_index(fei, fib_entry_pool,
+        ({
+	    vlib_cli_output (vm, "%d@%U",
+			     fei,
+			     format_fib_entry, fei,
+			     FIB_ENTRY_FORMAT_BRIEF);
+	}));
+    }
+
+    return (NULL);
+}
+
+VLIB_CLI_COMMAND (show_fib_entry, static) = {
+  .path = "show fib entry",
+  .function = show_fib_entry_command,
+  .short_help = "show fib entry",
+};
diff --git a/src/vnet/fib/fib_entry.h b/src/vnet/fib/fib_entry.h
new file mode 100644
index 00000000000..44a5f2e6d7f
--- /dev/null
+++ b/src/vnet/fib/fib_entry.h
@@ -0,0 +1,530 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __FIB_ENTRY_H__
+#define __FIB_ENTRY_H__
+
+#include <vnet/fib/fib_node.h>
+#include <vnet/fib/fib_entry_delegate.h>
+#include <vnet/adj/adj.h>
+#include <vnet/ip/ip.h>
+#include <vnet/dpo/dpo.h>
+
+/**
+ * The different sources that can create a route.
+ * The sources are defined here the thier relative priority order.
+ * The lower the value the higher the priority
+ */
+typedef enum fib_source_t_ {
+    /**
+     * Marker. Add new values after this one.
+     */
+    FIB_SOURCE_FIRST,
+    /**
+     * Special sources. These are for entries that are added to all
+     * FIBs by default, and should never be over-ridden (hence they
+     * are the highest priority)
+     */
+    FIB_SOURCE_SPECIAL = FIB_SOURCE_FIRST,
+    /**
+     * Classify. A route that links directly to a classify adj
+     */
+    FIB_SOURCE_CLASSIFY,
+    /**
+     * Route added as a result of interface configuration.
+     * this will also come from the API/CLI, but the distinction is
+     * that is from confiiguration on an interface, not a 'ip route' command
+     */
+    FIB_SOURCE_INTERFACE,
+    /**
+     * A high priority source a plugin can use
+     */
+    FIB_SOURCE_PLUGIN_HI,
+    /**
+     * From the control plane API
+     */
+    FIB_SOURCE_API,
+    /**
+     * From the CLI.
+     */
+    FIB_SOURCE_CLI,
+    /**
+     * LISP
+     */
+    FIB_SOURCE_LISP,
+    /**
+     * SRv6
+     */
+    FIB_SOURCE_SR,
+    /**
+     * IPv[46] Mapping
+     */
+    FIB_SOURCE_MAP,
+    /**
+     * SIXRD
+     */
+    FIB_SOURCE_SIXRD,
+    /**
+     * DHCP
+     */
+    FIB_SOURCE_DHCP,
+    /**
+     * Adjacency source.
+     * routes created as a result of ARP/ND entries. This is lower priority
+     * then the API/CLI. This is on purpose. trust me.
+     */
+    FIB_SOURCE_ADJ,
+    /**
+     * MPLS label. The prefix has been assigned a local label. This source
+     * never provides forwarding information, instead it acts as a place-holder
+     * so the association of label to prefix can be maintained
+     */
+    FIB_SOURCE_MPLS,
+    /**
+     * Attached Export source.
+     * routes created as a result of attahced export. routes thus sourced
+     * will be present in the export tables
+     */
+    FIB_SOURCE_AE,
+    /**
+     * Recursive resolution source.
+     * Used to install an entry that is the resolution traget of another.
+     */
+    FIB_SOURCE_RR,
+    /**
+     * uRPF bypass/exemption.
+     * Used to install an entry that is exempt from the loose uRPF check
+     */
+    FIB_SOURCE_URPF_EXEMPT,
+    /**
+     * The default route source.
+     * The default route is always added to the FIB table (like the
+     * special sources) but we need to be able to over-ride it with
+     * 'ip route' sources when provided
+     */
+    FIB_SOURCE_DEFAULT_ROUTE,
+    /**
+     * Marker. add new entries before this one.
+     */
+    FIB_SOURCE_LAST = FIB_SOURCE_DEFAULT_ROUTE,
+} __attribute__ ((packed)) fib_source_t;
+
+STATIC_ASSERT (sizeof(fib_source_t) == 1,
+	       "FIB too many sources");
+
+/**
+ * The maximum number of sources
+ */
+#define FIB_SOURCE_MAX (FIB_SOURCE_LAST+1)
+
+#define FIB_SOURCES {					\
+    [FIB_SOURCE_SPECIAL] = "special",			\
+    [FIB_SOURCE_INTERFACE] = "interface",		\
+    [FIB_SOURCE_API] = "API",			        \
+    [FIB_SOURCE_CLI] = "CLI",			        \
+    [FIB_SOURCE_ADJ] = "adjacency",			\
+    [FIB_SOURCE_MAP] = "MAP",			        \
+    [FIB_SOURCE_SR] = "SR",			        \
+    [FIB_SOURCE_SIXRD] = "SixRD",			\
+    [FIB_SOURCE_LISP] = "LISP", 			\
+    [FIB_SOURCE_CLASSIFY] = "classify",			\
+    [FIB_SOURCE_DHCP] = "DHCP",   			\
+    [FIB_SOURCE_RR] = "recursive-resolution",	        \
+    [FIB_SOURCE_AE] = "attached_export",	        \
+    [FIB_SOURCE_MPLS] = "mpls",           	        \
+    [FIB_SOURCE_URPF_EXEMPT] = "urpf-exempt",	        \
+    [FIB_SOURCE_DEFAULT_ROUTE] = "default-route",	\
+}
+
+#define FOR_EACH_FIB_SOURCE(_item) \
+    for (_item = FIB_SOURCE_FIRST; _item < FIB_SOURCE_MAX; _item++)
+
+/**
+ * The different sources that can create a route.
+ * The sources are defined here the thier relative priority order.
+ * The lower the value the higher the priority
+ */
+typedef enum fib_entry_attribute_t_ {
+    /**
+     * Marker. Add new values after this one.
+     */
+    FIB_ENTRY_ATTRIBUTE_FIRST,
+    /**
+     * Connected. The prefix is configured on an interface.
+     */
+    FIB_ENTRY_ATTRIBUTE_CONNECTED = FIB_ENTRY_ATTRIBUTE_FIRST,
+    /**
+     * Attached. The prefix is attached to an interface.
+     */
+    FIB_ENTRY_ATTRIBUTE_ATTACHED,
+    /**
+     * The route is an explicit drop.
+     */
+    FIB_ENTRY_ATTRIBUTE_DROP,
+    /**
+     * The route is exclusive. The client creating the route is
+     * providing an exclusive adjacency.
+     */
+    FIB_ENTRY_ATTRIBUTE_EXCLUSIVE,
+    /**
+     * The route is attached cross tables and thus imports covered
+     * prefixes from the other table.
+     */
+    FIB_ENTRY_ATTRIBUTE_IMPORT,
+    /**
+     * The prefix/address is local to this device
+     */
+    FIB_ENTRY_ATTRIBUTE_LOCAL,
+    /**
+     * Marker. add new entries before this one.
+     */
+    FIB_ENTRY_ATTRIBUTE_LAST = FIB_ENTRY_ATTRIBUTE_LOCAL,
+} fib_entry_attribute_t;
+
+/**
+ * The maximum number of sources
+ */
+#define FIB_ENTRY_ATTRIBUTE_MAX (FIB_ENTRY_ATTRIBUTE_LAST+1)
+
+#define FIB_ENTRY_ATTRIBUTES {		       		\
+    [FIB_ENTRY_ATTRIBUTE_CONNECTED] = "connected",	\
+    [FIB_ENTRY_ATTRIBUTE_ATTACHED]  = "attached",	\
+    [FIB_ENTRY_ATTRIBUTE_IMPORT]    = "import",	        \
+    [FIB_ENTRY_ATTRIBUTE_DROP]      = "drop",		\
+    [FIB_ENTRY_ATTRIBUTE_EXCLUSIVE] = "exclusive",      \
+    [FIB_ENTRY_ATTRIBUTE_LOCAL]     = "local",		\
+}
+
+#define FOR_EACH_FIB_ATTRIBUTE(_item)			\
+    for (_item = FIB_ENTRY_ATTRIBUTE_FIRST;		\
+	 _item < FIB_ENTRY_ATTRIBUTE_MAX;		\
+	 _item++)
+
+typedef enum fib_entry_flag_t_ {
+    FIB_ENTRY_FLAG_NONE      = 0,
+    FIB_ENTRY_FLAG_CONNECTED = (1 << FIB_ENTRY_ATTRIBUTE_CONNECTED),
+    FIB_ENTRY_FLAG_ATTACHED  = (1 << FIB_ENTRY_ATTRIBUTE_ATTACHED),
+    FIB_ENTRY_FLAG_DROP      = (1 << FIB_ENTRY_ATTRIBUTE_DROP),
+    FIB_ENTRY_FLAG_EXCLUSIVE = (1 << FIB_ENTRY_ATTRIBUTE_EXCLUSIVE),
+    FIB_ENTRY_FLAG_LOCAL     = (1 << FIB_ENTRY_ATTRIBUTE_LOCAL),
+    FIB_ENTRY_FLAG_IMPORT    = (1 << FIB_ENTRY_ATTRIBUTE_IMPORT),
+} fib_entry_flag_t;
+
+/**
+ * Flags for the source data
+ */
+typedef enum fib_entry_src_attribute_t_ {
+    /**
+     * Marker. Add new values after this one.
+     */
+    FIB_ENTRY_SRC_ATTRIBUTE_FIRST,
+    /**
+     * the source has been added to the entry
+     */
+    FIB_ENTRY_SRC_ATTRIBUTE_ADDED = FIB_ENTRY_SRC_ATTRIBUTE_FIRST,
+    /**
+     * the source is active/best
+     */
+    FIB_ENTRY_SRC_ATTRIBUTE_ACTIVE,
+    /**
+     * Marker. add new entries before this one.
+     */
+    FIB_ENTRY_SRC_ATTRIBUTE_LAST = FIB_ENTRY_SRC_ATTRIBUTE_ACTIVE,
+} fib_entry_src_attribute_t;
+
+#define FIB_ENTRY_SRC_ATTRIBUTE_MAX (FIB_ENTRY_SRC_ATTRIBUTE_LAST+1)
+
+#define FIB_ENTRY_SRC_ATTRIBUTES {		 \
+    [FIB_ENTRY_SRC_ATTRIBUTE_ADDED]  = "added",	 \
+    [FIB_ENTRY_SRC_ATTRIBUTE_ACTIVE] = "active", \
+}
+
+typedef enum fib_entry_src_flag_t_ {
+    FIB_ENTRY_SRC_FLAG_NONE   = 0,
+    FIB_ENTRY_SRC_FLAG_ADDED  = (1 << FIB_ENTRY_SRC_ATTRIBUTE_ADDED),
+    FIB_ENTRY_SRC_FLAG_ACTIVE = (1 << FIB_ENTRY_SRC_ATTRIBUTE_ACTIVE),
+} __attribute__ ((packed)) fib_entry_src_flag_t;
+
+/*
+ * Keep the size of the flags field to 2 bytes, so it
+ * can be placed next to the 2 bytes reference count
+ */
+STATIC_ASSERT (sizeof(fib_entry_src_flag_t) <= 2,
+	       "FIB entry flags field size too big");
+
+/**
+ * Information related to the source of a FIB entry
+ */
+typedef struct fib_entry_src_t_ {
+    /**
+     * A vector of path extensions
+     */
+    struct fib_path_ext_t_ *fes_path_exts;
+
+    /**
+     * The path-list created by the source
+     */
+    fib_node_index_t fes_pl;
+    /**
+     * Which source this info block is for
+     */
+    fib_source_t fes_src;
+    /**
+     * Flags on the source
+     */
+    fib_entry_src_flag_t fes_flags;
+
+    /**
+     * 1 bytes ref count. This is not the number of users of the Entry
+     * (which is itself not large, due to path-list sharing), but the number
+     * of times a given source has been added. Which is even fewer
+     */
+    u8 fes_ref_count;
+
+    /**
+     * Flags the source contributes to the entry
+     */
+    fib_entry_flag_t fes_entry_flags;
+    
+    /**
+     * Source specific info
+     */
+    union {
+	struct {
+	    /**
+	     * the index of the FIB entry that is the covering entry
+	     */
+	    fib_node_index_t fesr_cover;
+	    /**
+	     * This source's index in the cover's list
+	     */
+	    u32 fesr_sibling;
+	} rr;
+	struct {
+	    /**
+	     * the index of the FIB entry that is the covering entry
+	     */
+	    fib_node_index_t fesa_cover;
+	    /**
+	     * This source's index in the cover's list
+	     */
+	    u32 fesa_sibling;
+	} adj;
+	struct {
+	    /**
+	     * the index of the FIB entry that is the covering entry
+	     */
+	    fib_node_index_t fesi_cover;
+	    /**
+	     * This source's index in the cover's list
+	     */
+	    u32 fesi_sibling;
+	} interface;
+	struct {
+	    /**
+	     * This MPLS local label associated with the prefix.
+	     */
+	    mpls_label_t fesm_label;
+
+	    /**
+	     * the indicies of the LFIB entries created
+	     */
+	    fib_node_index_t fesm_lfes[2];
+	} mpls;
+	struct {
+	    /**
+	     * The source FIB index.
+	     */
+            fib_node_index_t fesl_fib_index;
+	} lisp;
+    };
+} fib_entry_src_t;
+
+/**
+ * An entry in a FIB table.
+ *
+ * This entry represents a route added to the FIB that is stored
+ * in one of the FIB tables.
+ */
+typedef struct fib_entry_t_ {
+    /**
+     * Base class. The entry's node representation in the graph.
+     */
+    fib_node_t fe_node;
+    /**
+     * The prefix of the route. this is const just to be sure.
+     * It is the entry's key/identity and so should never change.
+     */
+    const fib_prefix_t fe_prefix;
+    /**
+     * The index of the FIB table this entry is in
+     */
+    u32 fe_fib_index;
+    /**
+     * The load-balance used for forwarding.
+     *
+     * We don't share the EOS and non-EOS even in case when they could be
+     * because:
+     *   - complexity & reliability v. memory
+     *       determining the conditions where sharing is possible is non-trivial.
+     *   - separate LBs means we can get the EOS bit right in the MPLS label DPO
+     *     and so save a few clock cycles in the DP imposition node since we can
+     *     paint the header straight on without the need to check the packet
+     *     type to derive the EOS bit value.
+     */
+    dpo_id_t fe_lb; // [FIB_FORW_CHAIN_MPLS_NUM];
+    /**
+     * Vector of source infos.
+     * Most entries will only have 1 source. So we optimise for memory usage,
+     * which is preferable since we have many entries.
+     */
+    fib_entry_src_t *fe_srcs;
+    /**
+     * the path-list for which this entry is a child. This is also the path-list
+     * that is contributing forwarding for this entry.
+     */
+    fib_node_index_t fe_parent;
+    /**
+     * index of this entry in the parent's child list.
+     * This is set when this entry is added as a child, but can also
+     * be changed by the parent as it manages its list.
+     */
+    u32 fe_sibling;
+
+    /**
+     * A vector of delegates.
+     */
+    fib_entry_delegate_t *fe_delegates;
+} fib_entry_t;
+
+#define FOR_EACH_FIB_ENTRY_FLAG(_item) \
+    for (_item = FIB_ENTRY_FLAG_FIRST; _item < FIB_ENTRY_FLAG_MAX; _item++)
+
+#define FIB_ENTRY_FORMAT_BRIEF   (0x0)
+#define FIB_ENTRY_FORMAT_DETAIL  (0x1)
+#define FIB_ENTRY_FORMAT_DETAIL2 (0x2)
+
+extern u8 *format_fib_entry (u8 * s, va_list * args);
+
+extern fib_node_index_t fib_entry_create_special(u32 fib_index,
+						 const fib_prefix_t *prefix,
+						 fib_source_t source,
+						 fib_entry_flag_t flags,
+						 const dpo_id_t *dpo);
+
+extern fib_node_index_t fib_entry_create (u32 fib_index,
+					  const fib_prefix_t *prefix,
+					  fib_source_t source,
+					  fib_entry_flag_t flags,
+					  const fib_route_path_t *paths);
+extern void fib_entry_update (fib_node_index_t fib_entry_index,
+			      fib_source_t source,
+			      fib_entry_flag_t flags,
+			      const fib_route_path_t *paths);
+
+extern void fib_entry_path_add(fib_node_index_t fib_entry_index,
+			       fib_source_t source,
+			       fib_entry_flag_t flags,
+			       const fib_route_path_t *rpath);
+extern void fib_entry_special_add(fib_node_index_t fib_entry_index,
+				  fib_source_t source,
+				  fib_entry_flag_t flags,
+				  const dpo_id_t *dpo);
+extern void fib_entry_special_update(fib_node_index_t fib_entry_index,
+				     fib_source_t source,
+				     fib_entry_flag_t flags,
+				     const dpo_id_t *dpo);
+extern fib_entry_src_flag_t fib_entry_special_remove(fib_node_index_t fib_entry_index,
+						     fib_source_t source);
+
+extern fib_entry_src_flag_t fib_entry_path_remove(fib_node_index_t fib_entry_index,
+						  fib_source_t source,
+						  const fib_route_path_t *rpath);
+extern fib_entry_src_flag_t fib_entry_delete(fib_node_index_t fib_entry_index,
+					     fib_source_t source);
+
+extern void fib_entry_contribute_urpf(fib_node_index_t path_index,
+				      index_t urpf);
+extern void fib_entry_contribute_forwarding(
+    fib_node_index_t fib_entry_index,
+    fib_forward_chain_type_t type,
+    dpo_id_t *dpo);
+extern const dpo_id_t * fib_entry_contribute_ip_forwarding(
+    fib_node_index_t fib_entry_index);
+extern adj_index_t fib_entry_get_adj_for_source(
+    fib_node_index_t fib_entry_index,
+    fib_source_t source);
+extern const int fib_entry_get_dpo_for_source (
+    fib_node_index_t fib_entry_index,
+    fib_source_t source,
+    dpo_id_t *dpo);
+
+extern adj_index_t fib_entry_get_adj(fib_node_index_t fib_entry_index);
+
+extern int fib_entry_cmp_for_sort(void *i1, void *i2);
+
+extern void fib_entry_cover_changed(fib_node_index_t fib_entry);
+extern void fib_entry_cover_updated(fib_node_index_t fib_entry);
+extern int fib_entry_recursive_loop_detect(fib_node_index_t entry_index,
+					   fib_node_index_t **entry_indicies);
+
+extern void fib_entry_lock(fib_node_index_t fib_entry_index);
+extern void fib_entry_unlock(fib_node_index_t fib_entry_index);
+
+extern u32 fib_entry_child_add(fib_node_index_t fib_entry_index,
+			       fib_node_type_t type,
+			       fib_node_index_t child_index);
+extern void fib_entry_child_remove(fib_node_index_t fib_entry_index,
+				   u32 sibling_index);
+extern u32 fib_entry_get_resolving_interface(fib_node_index_t fib_entry_index);
+extern u32 fib_entry_get_resolving_interface_for_source(
+    fib_node_index_t fib_entry_index,
+    fib_source_t source);
+
+extern void fib_entry_encode(fib_node_index_t fib_entry_index,
+			     fib_route_path_encode_t **api_rpaths);
+extern void fib_entry_get_prefix(fib_node_index_t fib_entry_index,
+				 fib_prefix_t *pfx);
+extern u32 fib_entry_get_fib_index(fib_node_index_t fib_entry_index);
+extern void fib_entry_set_source_data(fib_node_index_t fib_entry_index,
+                                      fib_source_t source,
+                                      const void *data);
+extern const void* fib_entry_get_source_data(fib_node_index_t fib_entry_index,
+                                             fib_source_t source);
+
+extern fib_entry_flag_t fib_entry_get_flags(fib_node_index_t fib_entry_index);
+extern fib_entry_flag_t fib_entry_get_flags_for_source(
+    fib_node_index_t fib_entry_index,
+    fib_source_t source);
+extern fib_source_t fib_entry_get_best_source(fib_node_index_t fib_entry_index);
+extern int fib_entry_is_sourced(fib_node_index_t fib_entry_index,
+                                fib_source_t source);
+
+extern fib_node_index_t fib_entry_get_path_list(fib_node_index_t fib_entry_index);
+
+extern void fib_entry_module_init(void);
+
+/*
+ * unsafe... beware the raw pointer.
+ */
+extern fib_node_index_t fib_entry_get_index(const fib_entry_t * fib_entry);
+extern fib_entry_t * fib_entry_get(fib_node_index_t fib_entry_index);
+
+/*
+ * for testing purposes.
+ */
+extern u32 fib_entry_pool_size(void);
+
+#endif
diff --git a/src/vnet/fib/fib_entry_cover.c b/src/vnet/fib/fib_entry_cover.c
new file mode 100644
index 00000000000..147c5daa4fd
--- /dev/null
+++ b/src/vnet/fib/fib_entry_cover.c
@@ -0,0 +1,225 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vnet/fib/fib_entry_cover.h>
+#include <vnet/fib/fib_entry_src.h>
+#include <vnet/fib/fib_node_list.h>
+
+u32
+fib_entry_cover_track (fib_entry_t* cover,
+		       fib_node_index_t covered)
+{
+    fib_entry_delegate_t *fed;
+
+    FIB_ENTRY_DBG(cover, "cover-track %d", covered);
+
+    ASSERT(fib_entry_get_index(cover) != covered);
+
+    fed = fib_entry_delegate_get(cover, FIB_ENTRY_DELEGATE_COVERED);
+
+    if (NULL == fed)
+    {
+        fed = fib_entry_delegate_find_or_add(cover, FIB_ENTRY_DELEGATE_COVERED);
+        fed->fd_list = fib_node_list_create();
+    }
+
+    return (fib_node_list_push_front(fed->fd_list,
+                                     0, FIB_NODE_TYPE_ENTRY,
+                                     covered));
+}
+
+void
+fib_entry_cover_untrack (fib_entry_t* cover,
+			 u32 tracked_index)
+{
+    fib_entry_delegate_t *fed;
+
+    FIB_ENTRY_DBG(cover, "cover-untrack @ %d", tracked_index);
+
+    fed = fib_entry_delegate_get(cover, FIB_ENTRY_DELEGATE_COVERED);
+
+    if (NULL == fed)
+        return;
+
+    fib_node_list_remove(fed->fd_list, tracked_index);
+
+    if (0 == fib_node_list_get_size(fed->fd_list))
+    {
+        fib_node_list_destroy(&fed->fd_list);
+        fib_entry_delegate_remove(cover, FIB_ENTRY_DELEGATE_COVERED);        
+    }
+}
+
+/**
+ * Internal struct to hold user supplied paraneters for the cover walk
+ */
+typedef struct fib_enty_cover_walk_ctx_t_ {
+    fib_entry_t *cover;
+    fib_entry_covered_walk_t walk;
+    void *ctx;
+} fib_enty_cover_walk_ctx_t;
+
+static int
+fib_entry_cover_walk_node_ptr (fib_node_ptr_t *depend,
+			       void *args)
+{
+    fib_enty_cover_walk_ctx_t *ctx = args;
+
+    ctx->walk(ctx->cover, depend->fnp_index, ctx->ctx);
+
+    /* continue */
+    return (1);
+}
+
+void
+fib_entry_cover_walk (fib_entry_t *cover,
+		      fib_entry_covered_walk_t walk,
+		      void *args)
+{
+    fib_entry_delegate_t *fed;
+
+    fed = fib_entry_delegate_get(cover, FIB_ENTRY_DELEGATE_COVERED);
+
+    if (NULL == fed)
+        return;
+
+    fib_enty_cover_walk_ctx_t ctx = {
+        .cover = cover,
+        .walk = walk,
+        .ctx = args,
+    };
+
+    fib_node_list_walk(fed->fd_list,
+                       fib_entry_cover_walk_node_ptr,
+                       &ctx);
+}
+
+u32
+fib_entry_cover_get_size (fib_entry_t *cover)
+{
+    fib_entry_delegate_t *fed;
+
+    fed = fib_entry_delegate_get(cover, FIB_ENTRY_DELEGATE_COVERED);
+
+    if (NULL == fed)
+        return (0);
+
+    return (fib_node_list_get_size(fed->fd_list));
+}
+
+typedef struct fib_entry_cover_list_format_ctx_t_ {
+    u8 *s;
+} fib_entry_cover_list_format_ctx_t;
+
+static int
+fib_entry_covered_list_format_one (fib_entry_t *cover,
+				   fib_node_index_t covered,
+				   void *args)
+{
+    fib_entry_cover_list_format_ctx_t * ctx = args;
+
+    ctx->s = format(ctx->s, "%d, ", covered);
+
+    /* continue */
+    return (1);
+}
+
+u8*
+fib_entry_cover_list_format (fib_entry_t *fib_entry,
+			     u8 *s)
+{
+    fib_entry_cover_list_format_ctx_t ctx = {
+	.s = s,
+    };
+
+    fib_entry_cover_walk(fib_entry, 
+			 fib_entry_covered_list_format_one,
+			 &ctx);
+
+    return (ctx.s);
+}
+
+static int
+fib_entry_cover_change_one (fib_entry_t *cover,
+			    fib_node_index_t covered,
+			    void *args)
+{
+    fib_node_index_t new_cover;
+
+    /*
+     * The 3 entries involved here are:
+     *   cover - the least specific. It will cover both the others
+     *  new_cover - the enty just inserted below the cover
+     *  covered - the entry that was tracking the cover.
+     *
+     * The checks below are to determine if new_cover is a cover for covered.
+     */
+    new_cover = pointer_to_uword(args);
+
+    if (FIB_NODE_INDEX_INVALID == new_cover)
+    {
+	/*
+	 * nothing has been inserted, which implies the cover was removed.
+	 * 'cover' is thus the new cover.
+	 */
+	fib_entry_cover_changed(covered);
+    }
+    else if (new_cover != covered)
+    {
+	fib_prefix_t pfx_covered, pfx_new_cover;
+
+	fib_entry_get_prefix(covered, &pfx_covered);
+	fib_entry_get_prefix(new_cover, &pfx_new_cover);
+
+	if (fib_prefix_is_cover(&pfx_new_cover, &pfx_covered))
+	{
+	    fib_entry_cover_changed(covered);
+	}
+    }
+    /* continue */
+    return (1);
+}
+
+void
+fib_entry_cover_change_notify (fib_node_index_t cover_index,
+			       fib_node_index_t covered)
+{
+    fib_entry_t *cover;
+
+    cover = fib_entry_get(cover_index);
+
+    fib_entry_cover_walk(cover, 
+			 fib_entry_cover_change_one,
+			 uword_to_pointer(covered, void*));
+}
+
+static int
+fib_entry_cover_update_one (fib_entry_t *cover,
+			    fib_node_index_t covered,
+			    void *args)
+{
+    fib_entry_cover_updated(covered);
+
+    /* continue */
+    return (1);
+}
+
+void
+fib_entry_cover_update_notify (fib_entry_t *fib_entry)
+{
+    fib_entry_cover_walk(fib_entry, 
+			 fib_entry_cover_update_one,
+			 NULL);
+}
diff --git a/src/vnet/fib/fib_entry_cover.h b/src/vnet/fib/fib_entry_cover.h
new file mode 100644
index 00000000000..fbbbc211dc9
--- /dev/null
+++ b/src/vnet/fib/fib_entry_cover.h
@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __FIB_ENTRY_COVER_H__
+#define __FIB_ENTRY_COVER_H__
+
+#include "fib_entry.h"
+
+/**
+ * callback function used when walking the covered entries
+ */
+typedef int (*fib_entry_covered_walk_t)(fib_entry_t *cover,
+					fib_node_index_t covered,
+					void *ctx);
+
+extern u32 fib_entry_cover_track(fib_entry_t *cover,
+				 fib_node_index_t covered);
+
+extern void fib_entry_cover_untrack(fib_entry_t *cover,
+				    u32 tracked_index);
+
+extern void fib_entry_cover_walk(fib_entry_t *cover,
+				 fib_entry_covered_walk_t walk,
+				 void *ctx);
+
+extern void fib_entry_cover_change_notify(fib_node_index_t cover_index,
+					  fib_node_index_t covered_index);
+extern void fib_entry_cover_update_notify(fib_entry_t *cover);
+
+extern u32 fib_entry_cover_get_size(fib_entry_t *cover);
+
+extern u8* fib_entry_cover_list_format(fib_entry_t *fib_entry,
+				       u8 *s);
+
+#endif
diff --git a/src/vnet/fib/fib_entry_delegate.c b/src/vnet/fib/fib_entry_delegate.c
new file mode 100644
index 00000000000..a0d45f970b3
--- /dev/null
+++ b/src/vnet/fib/fib_entry_delegate.c
@@ -0,0 +1,149 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vnet/fib/fib_entry_delegate.h>
+#include <vnet/fib/fib_entry.h>
+
+static fib_entry_delegate_t *
+fib_entry_delegate_find_i (const fib_entry_t *fib_entry,
+                           fib_entry_delegate_type_t type,
+                           u32 *index)
+{
+    fib_entry_delegate_t *delegate;
+    int ii;
+
+    ii = 0;
+    vec_foreach(delegate, fib_entry->fe_delegates)
+    {
+	if (delegate->fd_type == type)
+	{
+            if (NULL != index)
+                *index = ii;
+
+	    return (delegate);
+	}
+	else
+	{
+	    ii++;
+	}
+    }
+
+    return (NULL);
+}
+
+fib_entry_delegate_t *
+fib_entry_delegate_get (const fib_entry_t *fib_entry,
+                        fib_entry_delegate_type_t type)
+{
+    return (fib_entry_delegate_find_i(fib_entry, type, NULL));
+}
+
+void
+fib_entry_delegate_remove (fib_entry_t *fib_entry,
+                           fib_entry_delegate_type_t type)
+{
+    fib_entry_delegate_t *fed;
+    u32 index = ~0;
+
+    fed = fib_entry_delegate_find_i(fib_entry, type, &index);
+
+    ASSERT(NULL != fed);
+
+    vec_del1(fib_entry->fe_delegates, index);
+}
+
+static int
+fib_entry_delegate_cmp_for_sort (void * v1,
+                                 void * v2)
+{
+    fib_entry_delegate_t *delegate1 = v1, *delegate2 = v2;
+
+    return (delegate1->fd_type - delegate2->fd_type);
+}
+
+static void
+fib_entry_delegate_init (fib_entry_t *fib_entry,
+                         fib_entry_delegate_type_t type)
+
+{
+    fib_entry_delegate_t delegate = {
+	.fd_entry_index = fib_entry_get_index(fib_entry),
+	.fd_type = type,
+    };
+
+    vec_add1(fib_entry->fe_delegates, delegate);
+    vec_sort_with_function(fib_entry->fe_delegates,
+			   fib_entry_delegate_cmp_for_sort);
+}
+
+fib_entry_delegate_t *
+fib_entry_delegate_find_or_add (fib_entry_t *fib_entry,
+                                fib_entry_delegate_type_t fdt)
+{
+    fib_entry_delegate_t *delegate;
+
+    delegate = fib_entry_delegate_get(fib_entry, fdt);
+
+    if (NULL == delegate)
+    {
+	fib_entry_delegate_init(fib_entry, fdt);
+    }
+
+    return (fib_entry_delegate_get(fib_entry, fdt));
+}
+
+fib_entry_delegate_type_t
+fib_entry_chain_type_to_delegate_type (fib_forward_chain_type_t fct)
+{
+    switch (fct)
+    {
+    case FIB_FORW_CHAIN_TYPE_UNICAST_IP4:
+        return (FIB_ENTRY_DELEGATE_CHAIN_UNICAST_IP4);
+    case FIB_FORW_CHAIN_TYPE_UNICAST_IP6:
+        return (FIB_ENTRY_DELEGATE_CHAIN_UNICAST_IP6);
+    case FIB_FORW_CHAIN_TYPE_MPLS_EOS:
+        return (FIB_ENTRY_DELEGATE_CHAIN_MPLS_EOS);
+    case FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS:
+        return (FIB_ENTRY_DELEGATE_CHAIN_MPLS_NON_EOS);
+    case FIB_FORW_CHAIN_TYPE_ETHERNET:
+        return (FIB_ENTRY_DELEGATE_CHAIN_ETHERNET);
+    }
+    ASSERT(0);
+    return (FIB_ENTRY_DELEGATE_CHAIN_UNICAST_IP4);
+}
+
+fib_forward_chain_type_t
+fib_entry_delegate_type_to_chain_type (fib_entry_delegate_type_t fdt)
+{
+    switch (fdt)
+    {
+    case FIB_ENTRY_DELEGATE_CHAIN_UNICAST_IP4:
+        return (FIB_FORW_CHAIN_TYPE_UNICAST_IP4);
+    case FIB_ENTRY_DELEGATE_CHAIN_UNICAST_IP6:
+        return (FIB_FORW_CHAIN_TYPE_UNICAST_IP6);
+    case FIB_ENTRY_DELEGATE_CHAIN_MPLS_EOS:
+        return (FIB_FORW_CHAIN_TYPE_MPLS_EOS);
+    case FIB_ENTRY_DELEGATE_CHAIN_MPLS_NON_EOS:
+        return (FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS);
+    case FIB_ENTRY_DELEGATE_CHAIN_ETHERNET:
+        return (FIB_FORW_CHAIN_TYPE_ETHERNET);
+    case FIB_ENTRY_DELEGATE_COVERED:
+    case FIB_ENTRY_DELEGATE_ATTACHED_IMPORT:
+    case FIB_ENTRY_DELEGATE_ATTACHED_EXPORT:
+        break;
+    }
+    ASSERT(0);
+    return (FIB_FORW_CHAIN_TYPE_UNICAST_IP4);
+}
diff --git a/src/vnet/fib/fib_entry_delegate.h b/src/vnet/fib/fib_entry_delegate.h
new file mode 100644
index 00000000000..6d3a6549f32
--- /dev/null
+++ b/src/vnet/fib/fib_entry_delegate.h
@@ -0,0 +1,124 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __FIB_ENTRY_DELEGATE_T__
+#define __FIB_ENTRY_DELEGATE_T__
+
+#include <vnet/fib/fib_node.h>
+
+/**
+ * Delegate types
+ */
+typedef enum fib_entry_delegate_type_t_ {
+    /**
+     * Forwarding chain types:
+     * for the vast majority of FIB entries only one chain is required - the
+     * one that forwards traffic matching the fib_entry_t's fib_prefix_t. For those
+     * fib_entry_t that are a resolution target for other fib_entry_t's they will also
+     * need the chain to provide forwarding for those children. We store these additional
+     * chains in delegates to save memory in the common case.
+     */
+    FIB_ENTRY_DELEGATE_CHAIN_UNICAST_IP4 = FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+    FIB_ENTRY_DELEGATE_CHAIN_UNICAST_IP6 = FIB_FORW_CHAIN_TYPE_UNICAST_IP6,
+    FIB_ENTRY_DELEGATE_CHAIN_MPLS_EOS = FIB_FORW_CHAIN_TYPE_MPLS_EOS,
+    FIB_ENTRY_DELEGATE_CHAIN_MPLS_NON_EOS = FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS,
+    FIB_ENTRY_DELEGATE_CHAIN_ETHERNET = FIB_FORW_CHAIN_TYPE_ETHERNET,
+    /**
+     * Dependency list of covered entries.
+     * these are more specific entries that are interested in changes
+     * to their respective cover
+     */
+    FIB_ENTRY_DELEGATE_COVERED,
+    /**
+     * Attached import/export functionality
+     */
+    FIB_ENTRY_DELEGATE_ATTACHED_IMPORT,
+    FIB_ENTRY_DELEGATE_ATTACHED_EXPORT,
+} fib_entry_delegate_type_t;
+
+#define FOR_EACH_DELEGATE_CHAIN(_entry, _fdt, _fed, _body)    \
+{                                                             \
+    for (_fdt = FIB_ENTRY_DELEGATE_CHAIN_UNICAST_IP4;         \
+         _fdt <= FIB_ENTRY_DELEGATE_CHAIN_ETHERNET;           \
+         _fdt++)                                              \
+    {                                                         \
+        _fed = fib_entry_delegate_get(_entry, _fdt);          \
+        if (NULL != _fed) {                                   \
+            _body;                                            \
+        }                                                     \
+    }                                                         \
+}
+
+/**
+ * A Delagate is a means to implmenet the Delagation design pattern; the extension of an
+ * objects functionality through the composition of, and delgation to, other objects.
+ * These 'other' objects are delegates. Delagates are thus attached to other FIB objects
+ * to extend their functionality.
+ */
+typedef struct fib_entry_delegate_t_
+{
+    /**
+     * The FIB entry object to which the delagate is attached
+     */
+    fib_node_index_t fd_entry_index;
+
+    /**
+     * The delagate type
+     */
+    fib_entry_delegate_type_t fd_type;
+
+    /**
+     * A union of data for the different delegate types
+     * These delegates are stored in a sparse vector on the entry, so they
+     * must all be of the same size. We could use indirection here for all types,
+     * i.e. store an index, that's ok for large delegates, like the attached export
+     * but for the chain delegates it's excessive
+     */
+    union
+    {
+        /**
+         * Valid for the forwarding chain delegates. The LB that is built.
+         */
+        dpo_id_t fd_dpo;
+
+        /**
+         * Valid for the attached import cases. An index of the importer/exporter
+         */
+        fib_node_index_t fd_index;
+
+        /**
+         * For the cover tracking. The node list;
+         */
+        fib_node_list_t fd_list;
+    };
+} fib_entry_delegate_t;
+
+struct fib_entry_t_;
+
+extern void fib_entry_delegate_remove(struct fib_entry_t_ *fib_entry,
+                                      fib_entry_delegate_type_t type);
+
+extern fib_entry_delegate_t *fib_entry_delegate_find_or_add(struct fib_entry_t_ *fib_entry,
+                                                            fib_entry_delegate_type_t fdt);
+extern fib_entry_delegate_t *fib_entry_delegate_get(const struct fib_entry_t_ *fib_entry,
+                                                    fib_entry_delegate_type_t type);
+
+extern fib_forward_chain_type_t fib_entry_delegate_type_to_chain_type(
+    fib_entry_delegate_type_t type);
+
+extern fib_entry_delegate_type_t fib_entry_chain_type_to_delegate_type(
+     fib_forward_chain_type_t type);
+
+#endif
diff --git a/src/vnet/fib/fib_entry_src.c b/src/vnet/fib/fib_entry_src.c
new file mode 100644
index 00000000000..060fac941d2
--- /dev/null
+++ b/src/vnet/fib/fib_entry_src.c
@@ -0,0 +1,1456 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vnet/adj/adj.h>
+#include <vnet/dpo/load_balance.h>
+#include <vnet/dpo/mpls_label_dpo.h>
+#include <vnet/dpo/drop_dpo.h>
+
+#include <vnet/fib/fib_entry_src.h>
+#include <vnet/fib/fib_table.h>
+#include <vnet/fib/fib_path_ext.h>
+#include <vnet/fib/fib_urpf_list.h>
+
+/*
+ * per-source type vft
+ */
+static fib_entry_src_vft_t fib_entry_src_vft[FIB_SOURCE_MAX];
+
+static fib_protocol_t
+fib_entry_get_proto (const fib_entry_t * fib_entry)
+{
+    return (fib_entry->fe_prefix.fp_proto);
+}
+
+void
+fib_entry_src_register (fib_source_t source,
+			const fib_entry_src_vft_t *vft)
+{
+    fib_entry_src_vft[source] = *vft;
+}
+
+static int
+fib_entry_src_cmp_for_sort (void * v1,
+			    void * v2)
+{
+    fib_entry_src_t *esrc1 = v1, *esrc2 = v2;
+
+    return (esrc1->fes_src - esrc2->fes_src);
+}
+
+void
+fib_entry_src_action_init (fib_entry_t *fib_entry,
+			   fib_source_t source)
+
+{
+    fib_entry_src_t esrc = {
+	.fes_pl = FIB_NODE_INDEX_INVALID,
+	.fes_flags = FIB_ENTRY_SRC_FLAG_NONE,
+	.fes_src = source,
+    };
+
+    if (NULL != fib_entry_src_vft[source].fesv_init)
+    {
+	fib_entry_src_vft[source].fesv_init(&esrc);
+    }
+
+    vec_add1(fib_entry->fe_srcs, esrc);
+    vec_sort_with_function(fib_entry->fe_srcs,
+			   fib_entry_src_cmp_for_sort);
+}
+
+static fib_entry_src_t *
+fib_entry_src_find (const fib_entry_t *fib_entry,
+		    fib_source_t source,
+		    u32 *index)
+
+{
+    fib_entry_src_t *esrc;
+    int ii;
+
+    ii = 0;
+    vec_foreach(esrc, fib_entry->fe_srcs)
+    {
+	if (esrc->fes_src == source)
+	{
+	    if (NULL != index)
+	    {
+		*index = ii;
+	    }
+	    return (esrc);
+	}
+	else
+	{
+	    ii++;
+	}
+    }
+
+    return (NULL);
+}
+
+int
+fib_entry_is_sourced (fib_node_index_t fib_entry_index,
+                      fib_source_t source)
+{
+    fib_entry_t *fib_entry;
+
+    fib_entry = fib_entry_get(fib_entry_index);
+
+    return (NULL != fib_entry_src_find(fib_entry, source, NULL));
+}
+
+static fib_entry_src_t *
+fib_entry_src_find_or_create (fib_entry_t *fib_entry,
+			      fib_source_t source,
+			      u32 *index)
+{
+    fib_entry_src_t *esrc;
+
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+
+    if (NULL == esrc)
+    {
+	fib_entry_src_action_init(fib_entry, source);
+    }
+
+    return (fib_entry_src_find(fib_entry, source, NULL));
+}
+
+void
+fib_entry_src_action_deinit (fib_entry_t *fib_entry,
+			     fib_source_t source)
+
+{
+    fib_entry_src_t *esrc;
+    u32 index = ~0;
+
+    esrc = fib_entry_src_find(fib_entry, source, &index);
+
+    ASSERT(NULL != esrc);
+
+    if (NULL != fib_entry_src_vft[source].fesv_deinit)
+    {
+	fib_entry_src_vft[source].fesv_deinit(esrc);
+    }
+
+    vec_free(esrc->fes_path_exts);
+    vec_del1(fib_entry->fe_srcs, index);
+}
+
+fib_entry_src_cover_res_t
+fib_entry_src_action_cover_change (fib_entry_t *fib_entry,
+				   fib_source_t source)
+{
+    if (NULL != fib_entry_src_vft[source].fesv_cover_change)
+    {
+	return (fib_entry_src_vft[source].fesv_cover_change(
+		    fib_entry_src_find(fib_entry, source, NULL),
+		    fib_entry));
+    }
+
+    fib_entry_src_cover_res_t res = {
+	.install = !0,
+	.bw_reason = FIB_NODE_BW_REASON_FLAG_NONE,
+    };
+    return (res);
+}
+
+fib_entry_src_cover_res_t
+fib_entry_src_action_cover_update (fib_entry_t *fib_entry,
+				   fib_source_t source)
+{
+    if (NULL != fib_entry_src_vft[source].fesv_cover_update)
+    {
+	return (fib_entry_src_vft[source].fesv_cover_update(
+		    fib_entry_src_find(fib_entry, source, NULL),
+		    fib_entry));
+    }
+
+    fib_entry_src_cover_res_t res = {
+	.install = !0,
+	.bw_reason = FIB_NODE_BW_REASON_FLAG_NONE,
+    };
+    return (res);
+}
+
+typedef struct fib_entry_src_collect_forwarding_ctx_t_
+{
+    load_balance_path_t * next_hops;
+    const fib_entry_t *fib_entry;
+    const fib_entry_src_t *esrc;
+    fib_forward_chain_type_t fct;
+    int is_recursive;
+} fib_entry_src_collect_forwarding_ctx_t;
+
+/**
+ * @brief Determine whether this FIB entry should use a load-balance MAP
+ * to support PIC edge fast convergence
+ */
+load_balance_flags_t
+fib_entry_calc_lb_flags (fib_entry_src_collect_forwarding_ctx_t *ctx)
+{
+    /**
+     * We'll use a LB map is the path-list has recursive paths.
+     * recursive paths implies BGP, and hence scale.
+     */
+    if (ctx->is_recursive)
+    {
+        return (LOAD_BALANCE_FLAG_USES_MAP);
+    }
+    return (LOAD_BALANCE_FLAG_NONE);
+}
+
+static int
+fib_entry_src_valid_out_label (mpls_label_t label)
+{
+    return ((MPLS_LABEL_IS_REAL(label) ||
+             MPLS_IETF_IPV4_EXPLICIT_NULL_LABEL == label ||
+             MPLS_IETF_IPV6_EXPLICIT_NULL_LABEL == label ||
+             MPLS_IETF_IMPLICIT_NULL_LABEL == label));
+}
+
+/**
+ * @brief Turn the chain type requested by the client into the one they
+ * really wanted
+ */
+fib_forward_chain_type_t
+fib_entry_chain_type_fixup (const fib_entry_t *entry,
+			    fib_forward_chain_type_t fct)
+{
+    ASSERT(FIB_FORW_CHAIN_TYPE_MPLS_EOS == fct);
+
+    /*
+     * The EOS chain is a tricky since one cannot know the adjacency
+     * to link to without knowing what the packets payload protocol
+     * will be once the label is popped.
+     */
+    fib_forward_chain_type_t dfct;
+
+    dfct = fib_entry_get_default_chain_type(entry);
+
+    if (FIB_FORW_CHAIN_TYPE_MPLS_EOS == dfct)
+    {
+        /*
+         * If the entry being asked is a eos-MPLS label entry,
+         * then use the payload-protocol field, that we stashed there
+         * for just this purpose
+         */
+        return (fib_forw_chain_type_from_dpo_proto(
+                    entry->fe_prefix.fp_payload_proto));
+    }
+    /*
+     * else give them what this entry would be by default. i.e. if it's a v6
+     * entry, then the label its local labelled should be carrying v6 traffic.
+     * If it's a non-EOS label entry, then there are more labels and we want
+     * a non-eos chain.
+     */
+    return (dfct);
+}
+
+static int
+fib_entry_src_collect_forwarding (fib_node_index_t pl_index,
+                                  fib_node_index_t path_index,
+                                  void *arg)
+{
+    fib_entry_src_collect_forwarding_ctx_t *ctx;
+    fib_path_ext_t *path_ext;
+
+    ctx = arg;
+
+    /*
+     * if the path is not resolved, don't include it.
+     */
+    if (!fib_path_is_resolved(path_index))
+    {
+        return (!0);
+    }
+
+    if (fib_path_is_recursive(path_index))
+    {
+        ctx->is_recursive = 1;
+    }
+
+    /*
+     * get the matching path-extension for the path being visited.
+     */
+    vec_foreach(path_ext, ctx->esrc->fes_path_exts)
+    {
+        if (path_ext->fpe_path_index == path_index)
+            break;
+    }
+    
+    if (NULL != path_ext &&
+        path_ext->fpe_path_index == path_index &&
+        fib_entry_src_valid_out_label(path_ext->fpe_label_stack[0]))
+    {
+        /*
+         * found a matching extension. stack it to obtain the forwarding
+         * info for this path.
+         */
+        ctx->next_hops = fib_path_ext_stack(path_ext, ctx->fib_entry, ctx->fct, ctx->next_hops);
+    }
+    else
+    {
+        load_balance_path_t *nh;
+
+        /*
+         * no extension => no out-going label for this path. that's OK
+         * in the case of an IP or EOS chain, but not for non-EOS
+         */
+        switch (ctx->fct)
+        {
+        case FIB_FORW_CHAIN_TYPE_UNICAST_IP4:
+        case FIB_FORW_CHAIN_TYPE_UNICAST_IP6:
+            /*
+             * EOS traffic with no label to stack, we need the IP Adj
+             */
+            vec_add2(ctx->next_hops, nh, 1);
+
+            nh->path_index = path_index;
+            nh->path_weight = fib_path_get_weight(path_index);
+            fib_path_contribute_forwarding(path_index, ctx->fct, &nh->path_dpo);
+
+            break;
+        case FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS:
+	    if (fib_path_is_exclusive(path_index) ||
+		fib_path_is_deag(path_index))
+	    {
+		vec_add2(ctx->next_hops, nh, 1);
+
+		nh->path_index = path_index;
+		nh->path_weight = fib_path_get_weight(path_index);
+		fib_path_contribute_forwarding(path_index,
+					       FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS,
+					       &nh->path_dpo);
+	    }
+            break;
+        case FIB_FORW_CHAIN_TYPE_MPLS_EOS:
+        {
+            /*
+             * no label. we need a chain based on the payload. fixup.
+             */
+            vec_add2(ctx->next_hops, nh, 1);
+
+            nh->path_index = path_index;
+            nh->path_weight = fib_path_get_weight(path_index);
+            fib_path_contribute_forwarding(path_index,
+                                           fib_entry_chain_type_fixup(ctx->fib_entry,
+                                                                      ctx->fct),
+                                           &nh->path_dpo);
+
+            break;
+        }
+        case FIB_FORW_CHAIN_TYPE_ETHERNET:
+	    ASSERT(0);
+	    break;
+        }
+    }
+
+    return (!0);
+}
+
+void
+fib_entry_src_mk_lb (fib_entry_t *fib_entry,
+		     const fib_entry_src_t *esrc,
+		     fib_forward_chain_type_t fct,
+		     dpo_id_t *dpo_lb)
+{
+    dpo_proto_t lb_proto;
+
+    /*
+     * If the entry has path extensions then we construct a load-balance
+     * by stacking the extensions on the forwarding chains of the paths.
+     * Otherwise we use the load-balance of the path-list
+     */
+    fib_entry_src_collect_forwarding_ctx_t ctx = {
+        .esrc = esrc,
+        .fib_entry = fib_entry,
+        .next_hops = NULL,
+        .is_recursive = 0,
+        .fct = fct,
+    };
+
+    lb_proto = fib_proto_to_dpo(fib_entry->fe_prefix.fp_proto);
+
+    fib_path_list_walk(esrc->fes_pl,
+                       fib_entry_src_collect_forwarding,
+                       &ctx);
+
+    if (esrc->fes_entry_flags & FIB_ENTRY_FLAG_EXCLUSIVE)
+    {
+	/*
+	 * the client provided the DPO that the entry should link to.
+	 * all entries must link to a LB, so if it is an LB already
+	 * then we can use it.
+	 */
+	if ((1 == vec_len(ctx.next_hops)) &&
+	    (DPO_LOAD_BALANCE == ctx.next_hops[0].path_dpo.dpoi_type))
+	{
+	    dpo_copy(dpo_lb, &ctx.next_hops[0].path_dpo);
+	    dpo_reset(&ctx.next_hops[0].path_dpo);
+	    return;
+	}
+    }
+
+    if (!dpo_id_is_valid(dpo_lb))
+    {
+        /*
+         * first time create
+         */
+        flow_hash_config_t fhc;
+
+        fhc = fib_table_get_flow_hash_config(fib_entry->fe_fib_index,
+                                             dpo_proto_to_fib(lb_proto));
+        dpo_set(dpo_lb,
+                DPO_LOAD_BALANCE,
+                lb_proto,
+                load_balance_create(0, lb_proto, fhc));
+    }
+
+    load_balance_multipath_update(dpo_lb,
+                                  ctx.next_hops,
+                                  fib_entry_calc_lb_flags(&ctx));
+    vec_free(ctx.next_hops);
+
+    /*
+     * if this entry is sourced by the uRPF-exempt source then we
+     * append the always present local0 interface (index 0) to the
+     * uRPF list so it is not empty. that way packets pass the loose check.
+     */
+    index_t ui = fib_path_list_get_urpf(esrc->fes_pl);
+
+    if (fib_entry_is_sourced(fib_entry_get_index(fib_entry),
+			     FIB_SOURCE_URPF_EXEMPT) &&
+	(0 == fib_urpf_check_size(ui)))
+    {
+	/*
+	 * The uRPF list we get from the path-list is shared by all
+	 * other users of the list, but the uRPF exemption applies
+	 * only to this prefix. So we need our own list.
+	 */
+	ui = fib_urpf_list_alloc_and_lock();
+	fib_urpf_list_append(ui, 0);
+	fib_urpf_list_bake(ui);
+	load_balance_set_urpf(dpo_lb->dpoi_index, ui);
+	fib_urpf_list_unlock(ui);
+    }
+    else
+    {
+	load_balance_set_urpf(dpo_lb->dpoi_index, ui);
+    }
+}
+
+void
+fib_entry_src_action_install (fib_entry_t *fib_entry,
+			      fib_source_t source)
+{
+    /*
+     * Install the forwarding chain for the given source into the forwarding
+     * tables
+     */
+    fib_forward_chain_type_t fct;
+    fib_entry_src_t *esrc;
+    int insert;
+
+    fct = fib_entry_get_default_chain_type(fib_entry);
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+
+    /*
+     * Every entry has its own load-balance object. All changes to the entry's
+     * forwarding result in an inplace modify of the load-balance. This means
+     * the load-balance object only needs to be added to the forwarding
+     * DB once, when it is created.
+     */
+    insert = !dpo_id_is_valid(&fib_entry->fe_lb);
+
+    fib_entry_src_mk_lb(fib_entry, esrc, fct, &fib_entry->fe_lb);
+
+    ASSERT(dpo_id_is_valid(&fib_entry->fe_lb));
+    FIB_ENTRY_DBG(fib_entry, "install: %d", fib_entry->fe_lb);
+
+    /*
+     * insert the adj into the data-plane forwarding trie
+     */
+    if (insert)
+    {
+       fib_table_fwding_dpo_update(fib_entry->fe_fib_index,
+                                   &fib_entry->fe_prefix,
+                                   &fib_entry->fe_lb);
+    }
+
+    /*
+     * if any of the other chain types are already created they will need
+     * updating too
+     */
+    fib_entry_delegate_type_t fdt;
+    fib_entry_delegate_t *fed;
+
+    FOR_EACH_DELEGATE_CHAIN(fib_entry, fdt, fed,
+    {
+        fib_entry_src_mk_lb(fib_entry, esrc,
+                            fib_entry_delegate_type_to_chain_type(fdt),
+                            &fed->fd_dpo);
+    });
+}
+
+void
+fib_entry_src_action_uninstall (fib_entry_t *fib_entry)
+{
+    /*
+     * uninstall the forwarding chain from the forwarding tables
+     */
+    FIB_ENTRY_DBG(fib_entry, "uninstall: %d",
+		  fib_entry->fe_adj_index);
+
+    if (dpo_id_is_valid(&fib_entry->fe_lb))
+    {
+	fib_table_fwding_dpo_remove(
+	    fib_entry->fe_fib_index,
+	    &fib_entry->fe_prefix,
+	    &fib_entry->fe_lb);
+
+	dpo_reset(&fib_entry->fe_lb);
+    }
+}
+
+static void
+fib_entry_recursive_loop_detect_i (fib_node_index_t path_list_index)
+{
+    fib_node_index_t *entries = NULL;
+
+    fib_path_list_recursive_loop_detect(path_list_index, &entries);
+
+    vec_free(entries);
+}
+
+void
+fib_entry_src_action_activate (fib_entry_t *fib_entry,
+			       fib_source_t source)
+
+{
+    int houston_we_are_go_for_install;
+    fib_entry_src_t *esrc;
+
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+
+    ASSERT(!(esrc->fes_flags & FIB_ENTRY_SRC_FLAG_ACTIVE));
+    ASSERT(esrc->fes_flags & FIB_ENTRY_SRC_FLAG_ADDED);
+
+    esrc->fes_flags |= FIB_ENTRY_SRC_FLAG_ACTIVE;
+
+    if (NULL != fib_entry_src_vft[source].fesv_activate)
+    {
+	houston_we_are_go_for_install =
+	    fib_entry_src_vft[source].fesv_activate(esrc, fib_entry);
+    }
+    else
+    {
+	/*
+	 * the source is not providing an activate function, we'll assume
+	 * therefore it has no objection to installing the entry
+	 */
+	houston_we_are_go_for_install = !0;
+    }
+
+    /*
+     * link to the path-list provided by the source, and go check
+     * if that forms any loops in the graph.
+     */
+    fib_entry->fe_parent = esrc->fes_pl;
+    fib_entry->fe_sibling =
+	fib_path_list_child_add(fib_entry->fe_parent,
+				FIB_NODE_TYPE_ENTRY,
+				fib_entry_get_index(fib_entry));
+
+    fib_entry_recursive_loop_detect_i(fib_entry->fe_parent);
+
+    FIB_ENTRY_DBG(fib_entry, "activate: %d",
+		  fib_entry->fe_parent);
+
+    if (0 != houston_we_are_go_for_install)
+    {
+	fib_entry_src_action_install(fib_entry, source);
+    }
+    else
+    {
+	fib_entry_src_action_uninstall(fib_entry);
+    }
+}
+
+void
+fib_entry_src_action_deactivate (fib_entry_t *fib_entry,
+				 fib_source_t source)
+
+{
+    fib_node_index_t path_list_index;
+    fib_entry_src_t *esrc;
+
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+
+    ASSERT(esrc->fes_flags & FIB_ENTRY_SRC_FLAG_ACTIVE);
+
+    if (NULL != fib_entry_src_vft[source].fesv_deactivate)
+    {
+	fib_entry_src_vft[source].fesv_deactivate(esrc, fib_entry);
+    }
+
+    esrc->fes_flags &= ~FIB_ENTRY_SRC_FLAG_ACTIVE;
+
+    FIB_ENTRY_DBG(fib_entry, "deactivate: %d", fib_entry->fe_parent);
+
+    /*
+     * un-link from an old path-list. Check for any loops this will clear
+     */
+    path_list_index = fib_entry->fe_parent;
+    fib_entry->fe_parent = FIB_NODE_INDEX_INVALID;
+
+    fib_entry_recursive_loop_detect_i(path_list_index);
+
+    /*
+     * this will unlock the path-list, so it may be invalid thereafter.
+     */
+    fib_path_list_child_remove(path_list_index, fib_entry->fe_sibling);
+    fib_entry->fe_sibling = FIB_NODE_INDEX_INVALID;
+}
+
+static void
+fib_entry_src_action_fwd_update (const fib_entry_t *fib_entry,
+				 fib_source_t source)
+{
+    fib_entry_src_t *esrc;
+
+    vec_foreach(esrc, fib_entry->fe_srcs)
+    {
+	if (NULL != fib_entry_src_vft[esrc->fes_src].fesv_fwd_update)
+	{
+	    fib_entry_src_vft[esrc->fes_src].fesv_fwd_update(esrc,
+							     fib_entry,
+							     source);
+	}
+    }
+}
+
+void
+fib_entry_src_action_reactivate (fib_entry_t *fib_entry,
+				 fib_source_t source)
+{
+    fib_node_index_t path_list_index;
+    fib_entry_src_t *esrc;
+
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+
+    ASSERT(esrc->fes_flags & FIB_ENTRY_SRC_FLAG_ACTIVE);
+
+    FIB_ENTRY_DBG(fib_entry, "reactivate: %d to %d",
+		  fib_entry->fe_parent,
+		  esrc->fes_pl);
+
+    if (fib_entry->fe_parent != esrc->fes_pl)
+    {
+	/*
+	 * un-link from an old path-list. Check for any loops this will clear
+	 */
+	path_list_index = fib_entry->fe_parent;
+	fib_entry->fe_parent = FIB_NODE_INDEX_INVALID;
+
+	/*
+	 * temporary lock so it doesn't get deleted when this entry is no
+	 * longer a child.
+	 */
+	fib_path_list_lock(path_list_index);
+
+	/*
+	 * this entry is no longer a child. after unlinking check if any loops
+	 * were broken
+	 */
+	fib_path_list_child_remove(path_list_index,
+				   fib_entry->fe_sibling);
+
+	fib_entry_recursive_loop_detect_i(path_list_index);
+
+	/*
+	 * link to the path-list provided by the source, and go check
+	 * if that forms any loops in the graph.
+	 */
+	fib_entry->fe_parent = esrc->fes_pl;
+	fib_entry->fe_sibling =
+	    fib_path_list_child_add(fib_entry->fe_parent,
+				    FIB_NODE_TYPE_ENTRY,
+				    fib_entry_get_index(fib_entry));
+
+	fib_entry_recursive_loop_detect_i(fib_entry->fe_parent);
+	fib_path_list_unlock(path_list_index);
+    }
+    fib_entry_src_action_install(fib_entry, source);
+    fib_entry_src_action_fwd_update(fib_entry, source);
+}
+
+void
+fib_entry_src_action_installed (const fib_entry_t *fib_entry,
+				fib_source_t source)
+{
+    fib_entry_src_t *esrc;
+
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+
+    if (NULL != fib_entry_src_vft[source].fesv_installed)
+    {
+	fib_entry_src_vft[source].fesv_installed(esrc,
+						 fib_entry);
+    }
+
+    fib_entry_src_action_fwd_update(fib_entry, source);
+}
+
+/*
+ * fib_entry_src_action_add
+ *
+ * Adding a source can result in a new fib_entry being created, which
+ * can inturn mean the pool is realloc'd and thus the entry passed as
+ * an argument it also realloc'd
+ * @return the original entry
+ */
+fib_entry_t *
+fib_entry_src_action_add (fib_entry_t *fib_entry,
+			  fib_source_t source,
+			  fib_entry_flag_t flags,
+			  const dpo_id_t *dpo)
+{
+    fib_node_index_t fib_entry_index;
+    fib_entry_src_t *esrc;
+
+    esrc = fib_entry_src_find_or_create(fib_entry, source, NULL);
+
+    esrc->fes_ref_count++;
+
+    if (1 != esrc->fes_ref_count)
+    {
+        /*
+         * we only want to add the source on the 0->1 transition
+         */
+        return (fib_entry);
+    }
+
+    esrc->fes_entry_flags = flags;
+
+    /*
+     * save variable so we can recover from a fib_entry realloc.
+     */
+    fib_entry_index = fib_entry_get_index(fib_entry);
+
+    if (NULL != fib_entry_src_vft[source].fesv_add)
+    {
+	fib_entry_src_vft[source].fesv_add(esrc,
+					   fib_entry,
+					   flags,
+					   fib_entry_get_proto(fib_entry),
+					   dpo);
+    }
+
+    fib_entry = fib_entry_get(fib_entry_index);
+
+    esrc->fes_flags |= FIB_ENTRY_SRC_FLAG_ADDED;
+
+    fib_path_list_lock(esrc->fes_pl);
+
+    /*
+     * the source owns a lock on the entry
+     */
+    fib_entry_lock(fib_entry_get_index(fib_entry));
+
+    return (fib_entry);
+}
+
+/*
+ * fib_entry_src_action_update
+ *
+ * Adding a source can result in a new fib_entry being created, which
+ * can inturn mean the pool is realloc'd and thus the entry passed as
+ * an argument it also realloc'd
+ * @return the original entry
+ */
+fib_entry_t *
+fib_entry_src_action_update (fib_entry_t *fib_entry,
+			     fib_source_t source,
+			     fib_entry_flag_t flags,
+			     const dpo_id_t *dpo)
+{
+    fib_node_index_t fib_entry_index, old_path_list_index;
+    fib_entry_src_t *esrc;
+
+    esrc = fib_entry_src_find_or_create(fib_entry, source, NULL);
+
+    if (NULL == esrc)
+	return (fib_entry_src_action_add(fib_entry, source, flags, dpo));
+
+    old_path_list_index = esrc->fes_pl;
+    esrc->fes_entry_flags = flags;
+
+    /*
+     * save variable so we can recover from a fib_entry realloc.
+     */
+    fib_entry_index = fib_entry_get_index(fib_entry);
+
+    if (NULL != fib_entry_src_vft[source].fesv_add)
+    {
+	fib_entry_src_vft[source].fesv_add(esrc,
+					   fib_entry,
+					   flags,
+					   fib_entry_get_proto(fib_entry),
+					   dpo);
+    }
+
+    fib_entry = fib_entry_get(fib_entry_index);
+
+    esrc->fes_flags |= FIB_ENTRY_SRC_FLAG_ADDED;
+
+    fib_path_list_lock(esrc->fes_pl);
+    fib_path_list_unlock(old_path_list_index);
+
+    return (fib_entry);
+}
+
+
+fib_entry_src_flag_t
+fib_entry_src_action_remove (fib_entry_t *fib_entry,
+			     fib_source_t source)
+
+{
+    fib_node_index_t old_path_list;
+    fib_entry_src_flag_t sflags;
+    fib_entry_src_t *esrc;
+
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+
+    if (NULL == esrc)
+	return (FIB_ENTRY_SRC_FLAG_ACTIVE);
+
+    esrc->fes_ref_count--;
+    sflags = esrc->fes_flags;
+
+    if (0 != esrc->fes_ref_count)
+    {
+        /*
+         * only remove the source on the 1->0 transisition
+         */
+        return (sflags);
+    }
+
+    if (esrc->fes_flags & FIB_ENTRY_SRC_FLAG_ACTIVE)
+    {
+	fib_entry_src_action_deactivate(fib_entry, source);
+    }
+
+    old_path_list = esrc->fes_pl;
+
+    if (NULL != fib_entry_src_vft[source].fesv_remove)
+    {
+	fib_entry_src_vft[source].fesv_remove(esrc);
+    }
+
+    fib_path_list_unlock(old_path_list);
+    fib_entry_unlock(fib_entry_get_index(fib_entry));
+
+    sflags &= ~FIB_ENTRY_SRC_FLAG_ADDED;
+    fib_entry_src_action_deinit(fib_entry, source);
+
+    return (sflags);
+}
+
+static inline int
+fib_route_recurses_via_self (const fib_prefix_t *prefix,
+			     const fib_route_path_t *rpath)
+{
+    /*
+     * not all zeros next hop &&
+     * is recursive path &&
+     * nexthop is same as the route's address
+     */
+    return ((!ip46_address_is_zero(&rpath->frp_addr)) &&
+	    (~0 == rpath->frp_sw_if_index) &&
+	    (0 == ip46_address_cmp(&rpath->frp_addr, &prefix->fp_addr)));
+
+}
+
+/*
+ * fib_route_attached_cross_table
+ *
+ * Return true the the route is attached via an interface that
+ * is not in the same table as the route
+ */
+static inline int
+fib_route_attached_cross_table (const fib_entry_t *fib_entry,
+				const fib_route_path_t *rpath)
+{
+    /*
+     * - All zeros next-hop
+     * - a valid interface
+     * - entry's fib index not equeal to interface's index
+     */
+    if (ip46_address_is_zero(&rpath->frp_addr) &&
+	(~0 != rpath->frp_sw_if_index) &&
+	(fib_entry->fe_fib_index != 
+	 fib_table_get_index_for_sw_if_index(fib_entry_get_proto(fib_entry),
+					     rpath->frp_sw_if_index)))
+    {
+	return (!0);
+    }
+    return (0);
+}
+
+/*
+ * fib_route_attached_cross_table
+ *
+ * Return true the the route is attached via an interface that
+ * is not in the same table as the route
+ */
+static inline int
+fib_path_is_attached (const fib_route_path_t *rpath)
+{
+    /*
+     * - All zeros next-hop
+     * - a valid interface
+     */
+    if (ip46_address_is_zero(&rpath->frp_addr) &&
+	(~0 != rpath->frp_sw_if_index))
+    {
+	return (!0);
+    }
+    return (0);
+}
+
+fib_path_list_flags_t
+fib_entry_src_flags_2_path_list_flags (fib_entry_flag_t eflags)
+{
+    fib_path_list_flags_t plf = FIB_PATH_LIST_FLAG_NONE;
+
+    if (eflags & FIB_ENTRY_FLAG_DROP)
+    {
+	plf |= FIB_PATH_LIST_FLAG_DROP;
+    }
+    if (eflags & FIB_ENTRY_FLAG_LOCAL)
+    {
+	plf |= FIB_PATH_LIST_FLAG_LOCAL;
+    }
+    if (eflags & FIB_ENTRY_FLAG_EXCLUSIVE)
+    {
+	plf |= FIB_PATH_LIST_FLAG_EXCLUSIVE;
+    }
+
+    return (plf);
+}
+
+static void
+fib_entry_flags_update (const fib_entry_t *fib_entry,
+			const fib_route_path_t *rpath,
+			fib_path_list_flags_t *pl_flags,
+			fib_entry_src_t *esrc)
+{
+    /*
+     * don't allow the addition of a recursive looped path for prefix
+     * via itself.
+     */
+    if (fib_route_recurses_via_self(&fib_entry->fe_prefix, rpath))	
+    {
+	/*
+	 * force the install of a drop path-list.
+	 * we want the entry to have some path-list, mainly so
+	 * the dodgy path can be rmeoved when the source stops playing
+	 * silly buggers.
+	 */
+	*pl_flags |= FIB_PATH_LIST_FLAG_DROP;
+    }
+    else
+    {
+	*pl_flags &= ~FIB_PATH_LIST_FLAG_DROP;
+    }
+
+    if ((esrc->fes_src == FIB_SOURCE_API) ||
+	(esrc->fes_src == FIB_SOURCE_CLI))
+    {
+	if (fib_path_is_attached(rpath))
+	{
+	    esrc->fes_entry_flags |= FIB_ENTRY_FLAG_ATTACHED;
+	}
+	else
+	{
+	    esrc->fes_entry_flags &= ~FIB_ENTRY_FLAG_ATTACHED;
+	}
+    }
+    if (fib_route_attached_cross_table(fib_entry, rpath))
+    {
+	esrc->fes_entry_flags |= FIB_ENTRY_FLAG_IMPORT;
+    }
+    else
+    {
+	esrc->fes_entry_flags &= ~FIB_ENTRY_FLAG_IMPORT;
+    }
+}
+
+/*
+ * fib_entry_src_path_ext_add
+ *
+ * append a path extension to the entry's list
+ */
+static void
+fib_entry_src_path_ext_append (fib_entry_src_t *esrc,
+			       const fib_route_path_t *rpath)
+{
+    if (NULL != rpath->frp_label_stack)
+    {
+	fib_path_ext_t *path_ext;
+
+	vec_add2(esrc->fes_path_exts, path_ext, 1);
+
+	fib_path_ext_init(path_ext, esrc->fes_pl, rpath);
+    }
+}
+
+/*
+ * fib_entry_src_path_ext_insert
+ *
+ * insert, sorted, a path extension to the entry's list.
+ * It's not strictly necessary in sort the path extensions, since each
+ * extension has the path index to which it resolves. However, by being
+ * sorted the load-balance produced has a deterministic order, not an order
+ * based on the sequence of extension additions. this is a considerable benefit.
+ */
+static void
+fib_entry_src_path_ext_insert (fib_entry_src_t *esrc,
+			       const fib_route_path_t *rpath)
+{
+    if (0 == vec_len(esrc->fes_path_exts))
+	return (fib_entry_src_path_ext_append(esrc, rpath));
+
+    if (NULL != rpath->frp_label_stack)
+    {
+	fib_path_ext_t path_ext;
+	int i = 0;
+
+	fib_path_ext_init(&path_ext, esrc->fes_pl, rpath);
+
+	while (i < vec_len(esrc->fes_path_exts) &&
+	       (fib_path_ext_cmp(&esrc->fes_path_exts[i], rpath) < 0))
+	{
+	    i++;
+	}
+
+	vec_insert_elts(esrc->fes_path_exts, &path_ext, 1, i);
+    }
+}
+
+/*
+ * fib_entry_src_action_add
+ *
+ * Adding a source can result in a new fib_entry being created, which
+ * can inturn mean the pool is realloc'd and thus the entry passed as
+ * an argument it also realloc'd
+ * @return the entry
+ */
+fib_entry_t*
+fib_entry_src_action_path_add (fib_entry_t *fib_entry,
+			       fib_source_t source,
+			       fib_entry_flag_t flags,
+			       const fib_route_path_t *rpath)
+{
+    fib_node_index_t old_path_list, fib_entry_index;
+    fib_path_list_flags_t pl_flags;
+    fib_path_ext_t *path_ext;
+    fib_entry_src_t *esrc;
+
+    /*
+     * save variable so we can recover from a fib_entry realloc.
+     */
+    fib_entry_index = fib_entry_get_index(fib_entry);
+
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+    if (NULL == esrc)
+    {
+	fib_entry =
+            fib_entry_src_action_add(fib_entry,
+                                     source,
+                                     flags,
+                                     drop_dpo_get(
+                                         fib_proto_to_dpo(
+                                             fib_entry_get_proto(fib_entry))));
+	esrc = fib_entry_src_find(fib_entry, source, NULL);
+    }
+
+    /*
+     * we are no doubt modifying a path-list. If the path-list
+     * is shared, and hence not modifiable, then the index returned
+     * will be for a different path-list. This FIB entry to needs
+     * to maintain its lock appropriately.
+     */
+    old_path_list = esrc->fes_pl;
+
+    ASSERT(NULL != fib_entry_src_vft[source].fesv_path_add);
+
+    pl_flags = fib_entry_src_flags_2_path_list_flags(fib_entry_get_flags_i(fib_entry));
+    fib_entry_flags_update(fib_entry, rpath, &pl_flags, esrc);
+
+    fib_entry_src_vft[source].fesv_path_add(esrc, fib_entry, pl_flags, rpath);
+    fib_entry = fib_entry_get(fib_entry_index);
+
+    /*
+     * re-resolve all the path-extensions with the new path-list
+     */
+    vec_foreach(path_ext, esrc->fes_path_exts)
+    {
+	fib_path_ext_resolve(path_ext, esrc->fes_pl);
+    }
+    /*
+     * if the path has a label we need to add a path extension
+     */
+    fib_entry_src_path_ext_insert(esrc, rpath);
+
+    fib_path_list_lock(esrc->fes_pl);
+    fib_path_list_unlock(old_path_list);
+
+    return (fib_entry);
+}
+
+/*
+ * fib_entry_src_action_swap
+ *
+ * The source is providing new paths to replace the old ones.
+ * Adding a source can result in a new fib_entry being created, which
+ * can inturn mean the pool is realloc'd and thus the entry passed as
+ * an argument it also realloc'd
+ * @return the entry
+ */
+fib_entry_t*
+fib_entry_src_action_path_swap (fib_entry_t *fib_entry,
+				fib_source_t source,
+				fib_entry_flag_t flags,				
+				const fib_route_path_t *rpaths)
+{
+    fib_node_index_t old_path_list, fib_entry_index;
+    fib_path_list_flags_t pl_flags;
+    const fib_route_path_t *rpath;
+    fib_path_ext_t *path_ext;
+    fib_entry_src_t *esrc;
+
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+
+    /*
+     * save variable so we can recover from a fib_entry realloc.
+     */
+    fib_entry_index = fib_entry_get_index(fib_entry);
+
+    if (NULL == esrc)
+    {
+	fib_entry = fib_entry_src_action_add(fib_entry,
+					     source,
+					     flags,
+                                             drop_dpo_get(
+                                                 fib_proto_to_dpo(
+                                                     fib_entry_get_proto(fib_entry))));
+	esrc = fib_entry_src_find(fib_entry, source, NULL);
+    }
+
+    /*
+     * swapping paths may create a new path-list (or may use an existing shared)
+     * but we are certainly getting a different one. This FIB entry to needs
+     * to maintain its lock appropriately.
+     */
+    old_path_list = esrc->fes_pl;
+
+    ASSERT(NULL != fib_entry_src_vft[source].fesv_path_swap);
+
+    pl_flags = fib_entry_src_flags_2_path_list_flags(flags);
+
+    vec_foreach(rpath, rpaths)
+    {
+	fib_entry_flags_update(fib_entry, rpath, &pl_flags, esrc);
+    }
+
+    fib_entry_src_vft[source].fesv_path_swap(esrc,
+					     fib_entry,
+					     pl_flags,
+					     rpaths);
+
+    vec_foreach(path_ext, esrc->fes_path_exts)
+    {
+	vec_free(path_ext->fpe_label_stack);
+    }
+    vec_free(esrc->fes_path_exts);
+
+    vec_foreach(rpath, rpaths)
+    {
+	fib_entry_src_path_ext_append(esrc, rpath);
+    }
+
+    fib_entry = fib_entry_get(fib_entry_index);
+
+    fib_path_list_lock(esrc->fes_pl);
+    fib_path_list_unlock(old_path_list);
+
+    return (fib_entry);
+}
+
+fib_entry_src_flag_t
+fib_entry_src_action_path_remove (fib_entry_t *fib_entry,
+				  fib_source_t source,
+				  const fib_route_path_t *rpath)
+{
+    fib_path_list_flags_t pl_flags;
+    fib_node_index_t old_path_list;
+    fib_path_ext_t *path_ext;
+    fib_entry_src_t *esrc;
+
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+
+    ASSERT(NULL != esrc);
+    ASSERT(esrc->fes_flags & FIB_ENTRY_SRC_FLAG_ADDED);
+
+    /*
+     * we no doubt modifying a path-list. If the path-list
+     * is shared, and hence not modifiable, then the index returned
+     * will be for a different path-list. This FIB entry to needs
+     * to maintain its lock appropriately.
+     */
+    old_path_list = esrc->fes_pl;
+
+    ASSERT(NULL != fib_entry_src_vft[source].fesv_path_remove);
+
+    pl_flags = fib_entry_src_flags_2_path_list_flags(fib_entry_get_flags_i(fib_entry));
+    fib_entry_flags_update(fib_entry, rpath, &pl_flags, esrc);
+
+    fib_entry_src_vft[source].fesv_path_remove(esrc, pl_flags, rpath);
+    /*
+     * find the matching path extension and remove it
+     */
+    vec_foreach(path_ext, esrc->fes_path_exts)
+    {
+	if (!fib_path_ext_cmp(path_ext, rpath))
+	{
+	    /*
+	     * delete the element moving the remaining elements down 1 position.
+	     * this preserves the sorted order.
+	     */
+	    vec_free(path_ext->fpe_label_stack);
+	    vec_delete(esrc->fes_path_exts, 1, (path_ext - esrc->fes_path_exts));
+	    break;
+	}
+    }
+    /*
+     * re-resolve all the path-extensions with the new path-list
+     */
+    vec_foreach(path_ext, esrc->fes_path_exts)
+    {
+	fib_path_ext_resolve(path_ext, esrc->fes_pl);
+    }
+
+    /*
+     * lock the new path-list, unlock the old if it had one
+     */
+    fib_path_list_unlock(old_path_list);
+
+    if (FIB_NODE_INDEX_INVALID != esrc->fes_pl) {
+	fib_path_list_lock(esrc->fes_pl);
+	return (FIB_ENTRY_SRC_FLAG_ADDED);
+    }
+    else
+    {
+	/*
+	 * no more paths left from this source
+	 */
+	fib_entry_src_action_remove(fib_entry, source);
+	return (FIB_ENTRY_SRC_FLAG_NONE);
+    }
+}
+
+u8*
+fib_entry_src_format (fib_entry_t *fib_entry,
+		      fib_source_t source,
+		      u8* s)
+{
+    fib_entry_src_t *esrc;
+
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+
+    if (NULL != fib_entry_src_vft[source].fesv_format)
+    {
+	return (fib_entry_src_vft[source].fesv_format(esrc, s));
+    }
+    return (s);
+}
+
+adj_index_t
+fib_entry_get_adj_for_source (fib_node_index_t fib_entry_index,
+			      fib_source_t source)
+{
+    fib_entry_t *fib_entry;
+    fib_entry_src_t *esrc;
+
+    if (FIB_NODE_INDEX_INVALID == fib_entry_index)
+	return (ADJ_INDEX_INVALID);
+
+    fib_entry = fib_entry_get(fib_entry_index);
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+
+    if (NULL != esrc)
+    {
+	if (FIB_NODE_INDEX_INVALID != esrc->fes_pl)
+	{
+	    return (fib_path_list_get_adj(
+			esrc->fes_pl,
+			fib_entry_get_default_chain_type(fib_entry)));
+	}
+    }
+    return (ADJ_INDEX_INVALID);
+}
+
+const int
+fib_entry_get_dpo_for_source (fib_node_index_t fib_entry_index,
+			      fib_source_t source,
+			      dpo_id_t *dpo)
+{
+    fib_entry_t *fib_entry;
+    fib_entry_src_t *esrc;
+
+    if (FIB_NODE_INDEX_INVALID == fib_entry_index)
+	return (0);
+
+    fib_entry = fib_entry_get(fib_entry_index);
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+
+    if (NULL != esrc)
+    {
+	if (FIB_NODE_INDEX_INVALID != esrc->fes_pl)
+	{
+	    fib_path_list_contribute_forwarding(
+		esrc->fes_pl,
+		fib_entry_get_default_chain_type(fib_entry),
+		dpo);
+
+	    return (dpo_id_is_valid(dpo));
+	}
+    }
+    return (0);
+}
+
+u32
+fib_entry_get_resolving_interface_for_source (fib_node_index_t entry_index,
+					      fib_source_t source)
+{
+    fib_entry_t *fib_entry;
+    fib_entry_src_t *esrc;
+
+    fib_entry = fib_entry_get(entry_index);
+
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+
+    if (NULL != esrc)
+    {
+	if (FIB_NODE_INDEX_INVALID != esrc->fes_pl)
+	{
+	    return (fib_path_list_get_resolving_interface(esrc->fes_pl));
+	}
+    }
+    return (~0);
+}
+
+fib_entry_flag_t
+fib_entry_get_flags_for_source (fib_node_index_t entry_index,
+				fib_source_t source)
+{
+    fib_entry_t *fib_entry;
+    fib_entry_src_t *esrc;
+
+    fib_entry = fib_entry_get(entry_index);
+
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+
+    if (NULL != esrc)
+    {
+	return (esrc->fes_entry_flags);
+    }
+
+    return (FIB_ENTRY_FLAG_NONE);
+}
+
+fib_entry_flag_t
+fib_entry_get_flags_i (const fib_entry_t *fib_entry)
+{
+    fib_entry_flag_t flags;
+
+    /*
+     * the vector of sources is deliberately arranged in priority order
+     */
+    if (0 == vec_len(fib_entry->fe_srcs))
+    {
+	flags = FIB_ENTRY_FLAG_NONE;
+    }
+    else
+    {
+	fib_entry_src_t *esrc;
+
+	esrc = vec_elt_at_index(fib_entry->fe_srcs, 0);
+	flags = esrc->fes_entry_flags;
+    }
+
+    return (flags);
+}
+
+void
+fib_entry_set_source_data (fib_node_index_t fib_entry_index,
+                           fib_source_t source,
+                           const void *data)
+{
+    fib_entry_t *fib_entry;
+    fib_entry_src_t *esrc;
+
+    fib_entry = fib_entry_get(fib_entry_index);
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+
+    if (NULL != esrc &&
+        NULL != fib_entry_src_vft[source].fesv_set_data)
+    {
+	fib_entry_src_vft[source].fesv_set_data(esrc, fib_entry, data);
+    }
+}
+
+const void*
+fib_entry_get_source_data (fib_node_index_t fib_entry_index,
+                           fib_source_t source)
+{
+    fib_entry_t *fib_entry;
+    fib_entry_src_t *esrc;
+
+    fib_entry = fib_entry_get(fib_entry_index);
+    esrc = fib_entry_src_find(fib_entry, source, NULL);
+
+    if (NULL != esrc &&
+        NULL != fib_entry_src_vft[source].fesv_get_data)
+    {
+	return (fib_entry_src_vft[source].fesv_get_data(esrc, fib_entry));
+    }
+    return (NULL);
+}
+
+void
+fib_entry_src_module_init (void)
+{
+    fib_entry_src_rr_register();
+    fib_entry_src_interface_register();
+    fib_entry_src_default_route_register();
+    fib_entry_src_special_register();
+    fib_entry_src_api_register();
+    fib_entry_src_adj_register();
+    fib_entry_src_mpls_register();
+    fib_entry_src_lisp_register();
+}
diff --git a/src/vnet/fib/fib_entry_src.h b/src/vnet/fib/fib_entry_src.h
new file mode 100644
index 00000000000..640c174db47
--- /dev/null
+++ b/src/vnet/fib/fib_entry_src.h
@@ -0,0 +1,296 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __FIB_ENTRY_SRC_H__
+#define __FIB_ENTRY_SRC_H__
+
+#include "fib_entry.h"
+#include "fib_path_list.h"
+#include "fib_internal.h"
+
+/**
+ * Debug macro
+ */
+#ifdef FIB_DEBUG
+#define FIB_ENTRY_DBG(_e, _fmt, _args...)		\
+{   		          				\
+    u8*__tmp = NULL;					\
+    __tmp = format(__tmp, "e:[%d:%U",			\
+		   fib_entry_get_index(_e),		\
+		   format_ip46_address,			\
+		   &_e->fe_prefix.fp_addr,		\
+		   IP46_TYPE_ANY);			\
+    __tmp = format(__tmp, "/%d]:",			\
+		   _e->fe_prefix.fp_len);		\
+    __tmp = format(__tmp, _fmt, ##_args);		\
+    clib_warning("%s", __tmp);				\
+    vec_free(__tmp);					\
+}
+#else
+#define FIB_ENTRY_DBG(_e, _fmt, _args...)
+#endif
+
+/**
+ * Source initialisation Function 
+ */
+typedef void (*fib_entry_src_init_t)(fib_entry_src_t *src);
+
+/**
+ * Source deinitialisation Function 
+ */
+typedef void (*fib_entry_src_deinit_t)(fib_entry_src_t *src);
+
+/**
+ * Source activation. Called when the source is the new best source on the entry.
+ * Return non-zero if the entry can now install, 0 otherwise
+ */
+typedef int (*fib_entry_src_activate_t)(fib_entry_src_t *src,
+					 const fib_entry_t *fib_entry);
+
+/**
+ * Source Deactivate. 
+ * Called when the source is no longer best source on the entry
+ */
+typedef void (*fib_entry_src_deactivate_t)(fib_entry_src_t *src,
+					   const fib_entry_t *fib_entry);
+
+/**
+ * Source Add.
+ * Called when the source is added to the entry
+ */
+typedef void (*fib_entry_src_add_t)(fib_entry_src_t *src,
+				    const fib_entry_t *entry,
+				    fib_entry_flag_t flags,
+				    fib_protocol_t proto,
+				    const dpo_id_t *dpo);
+
+/**
+ * Source Remove.
+ */
+typedef void (*fib_entry_src_remove_t)(fib_entry_src_t *src);
+
+/**
+ * Result from a cover update/change
+ */
+typedef struct fib_entry_src_cover_res_t_ {
+    u16 install;
+    fib_node_bw_reason_flag_t bw_reason;
+} fib_entry_src_cover_res_t;
+
+/**
+ * Cover changed. the source should re-evaluate its cover.
+ */
+typedef fib_entry_src_cover_res_t (*fib_entry_src_cover_change_t)(
+    fib_entry_src_t *src,
+    const fib_entry_t *fib_entry);
+
+/**
+ * Cover updated. The cover the source has, has updated (i.e. its forwarding)
+ * the source may need to re-evaluate.
+ */
+typedef fib_entry_src_cover_res_t (*fib_entry_src_cover_update_t)(
+    fib_entry_src_t *src,
+    const fib_entry_t *fib_entry);
+
+/**
+ * Forwarding updated. Notification that the forwarding information for the
+ * entry has been updated. This notification is sent to all sources, not just
+ * the active best.
+ */
+typedef void (*fib_entry_src_fwd_update_t)(fib_entry_src_t *src,
+					   const fib_entry_t *fib_entry,
+					   fib_source_t best_source);
+
+/**
+ * Installed. Notification that the source is now installed as
+ * the entry's forwarding source.
+ */
+typedef void (*fib_entry_src_installed_t)(fib_entry_src_t *src,
+					  const fib_entry_t *fib_entry);
+
+/**
+ * format.
+ */
+typedef u8* (*fib_entry_src_format_t)(fib_entry_src_t *src,
+				      u8* s);
+
+/**
+ * Source path add
+ * the source is adding a new path
+ */
+typedef void (*fib_entry_src_path_add_t)(fib_entry_src_t *src,
+					 const fib_entry_t *fib_entry,
+					 fib_path_list_flags_t pl_flags,
+					 const fib_route_path_t *path);
+
+/**
+ * Source path remove
+ * the source is remoinvg a path
+ */
+typedef void (*fib_entry_src_path_remove_t)(fib_entry_src_t *src,
+					    fib_path_list_flags_t pl_flags,
+					    const fib_route_path_t *path);
+
+/**
+ * Source path replace/swap
+ * the source is providing a new set of paths
+ */
+typedef void (*fib_entry_src_path_swap_t)(fib_entry_src_t *src,
+					  const fib_entry_t *fib_entry,
+					  fib_path_list_flags_t pl_flags,
+					  const fib_route_path_t *path);
+
+/**
+ * Set source specific opaque data
+ */
+typedef void (*fib_entry_src_set_data_t)(fib_entry_src_t *src,
+                                         const fib_entry_t *fib_entry,
+                                         const void *data);
+
+/**
+ * Get source specific opaque data
+ */
+typedef const void* (*fib_entry_src_get_data_t)(fib_entry_src_t *src,
+                                                const fib_entry_t *fib_entry);
+
+/**
+ * Virtual function table each FIB entry source will register
+ */
+typedef struct fib_entry_src_vft_t_ {
+    fib_entry_src_init_t fesv_init;
+    fib_entry_src_deinit_t fesv_deinit;
+    fib_entry_src_activate_t fesv_activate;
+    fib_entry_src_deactivate_t fesv_deactivate;
+    fib_entry_src_add_t fesv_add;
+    fib_entry_src_remove_t fesv_remove;
+    fib_entry_src_path_swap_t fesv_path_swap;
+    fib_entry_src_path_add_t fesv_path_add;
+    fib_entry_src_path_remove_t fesv_path_remove;
+    fib_entry_src_cover_change_t fesv_cover_change;
+    fib_entry_src_cover_update_t fesv_cover_update;
+    fib_entry_src_format_t fesv_format;
+    fib_entry_src_installed_t fesv_installed;
+    fib_entry_src_fwd_update_t fesv_fwd_update;
+    fib_entry_src_get_data_t fesv_get_data;
+    fib_entry_src_set_data_t fesv_set_data;
+} fib_entry_src_vft_t;
+
+#define FOR_EACH_SRC_ADDED(_entry, _src, _source, action)	\
+{								\
+    vec_foreach(_src, _entry->fe_srcs)				\
+    {								\
+	if (_src->fes_flags & FIB_ENTRY_SRC_FLAG_ADDED) {	\
+	    _source = _src->fes_src;				\
+	    do {						\
+		action;						\
+	    } while(0);						\
+	}							\
+    }								\
+}
+
+extern u8* fib_entry_src_format(fib_entry_t *entry,
+				fib_source_t source,
+				u8* s);
+
+extern void fib_entry_src_register(fib_source_t source,
+				   const fib_entry_src_vft_t *vft);
+
+extern void fib_entry_src_action_init(fib_entry_t *entry,
+				      fib_source_t source);
+
+extern void fib_entry_src_action_deinit(fib_entry_t *fib_entry,
+					fib_source_t source);
+
+extern fib_entry_src_cover_res_t fib_entry_src_action_cover_change(
+    fib_entry_t *entry,
+    fib_source_t source);
+
+extern fib_entry_src_cover_res_t fib_entry_src_action_cover_update(
+    fib_entry_t *fib_entry,
+    fib_source_t source);
+
+extern void fib_entry_src_action_activate(fib_entry_t *fib_entry,
+					  fib_source_t source);
+
+extern void fib_entry_src_action_deactivate(fib_entry_t *fib_entry,
+					    fib_source_t source);
+extern void fib_entry_src_action_reactivate(fib_entry_t *fib_entry,
+					    fib_source_t source);
+
+extern fib_entry_t* fib_entry_src_action_add(fib_entry_t *fib_entry,
+					     fib_source_t source,
+					     fib_entry_flag_t flags,
+					     const dpo_id_t *dpo);
+extern fib_entry_t* fib_entry_src_action_update(fib_entry_t *fib_entry,
+						fib_source_t source,
+						fib_entry_flag_t flags,
+						const dpo_id_t *dpo);
+
+extern fib_entry_src_flag_t fib_entry_src_action_remove(fib_entry_t *fib_entry,
+							fib_source_t source);
+
+extern void fib_entry_src_action_install(fib_entry_t *fib_entry,
+					 fib_source_t source);
+
+extern void fib_entry_src_action_uninstall(fib_entry_t *fib_entry);
+
+extern fib_entry_t* fib_entry_src_action_path_add(fib_entry_t *fib_entry,
+						  fib_source_t source,
+						  fib_entry_flag_t flags,
+						  const fib_route_path_t *path);
+
+extern fib_entry_t* fib_entry_src_action_path_swap(fib_entry_t *fib_entry,
+						   fib_source_t source,
+						   fib_entry_flag_t flags,
+						   const fib_route_path_t *path);
+
+extern fib_entry_src_flag_t fib_entry_src_action_path_remove(fib_entry_t *fib_entry,
+							     fib_source_t source,
+							     const fib_route_path_t *path);
+
+extern void fib_entry_src_action_installed(const fib_entry_t *fib_entry,
+					   fib_source_t source);
+
+extern fib_forward_chain_type_t fib_entry_get_default_chain_type(
+    const fib_entry_t *fib_entry);
+extern fib_entry_flag_t fib_entry_get_flags_i(const fib_entry_t *fib_entry);
+extern fib_path_list_flags_t fib_entry_src_flags_2_path_list_flags(
+    fib_entry_flag_t eflags);
+
+extern fib_forward_chain_type_t fib_entry_chain_type_fixup(const fib_entry_t *entry,
+                                                           fib_forward_chain_type_t fct);
+
+extern void fib_entry_src_mk_lb (fib_entry_t *fib_entry,
+				 const fib_entry_src_t *esrc,
+				 fib_forward_chain_type_t fct,
+				 dpo_id_t *dpo_lb);
+
+
+/*
+ * Per-source registration. declared here so we save a separate .h file for each
+ */
+extern void fib_entry_src_default_register(void);
+extern void fib_entry_src_rr_register(void);
+extern void fib_entry_src_interface_register(void);
+extern void fib_entry_src_default_route_register(void);
+extern void fib_entry_src_special_register(void);
+extern void fib_entry_src_api_register(void);
+extern void fib_entry_src_adj_register(void);
+extern void fib_entry_src_mpls_register(void);
+extern void fib_entry_src_lisp_register(void);
+
+extern void fib_entry_src_module_init(void);
+
+#endif
diff --git a/src/vnet/fib/fib_entry_src_adj.c b/src/vnet/fib/fib_entry_src_adj.c
new file mode 100644
index 00000000000..64f82a73e07
--- /dev/null
+++ b/src/vnet/fib/fib_entry_src_adj.c
@@ -0,0 +1,207 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "fib_entry.h"
+#include "fib_entry_src.h"
+#include "fib_path_list.h"
+#include "fib_table.h"
+#include "fib_entry_cover.h"
+#include "fib_attached_export.h"
+
+/**
+ * Source initialisation Function 
+ */
+static void
+fib_entry_src_adj_init (fib_entry_src_t *src)
+{
+    src->adj.fesa_cover = FIB_NODE_INDEX_INVALID;
+    src->adj.fesa_sibling = FIB_NODE_INDEX_INVALID;
+}
+
+static void
+fib_entry_src_adj_path_swap (fib_entry_src_t *src,
+			     const fib_entry_t *entry,
+			     fib_path_list_flags_t pl_flags,
+			     const fib_route_path_t *paths)
+{
+    src->fes_pl = fib_path_list_create(pl_flags, paths);
+}
+
+static void
+fib_entry_src_adj_remove (fib_entry_src_t *src)
+{
+    src->fes_pl = FIB_NODE_INDEX_INVALID;
+}
+
+
+/*
+ * Source activate. 
+ * Called when the source is teh new longer best source on the entry
+ */
+static int
+fib_entry_src_adj_activate (fib_entry_src_t *src,
+			    const fib_entry_t *fib_entry)
+{
+    fib_entry_t *cover;
+
+    /*
+     * find the covering prefix. become a dependent thereof.
+     * there should always be a cover, though it may be the default route.
+     */
+    src->adj.fesa_cover = fib_table_get_less_specific(fib_entry->fe_fib_index,
+						      &fib_entry->fe_prefix);
+
+    ASSERT(FIB_NODE_INDEX_INVALID != src->adj.fesa_cover);
+    ASSERT(fib_entry_get_index(fib_entry) != src->adj.fesa_cover);
+
+    cover = fib_entry_get(src->adj.fesa_cover);
+
+    ASSERT(cover != fib_entry);
+
+    src->adj.fesa_sibling =
+	fib_entry_cover_track(cover,
+			      fib_entry_get_index(fib_entry));
+
+    /*
+     * if the ocver is attached then this adj source entry can install, 
+     * via the adj. otherwise install a drop.
+     * This prevents ARP/ND entries that on interface X that do not belong
+     * on X's subnet from being added to the FIB. To do so would allow
+     * nefarious gratuitous ARP requests from attracting traffic to the sender.
+     *
+     * and yes, I really do mean attached and not connected.
+     * this abomination;
+     *   ip route add 10.0.0.0/24 Eth0
+     * is attached. and we want adj-fibs to install on Eth0.
+     */
+    return (FIB_ENTRY_FLAG_ATTACHED & fib_entry_get_flags_i(cover));
+}
+
+/*
+ * Source Deactivate. 
+ * Called when the source is no longer best source on the entry
+ */
+static void
+fib_entry_src_adj_deactivate (fib_entry_src_t *src,
+			      const fib_entry_t *fib_entry)
+{
+    fib_entry_t *cover;
+
+    /*
+     * remove the depednecy on the covering entry
+     */
+    ASSERT(FIB_NODE_INDEX_INVALID != src->adj.fesa_cover);
+    cover = fib_entry_get(src->adj.fesa_cover);
+
+    fib_entry_cover_untrack(cover, src->adj.fesa_sibling);
+
+    /*
+     * tell the cover this entry no longer needs exporting
+     */
+    fib_attached_export_covered_removed(cover, fib_entry_get_index(fib_entry));
+
+    src->adj.fesa_cover = FIB_NODE_INDEX_INVALID;
+}
+
+static u8*
+fib_entry_src_adj_format (fib_entry_src_t *src,
+			 u8* s)
+{
+    return (format(s, "cover:%d", src->adj.fesa_cover));
+}
+
+static void
+fib_entry_src_adj_installed (fib_entry_src_t *src,
+			     const fib_entry_t *fib_entry)
+{
+    /*
+     * The adj source now rules! poke our cover to get exported
+     */
+    fib_entry_t *cover;
+
+    ASSERT(FIB_NODE_INDEX_INVALID != src->adj.fesa_cover);
+    cover = fib_entry_get(src->adj.fesa_cover);
+
+    fib_attached_export_covered_added(cover,
+				      fib_entry_get_index(fib_entry));
+}
+
+static fib_entry_src_cover_res_t
+fib_entry_src_adj_cover_change (fib_entry_src_t *src,
+				const fib_entry_t *fib_entry)
+{
+    fib_entry_src_cover_res_t res = {
+	.install = !0,
+	.bw_reason = FIB_NODE_BW_REASON_FLAG_NONE,
+    };
+
+    fib_entry_src_adj_deactivate(src, fib_entry);
+
+    res.install = fib_entry_src_adj_activate(src, fib_entry);
+
+    if (res.install) {
+	/*
+	 * ADJ fib can install
+	 */
+	res.bw_reason = FIB_NODE_BW_REASON_FLAG_EVALUATE;
+    }
+
+    return (res);
+}
+
+/*
+ * fib_entry_src_adj_cover_update
+ */
+static fib_entry_src_cover_res_t
+fib_entry_src_adj_cover_update (fib_entry_src_t *src,
+                                const fib_entry_t *fib_entry)
+{
+    /*
+     * the cover has updated, i.e. its forwarding or flags
+     * have changed. do'nt decativate/activate here, since this
+     * prefix is updated during the covers walk.
+     */
+    fib_entry_src_cover_res_t res = {
+	.install = !0,
+	.bw_reason = FIB_NODE_BW_REASON_FLAG_NONE,
+    };
+    fib_entry_t *cover;
+
+    ASSERT(FIB_NODE_INDEX_INVALID != src->adj.fesa_cover);
+
+    cover = fib_entry_get(src->adj.fesa_cover);
+
+    res.install = (FIB_ENTRY_FLAG_ATTACHED & fib_entry_get_flags_i(cover));
+
+    return (res);
+}
+
+const static fib_entry_src_vft_t adj_src_vft = {
+    .fesv_init = fib_entry_src_adj_init,
+    .fesv_path_swap = fib_entry_src_adj_path_swap,
+    .fesv_remove = fib_entry_src_adj_remove,
+    .fesv_activate = fib_entry_src_adj_activate,
+    .fesv_deactivate = fib_entry_src_adj_deactivate,
+    .fesv_format = fib_entry_src_adj_format,
+    .fesv_installed = fib_entry_src_adj_installed,
+    .fesv_cover_change = fib_entry_src_adj_cover_change,
+    .fesv_cover_update = fib_entry_src_adj_cover_update,
+};
+
+void
+fib_entry_src_adj_register (void)
+{
+    fib_entry_src_register(FIB_SOURCE_ADJ, &adj_src_vft);
+}
diff --git a/src/vnet/fib/fib_entry_src_api.c b/src/vnet/fib/fib_entry_src_api.c
new file mode 100644
index 00000000000..edc8a47bc17
--- /dev/null
+++ b/src/vnet/fib/fib_entry_src_api.c
@@ -0,0 +1,119 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "fib_entry.h"
+#include "fib_entry_src.h"
+#include "fib_path_list.h"
+
+/**
+ * Source initialisation Function 
+ */
+static void
+fib_entry_src_api_init (fib_entry_src_t *src)
+{
+}
+
+/**
+ * Source deinitialisation Function 
+ */
+static void
+fib_entry_src_api_deinit (fib_entry_src_t *src)
+{
+}
+
+static void
+fib_entry_src_api_path_swap (fib_entry_src_t *src,
+			     const fib_entry_t *entry,
+			     fib_path_list_flags_t pl_flags,
+			     const fib_route_path_t *paths)
+{
+    src->fes_pl = fib_path_list_create((FIB_PATH_LIST_FLAG_SHARED | pl_flags),
+				       paths);
+}
+
+static void
+fib_entry_src_api_path_add (fib_entry_src_t *src,
+			    const fib_entry_t *entry,
+			    fib_path_list_flags_t pl_flags,
+			    const fib_route_path_t *paths)
+{
+    if (FIB_NODE_INDEX_INVALID == src->fes_pl)
+    {	
+	src->fes_pl =
+	    fib_path_list_create((FIB_PATH_LIST_FLAG_SHARED | pl_flags), paths);
+    }
+    else
+    {
+	src->fes_pl =
+	    fib_path_list_copy_and_path_add(src->fes_pl,
+					    (FIB_PATH_LIST_FLAG_SHARED | pl_flags),
+					    paths);
+    }
+}
+
+static void
+fib_entry_src_api_path_remove (fib_entry_src_t *src,
+			       fib_path_list_flags_t pl_flags,
+			       const fib_route_path_t *paths)
+{
+    if (FIB_NODE_INDEX_INVALID != src->fes_pl)
+    {
+	src->fes_pl =
+	    fib_path_list_copy_and_path_remove(src->fes_pl,
+					       (FIB_PATH_LIST_FLAG_SHARED | pl_flags),
+					       paths);
+    }
+}
+
+static void
+fib_entry_src_api_add (fib_entry_src_t *src,
+		       const fib_entry_t *entry,
+		       fib_entry_flag_t flags,
+		       fib_protocol_t proto,
+		       const dpo_id_t *dpo)
+{
+    if (FIB_ENTRY_FLAG_NONE != flags)
+    {
+	src->fes_pl = fib_path_list_create_special(
+	                  proto,
+			  fib_entry_src_flags_2_path_list_flags(flags),
+			  dpo);
+    }
+}
+
+static void
+fib_entry_src_api_remove (fib_entry_src_t *src)
+{
+    src->fes_pl = FIB_NODE_INDEX_INVALID;
+}
+
+const static fib_entry_src_vft_t api_src_vft = {
+    .fesv_init = fib_entry_src_api_init,
+    .fesv_deinit = fib_entry_src_api_deinit,
+    .fesv_add = fib_entry_src_api_add,
+    .fesv_remove = fib_entry_src_api_remove,
+    .fesv_path_add = fib_entry_src_api_path_add,
+    .fesv_path_swap = fib_entry_src_api_path_swap,
+    .fesv_path_remove = fib_entry_src_api_path_remove,
+};
+
+void
+fib_entry_src_api_register (void)
+{
+    fib_entry_src_register(FIB_SOURCE_PLUGIN_HI, &api_src_vft);
+    fib_entry_src_register(FIB_SOURCE_API, &api_src_vft);
+    fib_entry_src_register(FIB_SOURCE_CLI, &api_src_vft);
+    fib_entry_src_register(FIB_SOURCE_DHCP, &api_src_vft);
+}
diff --git a/src/vnet/fib/fib_entry_src_default.c b/src/vnet/fib/fib_entry_src_default.c
new file mode 100644
index 00000000000..9846cf56e64
--- /dev/null
+++ b/src/vnet/fib/fib_entry_src_default.c
@@ -0,0 +1,121 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "fib_entry.h"
+#include "fib_entry_src.h"
+#include "fib_path_list.h"
+
+/**
+ * Source initialisation Function 
+ */
+static void
+fib_entry_src_default_init (fib_entry_src_t *src)
+{
+}
+
+/**
+ * Source deinitialisation Function 
+ */
+static void
+fib_entry_src_default_deinit (fib_entry_src_t *src)
+{
+}
+
+static void
+fib_entry_src_cover_change (fib_entry_src_t *src)
+{
+}
+
+/**
+ * Source deinitialisation Function 
+ */
+static void
+fib_entry_src_default_deinit (fib_entry_src_t *src)
+{
+}
+
+static void
+fib_entry_src_default_path_add (fib_entry_src_t *src,
+				fib_protocol_t proto,
+				const ip46_address_t *next_hop,
+				u32 next_hop_sw_if_index,
+				u32 next_hop_fib_index,
+				u32 next_hop_weight)
+{
+}
+
+static void
+fib_entry_src_default_path_remove (fib_entry_src_t *src,
+				     fib_protocol_t proto,
+				     const ip46_address_t *next_hop,
+				     u32 next_hop_sw_if_index,
+				     u32 next_hop_fib_index,
+				     u32 next_hop_weight)
+{
+}
+
+
+/*
+ * Source activate. 
+ * Called when the source is teh new longer best source on the entry
+ */
+static void
+fib_entry_src_default_activate (fib_entry_src_t *src,
+				  const fib_entry_t *fib_entry)
+{
+}
+
+/*
+ * Source Deactivate. 
+ * Called when the source is no longer best source on the entry
+ */
+static void
+fib_entry_src_default_deactivate (fib_entry_src_t *src,
+				    const fib_entry_t *fib_entry)
+{
+}
+
+static void
+fib_entry_src_default_add (fib_entry_src_t *src,
+			     fib_entry_flag_t flags,
+			     fib_protocol_t proto)
+{
+}
+
+static void
+fib_entry_src_default_remove (fib_entry_src_t *src)			     
+{
+}
+
+const static fib_entry_src_vft_t default_src_vft = {
+    .fesv_init = fib_entry_src_default_init,
+    .fesv_deinit = fib_entry_src_default_deinit,
+    .fesv_add = fib_entry_src_default_add,
+    .fesv_remove = fib_entry_src_default_remove,
+    .fesv_path_add = fib_entry_src_default_path_add,
+    .fesv_path_remove = fib_entry_src_default_path_remove,
+    .fesv_activate = fib_entry_src_default_activate,
+    .fesv_deactivate = fib_entry_src_default_deactivate,
+};
+
+void
+fib_entry_src_default_register (void)
+{
+    fib_source_t source;
+
+    FOR_EACH_FIB_SOURCE(source) {
+	fib_entry_src_register(source, &default_src_vft);    
+    }
+}
diff --git a/src/vnet/fib/fib_entry_src_default_route.c b/src/vnet/fib/fib_entry_src_default_route.c
new file mode 100644
index 00000000000..9f4e7c36952
--- /dev/null
+++ b/src/vnet/fib/fib_entry_src_default_route.c
@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "fib_entry.h"
+#include "fib_entry_src.h"
+
+/**
+ * Source initialisation Function 
+ */
+static void
+fib_entry_src_default_route_init (fib_entry_src_t *src)
+{
+    src->fes_flags = FIB_ENTRY_SRC_FLAG_NONE;
+}
+
+static void
+fib_entry_src_default_route_remove (fib_entry_src_t *src)
+{
+    src->fes_pl = FIB_NODE_INDEX_INVALID;
+}
+
+static void
+fib_entry_src_default_route_add (fib_entry_src_t *src,
+				 const fib_entry_t *entry,
+				 fib_entry_flag_t flags,
+				 fib_protocol_t proto,
+				 const dpo_id_t *dpo)
+{
+    src->fes_pl = fib_path_list_create_special(proto,
+					       FIB_PATH_LIST_FLAG_DROP,
+					       dpo);
+}
+
+const static fib_entry_src_vft_t interface_src_vft = {
+    .fesv_init = fib_entry_src_default_route_init,
+    .fesv_add = fib_entry_src_default_route_add,
+    .fesv_remove = fib_entry_src_default_route_remove,
+};
+
+void
+fib_entry_src_default_route_register (void)
+{
+    fib_entry_src_register(FIB_SOURCE_DEFAULT_ROUTE, &interface_src_vft);    
+}
+
+
diff --git a/src/vnet/fib/fib_entry_src_interface.c b/src/vnet/fib/fib_entry_src_interface.c
new file mode 100644
index 00000000000..ca04716ed8f
--- /dev/null
+++ b/src/vnet/fib/fib_entry_src_interface.c
@@ -0,0 +1,195 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "fib_entry.h"
+#include "fib_entry_src.h"
+#include "fib_path_list.h"
+#include "fib_internal.h"
+#include "fib_table.h"
+#include "fib_entry_cover.h"
+#include "fib_attached_export.h"
+
+/**
+ * Source initialisation Function 
+ */
+static void
+fib_entry_src_interface_init (fib_entry_src_t *src)
+{
+    src->interface.fesi_cover = FIB_NODE_INDEX_INVALID;
+    src->interface.fesi_sibling = FIB_NODE_INDEX_INVALID;
+}
+
+static void
+fib_entry_src_interface_path_swap (fib_entry_src_t *src,
+				   const fib_entry_t *entry,
+				   fib_path_list_flags_t pl_flags,
+				   const fib_route_path_t *paths)
+{
+    ip_adjacency_t *adj;
+
+    src->fes_pl = fib_path_list_create(pl_flags, paths);
+
+    /*
+     * this is a hack to get the entry's prefix into the glean adjacnecy
+     * so that it is available for fast retreival in the switch path.
+     */
+    if (!(FIB_ENTRY_FLAG_LOCAL & src->fes_entry_flags))
+    {
+        adj = adj_get(fib_path_list_get_adj(
+			  src->fes_pl,
+			  fib_entry_get_default_chain_type(entry)));
+
+	if (IP_LOOKUP_NEXT_GLEAN == adj->lookup_next_index)
+        {
+            /*
+             * the connected prefix will link to a glean on a non-p2p
+             * interface.
+             */
+            adj->sub_type.glean.receive_addr = entry->fe_prefix.fp_addr;
+        }
+    }
+}
+
+/*
+ * Source activate. 
+ * Called when the source is teh new longer best source on the entry
+ */
+static int
+fib_entry_src_interface_activate (fib_entry_src_t *src,
+				  const fib_entry_t *fib_entry)
+{
+    fib_entry_t *cover;
+
+    if (FIB_ENTRY_FLAG_LOCAL & src->fes_entry_flags)
+    {
+	/*
+	 * Track the covering attached/connected cover. This is so that
+	 * during an attached export of the cover, this local prefix is
+	 * also exported
+	 */
+	src->interface.fesi_cover =
+	    fib_table_get_less_specific(fib_entry->fe_fib_index,
+					&fib_entry->fe_prefix);
+
+	ASSERT(FIB_NODE_INDEX_INVALID != src->interface.fesi_cover);
+
+	cover = fib_entry_get(src->interface.fesi_cover);
+
+	src->interface.fesi_sibling =
+	    fib_entry_cover_track(cover, fib_entry_get_index(fib_entry));
+    }
+
+    return (!0);
+}
+
+
+/*
+ * Source Deactivate. 
+ * Called when the source is no longer best source on the entry
+ */
+static void
+fib_entry_src_interface_deactivate (fib_entry_src_t *src,
+				    const fib_entry_t *fib_entry)
+{
+    fib_entry_t *cover;
+
+    /*
+     * remove the depednecy on the covering entry
+     */
+    if (FIB_NODE_INDEX_INVALID != src->interface.fesi_cover)
+    {
+	cover = fib_entry_get(src->interface.fesi_cover);
+
+	fib_entry_cover_untrack(cover, src->interface.fesi_sibling);
+
+	src->interface.fesi_cover = FIB_NODE_INDEX_INVALID;
+    }
+}
+
+static fib_entry_src_cover_res_t
+fib_entry_src_interface_cover_change (fib_entry_src_t *src,
+				      const fib_entry_t *fib_entry)
+{
+    fib_entry_src_cover_res_t res = {
+	.install = !0,
+	.bw_reason = FIB_NODE_BW_REASON_FLAG_NONE,
+    };
+
+    if (FIB_NODE_INDEX_INVALID == src->interface.fesi_cover)
+    {
+	/*
+	 * not tracking the cover. surprised we got poked?
+	 */
+	return (res);
+    }
+
+    /*
+     * this function is called when this entry's cover has a more specific
+     * entry inserted benaeth it. That does not necessarily mean that this
+     * entry is covered by the new prefix. check that
+     */
+    if (src->rr.fesr_cover != fib_table_get_less_specific(fib_entry->fe_fib_index,
+							  &fib_entry->fe_prefix))
+    {
+	fib_entry_src_interface_deactivate(src, fib_entry);
+	fib_entry_src_interface_activate(src, fib_entry);
+    }
+    return (res);
+}
+
+static void
+fib_entry_src_interface_installed (fib_entry_src_t *src,
+				   const fib_entry_t *fib_entry)
+{
+    /*
+     * The interface source now rules! poke our cover to get exported
+     */
+    fib_entry_t *cover;
+
+    if (FIB_NODE_INDEX_INVALID != src->interface.fesi_cover)
+    {
+	cover = fib_entry_get(src->interface.fesi_cover);
+
+	fib_attached_export_covered_added(cover,
+					  fib_entry_get_index(fib_entry));
+    }
+}
+
+static u8*
+fib_entry_src_interface_format (fib_entry_src_t *src,
+				u8* s)
+{
+    return (format(s, "cover:%d", src->interface.fesi_cover));
+}
+
+const static fib_entry_src_vft_t interface_src_vft = {
+    .fesv_init = fib_entry_src_interface_init,
+    .fesv_path_swap = fib_entry_src_interface_path_swap,
+    .fesv_activate = fib_entry_src_interface_activate,
+    .fesv_deactivate = fib_entry_src_interface_deactivate,
+    .fesv_format = fib_entry_src_interface_format,
+    .fesv_installed = fib_entry_src_interface_installed,
+    .fesv_cover_change = fib_entry_src_interface_cover_change,
+    /*
+     * not concerned about updates to the cover. the cover will
+     * decide to export or not
+     */
+};
+
+void
+fib_entry_src_interface_register (void)
+{
+    fib_entry_src_register(FIB_SOURCE_INTERFACE, &interface_src_vft);    
+}
diff --git a/src/vnet/fib/fib_entry_src_lisp.c b/src/vnet/fib/fib_entry_src_lisp.c
new file mode 100644
index 00000000000..7f8b91bbab6
--- /dev/null
+++ b/src/vnet/fib/fib_entry_src_lisp.c
@@ -0,0 +1,133 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "fib_entry.h"
+#include "fib_entry_src.h"
+#include "fib_path_list.h"
+
+/**
+ * Source initialisation Function 
+ */
+static void
+fib_entry_src_lisp_init (fib_entry_src_t *src)
+{
+}
+
+/**
+ * Source deinitialisation Function 
+ */
+static void
+fib_entry_src_lisp_deinit (fib_entry_src_t *src)
+{
+}
+
+static void
+fib_entry_src_lisp_path_swap (fib_entry_src_t *src,
+			      const fib_entry_t *entry,
+			      fib_path_list_flags_t pl_flags,
+			     const fib_route_path_t *paths)
+{
+    src->fes_pl = fib_path_list_create((FIB_PATH_LIST_FLAG_SHARED | pl_flags),
+				       paths);
+}
+
+static void
+fib_entry_src_lisp_path_add (fib_entry_src_t *src,
+			    const fib_entry_t *entry,
+			    fib_path_list_flags_t pl_flags,
+			    const fib_route_path_t *paths)
+{
+    if (FIB_NODE_INDEX_INVALID == src->fes_pl)
+    {	
+	src->fes_pl =
+	    fib_path_list_create((FIB_PATH_LIST_FLAG_SHARED | pl_flags), paths);
+    }
+    else
+    {
+	src->fes_pl =
+	    fib_path_list_copy_and_path_add(src->fes_pl,
+					    (FIB_PATH_LIST_FLAG_SHARED | pl_flags),
+					    paths);
+    }
+}
+
+static void
+fib_entry_src_lisp_path_remove (fib_entry_src_t *src,
+			       fib_path_list_flags_t pl_flags,
+			       const fib_route_path_t *paths)
+{
+    if (FIB_NODE_INDEX_INVALID != src->fes_pl)
+    {
+	src->fes_pl =
+	    fib_path_list_copy_and_path_remove(src->fes_pl,
+					       (FIB_PATH_LIST_FLAG_SHARED | pl_flags),
+					       paths);
+    }
+}
+
+static void
+fib_entry_src_lisp_add (fib_entry_src_t *src,
+		       const fib_entry_t *entry,
+		       fib_entry_flag_t flags,
+		       fib_protocol_t proto,
+		       const dpo_id_t *dpo)
+{
+    if (FIB_ENTRY_FLAG_NONE != flags)
+    {
+	src->fes_pl = fib_path_list_create_special(
+	                  proto,
+			  fib_entry_src_flags_2_path_list_flags(flags),
+			  dpo);
+    }
+}
+
+static void
+fib_entry_src_lisp_remove (fib_entry_src_t *src)
+{
+    src->fes_pl = FIB_NODE_INDEX_INVALID;
+}
+
+static void
+fib_entry_src_lisp_set_data (fib_entry_src_t *src,
+                             const fib_entry_t *entry,
+                             const void *data)
+{
+    src->lisp.fesl_fib_index = *(u32*)data;
+}
+
+static const void*
+fib_entry_src_lisp_get_data (fib_entry_src_t *src,
+                             const fib_entry_t *entry)
+{
+    return (&(src->lisp.fesl_fib_index));
+}
+
+const static fib_entry_src_vft_t api_src_vft = {
+    .fesv_init = fib_entry_src_lisp_init,
+    .fesv_deinit = fib_entry_src_lisp_deinit,
+    .fesv_add = fib_entry_src_lisp_add,
+    .fesv_remove = fib_entry_src_lisp_remove,
+    .fesv_path_add = fib_entry_src_lisp_path_add,
+    .fesv_path_swap = fib_entry_src_lisp_path_swap,
+    .fesv_path_remove = fib_entry_src_lisp_path_remove,
+    .fesv_set_data = fib_entry_src_lisp_set_data,
+    .fesv_get_data = fib_entry_src_lisp_get_data,
+};
+
+void
+fib_entry_src_lisp_register (void)
+{
+    fib_entry_src_register(FIB_SOURCE_LISP, &api_src_vft);
+}
diff --git a/src/vnet/fib/fib_entry_src_mpls.c b/src/vnet/fib/fib_entry_src_mpls.c
new file mode 100644
index 00000000000..14c7310fbf3
--- /dev/null
+++ b/src/vnet/fib/fib_entry_src_mpls.c
@@ -0,0 +1,196 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vnet/mpls/mpls_types.h>
+#include <vnet/dpo/drop_dpo.h>
+
+#include <vnet/fib/fib_table.h>
+#include <vnet/fib/fib_entry.h>
+#include <vnet/fib/fib_entry_src.h>
+#include <vnet/fib/mpls_fib.h>
+
+/**
+ * Source initialisation Function 
+ */
+static void
+fib_entry_src_mpls_init (fib_entry_src_t *src)
+{
+    mpls_eos_bit_t eos;
+
+    src->fes_flags = FIB_ENTRY_SRC_FLAG_NONE;
+    src->mpls.fesm_label = MPLS_LABEL_INVALID;
+
+    FOR_EACH_MPLS_EOS_BIT(eos)
+    {
+	src->mpls.fesm_lfes[eos] = FIB_NODE_INDEX_INVALID;
+    }
+}
+
+/**
+ * Source deinitialisation Function 
+ */
+static void
+fib_entry_src_mpls_deinit (fib_entry_src_t *src)
+{
+}
+
+static void
+fib_entry_src_mpls_remove (fib_entry_src_t *src)
+{
+    src->fes_pl = FIB_NODE_INDEX_INVALID;
+    src->mpls.fesm_label = MPLS_LABEL_INVALID;
+}
+
+static void
+fib_entry_src_mpls_add (fib_entry_src_t *src,
+                        const fib_entry_t *entry,
+                        fib_entry_flag_t flags,
+                        fib_protocol_t proto,
+                        const dpo_id_t *dpo)
+{
+    src->fes_pl =
+	fib_path_list_create_special(proto,
+				     FIB_PATH_LIST_FLAG_DROP,
+				     drop_dpo_get(fib_proto_to_dpo(proto)));
+}
+
+static void
+fib_entry_src_mpls_set_data (fib_entry_src_t *src,
+                             const fib_entry_t *entry,
+                             const void *data)
+{
+    fib_protocol_t payload_proto;
+    fib_node_index_t fei;
+    mpls_label_t label;
+    mpls_eos_bit_t eos;
+
+    /*
+     * post MPLS table alloc and the possible rea-alloc of fib entrys
+     * the entry pointer will no longer be valid. so save its index
+     */
+    payload_proto = entry->fe_prefix.fp_proto;
+    fei = fib_entry_get_index(entry);
+    label = *(mpls_label_t*)data;
+
+    if (MPLS_LABEL_INVALID == label)
+    {
+        /*
+         * removing the local label
+         */
+        FOR_EACH_MPLS_EOS_BIT(eos)
+        {
+	    fib_table_entry_delete_index(src->mpls.fesm_lfes[eos],
+					 FIB_SOURCE_SPECIAL);
+        }
+        fib_table_unlock(MPLS_FIB_DEFAULT_TABLE_ID, FIB_PROTOCOL_MPLS);
+        src->mpls.fesm_label = label;
+    }
+    else
+    {
+	fib_prefix_t prefix = {
+	    .fp_proto = FIB_PROTOCOL_MPLS,
+	    .fp_label = label,
+	};
+	fib_node_index_t fib_index;
+	dpo_id_t dpo = DPO_INVALID;
+
+        /*
+         * adding a new local label. make sure the MPLS fib exists.
+         */
+        if (MPLS_LABEL_INVALID == src->mpls.fesm_label)
+        {
+            fib_index =
+		fib_table_find_or_create_and_lock(FIB_PROTOCOL_MPLS,
+						  MPLS_FIB_DEFAULT_TABLE_ID);
+        }
+	else
+	{
+	    fib_index = mpls_fib_index_from_table_id(MPLS_FIB_DEFAULT_TABLE_ID);
+
+	    /*
+	     * if this is a change in label, reomve the old one first
+	     */
+	    if (src->mpls.fesm_label != label)
+	    {
+		FOR_EACH_MPLS_EOS_BIT(eos)
+		{
+		    ASSERT(FIB_NODE_INDEX_INVALID != src->mpls.fesm_lfes[eos]);
+		    fib_table_entry_delete_index(src->mpls.fesm_lfes[eos],
+						 FIB_SOURCE_SPECIAL);
+		}
+	    }
+	}
+
+        src->mpls.fesm_label = label;
+
+	FOR_EACH_MPLS_EOS_BIT(eos)
+	{
+	    prefix.fp_eos = eos;
+	    prefix.fp_payload_proto = fib_proto_to_dpo(payload_proto);
+
+	    fib_entry_contribute_forwarding(fei,
+					    (eos ?
+					     FIB_FORW_CHAIN_TYPE_MPLS_EOS :
+					     FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS),
+					    &dpo);
+	    src->mpls.fesm_lfes[eos] = 
+		fib_table_entry_special_dpo_add(fib_index,
+						&prefix,
+						FIB_SOURCE_SPECIAL,
+						FIB_ENTRY_FLAG_EXCLUSIVE,
+						&dpo);
+	    dpo_reset(&dpo);
+	}
+    }
+}
+
+static const void *
+fib_entry_src_mpls_get_data (fib_entry_src_t *src,
+                             const fib_entry_t *entry)
+{
+    return (&(src->mpls.fesm_label));
+}
+
+static u8*
+fib_entry_src_mpls_format (fib_entry_src_t *src,
+			   u8* s)
+{
+    return (format(s, "MPLS local-label:%d", src->mpls.fesm_label));
+}
+
+const static fib_entry_src_vft_t mpls_src_vft = {
+    .fesv_init = fib_entry_src_mpls_init,
+    .fesv_deinit = fib_entry_src_mpls_deinit,
+    .fesv_add = fib_entry_src_mpls_add,
+    .fesv_remove = fib_entry_src_mpls_remove,
+    .fesv_format = fib_entry_src_mpls_format,
+    .fesv_set_data = fib_entry_src_mpls_set_data,
+    .fesv_get_data = fib_entry_src_mpls_get_data,
+    /*
+     * .fesv_fwd_update = fib_entry_src_mpls_fwd_update,
+     *  When the forwarding for the IP entry is updated, any MPLS chains
+     * it has created are also updated. Since the MPLS entry will have already
+     * installed that chain/load-balance there is no need to update the netry
+     * FIXME: later: propagate any walk to the children of the MPLS entry. for SR
+     */
+};
+
+void
+fib_entry_src_mpls_register (void)
+{
+    fib_entry_src_register(FIB_SOURCE_MPLS, &mpls_src_vft);    
+}
+
+
diff --git a/src/vnet/fib/fib_entry_src_rr.c b/src/vnet/fib/fib_entry_src_rr.c
new file mode 100644
index 00000000000..ff15c54e281
--- /dev/null
+++ b/src/vnet/fib/fib_entry_src_rr.c
@@ -0,0 +1,293 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vlib/vlib.h>
+#include <vnet/ip/format.h>
+#include <vnet/ip/lookup.h>
+#include <vnet/adj/adj.h>
+#include <vnet/dpo/drop_dpo.h>
+
+#include "fib_entry_src.h"
+#include "fib_entry_cover.h"
+#include "fib_entry.h"
+#include "fib_table.h"
+
+/*
+ * fib_entry_src_rr_resolve_via_connected
+ *
+ * Resolve via a connected cover.
+ */
+static void
+fib_entry_src_rr_resolve_via_connected (fib_entry_src_t *src,
+					const fib_entry_t *fib_entry,
+					const fib_entry_t *cover)
+{
+    const fib_route_path_t path = {
+	.frp_proto = fib_entry->fe_prefix.fp_proto,
+	.frp_addr = fib_entry->fe_prefix.fp_addr,
+	.frp_sw_if_index = fib_entry_get_resolving_interface(
+	                       fib_entry_get_index(cover)),
+	.frp_fib_index = ~0,
+	.frp_weight = 1,
+    };
+    fib_route_path_t *paths = NULL;
+    vec_add1(paths, path);
+
+    /*
+     * since the cover is connected, the address this entry corresponds
+     * to is a peer (ARP-able for) on the interface to which the cover is
+     * connected. The fact we resolve via the cover, just means this RR
+     * source is the first SRC to use said peer. The ARP source will be along
+     * shortly to over-rule this RR source.
+     */
+    src->fes_pl = fib_path_list_create(FIB_PATH_LIST_FLAG_NONE, paths);
+    src->fes_entry_flags = fib_entry_get_flags(fib_entry_get_index(cover));
+
+    vec_free(paths);
+}
+
+
+/**
+ * Source initialisation Function 
+ */
+static void
+fib_entry_src_rr_init (fib_entry_src_t *src)
+{
+    src->rr.fesr_cover = FIB_NODE_INDEX_INVALID;
+    src->rr.fesr_sibling = FIB_NODE_INDEX_INVALID;
+}
+
+/*
+ * Source activation. Called when the source is the new best source on the entry
+ */
+static int
+fib_entry_src_rr_activate (fib_entry_src_t *src,
+			   const fib_entry_t *fib_entry)
+{
+    fib_entry_t *cover;
+
+    /*
+     * find the covering prefix. become a dependent thereof.
+     * for IP there should always be a cover, though it may be the default route.
+     * For MPLS there is never a cover.
+     */
+    if (FIB_PROTOCOL_MPLS == fib_entry->fe_prefix.fp_proto)
+    {
+	src->fes_pl = fib_path_list_create_special(FIB_PROTOCOL_MPLS,
+						   FIB_PATH_LIST_FLAG_DROP,
+						   NULL);
+	fib_path_list_lock(src->fes_pl);
+	return (!0);
+    }
+
+    src->rr.fesr_cover = fib_table_get_less_specific(fib_entry->fe_fib_index,
+						     &fib_entry->fe_prefix);
+
+    ASSERT(FIB_NODE_INDEX_INVALID != src->rr.fesr_cover);
+
+    cover = fib_entry_get(src->rr.fesr_cover);
+
+    src->rr.fesr_sibling =
+	fib_entry_cover_track(cover, fib_entry_get_index(fib_entry));
+
+    /*
+     * if the ocver is attached then install an attached-host path
+     * (like an adj-fib). Otherwise inherit the forwarding from the cover
+     */
+    if (FIB_ENTRY_FLAG_ATTACHED & fib_entry_get_flags_i(cover))
+    {
+	fib_entry_src_rr_resolve_via_connected(src, fib_entry, cover);
+    }
+    else
+    {
+        /*
+         * use the path-list of the cover, unless it would form a loop.
+         * that is unless the cover is via this entry.
+         * If a loop were to form it would be a 1 level loop (i.e. X via X),
+         * and there would be 2 locks on the path-list; one since its used
+         * by the cover, and 1 from here. The first lock will go when the
+         * cover is removed, the second, and last, when the covered walk
+         * occurs during the cover's removel - this is not a place where
+         * we can handle last lock gone.
+         * In short, don't let the loop form. The usual rules of 'we must
+         * let it form so we know when it breaks' don't apply here, since
+         * the loop will break when the cover changes, and this function
+         * will be called again when that happens.
+         */
+        fib_node_index_t *entries = NULL;
+        fib_protocol_t proto;
+
+        proto = fib_entry->fe_prefix.fp_proto;
+        vec_add1(entries, fib_entry_get_index(fib_entry));
+
+        if (fib_path_list_recursive_loop_detect(cover->fe_parent,
+                                                &entries))
+        {
+            src->fes_pl = fib_path_list_create_special(
+                              proto,
+                              FIB_PATH_LIST_FLAG_DROP,
+                              drop_dpo_get(fib_proto_to_dpo(proto)));
+        }
+        else
+        {
+            src->fes_pl = cover->fe_parent;
+        }
+        vec_free(entries);
+
+    }
+    fib_path_list_lock(src->fes_pl);
+
+    /*
+     * return go for install
+     */
+    return (!0);
+}
+
+/**
+ * Source Deactivate. 
+ * Called when the source is no longer best source on the entry
+ */
+static void
+fib_entry_src_rr_deactivate (fib_entry_src_t *src,
+			     const fib_entry_t *fib_entry)
+{
+    fib_entry_t *cover;
+
+    /*
+     * remove the depednecy on the covering entry
+     */
+    if (FIB_NODE_INDEX_INVALID != src->rr.fesr_cover)
+    {
+	cover = fib_entry_get(src->rr.fesr_cover);
+	fib_entry_cover_untrack(cover, src->rr.fesr_sibling);
+	src->rr.fesr_cover = FIB_NODE_INDEX_INVALID;
+    }
+
+    fib_path_list_unlock(src->fes_pl);
+    src->fes_pl = FIB_NODE_INDEX_INVALID;
+    src->fes_entry_flags = FIB_ENTRY_FLAG_NONE;
+}
+
+static fib_entry_src_cover_res_t
+fib_entry_src_rr_cover_change (fib_entry_src_t *src,
+			       const fib_entry_t *fib_entry)
+{
+    fib_entry_src_cover_res_t res = {
+	.install = !0,
+	.bw_reason = FIB_NODE_BW_REASON_FLAG_NONE,
+    };
+
+    if (FIB_NODE_INDEX_INVALID == src->rr.fesr_cover)
+    {
+	/*
+	 * the source may be added, but it is not active
+	 * if it is not tracking the cover.
+	 */
+	return (res);
+    }
+
+    /*
+     * this function is called when this entry's cover has a more specific
+     * entry inserted benaeth it. That does not necessarily mean that this
+     * entry is covered by the new prefix. check that
+     */
+    if (src->rr.fesr_cover != fib_table_get_less_specific(fib_entry->fe_fib_index,
+							  &fib_entry->fe_prefix))
+    {
+	fib_entry_src_rr_deactivate(src, fib_entry);
+	fib_entry_src_rr_activate(src, fib_entry);
+
+	/*
+	 * dependent children need to re-resolve to the new forwarding info
+	 */
+	res.bw_reason = FIB_NODE_BW_REASON_FLAG_EVALUATE;
+    }
+    return (res);
+}
+
+/*
+ * fib_entry_src_rr_cover_update
+ *
+ * This entry's cover has updated its forwarding info. This entry
+ * will need to re-inheret.
+ */
+static fib_entry_src_cover_res_t
+fib_entry_src_rr_cover_update (fib_entry_src_t *src,
+			       const fib_entry_t *fib_entry)
+{
+    fib_entry_src_cover_res_t res = {
+	.install = !0,
+	.bw_reason = FIB_NODE_BW_REASON_FLAG_NONE,
+    };
+    fib_node_index_t old_path_list;
+    fib_entry_t *cover;
+
+    if (FIB_NODE_INDEX_INVALID == src->rr.fesr_cover)
+    {
+	/*
+	 * the source may be added, but it is not active
+	 * if it is not tracking the cover.
+	 */
+	return (res);
+    }
+
+    cover = fib_entry_get(src->rr.fesr_cover);
+    old_path_list = src->fes_pl;
+
+    /*
+     * if the ocver is attached then install an attached-host path
+     * (like an adj-fib). Otherwise inherit the forwarding from the cover
+     */
+    if (FIB_ENTRY_FLAG_ATTACHED & fib_entry_get_flags_i(cover))
+    {
+	fib_entry_src_rr_resolve_via_connected(src, fib_entry, cover);
+    }
+    else
+    {
+	src->fes_pl = cover->fe_parent;
+    }
+    fib_path_list_lock(src->fes_pl);
+    fib_path_list_unlock(old_path_list);
+
+    /*
+     * dependent children need to re-resolve to the new forwarding info
+     */
+    res.bw_reason = FIB_NODE_BW_REASON_FLAG_EVALUATE;
+
+    return (res);
+}
+
+static u8*
+fib_entry_src_rr_format (fib_entry_src_t *src,
+			 u8* s)
+{
+    return (format(s, "cover:%d", src->rr.fesr_cover));
+}
+
+const static fib_entry_src_vft_t rr_src_vft = {
+    .fesv_init = fib_entry_src_rr_init,
+    .fesv_activate = fib_entry_src_rr_activate,
+    .fesv_deactivate = fib_entry_src_rr_deactivate,
+    .fesv_cover_change = fib_entry_src_rr_cover_change,
+    .fesv_cover_update = fib_entry_src_rr_cover_update,
+    .fesv_format = fib_entry_src_rr_format,
+};
+
+void
+fib_entry_src_rr_register (void)
+{
+    fib_entry_src_register(FIB_SOURCE_RR, &rr_src_vft);    
+    fib_entry_src_register(FIB_SOURCE_URPF_EXEMPT, &rr_src_vft);    
+}
diff --git a/src/vnet/fib/fib_entry_src_special.c b/src/vnet/fib/fib_entry_src_special.c
new file mode 100644
index 00000000000..52a6134e337
--- /dev/null
+++ b/src/vnet/fib/fib_entry_src_special.c
@@ -0,0 +1,71 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "fib_entry.h"
+#include "fib_entry_src.h"
+
+/**
+ * Source initialisation Function
+ */
+static void
+fib_entry_src_special_init (fib_entry_src_t *src)
+{
+    src->fes_flags = FIB_ENTRY_SRC_FLAG_NONE;
+}
+
+/**
+ * Source deinitialisation Function
+ */
+static void
+fib_entry_src_special_deinit (fib_entry_src_t *src)
+{
+}
+
+static void
+fib_entry_src_special_remove (fib_entry_src_t *src)
+{
+    src->fes_pl = FIB_NODE_INDEX_INVALID;
+}
+
+static void
+fib_entry_src_special_add (fib_entry_src_t *src,
+			   const fib_entry_t *entry,
+			   fib_entry_flag_t flags,
+			   fib_protocol_t proto,
+			   const dpo_id_t *dpo)
+{
+    src->fes_pl =
+	fib_path_list_create_special(proto,
+				     fib_entry_src_flags_2_path_list_flags(flags),
+				     dpo);
+}
+
+const static fib_entry_src_vft_t special_src_vft = {
+    .fesv_init = fib_entry_src_special_init,
+    .fesv_deinit = fib_entry_src_special_deinit,
+    .fesv_add = fib_entry_src_special_add,
+    .fesv_remove = fib_entry_src_special_remove,
+};
+
+void
+fib_entry_src_special_register (void)
+{
+    fib_entry_src_register(FIB_SOURCE_SPECIAL, &special_src_vft);
+    fib_entry_src_register(FIB_SOURCE_MAP, &special_src_vft);
+    fib_entry_src_register(FIB_SOURCE_SIXRD, &special_src_vft);
+    fib_entry_src_register(FIB_SOURCE_CLASSIFY, &special_src_vft);
+    fib_entry_src_register(FIB_SOURCE_SR, &special_src_vft);
+    fib_entry_src_register(FIB_SOURCE_AE, &special_src_vft);
+}
diff --git a/src/vnet/fib/fib_internal.h b/src/vnet/fib/fib_internal.h
new file mode 100644
index 00000000000..2d980bcce0a
--- /dev/null
+++ b/src/vnet/fib/fib_internal.h
@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __FIB_INTERNAL_H__
+#define __FIB_INTERNAL_H__
+
+#include <vnet/ip/ip.h>
+#include <vnet/dpo/dpo.h>
+
+/**
+ * Big train switch; FIB debugs on or off
+ */
+#undef FIB_DEBUG
+
+extern void fib_prefix_from_mpls_label(mpls_label_t label,
+				       fib_prefix_t *prf);
+
+extern int fib_route_path_cmp(const fib_route_path_t *rpath1,
+			      const fib_route_path_t *rpath2);
+
+/**
+ * @brief
+ *  Add or update an entry in the FIB's forwarding table.
+ * This is called from the fib_entry code. It is not meant to be used
+ * by the client/source.
+ *
+ * @param fib_index
+ *  The index of the FIB
+ *
+ * @param prefix
+ *  The prefix for the entry to add/update
+ *
+ * @param dpo
+ *  The data-path object to use for forwarding
+ */
+extern void fib_table_fwding_dpo_update(u32 fib_index,
+					const fib_prefix_t *prefix,
+					const dpo_id_t *dpo);
+/**
+ * @brief
+ *  remove an entry in the FIB's forwarding table
+ *
+ * @param fib_index
+ *  The index of the FIB
+ *
+ * @param prefix
+ *  The prefix for the entry to add/update
+ *
+ * @param dpo
+ *  The data-path object to use for forwarding
+ */
+extern void fib_table_fwding_dpo_remove(u32 fib_index,
+					const fib_prefix_t *prefix,
+					const dpo_id_t *dpo);
+
+
+#endif
diff --git a/src/vnet/fib/fib_node.c b/src/vnet/fib/fib_node.c
new file mode 100644
index 00000000000..db3e22bb3b8
--- /dev/null
+++ b/src/vnet/fib/fib_node.c
@@ -0,0 +1,277 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vnet/fib/fib_node.h>
+#include <vnet/fib/fib_node_list.h>
+
+/*
+ * The per-type vector of virtual function tables
+ */
+static fib_node_vft_t *fn_vfts;
+
+/**
+ * The last registered new type
+ */
+static fib_node_type_t last_new_type = FIB_NODE_TYPE_LAST;
+
+/*
+ * the node type names
+ */
+static const char *fn_type_names[] = FIB_NODE_TYPES;
+
+const char*
+fib_node_type_get_name (fib_node_type_t type)
+{
+    if (type < FIB_NODE_TYPE_LAST)
+	return (fn_type_names[type]);
+    else
+    {
+	if (NULL != fn_vfts[type].fnv_format)
+	{
+	    return ("fixme");
+	}
+	else
+	{
+	    return ("unknown");
+	}
+    }
+}
+
+/**
+ * fib_node_register_type
+ *
+ * Register the function table for a given type
+ */
+void
+fib_node_register_type (fib_node_type_t type,
+			const fib_node_vft_t *vft)
+{
+    /*
+     * assert that one only registration is made per-node type
+     */
+    if (vec_len(fn_vfts) > type)
+	ASSERT(NULL == fn_vfts[type].fnv_get);
+
+    /*
+     * Assert that we are getting each of the required functions
+     */
+    ASSERT(NULL != vft->fnv_get);
+    ASSERT(NULL != vft->fnv_last_lock);
+
+    vec_validate(fn_vfts, type);
+    fn_vfts[type] = *vft;
+}
+
+fib_node_type_t
+fib_node_register_new_type (const fib_node_vft_t *vft)
+{
+    fib_node_type_t new_type;
+
+    new_type = ++last_new_type;
+
+    fib_node_register_type(new_type, vft);
+
+    return (new_type);
+}   
+
+static u8*
+fib_node_format (fib_node_ptr_t *fnp, u8*s)
+{
+    return (format(s, "{%s:%d}", fn_type_names[fnp->fnp_type], fnp->fnp_index)); 
+}
+
+u32
+fib_node_child_add (fib_node_type_t parent_type,
+                    fib_node_index_t parent_index,
+                    fib_node_type_t type,
+		    fib_node_index_t index)
+{
+    fib_node_t *parent;
+
+    parent = fn_vfts[parent_type].fnv_get(parent_index);
+
+    /*
+     * return the index of the sibling in the child list
+     */
+    fib_node_lock(parent);
+
+    if (FIB_NODE_INDEX_INVALID == parent->fn_children)
+    {
+        parent->fn_children = fib_node_list_create();
+    }   
+
+    return (fib_node_list_push_front(parent->fn_children,
+                                     0, type,
+                                     index));
+}
+
+void
+fib_node_child_remove (fib_node_type_t parent_type,
+                       fib_node_index_t parent_index,
+                       fib_node_index_t sibling_index)
+{
+    fib_node_t *parent;
+
+    parent = fn_vfts[parent_type].fnv_get(parent_index);
+
+    fib_node_list_remove(parent->fn_children, sibling_index);
+
+    if (0 == fib_node_list_get_size(parent->fn_children))
+    {
+        fib_node_list_destroy(&parent->fn_children);
+    }
+
+    fib_node_unlock(parent);
+}
+
+u32
+fib_node_get_n_children (fib_node_type_t parent_type,
+                         fib_node_index_t parent_index)
+{
+    fib_node_t *parent;
+
+    parent = fn_vfts[parent_type].fnv_get(parent_index);
+
+    return (fib_node_list_get_size(parent->fn_children));
+}
+
+
+fib_node_back_walk_rc_t
+fib_node_back_walk_one (fib_node_ptr_t *ptr,
+                        fib_node_back_walk_ctx_t *ctx)
+{
+    fib_node_t *node;
+
+    node = fn_vfts[ptr->fnp_type].fnv_get(ptr->fnp_index);
+
+    return (fn_vfts[ptr->fnp_type].fnv_back_walk(node, ctx));
+}
+
+static int
+fib_node_ptr_format_one_child (fib_node_ptr_t *ptr,
+			       void *arg)
+{
+    u8 **s = (u8**) arg;
+
+    *s = fib_node_format(ptr, *s);
+
+    return (1);
+}
+
+u8*
+fib_node_children_format (fib_node_list_t list,
+			  u8 *s)
+{
+    fib_node_list_walk(list, fib_node_ptr_format_one_child, (void*)&s);
+
+    return (s);
+}
+
+void
+fib_node_init (fib_node_t *node,
+	       fib_node_type_t type)
+{
+#if CLIB_DEBUG > 0
+    /**
+     * The node's type. make sure we are dynamic/down casting correctly
+     */
+    node->fn_type = type;
+#endif
+    node->fn_locks = 0;
+    node->fn_vft = &fn_vfts[type];
+    node->fn_children = FIB_NODE_INDEX_INVALID;
+}
+
+void
+fib_node_deinit (fib_node_t *node)
+{
+    fib_node_list_destroy(&node->fn_children);
+}
+
+void
+fib_node_lock (fib_node_t *node)
+{
+    node->fn_locks++;
+}
+
+void
+fib_node_unlock (fib_node_t *node)
+{
+    node->fn_locks--;
+
+    if (0 == node->fn_locks)
+    {
+	node->fn_vft->fnv_last_lock(node);
+    }
+}
+
+void
+fib_show_memory_usage (const char *name,
+		       u32 in_use_elts,
+		       u32 allocd_elts,
+		       size_t size_elt)
+{
+    vlib_cli_output (vlib_get_main(), "%=30s %=5d %=8d/%=9d   %d/%d ",
+		     name, size_elt,
+		     in_use_elts, allocd_elts,
+		     in_use_elts*size_elt, allocd_elts*size_elt);
+}
+
+static clib_error_t *
+fib_memory_show (vlib_main_t * vm,
+		 unformat_input_t * input,
+		 vlib_cli_command_t * cmd)
+{
+    fib_node_vft_t *vft;
+
+    vlib_cli_output (vm, "FIB memory");
+    vlib_cli_output (vm, "%=30s %=5s %=8s/%=9s   totals",
+		     "Name","Size", "in-use", "allocated");
+
+    vec_foreach(vft, fn_vfts)
+    {
+	if (NULL != vft->fnv_mem_show)
+	    vft->fnv_mem_show();
+    }
+
+    fib_node_list_memory_show();
+
+    return (NULL);
+}
+
+/* *INDENT-OFF* */
+/*?
+ * The '<em>sh fib memory </em>' command displays the memory usage for each
+ * FIB object type.
+ *
+ * @cliexpar
+ * @cliexstart{show fib memory}
+ * FIB memory
+ *             Name               Size  in-use /allocated   totals
+ *             Entry              120     11   /    11      1320/1320
+ *         Entry Source            32     11   /    11      352/352
+ *     Entry Path-Extensions       44      0   /    0       0/0
+ *           Path-list             40     11   /    11      440/440
+ *             Path                88     11   /    11      968/968
+ *      Node-list elements         20     11   /    11      220/220
+ *        Node-list heads          8      13   /    13      104/104
+ * @cliexend
+?*/
+VLIB_CLI_COMMAND (show_fib_memory, static) = {
+    .path = "show fib memory",
+    .function = fib_memory_show,
+    .short_help = "show fib memory",
+};
+/* *INDENT-ON* */
diff --git a/src/vnet/fib/fib_node.h b/src/vnet/fib/fib_node.h
new file mode 100644
index 00000000000..3ad8ee95b64
--- /dev/null
+++ b/src/vnet/fib/fib_node.h
@@ -0,0 +1,371 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __FIB_NODE_H__
+#define __FIB_NODE_H__
+
+#include <vnet/fib/fib_types.h>
+
+/**
+ * The types of nodes in a FIB graph
+ */
+typedef enum fib_node_type_t_ {
+    /**
+     * Marker. New types after this one.
+     */
+    FIB_NODE_TYPE_FIRST = 0,
+    /**
+     * See the respective fib_*.h files for descriptions of these objects.
+     */
+    FIB_NODE_TYPE_WALK,
+    FIB_NODE_TYPE_ENTRY,
+    FIB_NODE_TYPE_PATH_LIST,
+    FIB_NODE_TYPE_PATH,
+    FIB_NODE_TYPE_ADJ,
+    FIB_NODE_TYPE_MPLS_ENTRY,
+    FIB_NODE_TYPE_MPLS_TUNNEL,
+    FIB_NODE_TYPE_LISP_GPE_FWD_ENTRY,
+    FIB_NODE_TYPE_LISP_ADJ,
+    FIB_NODE_TYPE_GRE_TUNNEL,
+    FIB_NODE_TYPE_VXLAN_TUNNEL,
+    /**
+     * Marker. New types before this one. leave the test last.
+     */
+    FIB_NODE_TYPE_TEST,
+    FIB_NODE_TYPE_LAST = FIB_NODE_TYPE_TEST,
+} fib_node_type_t;
+
+#define FIB_NODE_TYPE_MAX (FIB_NODE_TYPE_LAST + 1)
+
+#define FIB_NODE_TYPES {                          \
+    [FIB_NODE_TYPE_ENTRY]     = "entry",          \
+    [FIB_NODE_TYPE_WALK]      = "walk",           \
+    [FIB_NODE_TYPE_PATH_LIST] = "path-list",      \
+    [FIB_NODE_TYPE_PATH]      = "path",           \
+    [FIB_NODE_TYPE_MPLS_ENTRY] = "mpls-entry",    \
+    [FIB_NODE_TYPE_MPLS_TUNNEL] = "mpls-tunnel",  \
+    [FIB_NODE_TYPE_ADJ] = "adj",                  \
+    [FIB_NODE_TYPE_LISP_GPE_FWD_ENTRY] = "lisp-gpe-fwd-entry", \
+    [FIB_NODE_TYPE_LISP_ADJ] = "lisp-adj", \
+    [FIB_NODE_TYPE_GRE_TUNNEL] = "gre-tunnel", \
+    [FIB_NODE_TYPE_VXLAN_TUNNEL] = "vxlan-tunnel", \
+}
+
+/**
+ * Reasons for backwalking the FIB object graph
+ */
+typedef enum fib_node_back_walk_reason_t_ {
+    /**
+     * Marker. Add new ones after.
+     */
+    FIB_NODE_BW_REASON_FIRST = 0,
+    /**
+     * Walk to re-resolve the child.
+     * Used when the parent is no longer a valid resolution target
+     */
+    FIB_NODE_BW_REASON_RESOLVE = FIB_NODE_BW_REASON_FIRST,
+    /**
+     * Walk to re-evaluate the forwarding contributed by the parent.
+     * Used when a parent's forwarding changes and the child needs to
+     * incorporate this change in its forwarding.
+     */
+    FIB_NODE_BW_REASON_EVALUATE,
+    /**
+     * A resolving interface has come up
+     */
+    FIB_NODE_BW_REASON_INTERFACE_UP,
+    /**
+     * A resolving interface has gone down
+     */
+    FIB_NODE_BW_REASON_INTERFACE_DOWN,
+    /**
+     * A resolving interface has been deleted.
+     */
+    FIB_NODE_BW_REASON_INTERFACE_DELETE,
+    /**
+     * Walk to re-collapse the multipath adjs when the rewrite of
+     * a unipath adjacency changes
+     */
+    FIB_NODE_BW_REASON_ADJ_UPDATE,
+    /**
+     * Walk to update children to inform them the adjacency is now down.
+     */
+    FIB_NODE_BW_REASON_ADJ_DOWN,
+    /**
+     * Marker. Add new before and update
+     */
+    FIB_NODE_BW_REASON_LAST = FIB_NODE_BW_REASON_ADJ_DOWN,
+} fib_node_back_walk_reason_t;
+
+#define FIB_NODE_BW_REASONS {			            \
+    [FIB_NODE_BW_REASON_RESOLVE] = "resolve",	            \
+    [FIB_NODE_BW_REASON_EVALUATE] = "evaluate",             \
+    [FIB_NODE_BW_REASON_INTERFACE_UP] = "if-up",            \
+    [FIB_NODE_BW_REASON_INTERFACE_DOWN] = "if-down",        \
+    [FIB_NODE_BW_REASON_INTERFACE_DELETE] = "if-delete",    \
+    [FIB_NODE_BW_REASON_ADJ_UPDATE] = "adj-update",         \
+    [FIB_NODE_BW_REASON_ADJ_DOWN] = "adj-down",             \
+}
+
+#define FOR_EACH_FIB_NODE_BW_REASON(_item) \
+    for (_item = FIB_NODE_BW_REASON_FIRST; \
+	 _item <= FIB_NODE_BW_REASON_LAST; \
+	 _item++)
+
+/**
+ * Flags enum constructed from the reaons
+ */
+typedef enum fib_node_bw_reason_flag_t_ {
+    FIB_NODE_BW_REASON_FLAG_NONE = 0,
+    FIB_NODE_BW_REASON_FLAG_RESOLVE = (1 << FIB_NODE_BW_REASON_RESOLVE),
+    FIB_NODE_BW_REASON_FLAG_EVALUATE = (1 << FIB_NODE_BW_REASON_EVALUATE),
+    FIB_NODE_BW_REASON_FLAG_INTERFACE_UP = (1 << FIB_NODE_BW_REASON_INTERFACE_UP),
+    FIB_NODE_BW_REASON_FLAG_INTERFACE_DOWN = (1 << FIB_NODE_BW_REASON_INTERFACE_DOWN),
+    FIB_NODE_BW_REASON_FLAG_INTERFACE_DELETE = (1 << FIB_NODE_BW_REASON_INTERFACE_DELETE),
+    FIB_NODE_BW_REASON_FLAG_ADJ_UPDATE = (1 << FIB_NODE_BW_REASON_ADJ_UPDATE),
+    FIB_NODE_BW_REASON_FLAG_ADJ_DOWN = (1 << FIB_NODE_BW_REASON_ADJ_DOWN),
+} __attribute__ ((packed)) fib_node_bw_reason_flag_t;
+
+STATIC_ASSERT(sizeof(fib_node_bw_reason_flag_t) < 2,
+	      "BW Reason enum < 2 byte. Consequences for cover_upd_res_t");
+
+/**
+ * Flags on the walk
+ */
+typedef enum fib_node_bw_flags_t_
+{
+    /**
+     * Force the walk to be synchronous
+     */
+    FIB_NODE_BW_FLAG_FORCE_SYNC = (1 << 0),
+} fib_node_bw_flags_t;
+
+/**
+ * Forward eclarations
+ */
+struct fib_node_t_;
+
+/**
+ * A representation of one pointer to another node.
+ * To fully qualify a node, one must know its type and its index so it
+ * can be retrieved from the appropriate pool. Direct pointers to nodes
+ * are forbidden, since all nodes are allocated from pools, which are vectors,
+ * and thus subject to realloc at any time.
+ */
+typedef struct fib_node_ptr_t_ {
+    /**
+     * node type
+     */
+    fib_node_type_t fnp_type;
+    /**
+     * node's index
+     */
+    fib_node_index_t fnp_index;
+} fib_node_ptr_t;
+
+/**
+ * @brief A list of FIB nodes.
+ */
+typedef u32 fib_node_list_t;
+
+/**
+ * Context passed between object during a back walk.
+ */
+typedef struct fib_node_back_walk_ctx_t_ {
+    /**
+     * The reason/trigger for the backwalk
+     */
+    fib_node_bw_reason_flag_t fnbw_reason;
+
+    /**
+     * additional flags for the walk
+     */
+    fib_node_bw_flags_t fnbw_flags;
+
+    /**
+     * the number of levels the walk has already traversed.
+     * this value is maintained by the walk infra, tp limit the depth of
+     * a walk so it does not run indefinately the presence of a loop/cycle
+     * in the graph.
+     */
+    u32 fnbw_depth;
+} fib_node_back_walk_ctx_t;
+
+/**
+ * We consider a depth of 32 to be sufficient to cover all sane
+ * network topologies. Anything more is then an indication that
+ * there is a loop/cycle in the FIB graph.
+ * Note that all object types contribute to 1 to the depth.
+ */
+#define FIB_NODE_GRAPH_MAX_DEPTH ((u32)32)
+
+/**
+ * A callback function for walking a node dependency list
+ */
+typedef int (*fib_node_ptr_walk_t)(fib_node_ptr_t *depend,
+				   void *ctx);
+
+/**
+ * A list of dependent nodes.
+ * This is currently implemented as a hash_table of fib_node_ptr_t
+ */
+typedef fib_node_ptr_t fib_node_ptr_list_t;
+
+/**
+ * Return code from a back walk function
+ */
+typedef enum fib_node_back_walk_rc_t_ {
+    FIB_NODE_BACK_WALK_MERGE,
+    FIB_NODE_BACK_WALK_CONTINUE,
+} fib_node_back_walk_rc_t;
+
+/**
+ * Function definition to backwalk a FIB node
+ */
+typedef fib_node_back_walk_rc_t (*fib_node_back_walk_t)(
+    struct fib_node_t_ *node,
+    fib_node_back_walk_ctx_t *ctx);
+
+/**
+ * Function definition to get a FIB node from its index
+ */
+typedef struct fib_node_t_* (*fib_node_get_t)(fib_node_index_t index);
+
+/**
+ * Function definition to inform the FIB node that its last lock has gone.
+ */
+typedef void (*fib_node_last_lock_gone_t)(struct fib_node_t_ *node);
+
+/**
+ * Function definition to display the amount of memory used by a type.
+ * Implementations should call fib_show_memory_usage()
+ */
+typedef void (*fib_node_memory_show_t)(void);
+
+/**
+ * A FIB graph nodes virtual function table
+ */
+typedef struct fib_node_vft_t_ {
+    fib_node_get_t fnv_get;
+    fib_node_last_lock_gone_t fnv_last_lock;
+    fib_node_back_walk_t fnv_back_walk;
+    format_function_t *fnv_format;
+    fib_node_memory_show_t fnv_mem_show;
+} fib_node_vft_t;
+
+/**
+ * An node in the FIB graph
+ *
+ * Objects in the FIB form a graph. 
+ */
+typedef struct fib_node_t_ {
+#if CLIB_DEBUG > 0
+    /**
+     * The node's type. make sure we are dynamic/down casting correctly
+     */
+    fib_node_type_t fn_type;
+#endif
+    /**
+     * The node's VFT.
+     * we could store the type here instead, and lookup the VFT using that. But
+     * I like this better,
+     */
+    const fib_node_vft_t *fn_vft;
+
+    /**
+     * Vector of nodes that depend upon/use/share this node
+     */
+    fib_node_list_t fn_children;
+
+    /**
+     * Number of dependents on this node. This number includes the number
+     * of children
+     */
+    u32 fn_locks;
+} fib_node_t;
+
+/**
+ * @brief
+ *  Register the function table for a given type
+ *
+ * @param ft
+ *  FIB node type
+ *
+ * @param vft
+ * virtual function table
+ */
+extern void fib_node_register_type (fib_node_type_t ft,
+				    const fib_node_vft_t *vft);
+
+/**
+ * @brief
+ *  Create a new FIB node type and Register the function table for it.
+ *
+ * @param vft
+ * virtual function table
+ *
+ * @return new FIB node type
+ */
+extern fib_node_type_t fib_node_register_new_type (const fib_node_vft_t *vft);
+
+/**
+ * @brief Show the memory usage for a type
+ *
+ * This should be invoked by the type in response to the infra calling
+ * its registered memory show function
+ *
+ * @param name the name of the type
+ * @param in_use_elts The number of elements in use
+ * @param allocd_elts The number of allocated pool elemenets
+ * @param size_elt The size of one element
+ */
+extern void fib_show_memory_usage(const char *name,
+				  u32 in_use_elts,
+				  u32 allocd_elts,
+				  size_t size_elt);
+
+extern void fib_node_init(fib_node_t *node,
+			  fib_node_type_t ft);
+extern void fib_node_deinit(fib_node_t *node);
+
+extern void fib_node_lock(fib_node_t *node);
+extern void fib_node_unlock(fib_node_t *node);
+
+extern u32 fib_node_get_n_children(fib_node_type_t parent_type,
+                                   fib_node_index_t parent_index);
+extern u32 fib_node_child_add(fib_node_type_t parent_type,
+			      fib_node_index_t parent_index,
+			      fib_node_type_t child_type,
+			      fib_node_index_t child_index);
+extern void fib_node_child_remove(fib_node_type_t parent_type,
+                                  fib_node_index_t parent_index,
+                                  fib_node_index_t sibling_index);
+
+extern fib_node_back_walk_rc_t fib_node_back_walk_one(fib_node_ptr_t *ptr,
+                                                      fib_node_back_walk_ctx_t *ctx);
+
+extern u8* fib_node_children_format(fib_node_list_t list,
+				    u8 *s);
+
+extern const char* fib_node_type_get_name(fib_node_type_t type);
+
+static inline int
+fib_node_index_is_valid (fib_node_index_t ni)
+{
+    return (FIB_NODE_INDEX_INVALID != ni);
+}
+
+#endif
+
diff --git a/src/vnet/fib/fib_node_list.c b/src/vnet/fib/fib_node_list.c
new file mode 100644
index 00000000000..ceb951b466b
--- /dev/null
+++ b/src/vnet/fib/fib_node_list.c
@@ -0,0 +1,390 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/**
+ * @brief a hetrogeneous w.r.t. FIB node type, of FIB nodes.
+ * Since we cannot use C pointers, due to memeory reallocs, the next/prev
+ * are described as key:{type,index}.
+ */
+
+#include <vnet/fib/fib_node_list.h>
+
+/**
+ * @brief An element in the list
+ */
+typedef struct fib_node_list_elt_t_
+{
+    /**
+     * The index of the list this element is in
+     */
+    fib_node_list_t fnle_list;
+
+    /**
+     * The owner of this element
+     */
+    fib_node_ptr_t fnle_owner;
+
+    /**
+     * The next element in the list
+     */
+    u32 fnle_next;
+
+    /**
+     * The previous element in the list
+     */
+    u32 fnle_prev;
+} fib_node_list_elt_t;
+
+/**
+ * @brief A list of FIB nodes
+ */
+typedef struct fib_node_list_head_t_
+{
+    /**
+     * The head element
+     */
+    u32 fnlh_head;
+
+    /**
+     * Number of elements in the list
+     */
+    u32 fnlh_n_elts;
+} fib_node_list_head_t;
+
+/**
+ * Pools of list elements and heads
+ */
+static fib_node_list_elt_t *fib_node_list_elt_pool;
+static fib_node_list_head_t *fib_node_list_head_pool;
+
+static index_t
+fib_node_list_elt_get_index (fib_node_list_elt_t *elt)
+{
+    return (elt - fib_node_list_elt_pool);
+}
+
+static fib_node_list_elt_t *
+fib_node_list_elt_get (index_t fi)
+{
+    return (pool_elt_at_index(fib_node_list_elt_pool, fi));
+}
+
+static index_t
+fib_node_list_head_get_index (fib_node_list_head_t *head)
+{
+    return (head - fib_node_list_head_pool);
+}
+static fib_node_list_head_t *
+fib_node_list_head_get (fib_node_list_t fi)
+{
+    return (pool_elt_at_index(fib_node_list_head_pool, fi));
+}
+
+static fib_node_list_elt_t *
+fib_node_list_elt_create (fib_node_list_head_t *head,
+                          int id,
+                          fib_node_type_t type,
+                          fib_node_index_t index)
+{
+    fib_node_list_elt_t *elt;
+
+    pool_get(fib_node_list_elt_pool, elt);
+
+    elt->fnle_list = fib_node_list_head_get_index(head);
+    elt->fnle_owner.fnp_type  = type;
+    elt->fnle_owner.fnp_index = index;
+
+    elt->fnle_next = FIB_NODE_INDEX_INVALID;
+    elt->fnle_prev = FIB_NODE_INDEX_INVALID;
+
+    return (elt);
+}
+
+static void
+fib_node_list_head_init (fib_node_list_head_t *head)
+{
+    head->fnlh_n_elts = 0;
+    head->fnlh_head = FIB_NODE_INDEX_INVALID;
+}
+
+/**
+ * @brief Create a new node list.
+ */
+fib_node_list_t
+fib_node_list_create (void)
+{
+    fib_node_list_head_t *head;
+
+    pool_get(fib_node_list_head_pool, head);
+
+    fib_node_list_head_init(head);
+
+    return (fib_node_list_head_get_index(head));
+}
+
+void
+fib_node_list_destroy (fib_node_list_t *list)
+{
+    fib_node_list_head_t *head;
+
+    if (FIB_NODE_INDEX_INVALID == *list)
+        return;
+
+    head = fib_node_list_head_get(*list);
+    ASSERT(0 == head->fnlh_n_elts);
+
+    pool_put(fib_node_list_head_pool, head);
+    *list = FIB_NODE_INDEX_INVALID;
+}
+
+
+/**
+ * @brief Insert an element at the from of the list.
+ */
+u32
+fib_node_list_push_front (fib_node_list_t list,
+                          int owner_id,
+                          fib_node_type_t type,
+                          fib_node_index_t index)
+{
+    fib_node_list_elt_t *elt, *next;
+    fib_node_list_head_t *head;
+
+    head = fib_node_list_head_get(list);
+    elt = fib_node_list_elt_create(head, owner_id, type, index);
+
+    elt->fnle_prev = FIB_NODE_INDEX_INVALID;
+    elt->fnle_next = head->fnlh_head;
+
+    if (FIB_NODE_INDEX_INVALID != head->fnlh_head)
+    {
+        next = fib_node_list_elt_get(head->fnlh_head);
+        next->fnle_prev = fib_node_list_elt_get_index(elt);
+    }
+    head->fnlh_head = fib_node_list_elt_get_index(elt);
+
+    head->fnlh_n_elts++;
+
+    return (fib_node_list_elt_get_index(elt));
+}
+
+u32
+fib_node_list_push_back (fib_node_list_t list,
+                        int owner_id,
+                        fib_node_type_t type,
+                        fib_node_index_t index)
+{
+    ASSERT(0);
+    return (FIB_NODE_INDEX_INVALID);
+}
+
+static void
+fib_node_list_extract (fib_node_list_head_t *head,
+                       fib_node_list_elt_t *elt)
+{
+    fib_node_list_elt_t *next, *prev;
+
+    if (FIB_NODE_INDEX_INVALID != elt->fnle_next)
+    {
+        next = fib_node_list_elt_get(elt->fnle_next);
+        next->fnle_prev = elt->fnle_prev;
+    }
+
+    if (FIB_NODE_INDEX_INVALID != elt->fnle_prev)
+    {
+        prev = fib_node_list_elt_get(elt->fnle_prev);
+        prev->fnle_next = elt->fnle_next;
+    }
+    else
+    {
+        ASSERT (fib_node_list_elt_get_index(elt) == head->fnlh_head);
+        head->fnlh_head = elt->fnle_next;
+    }
+}
+
+static void
+fib_node_list_insert_after (fib_node_list_head_t *head,
+                            fib_node_list_elt_t *prev,
+                            fib_node_list_elt_t *elt)
+{
+    fib_node_list_elt_t *next;
+
+    elt->fnle_next = prev->fnle_next;
+    if (FIB_NODE_INDEX_INVALID != prev->fnle_next)
+    {
+        next = fib_node_list_elt_get(prev->fnle_next);
+        next->fnle_prev = fib_node_list_elt_get_index(elt);
+    }
+    prev->fnle_next = fib_node_list_elt_get_index(elt);
+    elt->fnle_prev = fib_node_list_elt_get_index(prev);
+}
+
+void
+fib_node_list_remove (fib_node_list_t list,
+                      u32 sibling)
+{
+    fib_node_list_head_t *head;
+    fib_node_list_elt_t *elt;
+
+    head = fib_node_list_head_get(list);
+    elt  = fib_node_list_elt_get(sibling);
+
+    fib_node_list_extract(head, elt);
+
+    head->fnlh_n_elts--;
+    pool_put(fib_node_list_elt_pool, elt);
+}
+
+void
+fib_node_list_elt_remove (u32 sibling)
+{
+    fib_node_list_elt_t *elt;
+
+    elt = fib_node_list_elt_get(sibling);
+
+    fib_node_list_remove(elt->fnle_list, sibling);
+}
+
+/**
+ * @brief Advance the sibling one step (toward the tail) in the list.
+ * return 0 if at the end of the list, 1 otherwise.
+ */
+int
+fib_node_list_advance (u32 sibling)
+{
+    fib_node_list_elt_t *elt, *next;
+    fib_node_list_head_t *head;
+
+    elt = fib_node_list_elt_get(sibling);
+    head = fib_node_list_head_get(elt->fnle_list);
+
+    if (FIB_NODE_INDEX_INVALID != elt->fnle_next)
+    {
+        /*
+         * not at the end of the list
+         */
+        next = fib_node_list_elt_get(elt->fnle_next);
+
+        fib_node_list_extract(head, elt);
+        fib_node_list_insert_after(head, next, elt);
+
+        return (1);
+    }
+    else
+    {
+        return (0);
+    }
+}
+
+int
+fib_node_list_elt_get_next (u32 sibling,
+                            fib_node_ptr_t *ptr)
+{
+    fib_node_list_elt_t *elt, *next;
+
+    elt = fib_node_list_elt_get(sibling);
+
+    if (FIB_NODE_INDEX_INVALID != elt->fnle_next)
+    {
+        next = fib_node_list_elt_get(elt->fnle_next);
+
+        *ptr = next->fnle_owner;
+        return (1);
+    }
+    else
+    {
+        ptr->fnp_index = FIB_NODE_INDEX_INVALID;
+        return (0);
+    }
+}
+
+u32
+fib_node_list_get_size (fib_node_list_t list)
+{
+    fib_node_list_head_t *head;
+
+    if (FIB_NODE_INDEX_INVALID == list)
+    {
+        return (0);
+    }
+
+    head = fib_node_list_head_get(list);
+
+    return (head->fnlh_n_elts);
+}
+
+int
+fib_node_list_get_front (fib_node_list_t list,
+                         fib_node_ptr_t *ptr)
+{
+    fib_node_list_head_t *head;
+    fib_node_list_elt_t *elt;
+
+
+    if (0 == fib_node_list_get_size(list))
+    {
+        ptr->fnp_index = FIB_NODE_INDEX_INVALID;
+        return (0);
+    }
+
+    head = fib_node_list_head_get(list);
+    elt = fib_node_list_elt_get(head->fnlh_head);
+    
+    *ptr = elt->fnle_owner;
+
+    return (1);
+}
+
+/**
+ * @brief Walk the list of node. This must be safe w.r.t. the removal
+ * of nodes during the walk.
+ */
+void
+fib_node_list_walk (fib_node_list_t list,
+                    fib_node_list_walk_cb_t fn,
+                    void *args)
+{
+    fib_node_list_elt_t *elt;
+    fib_node_list_head_t *head;
+    u32 sibling;
+
+    if (FIB_NODE_INDEX_INVALID == list)
+    {
+        return;
+    }
+
+    head = fib_node_list_head_get(list);
+    sibling = head->fnlh_head;
+
+    while (FIB_NODE_INDEX_INVALID != sibling)
+    {
+        elt = fib_node_list_elt_get(sibling);
+        sibling = elt->fnle_next;
+
+        fn(&elt->fnle_owner, args);
+    }
+}
+
+void
+fib_node_list_memory_show (void)
+{
+    fib_show_memory_usage("Node-list elements",
+			  pool_elts(fib_node_list_elt_pool),
+			  pool_len(fib_node_list_elt_pool),
+			  sizeof(fib_node_list_elt_t));
+    fib_show_memory_usage("Node-list heads",
+			  pool_elts(fib_node_list_head_pool),
+			  pool_len(fib_node_list_head_pool),
+			  sizeof(fib_node_list_head_t));
+}
diff --git a/src/vnet/fib/fib_node_list.h b/src/vnet/fib/fib_node_list.h
new file mode 100644
index 00000000000..9567b9669e8
--- /dev/null
+++ b/src/vnet/fib/fib_node_list.h
@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/**
+ * @brief a hetrogeneous w.r.t. FIB node type, list of FIB nodes.
+ * Since we cannot use C pointers, due to memeory reallocs, the next/prev
+ * are described as an index to an element. Each element contains a pointer
+ * (key:{type, index}) to a FIB node.
+ */
+
+#ifndef __FIB_NODE_LIST_H__
+#define __FIB_NODE_LIST_H__
+
+#include <vnet/fib/fib_node.h>
+
+extern fib_node_list_t fib_node_list_create(void);
+extern void fib_node_list_destroy(fib_node_list_t *list);
+
+extern u32 fib_node_list_push_front(fib_node_list_t head,
+                                    int owner_id,
+                                    fib_node_type_t type,
+                                    fib_node_index_t index);
+extern u32 fib_node_list_push_back(fib_node_list_t head,
+                                   int owner_id,
+                                   fib_node_type_t type,
+                                   fib_node_index_t index);
+extern void fib_node_list_remove(fib_node_list_t head,
+                                 u32 sibling);
+extern void fib_node_list_elt_remove(u32 sibling);
+
+extern int fib_node_list_advance(u32 sibling);
+
+extern int fib_node_list_get_front(fib_node_list_t head,
+                                   fib_node_ptr_t *ptr);
+
+extern int fib_node_list_elt_get_next(u32 elt,
+                                      fib_node_ptr_t *ptr);
+
+extern u32 fib_node_list_get_size(fib_node_list_t head);
+
+/**
+ * @brief Callback function invoked during a list walk
+ */
+typedef int (*fib_node_list_walk_cb_t)(fib_node_ptr_t *owner,
+                                       void *args);
+
+extern void fib_node_list_walk(fib_node_list_t head,
+                               fib_node_list_walk_cb_t fn,
+                               void *args);
+
+extern void fib_node_list_memory_show(void);
+
+#endif
diff --git a/src/vnet/fib/fib_path.c b/src/vnet/fib/fib_path.c
new file mode 100644
index 00000000000..809e3e166da
--- /dev/null
+++ b/src/vnet/fib/fib_path.c
@@ -0,0 +1,2001 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vlib/vlib.h>
+#include <vnet/vnet.h>
+#include <vnet/ip/format.h>
+#include <vnet/ip/ip.h>
+#include <vnet/dpo/drop_dpo.h>
+#include <vnet/dpo/receive_dpo.h>
+#include <vnet/dpo/load_balance_map.h>
+#include <vnet/dpo/lookup_dpo.h>
+
+#include <vnet/adj/adj.h>
+
+#include <vnet/fib/fib_path.h>
+#include <vnet/fib/fib_node.h>
+#include <vnet/fib/fib_table.h>
+#include <vnet/fib/fib_entry.h>
+#include <vnet/fib/fib_path_list.h>
+#include <vnet/fib/fib_internal.h>
+#include <vnet/fib/fib_urpf_list.h>
+
+/**
+ * Enurmeration of path types
+ */
+typedef enum fib_path_type_t_ {
+    /**
+     * Marker. Add new types after this one.
+     */
+    FIB_PATH_TYPE_FIRST = 0,
+    /**
+     * Attached-nexthop. An interface and a nexthop are known.
+     */
+    FIB_PATH_TYPE_ATTACHED_NEXT_HOP = FIB_PATH_TYPE_FIRST,
+    /**
+     * attached. Only the interface is known.
+     */
+    FIB_PATH_TYPE_ATTACHED,
+    /**
+     * recursive. Only the next-hop is known.
+     */
+    FIB_PATH_TYPE_RECURSIVE,
+    /**
+     * special. nothing is known. so we drop.
+     */
+    FIB_PATH_TYPE_SPECIAL,
+    /**
+     * exclusive. user provided adj.
+     */
+    FIB_PATH_TYPE_EXCLUSIVE,
+    /**
+     * deag. Link to a lookup adj in the next table
+     */
+    FIB_PATH_TYPE_DEAG,
+    /**
+     * receive. it's for-us.
+     */
+    FIB_PATH_TYPE_RECEIVE,
+    /**
+     * Marker. Add new types before this one, then update it.
+     */
+    FIB_PATH_TYPE_LAST = FIB_PATH_TYPE_RECEIVE,
+} __attribute__ ((packed)) fib_path_type_t;
+
+/**
+ * The maximum number of path_types
+ */
+#define FIB_PATH_TYPE_MAX (FIB_PATH_TYPE_LAST + 1)
+
+#define FIB_PATH_TYPES {					\
+    [FIB_PATH_TYPE_ATTACHED_NEXT_HOP] = "attached-nexthop",	\
+    [FIB_PATH_TYPE_ATTACHED]          = "attached",		\
+    [FIB_PATH_TYPE_RECURSIVE]         = "recursive",	        \
+    [FIB_PATH_TYPE_SPECIAL]           = "special",	        \
+    [FIB_PATH_TYPE_EXCLUSIVE]         = "exclusive",	        \
+    [FIB_PATH_TYPE_DEAG]              = "deag",	                \
+    [FIB_PATH_TYPE_RECEIVE]           = "receive",	        \
+}
+
+#define FOR_EACH_FIB_PATH_TYPE(_item) \
+    for (_item = FIB_PATH_TYPE_FIRST; _item <= FIB_PATH_TYPE_LAST; _item++)
+
+/**
+ * Enurmeration of path operational (i.e. derived) attributes
+ */
+typedef enum fib_path_oper_attribute_t_ {
+    /**
+     * Marker. Add new types after this one.
+     */
+    FIB_PATH_OPER_ATTRIBUTE_FIRST = 0,
+    /**
+     * The path forms part of a recursive loop.
+     */
+    FIB_PATH_OPER_ATTRIBUTE_RECURSIVE_LOOP = FIB_PATH_OPER_ATTRIBUTE_FIRST,
+    /**
+     * The path is resolved
+     */
+    FIB_PATH_OPER_ATTRIBUTE_RESOLVED,
+    /**
+     * The path has become a permanent drop.
+     */
+    FIB_PATH_OPER_ATTRIBUTE_DROP,
+    /**
+     * Marker. Add new types before this one, then update it.
+     */
+    FIB_PATH_OPER_ATTRIBUTE_LAST = FIB_PATH_OPER_ATTRIBUTE_DROP,
+} __attribute__ ((packed)) fib_path_oper_attribute_t;
+
+/**
+ * The maximum number of path operational attributes
+ */
+#define FIB_PATH_OPER_ATTRIBUTE_MAX (FIB_PATH_OPER_ATTRIBUTE_LAST + 1)
+
+#define FIB_PATH_OPER_ATTRIBUTES {					\
+    [FIB_PATH_OPER_ATTRIBUTE_RECURSIVE_LOOP] = "recursive-loop",	\
+    [FIB_PATH_OPER_ATTRIBUTE_RESOLVED]       = "resolved",	        \
+    [FIB_PATH_OPER_ATTRIBUTE_DROP]           = "drop",		        \
+}
+
+#define FOR_EACH_FIB_PATH_OPER_ATTRIBUTE(_item) \
+    for (_item = FIB_PATH_OPER_ATTRIBUTE_FIRST; \
+	 _item <= FIB_PATH_OPER_ATTRIBUTE_LAST; \
+	 _item++)
+
+/**
+ * Path flags from the attributes
+ */
+typedef enum fib_path_oper_flags_t_ {
+    FIB_PATH_OPER_FLAG_NONE = 0,
+    FIB_PATH_OPER_FLAG_RECURSIVE_LOOP = (1 << FIB_PATH_OPER_ATTRIBUTE_RECURSIVE_LOOP),
+    FIB_PATH_OPER_FLAG_DROP = (1 << FIB_PATH_OPER_ATTRIBUTE_DROP),
+    FIB_PATH_OPER_FLAG_RESOLVED = (1 << FIB_PATH_OPER_ATTRIBUTE_RESOLVED),
+} __attribute__ ((packed)) fib_path_oper_flags_t;
+
+/**
+ * A FIB path
+ */
+typedef struct fib_path_t_ {
+    /**
+     * A path is a node in the FIB graph.
+     */
+    fib_node_t fp_node;
+
+    /**
+     * The index of the path-list to which this path belongs
+     */
+    u32 fp_pl_index;
+
+    /**
+     * This marks the start of the memory area used to hash
+     * the path
+     */
+    STRUCT_MARK(path_hash_start);
+
+    /**
+     * Configuration Flags
+     */
+    fib_path_cfg_flags_t fp_cfg_flags;
+
+    /**
+     * The type of the path. This is the selector for the union
+     */
+    fib_path_type_t fp_type;
+
+    /**
+     * The protocol of the next-hop, i.e. the address family of the
+     * next-hop's address. We can't derive this from the address itself
+     * since the address can be all zeros
+     */
+    fib_protocol_t fp_nh_proto;
+
+    /**
+     * UCMP [unnormalised] weigt
+     */
+    u32 fp_weight;
+
+    /**
+     * per-type union of the data required to resolve the path
+     */
+    union {
+	struct {
+	    /**
+	     * The next-hop
+	     */
+	    ip46_address_t fp_nh;
+	    /**
+	     * The interface
+	     */
+	    u32 fp_interface;
+	} attached_next_hop;
+	struct {
+	    /**
+	     * The interface
+	     */
+	    u32 fp_interface;
+	} attached;
+	struct {
+	    union
+	    {
+		/**
+		 * The next-hop
+		 */
+		ip46_address_t fp_ip;
+		/**
+		 * The local label to resolve through.
+		 */
+		mpls_label_t fp_local_label;
+	    } fp_nh;
+	    /**
+	     * The FIB table index in which to find the next-hop.
+	     * This needs to be fixed. We should lookup the adjacencies in
+	     * a separate table of adjacencies, rather than from the FIB.
+	     * Two reasons I can think of:
+	     *   - consider:
+	     *       int ip addr Gig0 10.0.0.1/24
+	     *       ip route 10.0.0.2/32 via Gig1 192.168.1.2
+	     *       ip route 1.1.1.1/32 via Gig0 10.0.0.2
+	     *     this is perfectly valid.
+	     *     Packets addressed to 10.0.0.2 should be sent via Gig1.
+	     *     Packets address to 1.1.1.1 should be sent via Gig0.
+	     *    when we perform the adj resolution from the FIB for the path
+	     *    "via Gig0 10.0.0.2" the lookup will result in the route via Gig1
+	     *    and so we will pick up the adj via Gig1 - which was not what the
+	     *    operator wanted.
+	     *  - we can only return link-type IPv4 and so not the link-type MPLS.
+	     *    more on this in a later commit.
+	     *
+	     * The table ID should only belong to a recursive path and indicate
+	     * which FIB should be used to resolve the next-hop.
+	     */
+	    fib_node_index_t fp_tbl_id;
+	} recursive;
+	struct {
+	    /**
+	     * The FIB index in which to perfom the next lookup
+	     */
+	    fib_node_index_t fp_tbl_id;
+	} deag;
+	struct {
+	} special;
+	struct {
+	    /**
+	     * The user provided 'exclusive' DPO
+	     */
+	    dpo_id_t fp_ex_dpo;
+	} exclusive;
+	struct {
+	    /**
+	     * The interface on which the local address is configured
+	     */
+	    u32 fp_interface;
+	    /**
+	     * The next-hop
+	     */
+	    ip46_address_t fp_addr;
+	} receive;
+    };
+    STRUCT_MARK(path_hash_end);
+
+    /**
+     * Memebers in this last section represent information that is
+     * dervied during resolution. It should not be copied to new paths
+     * nor compared.
+     */
+
+    /**
+     * Operational Flags
+     */
+    fib_path_oper_flags_t fp_oper_flags;
+
+    /**
+     * the resolving via fib. not part of the union, since it it not part
+     * of the path's hash.
+     */
+    fib_node_index_t fp_via_fib;
+
+    /**
+     * The Data-path objects through which this path resolves for IP.
+     */
+    dpo_id_t fp_dpo;
+
+    /**
+     * the index of this path in the parent's child list.
+     */
+    u32 fp_sibling;
+} fib_path_t;
+
+/*
+ * Array of strings/names for the path types and attributes
+ */
+static const char *fib_path_type_names[] = FIB_PATH_TYPES;
+static const char *fib_path_oper_attribute_names[] = FIB_PATH_OPER_ATTRIBUTES;
+static const char *fib_path_cfg_attribute_names[]  = FIB_PATH_CFG_ATTRIBUTES;
+
+/*
+ * The memory pool from which we allocate all the paths
+ */
+static fib_path_t *fib_path_pool;
+
+/*
+ * Debug macro
+ */
+#ifdef FIB_DEBUG
+#define FIB_PATH_DBG(_p, _fmt, _args...)			\
+{       		          				\
+    u8 *_tmp = NULL;						\
+    _tmp = fib_path_format(fib_path_get_index(_p), _tmp);	\
+    clib_warning("path:[%d:%s]:" _fmt,				\
+		 fib_path_get_index(_p), _tmp,			\
+		 ##_args);					\
+    vec_free(_tmp);						\
+}
+#else
+#define FIB_PATH_DBG(_p, _fmt, _args...)
+#endif
+
+static fib_path_t *
+fib_path_get (fib_node_index_t index)
+{
+    return (pool_elt_at_index(fib_path_pool, index));
+}
+
+static fib_node_index_t 
+fib_path_get_index (fib_path_t *path)
+{
+    return (path - fib_path_pool);
+}
+
+static fib_node_t *
+fib_path_get_node (fib_node_index_t index)
+{
+    return ((fib_node_t*)fib_path_get(index));
+}
+
+static fib_path_t*
+fib_path_from_fib_node (fib_node_t *node)
+{
+#if CLIB_DEBUG > 0
+    ASSERT(FIB_NODE_TYPE_PATH == node->fn_type);
+#endif
+    return ((fib_path_t*)node);
+}
+
+u8 *
+format_fib_path (u8 * s, va_list * args)
+{
+    fib_path_t *path = va_arg (*args, fib_path_t *);
+    vnet_main_t * vnm = vnet_get_main();
+    fib_path_oper_attribute_t oattr;
+    fib_path_cfg_attribute_t cattr;
+
+    s = format (s, "      index:%d ", fib_path_get_index(path));
+    s = format (s, "pl-index:%d ", path->fp_pl_index);
+    s = format (s, "%U ", format_fib_protocol, path->fp_nh_proto);
+    s = format (s, "weight=%d ", path->fp_weight);
+    s = format (s, "%s: ", fib_path_type_names[path->fp_type]);
+    if (FIB_PATH_OPER_FLAG_NONE != path->fp_oper_flags) {
+	s = format(s, " oper-flags:");
+	FOR_EACH_FIB_PATH_OPER_ATTRIBUTE(oattr) {
+	    if ((1<<oattr) & path->fp_oper_flags) {
+		s = format (s, "%s,", fib_path_oper_attribute_names[oattr]);
+	    }
+	}
+    }
+    if (FIB_PATH_CFG_FLAG_NONE != path->fp_cfg_flags) {
+	s = format(s, " cfg-flags:");
+	FOR_EACH_FIB_PATH_CFG_ATTRIBUTE(cattr) {
+	    if ((1<<cattr) & path->fp_cfg_flags) {
+		s = format (s, "%s,", fib_path_cfg_attribute_names[cattr]);
+	    }
+	}
+    }
+    s = format(s, "\n       ");
+
+    switch (path->fp_type)
+    {
+    case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
+	s = format (s, "%U", format_ip46_address,
+		    &path->attached_next_hop.fp_nh,
+		    IP46_TYPE_ANY);
+	if (path->fp_oper_flags & FIB_PATH_OPER_FLAG_DROP)
+	{
+	    s = format (s, " if_index:%d", path->attached_next_hop.fp_interface);
+	}
+	else
+	{
+	    s = format (s, " %U",
+			format_vnet_sw_interface_name,
+			vnm,
+			vnet_get_sw_interface(
+			    vnm,
+			    path->attached_next_hop.fp_interface));
+	    if (vnet_sw_interface_is_p2p(vnet_get_main(),
+					 path->attached_next_hop.fp_interface))
+	    {
+		s = format (s, " (p2p)");
+	    }
+	}
+	if (!dpo_id_is_valid(&path->fp_dpo))
+	{
+	    s = format(s, "\n          unresolved");
+	}
+	else
+	{
+	    s = format(s, "\n          %U",
+		       format_dpo_id,
+		       &path->fp_dpo, 13);
+	}
+	break;
+    case FIB_PATH_TYPE_ATTACHED:
+	if (path->fp_oper_flags & FIB_PATH_OPER_FLAG_DROP)
+	{
+	    s = format (s, " if_index:%d", path->attached_next_hop.fp_interface);
+	}
+	else
+	{
+	    s = format (s, " %U",
+			format_vnet_sw_interface_name,
+			vnm,
+			vnet_get_sw_interface(
+			    vnm,
+			    path->attached.fp_interface));
+	}
+	break;
+    case FIB_PATH_TYPE_RECURSIVE:
+	if (FIB_PROTOCOL_MPLS == path->fp_nh_proto)
+	{
+	    s = format (s, "via %U",
+			format_mpls_unicast_label,
+			path->recursive.fp_nh.fp_local_label);
+	}
+	else
+	{
+	    s = format (s, "via %U",
+			format_ip46_address,
+			&path->recursive.fp_nh.fp_ip,
+			IP46_TYPE_ANY);
+	}
+	s = format (s, " in fib:%d",
+		    path->recursive.fp_tbl_id,
+		    path->fp_via_fib); 
+	s = format (s, " via-fib:%d", path->fp_via_fib); 
+	s = format (s, " via-dpo:[%U:%d]",
+		    format_dpo_type, path->fp_dpo.dpoi_type, 
+		    path->fp_dpo.dpoi_index);
+
+	break;
+    case FIB_PATH_TYPE_RECEIVE:
+    case FIB_PATH_TYPE_SPECIAL:
+    case FIB_PATH_TYPE_DEAG:
+    case FIB_PATH_TYPE_EXCLUSIVE:
+	if (dpo_id_is_valid(&path->fp_dpo))
+	{
+	    s = format(s, "%U", format_dpo_id,
+		       &path->fp_dpo, 2);
+	}
+	break;
+    }
+    return (s);
+}
+
+u8 *
+fib_path_format (fib_node_index_t pi, u8 *s)
+{
+    fib_path_t *path;
+
+    path = fib_path_get(pi);
+    ASSERT(NULL != path);
+
+    return (format (s, "%U", format_fib_path, path));
+}
+
+u8 *
+fib_path_adj_format (fib_node_index_t pi,
+		     u32 indent,
+		     u8 *s)
+{
+    fib_path_t *path;
+
+    path = fib_path_get(pi);
+    ASSERT(NULL != path);
+
+    if (!dpo_id_is_valid(&path->fp_dpo))
+    {
+	s = format(s, " unresolved");
+    }
+    else
+    {
+	s = format(s, "%U", format_dpo_id,
+		   &path->fp_dpo, 2);
+    }
+
+    return (s);
+}
+
+/*
+ * fib_path_last_lock_gone
+ *
+ * We don't share paths, we share path lists, so the [un]lock functions
+ * are no-ops
+ */
+static void
+fib_path_last_lock_gone (fib_node_t *node)
+{
+    ASSERT(0);
+}
+
+static const adj_index_t
+fib_path_attached_next_hop_get_adj (fib_path_t *path,
+				    vnet_link_t link)
+{
+    if (vnet_sw_interface_is_p2p(vnet_get_main(),
+				 path->attached_next_hop.fp_interface))
+    {
+	/*
+	 * if the interface is p2p then the adj for the specific
+	 * neighbour on that link will never exist. on p2p links
+	 * the subnet address (the attached route) links to the
+	 * auto-adj (see below), we want that adj here too.
+	 */
+	return (adj_nbr_add_or_lock(path->fp_nh_proto,
+				    link,
+				    &zero_addr,
+				    path->attached_next_hop.fp_interface));
+    }
+    else
+    {
+	return (adj_nbr_add_or_lock(path->fp_nh_proto,
+				    link,
+				    &path->attached_next_hop.fp_nh,
+				    path->attached_next_hop.fp_interface));
+    }
+}
+
+static void
+fib_path_attached_next_hop_set (fib_path_t *path)
+{
+    /*
+     * resolve directly via the adjacnecy discribed by the
+     * interface and next-hop
+     */
+    if (!vnet_sw_interface_is_admin_up(vnet_get_main(),
+				      path->attached_next_hop.fp_interface))
+    {
+	path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
+    }
+
+    dpo_set(&path->fp_dpo,
+	    DPO_ADJACENCY,
+	    fib_proto_to_dpo(path->fp_nh_proto),
+	    fib_path_attached_next_hop_get_adj(
+		 path,
+		 fib_proto_to_link(path->fp_nh_proto)));
+
+    /*
+     * become a child of the adjacency so we receive updates
+     * when its rewrite changes
+     */
+    path->fp_sibling = adj_child_add(path->fp_dpo.dpoi_index,
+				     FIB_NODE_TYPE_PATH,
+				     fib_path_get_index(path));
+}
+
+/*
+ * create of update the paths recursive adj
+ */
+static void
+fib_path_recursive_adj_update (fib_path_t *path,
+			       fib_forward_chain_type_t fct,
+			       dpo_id_t *dpo)
+{
+    dpo_id_t via_dpo = DPO_INVALID;
+
+    /*
+     * get the DPO to resolve through from the via-entry
+     */
+    fib_entry_contribute_forwarding(path->fp_via_fib,
+				    fct,
+				    &via_dpo);
+
+
+    /*
+     * hope for the best - clear if restrictions apply.
+     */
+    path->fp_oper_flags |= FIB_PATH_OPER_FLAG_RESOLVED;
+
+    /*
+     * Validate any recursion constraints and over-ride the via
+     * adj if not met
+     */
+    if (path->fp_oper_flags & FIB_PATH_OPER_FLAG_RECURSIVE_LOOP)
+    {
+	path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
+	dpo_copy(&via_dpo, drop_dpo_get(fib_proto_to_dpo(path->fp_nh_proto)));
+    }
+    else if (path->fp_cfg_flags & FIB_PATH_CFG_FLAG_RESOLVE_HOST)
+    {
+	/*
+	 * the via FIB must be a host route.
+	 * note the via FIB just added will always be a host route
+	 * since it is an RR source added host route. So what we need to
+	 * check is whether the route has other sources. If it does then
+	 * some other source has added it as a host route. If it doesn't
+	 * then it was added only here and inherits forwarding from a cover.
+	 * the cover is not a host route.
+	 * The RR source is the lowest priority source, so we check if it
+	 * is the best. if it is there are no other sources.
+	 */
+	if (fib_entry_get_best_source(path->fp_via_fib) >= FIB_SOURCE_RR)
+	{
+	    path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
+            dpo_copy(&via_dpo, drop_dpo_get(fib_proto_to_dpo(path->fp_nh_proto)));
+
+            /*
+             * PIC edge trigger. let the load-balance maps know
+             */
+            load_balance_map_path_state_change(fib_path_get_index(path));
+	}
+    }
+    else if (path->fp_cfg_flags & FIB_PATH_CFG_FLAG_RESOLVE_ATTACHED)
+    {
+	/*
+	 * RR source entries inherit the flags from the cover, so
+	 * we can check the via directly
+	 */
+	if (!(FIB_ENTRY_FLAG_ATTACHED & fib_entry_get_flags(path->fp_via_fib)))
+	{
+	    path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
+            dpo_copy(&via_dpo, drop_dpo_get(fib_proto_to_dpo(path->fp_nh_proto)));
+
+            /*
+             * PIC edge trigger. let the load-balance maps know
+             */
+            load_balance_map_path_state_change(fib_path_get_index(path));
+	}
+    }
+
+    /*
+     * update the path's contributed DPO
+     */
+    dpo_copy(dpo, &via_dpo);
+
+    FIB_PATH_DBG(path, "recursive update: %U",
+		 fib_get_lookup_main(path->fp_nh_proto),
+		 &path->fp_dpo, 2);
+
+    dpo_reset(&via_dpo);
+}
+
+/*
+ * fib_path_is_permanent_drop
+ *
+ * Return !0 if the path is configured to permanently drop,
+ * despite other attributes.
+ */
+static int
+fib_path_is_permanent_drop (fib_path_t *path)
+{
+    return ((path->fp_cfg_flags & FIB_PATH_CFG_FLAG_DROP) ||
+	    (path->fp_oper_flags & FIB_PATH_OPER_FLAG_DROP));
+}
+
+/*
+ * fib_path_unresolve
+ *
+ * Remove our dependency on the resolution target
+ */
+static void
+fib_path_unresolve (fib_path_t *path)
+{
+    /*
+     * the forced drop path does not need unresolving
+     */
+    if (fib_path_is_permanent_drop(path))
+    {
+	return;
+    }
+
+    switch (path->fp_type)
+    {
+    case FIB_PATH_TYPE_RECURSIVE:
+	if (FIB_NODE_INDEX_INVALID != path->fp_via_fib)
+	{
+	    fib_prefix_t pfx;
+
+	    fib_entry_get_prefix(path->fp_via_fib, &pfx);
+	    fib_entry_child_remove(path->fp_via_fib,
+				   path->fp_sibling);
+	    fib_table_entry_special_remove(path->recursive.fp_tbl_id,
+					   &pfx,
+					   FIB_SOURCE_RR);
+	    path->fp_via_fib = FIB_NODE_INDEX_INVALID;
+	}
+	break;
+    case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
+    case FIB_PATH_TYPE_ATTACHED:
+	adj_child_remove(path->fp_dpo.dpoi_index,
+			 path->fp_sibling);
+        adj_unlock(path->fp_dpo.dpoi_index);
+        break;
+    case FIB_PATH_TYPE_EXCLUSIVE:
+	dpo_reset(&path->exclusive.fp_ex_dpo);
+        break;
+    case FIB_PATH_TYPE_SPECIAL:
+    case FIB_PATH_TYPE_RECEIVE:
+    case FIB_PATH_TYPE_DEAG:
+        /*
+         * these hold only the path's DPO, which is reset below.
+         */
+	break;
+    }
+
+    /*
+     * release the adj we were holding and pick up the
+     * drop just in case.
+     */
+    dpo_reset(&path->fp_dpo);
+    path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
+
+    return;
+}
+
+static fib_forward_chain_type_t
+fib_path_proto_to_chain_type (fib_protocol_t proto)
+{
+    switch (proto)
+    {
+    case FIB_PROTOCOL_IP4:
+	return (FIB_FORW_CHAIN_TYPE_UNICAST_IP4);
+    case FIB_PROTOCOL_IP6:
+	return (FIB_FORW_CHAIN_TYPE_UNICAST_IP6);
+    case FIB_PROTOCOL_MPLS:
+	return (FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS);
+    }
+    return (FIB_FORW_CHAIN_TYPE_UNICAST_IP4);
+}
+
+/*
+ * fib_path_back_walk_notify
+ *
+ * A back walk has reach this path.
+ */
+static fib_node_back_walk_rc_t
+fib_path_back_walk_notify (fib_node_t *node,
+			   fib_node_back_walk_ctx_t *ctx)
+{
+    fib_path_t *path;
+
+    path = fib_path_from_fib_node(node);
+
+    switch (path->fp_type)
+    {
+    case FIB_PATH_TYPE_RECURSIVE:
+	if (FIB_NODE_BW_REASON_FLAG_EVALUATE & ctx->fnbw_reason)
+	{
+	    /*
+	     * modify the recursive adjacency to use the new forwarding
+	     * of the via-fib.
+	     * this update is visible to packets in flight in the DP.
+	     */
+	    fib_path_recursive_adj_update(
+		path,
+		fib_path_proto_to_chain_type(path->fp_nh_proto),
+		&path->fp_dpo);
+	}
+	if ((FIB_NODE_BW_REASON_FLAG_ADJ_UPDATE & ctx->fnbw_reason) ||
+            (FIB_NODE_BW_REASON_FLAG_ADJ_DOWN   & ctx->fnbw_reason))
+	{
+	    /*
+	     * ADJ updates (complete<->incomplete) do not need to propagate to
+	     * recursive entries.
+	     * The only reason its needed as far back as here, is that the adj
+	     * and the incomplete adj are a different DPO type, so the LBs need
+	     * to re-stack.
+	     * If this walk was quashed in the fib_entry, then any non-fib_path
+	     * children (like tunnels that collapse out the LB when they stack)
+	     * would not see the update.
+	     */
+	    return (FIB_NODE_BACK_WALK_CONTINUE);
+	}
+	break;
+    case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
+	/*
+FIXME comment
+	 * ADJ_UPDATE backwalk pass silently through here and up to
+	 * the path-list when the multipath adj collapse occurs.
+	 * The reason we do this is that the assumtption is that VPP
+	 * runs in an environment where the Control-Plane is remote
+	 * and hence reacts slowly to link up down. In order to remove
+	 * this down link from the ECMP set quickly, we back-walk.
+	 * VPP also has dedicated CPUs, so we are not stealing resources
+	 * from the CP to do so.
+	 */
+	if (FIB_NODE_BW_REASON_FLAG_INTERFACE_UP & ctx->fnbw_reason)
+	{
+            if (path->fp_oper_flags & FIB_PATH_OPER_FLAG_RESOLVED)
+            {
+                /*
+                 * alreday resolved. no need to walk back again
+                 */
+                return (FIB_NODE_BACK_WALK_CONTINUE);
+            }
+	    path->fp_oper_flags |= FIB_PATH_OPER_FLAG_RESOLVED;
+	}
+	if (FIB_NODE_BW_REASON_FLAG_INTERFACE_DOWN & ctx->fnbw_reason)
+	{
+            if (!(path->fp_oper_flags & FIB_PATH_OPER_FLAG_RESOLVED))
+            {
+                /*
+                 * alreday unresolved. no need to walk back again
+                 */
+                return (FIB_NODE_BACK_WALK_CONTINUE);
+            }
+	    path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
+	}
+	if (FIB_NODE_BW_REASON_FLAG_INTERFACE_DELETE & ctx->fnbw_reason)
+	{
+	    /*
+	     * The interface this path resolves through has been deleted.
+	     * This will leave the path in a permanent drop state. The route
+	     * needs to be removed and readded (and hence the path-list deleted)
+	     * before it can forward again.
+	     */
+	    fib_path_unresolve(path);
+	    path->fp_oper_flags |= FIB_PATH_OPER_FLAG_DROP;
+	}
+        if (FIB_NODE_BW_REASON_FLAG_ADJ_UPDATE & ctx->fnbw_reason)
+	{
+            /*
+             * restack the DPO to pick up the correct DPO sub-type
+             */
+            uword if_is_up;
+            adj_index_t ai;
+
+            if_is_up = vnet_sw_interface_is_admin_up(
+                           vnet_get_main(),
+                           path->attached_next_hop.fp_interface);
+
+            if (if_is_up)
+            {
+                path->fp_oper_flags |= FIB_PATH_OPER_FLAG_RESOLVED;
+            }
+
+            ai = fib_path_attached_next_hop_get_adj(
+                     path,
+                     fib_proto_to_link(path->fp_nh_proto));
+
+            dpo_set(&path->fp_dpo, DPO_ADJACENCY,
+                    fib_proto_to_dpo(path->fp_nh_proto),
+                    ai);
+            adj_unlock(ai);
+
+            if (!if_is_up)
+            {
+                /*
+                 * If the interface is not up there is no reason to walk
+                 * back to children. if we did they would only evalute
+                 * that this path is unresolved and hence it would
+                 * not contribute the adjacency - so it would be wasted
+                 * CPU time.
+                 */
+                return (FIB_NODE_BACK_WALK_CONTINUE);
+            }
+        }
+        if (FIB_NODE_BW_REASON_FLAG_ADJ_DOWN & ctx->fnbw_reason)
+	{
+            if (!(path->fp_oper_flags & FIB_PATH_OPER_FLAG_RESOLVED))
+            {
+                /*
+                 * alreday unresolved. no need to walk back again
+                 */
+                return (FIB_NODE_BACK_WALK_CONTINUE);
+            }
+            /*
+             * the adj has gone down. the path is no longer resolved.
+             */
+	    path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
+        }
+	break;
+    case FIB_PATH_TYPE_ATTACHED:
+	/*
+	 * FIXME; this could schedule a lower priority walk, since attached
+	 * routes are not usually in ECMP configurations so the backwalk to
+	 * the FIB entry does not need to be high priority
+	 */
+	if (FIB_NODE_BW_REASON_FLAG_INTERFACE_UP & ctx->fnbw_reason)
+	{
+	    path->fp_oper_flags |= FIB_PATH_OPER_FLAG_RESOLVED;
+	}
+	if (FIB_NODE_BW_REASON_FLAG_INTERFACE_DOWN & ctx->fnbw_reason)
+	{
+	    path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
+	}
+	if (FIB_NODE_BW_REASON_FLAG_INTERFACE_DELETE & ctx->fnbw_reason)
+	{
+	    fib_path_unresolve(path);
+	    path->fp_oper_flags |= FIB_PATH_OPER_FLAG_DROP;
+	}
+	break;
+    case FIB_PATH_TYPE_DEAG:
+	/*
+	 * FIXME When VRF delete is allowed this will need a poke.
+	 */
+    case FIB_PATH_TYPE_SPECIAL:
+    case FIB_PATH_TYPE_RECEIVE:
+    case FIB_PATH_TYPE_EXCLUSIVE:
+	/*
+	 * these path types have no parents. so to be
+	 * walked from one is unexpected.
+	 */
+	ASSERT(0);
+	break;
+    }
+
+    /*
+     * propagate the backwalk further to the path-list
+     */
+    fib_path_list_back_walk(path->fp_pl_index, ctx);
+
+    return (FIB_NODE_BACK_WALK_CONTINUE);
+}
+
+static void
+fib_path_memory_show (void)
+{
+    fib_show_memory_usage("Path",
+			  pool_elts(fib_path_pool),
+			  pool_len(fib_path_pool),
+			  sizeof(fib_path_t));
+}
+
+/*
+ * The FIB path's graph node virtual function table
+ */
+static const fib_node_vft_t fib_path_vft = {
+    .fnv_get = fib_path_get_node,
+    .fnv_last_lock = fib_path_last_lock_gone,
+    .fnv_back_walk = fib_path_back_walk_notify,
+    .fnv_mem_show = fib_path_memory_show,
+};
+
+static fib_path_cfg_flags_t
+fib_path_route_flags_to_cfg_flags (const fib_route_path_t *rpath)
+{
+    fib_path_cfg_flags_t cfg_flags = FIB_PATH_CFG_FLAG_NONE;
+
+    if (rpath->frp_flags & FIB_ROUTE_PATH_RESOLVE_VIA_HOST)
+	cfg_flags |= FIB_PATH_CFG_FLAG_RESOLVE_HOST;
+    if (rpath->frp_flags & FIB_ROUTE_PATH_RESOLVE_VIA_ATTACHED)
+	cfg_flags |= FIB_PATH_CFG_FLAG_RESOLVE_ATTACHED;
+
+    return (cfg_flags);
+}
+
+/*
+ * fib_path_create
+ *
+ * Create and initialise a new path object.
+ * return the index of the path.
+ */
+fib_node_index_t
+fib_path_create (fib_node_index_t pl_index,
+		 fib_protocol_t nh_proto,
+		 fib_path_cfg_flags_t flags,
+		 const fib_route_path_t *rpath)
+{
+    fib_path_t *path;
+
+    pool_get(fib_path_pool, path);
+    memset(path, 0, sizeof(*path));
+
+    fib_node_init(&path->fp_node,
+		  FIB_NODE_TYPE_PATH);
+
+    dpo_reset(&path->fp_dpo);
+    path->fp_pl_index = pl_index;
+    path->fp_nh_proto = nh_proto;
+    path->fp_via_fib = FIB_NODE_INDEX_INVALID;
+    path->fp_weight = rpath->frp_weight;
+    if (0 == path->fp_weight)
+    {
+        /*
+         * a weight of 0 is a meaningless value. We could either reject it, and thus force
+         * clients to always use 1, or we can accept it and fixup approrpiately.
+         */
+        path->fp_weight = 1;
+    }
+    path->fp_cfg_flags = flags;
+    path->fp_cfg_flags |= fib_path_route_flags_to_cfg_flags(rpath);
+
+    /*
+     * deduce the path's tpye from the parementers and save what is needed.
+     */
+    if (~0 != rpath->frp_sw_if_index)
+    {
+	if (flags & FIB_PATH_CFG_FLAG_LOCAL)
+	{
+	    path->fp_type = FIB_PATH_TYPE_RECEIVE;
+	    path->receive.fp_interface = rpath->frp_sw_if_index;
+            path->receive.fp_addr = rpath->frp_addr;
+	}
+	else
+	{
+	    if (ip46_address_is_zero(&rpath->frp_addr))
+	    {
+		path->fp_type = FIB_PATH_TYPE_ATTACHED;
+		path->attached.fp_interface = rpath->frp_sw_if_index;
+	    }
+	    else
+	    {
+		path->fp_type = FIB_PATH_TYPE_ATTACHED_NEXT_HOP;
+		path->attached_next_hop.fp_interface = rpath->frp_sw_if_index;
+		path->attached_next_hop.fp_nh = rpath->frp_addr;
+	    }
+	}
+    }
+    else
+    {
+	if (ip46_address_is_zero(&rpath->frp_addr))
+	{
+	    if (~0 == rpath->frp_fib_index)
+	    {
+		path->fp_type = FIB_PATH_TYPE_SPECIAL;
+	    }
+	    else
+	    {
+		path->fp_type = FIB_PATH_TYPE_DEAG;
+		path->deag.fp_tbl_id = rpath->frp_fib_index;
+	    }		
+	}
+	else
+	{
+	    path->fp_type = FIB_PATH_TYPE_RECURSIVE;
+	    if (FIB_PROTOCOL_MPLS == path->fp_nh_proto)
+	    {
+		path->recursive.fp_nh.fp_local_label = rpath->frp_local_label;
+	    }
+	    else
+	    {
+		path->recursive.fp_nh.fp_ip = rpath->frp_addr;
+	    }
+	    path->recursive.fp_tbl_id = rpath->frp_fib_index;
+	}
+    }
+
+    FIB_PATH_DBG(path, "create");
+
+    return (fib_path_get_index(path));
+}
+
+/*
+ * fib_path_create_special
+ *
+ * Create and initialise a new path object.
+ * return the index of the path.
+ */
+fib_node_index_t
+fib_path_create_special (fib_node_index_t pl_index,
+			 fib_protocol_t nh_proto,
+			 fib_path_cfg_flags_t flags,
+			 const dpo_id_t *dpo)
+{
+    fib_path_t *path;
+
+    pool_get(fib_path_pool, path);
+    memset(path, 0, sizeof(*path));
+
+    fib_node_init(&path->fp_node,
+		  FIB_NODE_TYPE_PATH);
+    dpo_reset(&path->fp_dpo);
+
+    path->fp_pl_index = pl_index;
+    path->fp_weight = 1;
+    path->fp_nh_proto = nh_proto;
+    path->fp_via_fib = FIB_NODE_INDEX_INVALID;
+    path->fp_cfg_flags = flags;
+
+    if (FIB_PATH_CFG_FLAG_DROP & flags)
+    {
+	path->fp_type = FIB_PATH_TYPE_SPECIAL;
+    }
+    else if (FIB_PATH_CFG_FLAG_LOCAL & flags)
+    {
+	path->fp_type = FIB_PATH_TYPE_RECEIVE;
+	path->attached.fp_interface = FIB_NODE_INDEX_INVALID;
+    }
+    else
+    {
+	path->fp_type = FIB_PATH_TYPE_EXCLUSIVE;
+	ASSERT(NULL != dpo);
+	dpo_copy(&path->exclusive.fp_ex_dpo, dpo);
+    }
+
+    return (fib_path_get_index(path));
+}
+
+/*
+ * fib_path_copy
+ *
+ * Copy a path. return index of new path.
+ */
+fib_node_index_t
+fib_path_copy (fib_node_index_t path_index,
+	       fib_node_index_t path_list_index)
+{
+    fib_path_t *path, *orig_path;
+
+    pool_get(fib_path_pool, path);
+
+    orig_path = fib_path_get(path_index);
+    ASSERT(NULL != orig_path);
+
+    memcpy(path, orig_path, sizeof(*path));
+
+    FIB_PATH_DBG(path, "create-copy:%d", path_index);
+
+    /*
+     * reset the dynamic section
+     */
+    fib_node_init(&path->fp_node, FIB_NODE_TYPE_PATH);
+    path->fp_oper_flags     = FIB_PATH_OPER_FLAG_NONE;
+    path->fp_pl_index  = path_list_index;
+    path->fp_via_fib   = FIB_NODE_INDEX_INVALID;
+    memset(&path->fp_dpo, 0, sizeof(path->fp_dpo));
+    dpo_reset(&path->fp_dpo);
+
+    return (fib_path_get_index(path));
+}
+
+/*
+ * fib_path_destroy
+ *
+ * destroy a path that is no longer required
+ */
+void
+fib_path_destroy (fib_node_index_t path_index)
+{
+    fib_path_t *path;
+
+    path = fib_path_get(path_index);
+
+    ASSERT(NULL != path);
+    FIB_PATH_DBG(path, "destroy");
+
+    fib_path_unresolve(path);
+
+    fib_node_deinit(&path->fp_node);
+    pool_put(fib_path_pool, path);
+}
+
+/*
+ * fib_path_destroy
+ *
+ * destroy a path that is no longer required
+ */
+uword
+fib_path_hash (fib_node_index_t path_index)
+{
+    fib_path_t *path;
+
+    path = fib_path_get(path_index);
+
+    return (hash_memory(STRUCT_MARK_PTR(path, path_hash_start),
+			(STRUCT_OFFSET_OF(fib_path_t, path_hash_end) -
+			 STRUCT_OFFSET_OF(fib_path_t, path_hash_start)),
+			0));
+}
+
+/*
+ * fib_path_cmp_i
+ *
+ * Compare two paths for equivalence.
+ */
+static int
+fib_path_cmp_i (const fib_path_t *path1,
+		const fib_path_t *path2)
+{
+    int res;
+
+    res = 1;
+
+    /*
+     * paths of different types and protocol are not equal.
+     * different weights only are the same path.
+     */
+    if (path1->fp_type != path2->fp_type)
+    {
+	res = (path1->fp_type - path2->fp_type);
+    }
+    if (path1->fp_nh_proto != path2->fp_nh_proto)
+    {
+	res = (path1->fp_nh_proto - path2->fp_nh_proto);
+    }
+    else
+    {
+	/*
+	 * both paths are of the same type.
+	 * consider each type and its attributes in turn.
+	 */
+	switch (path1->fp_type)
+	{
+	case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
+	    res = ip46_address_cmp(&path1->attached_next_hop.fp_nh,
+				   &path2->attached_next_hop.fp_nh);
+	    if (0 == res) {
+		res = vnet_sw_interface_compare(
+			  vnet_get_main(),
+			  path1->attached_next_hop.fp_interface,
+			  path2->attached_next_hop.fp_interface);
+	    }
+	    break;
+	case FIB_PATH_TYPE_ATTACHED:
+	    res = vnet_sw_interface_compare(
+		      vnet_get_main(),
+		      path1->attached.fp_interface,
+		      path2->attached.fp_interface);
+	    break;
+	case FIB_PATH_TYPE_RECURSIVE:
+	    res = ip46_address_cmp(&path1->recursive.fp_nh,
+				   &path2->recursive.fp_nh);
+ 
+	    if (0 == res)
+	    {
+		res = (path1->recursive.fp_tbl_id - path2->recursive.fp_tbl_id);
+	    }
+	    break;
+	case FIB_PATH_TYPE_DEAG:
+	    res = (path1->deag.fp_tbl_id - path2->deag.fp_tbl_id);
+	    break;
+	case FIB_PATH_TYPE_SPECIAL:
+	case FIB_PATH_TYPE_RECEIVE:
+	case FIB_PATH_TYPE_EXCLUSIVE:
+	    res = 0;
+	    break;
+	}
+    }
+    return (res);
+}
+
+/*
+ * fib_path_cmp_for_sort
+ *
+ * Compare two paths for equivalence. Used during path sorting.
+ * As usual 0 means equal.
+ */
+int
+fib_path_cmp_for_sort (void * v1,
+		       void * v2)
+{
+    fib_node_index_t *pi1 = v1, *pi2 = v2;
+    fib_path_t *path1, *path2;
+
+    path1 = fib_path_get(*pi1);
+    path2 = fib_path_get(*pi2);
+
+    return (fib_path_cmp_i(path1, path2));
+}
+
+/*
+ * fib_path_cmp
+ *
+ * Compare two paths for equivalence.
+ */
+int
+fib_path_cmp (fib_node_index_t pi1,
+	      fib_node_index_t pi2)
+{
+    fib_path_t *path1, *path2;
+
+    path1 = fib_path_get(pi1);
+    path2 = fib_path_get(pi2);
+
+    return (fib_path_cmp_i(path1, path2));
+}
+
+int
+fib_path_cmp_w_route_path (fib_node_index_t path_index,
+			   const fib_route_path_t *rpath)
+{
+    fib_path_t *path;
+    int res;
+
+    path = fib_path_get(path_index);
+
+    res = 1;
+
+    if (path->fp_weight != rpath->frp_weight)
+    {
+	res = (path->fp_weight - rpath->frp_weight);
+    }
+    else
+    {
+	/*
+	 * both paths are of the same type.
+	 * consider each type and its attributes in turn.
+	 */
+	switch (path->fp_type)
+	{
+	case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
+	    res = ip46_address_cmp(&path->attached_next_hop.fp_nh,
+				   &rpath->frp_addr);
+	    if (0 == res)
+	    {
+		res = vnet_sw_interface_compare(
+			  vnet_get_main(),
+			  path->attached_next_hop.fp_interface,
+			  rpath->frp_sw_if_index);
+	    }
+	    break;
+	case FIB_PATH_TYPE_ATTACHED:
+	    res = vnet_sw_interface_compare(
+		      vnet_get_main(),
+		      path->attached.fp_interface,
+		      rpath->frp_sw_if_index);
+	    break;
+	case FIB_PATH_TYPE_RECURSIVE:
+            if (FIB_PROTOCOL_MPLS == path->fp_nh_proto)
+            {
+                res = path->recursive.fp_nh.fp_local_label - rpath->frp_local_label;
+            }
+            else
+            {
+                res = ip46_address_cmp(&path->recursive.fp_nh.fp_ip,
+                                       &rpath->frp_addr);
+            }
+
+            if (0 == res)
+            {
+                res = (path->recursive.fp_tbl_id - rpath->frp_fib_index);
+            }
+	    break;
+	case FIB_PATH_TYPE_DEAG:
+	    res = (path->deag.fp_tbl_id - rpath->frp_fib_index);
+	    break;
+	case FIB_PATH_TYPE_SPECIAL:
+	case FIB_PATH_TYPE_RECEIVE:
+	case FIB_PATH_TYPE_EXCLUSIVE:
+	    res = 0;
+	    break;
+	}
+    }
+    return (res);
+}
+
+/*
+ * fib_path_recursive_loop_detect
+ *
+ * A forward walk of the FIB object graph to detect for a cycle/loop. This
+ * walk is initiated when an entry is linking to a new path list or from an old.
+ * The entry vector passed contains all the FIB entrys that are children of this
+ * path (it is all the entries encountered on the walk so far). If this vector
+ * contains the entry this path resolve via, then a loop is about to form.
+ * The loop must be allowed to form, since we need the dependencies in place
+ * so that we can track when the loop breaks.
+ * However, we MUST not produce a loop in the forwarding graph (else packets
+ * would loop around the switch path until the loop breaks), so we mark recursive
+ * paths as looped so that they do not contribute forwarding information.
+ * By marking the path as looped, an etry such as;
+ *    X/Y
+ *     via a.a.a.a (looped)
+ *     via b.b.b.b (not looped)
+ * can still forward using the info provided by b.b.b.b only
+ */
+int
+fib_path_recursive_loop_detect (fib_node_index_t path_index,
+				fib_node_index_t **entry_indicies)
+{
+    fib_path_t *path;
+
+    path = fib_path_get(path_index);
+
+    /*
+     * the forced drop path is never looped, cos it is never resolved.
+     */
+    if (fib_path_is_permanent_drop(path))
+    {
+	return (0);
+    }
+
+    switch (path->fp_type)
+    {
+    case FIB_PATH_TYPE_RECURSIVE:
+    {
+	fib_node_index_t *entry_index, *entries;
+	int looped = 0;
+	entries = *entry_indicies;
+
+	vec_foreach(entry_index, entries) {
+	    if (*entry_index == path->fp_via_fib)
+	    {
+		/*
+		 * the entry that is about to link to this path-list (or
+		 * one of this path-list's children) is the same entry that
+		 * this recursive path resolves through. this is a cycle.
+		 * abort the walk.
+		 */
+		looped = 1;
+		break;
+	    }
+	}
+
+	if (looped)
+	{
+	    FIB_PATH_DBG(path, "recursive loop formed");
+	    path->fp_oper_flags |= FIB_PATH_OPER_FLAG_RECURSIVE_LOOP;
+
+	    dpo_copy(&path->fp_dpo,
+                    drop_dpo_get(fib_proto_to_dpo(path->fp_nh_proto)));
+	}
+	else
+	{
+	    /*
+	     * no loop here yet. keep forward walking the graph.
+	     */	    
+	    if (fib_entry_recursive_loop_detect(path->fp_via_fib, entry_indicies))
+	    {
+		FIB_PATH_DBG(path, "recursive loop formed");
+		path->fp_oper_flags |= FIB_PATH_OPER_FLAG_RECURSIVE_LOOP;
+	    }
+	    else
+	    {
+		FIB_PATH_DBG(path, "recursive loop cleared");
+		path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RECURSIVE_LOOP;
+	    }
+	}
+	break;
+    }
+    case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
+    case FIB_PATH_TYPE_ATTACHED:
+    case FIB_PATH_TYPE_SPECIAL:
+    case FIB_PATH_TYPE_DEAG:
+    case FIB_PATH_TYPE_RECEIVE:
+    case FIB_PATH_TYPE_EXCLUSIVE:
+	/*
+	 * these path types cannot be part of a loop, since they are the leaves
+	 * of the graph.
+	 */
+	break;
+    }
+
+    return (fib_path_is_looped(path_index));
+}
+
+int
+fib_path_resolve (fib_node_index_t path_index)
+{
+    fib_path_t *path;
+
+    path = fib_path_get(path_index);
+
+    /*
+     * hope for the best.
+     */
+    path->fp_oper_flags |= FIB_PATH_OPER_FLAG_RESOLVED;
+
+    /*
+     * the forced drop path resolves via the drop adj
+     */
+    if (fib_path_is_permanent_drop(path))
+    {
+	dpo_copy(&path->fp_dpo,
+                 drop_dpo_get(fib_proto_to_dpo(path->fp_nh_proto)));
+	path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
+	return (fib_path_is_resolved(path_index));
+    }
+
+    switch (path->fp_type)
+    {
+    case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
+	fib_path_attached_next_hop_set(path);
+	break;
+    case FIB_PATH_TYPE_ATTACHED:
+	/*
+	 * path->attached.fp_interface
+	 */
+	if (!vnet_sw_interface_is_admin_up(vnet_get_main(),
+					   path->attached.fp_interface))
+	{
+	    path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
+	}
+	if (vnet_sw_interface_is_p2p(vnet_get_main(),
+				     path->attached.fp_interface))
+	{
+	    /*
+	     * point-2-point interfaces do not require a glean, since
+	     * there is nothing to ARP. Install a rewrite/nbr adj instead
+	     */
+	    dpo_set(&path->fp_dpo,
+		    DPO_ADJACENCY,
+		    fib_proto_to_dpo(path->fp_nh_proto),
+		    adj_nbr_add_or_lock(
+			path->fp_nh_proto,
+			fib_proto_to_link(path->fp_nh_proto),
+			&zero_addr,
+			path->attached.fp_interface));
+	}
+	else
+	{
+	    dpo_set(&path->fp_dpo,
+		    DPO_ADJACENCY_GLEAN,
+		    fib_proto_to_dpo(path->fp_nh_proto),
+		    adj_glean_add_or_lock(path->fp_nh_proto,
+					  path->attached.fp_interface,
+					  NULL));
+	}
+	/*
+	 * become a child of the adjacency so we receive updates
+	 * when the interface state changes
+	 */
+	path->fp_sibling = adj_child_add(path->fp_dpo.dpoi_index,
+					 FIB_NODE_TYPE_PATH,
+					 fib_path_get_index(path));
+
+	break;
+    case FIB_PATH_TYPE_RECURSIVE:
+    {
+	/*
+	 * Create a RR source entry in the table for the address
+	 * that this path recurses through.
+	 * This resolve action is recursive, hence we may create
+	 * more paths in the process. more creates mean maybe realloc
+	 * of this path.
+	 */
+	fib_node_index_t fei;
+	fib_prefix_t pfx;
+
+	ASSERT(FIB_NODE_INDEX_INVALID == path->fp_via_fib);
+
+	if (FIB_PROTOCOL_MPLS == path->fp_nh_proto)
+	{
+	    fib_prefix_from_mpls_label(path->recursive.fp_nh.fp_local_label, &pfx);
+	}
+	else
+	{
+	    fib_prefix_from_ip46_addr(&path->recursive.fp_nh.fp_ip, &pfx);
+	}
+
+	fei = fib_table_entry_special_add(path->recursive.fp_tbl_id,
+					  &pfx,
+					  FIB_SOURCE_RR,
+					  FIB_ENTRY_FLAG_NONE,
+					  ADJ_INDEX_INVALID);
+
+	path = fib_path_get(path_index);
+	path->fp_via_fib = fei;
+
+	/*
+	 * become a dependent child of the entry so the path is 
+	 * informed when the forwarding for the entry changes.
+	 */
+	path->fp_sibling = fib_entry_child_add(path->fp_via_fib,
+					       FIB_NODE_TYPE_PATH,
+					       fib_path_get_index(path));
+
+	/*
+	 * create and configure the IP DPO
+	 */
+	fib_path_recursive_adj_update(
+	    path,
+	    fib_path_proto_to_chain_type(path->fp_nh_proto),
+	    &path->fp_dpo);
+
+	break;
+    }
+    case FIB_PATH_TYPE_SPECIAL:
+	/*
+	 * Resolve via the drop
+	 */
+	dpo_copy(&path->fp_dpo,
+                 drop_dpo_get(fib_proto_to_dpo(path->fp_nh_proto)));
+	break;
+    case FIB_PATH_TYPE_DEAG:
+	/*
+	 * Resolve via a lookup DPO.
+         * FIXME. control plane should add routes with a table ID
+	 */
+	lookup_dpo_add_or_lock_w_fib_index(path->deag.fp_tbl_id,
+                                          fib_proto_to_dpo(path->fp_nh_proto),
+                                          LOOKUP_INPUT_DST_ADDR,
+                                          LOOKUP_TABLE_FROM_CONFIG,
+                                          &path->fp_dpo);
+	break;
+    case FIB_PATH_TYPE_RECEIVE:
+	/*
+	 * Resolve via a receive DPO.
+	 */
+	receive_dpo_add_or_lock(fib_proto_to_dpo(path->fp_nh_proto),
+                                path->receive.fp_interface,
+                                &path->receive.fp_addr,
+                                &path->fp_dpo);
+	break;
+    case FIB_PATH_TYPE_EXCLUSIVE:
+	/*
+	 * Resolve via the user provided DPO
+	 */
+	dpo_copy(&path->fp_dpo, &path->exclusive.fp_ex_dpo);
+	break;
+    }
+
+    return (fib_path_is_resolved(path_index));
+}
+
+u32
+fib_path_get_resolving_interface (fib_node_index_t path_index)
+{
+    fib_path_t *path;
+
+    path = fib_path_get(path_index);
+
+    switch (path->fp_type)
+    {
+    case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
+	return (path->attached_next_hop.fp_interface);
+    case FIB_PATH_TYPE_ATTACHED:
+	return (path->attached.fp_interface);
+    case FIB_PATH_TYPE_RECEIVE:
+	return (path->receive.fp_interface);
+    case FIB_PATH_TYPE_RECURSIVE:
+	return (fib_entry_get_resolving_interface(path->fp_via_fib));    
+    case FIB_PATH_TYPE_SPECIAL:
+    case FIB_PATH_TYPE_DEAG:
+    case FIB_PATH_TYPE_EXCLUSIVE:
+	break;
+    }
+    return (~0);
+}
+
+adj_index_t
+fib_path_get_adj (fib_node_index_t path_index)
+{
+    fib_path_t *path;
+
+    path = fib_path_get(path_index);
+
+    ASSERT(dpo_is_adj(&path->fp_dpo));
+    if (dpo_is_adj(&path->fp_dpo))
+    {
+	return (path->fp_dpo.dpoi_index);
+    }
+    return (ADJ_INDEX_INVALID);
+}
+
+int
+fib_path_get_weight (fib_node_index_t path_index)
+{
+    fib_path_t *path;
+
+    path = fib_path_get(path_index);
+
+    ASSERT(path);
+
+    return (path->fp_weight);
+}
+
+/**
+ * @brief Contribute the path's adjacency to the list passed.
+ * By calling this function over all paths, recursively, a child
+ * can construct its full set of forwarding adjacencies, and hence its
+ * uRPF list.
+ */
+void
+fib_path_contribute_urpf (fib_node_index_t path_index,
+			  index_t urpf)
+{
+    fib_path_t *path;
+
+    if (!fib_path_is_resolved(path_index))
+	return;
+
+    path = fib_path_get(path_index);
+
+    switch (path->fp_type)
+    {
+    case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
+	fib_urpf_list_append(urpf, path->attached_next_hop.fp_interface);
+	break;
+
+    case FIB_PATH_TYPE_ATTACHED:
+	fib_urpf_list_append(urpf, path->attached.fp_interface);
+	break;
+
+    case FIB_PATH_TYPE_RECURSIVE:
+	fib_entry_contribute_urpf(path->fp_via_fib, urpf);
+	break;
+
+    case FIB_PATH_TYPE_EXCLUSIVE:
+    case FIB_PATH_TYPE_SPECIAL:
+	/*
+	 * these path types may link to an adj, if that's what
+	 * the clinet gave
+	 */
+	if (dpo_is_adj(&path->fp_dpo))
+	{
+	    ip_adjacency_t *adj;
+
+	    adj = adj_get(path->fp_dpo.dpoi_index);
+
+	    fib_urpf_list_append(urpf, adj->rewrite_header.sw_if_index);
+	}
+	break;
+
+    case FIB_PATH_TYPE_DEAG:
+    case FIB_PATH_TYPE_RECEIVE:
+	/*
+	 * these path types don't link to an adj
+	 */
+	break;
+    }
+}
+
+void
+fib_path_contribute_forwarding (fib_node_index_t path_index,
+				fib_forward_chain_type_t fct,
+				dpo_id_t *dpo)
+{
+    fib_path_t *path;
+
+    path = fib_path_get(path_index);
+
+    ASSERT(path);
+    ASSERT(FIB_FORW_CHAIN_TYPE_MPLS_EOS != fct);
+
+    FIB_PATH_DBG(path, "contribute");
+
+    /*
+     * The DPO stored in the path was created when the path was resolved.
+     * This then represents the path's 'native' protocol; IP.
+     * For all others will need to go find something else.
+     */
+    if (fib_path_proto_to_chain_type(path->fp_nh_proto) == fct)
+    {
+	dpo_copy(dpo, &path->fp_dpo);
+    }
+    else
+    {
+	switch (path->fp_type)
+	{
+	case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
+	    switch (fct)
+	    {
+	    case FIB_FORW_CHAIN_TYPE_UNICAST_IP4:
+	    case FIB_FORW_CHAIN_TYPE_UNICAST_IP6:
+	    case FIB_FORW_CHAIN_TYPE_MPLS_EOS:
+	    case FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS:
+	    case FIB_FORW_CHAIN_TYPE_ETHERNET:
+	    {
+		adj_index_t ai;
+
+		/*
+		 * get a appropriate link type adj.
+		 */
+		ai = fib_path_attached_next_hop_get_adj(
+		         path,
+			 fib_forw_chain_type_to_link_type(fct));
+		dpo_set(dpo, DPO_ADJACENCY,
+			fib_forw_chain_type_to_dpo_proto(fct), ai);
+		adj_unlock(ai);
+
+		break;
+	    }
+	    }
+	    break;
+	case FIB_PATH_TYPE_RECURSIVE:
+	    switch (fct)
+	    {
+	    case FIB_FORW_CHAIN_TYPE_MPLS_EOS:
+	    case FIB_FORW_CHAIN_TYPE_UNICAST_IP4:
+	    case FIB_FORW_CHAIN_TYPE_UNICAST_IP6:
+	    case FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS:
+		fib_path_recursive_adj_update(path, fct, dpo);
+		break;
+	    case FIB_FORW_CHAIN_TYPE_ETHERNET:
+		ASSERT(0);
+		break;
+	    }
+	    break;
+	case FIB_PATH_TYPE_DEAG:
+	    switch (fct)
+	    {
+	    case FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS:
+                lookup_dpo_add_or_lock_w_table_id(MPLS_FIB_DEFAULT_TABLE_ID,
+                                                  DPO_PROTO_MPLS,
+                                                  LOOKUP_INPUT_DST_ADDR,
+                                                  LOOKUP_TABLE_FROM_CONFIG,
+                                                  dpo);
+                break;
+	    case FIB_FORW_CHAIN_TYPE_UNICAST_IP4:
+	    case FIB_FORW_CHAIN_TYPE_UNICAST_IP6:
+	    case FIB_FORW_CHAIN_TYPE_MPLS_EOS:
+		dpo_copy(dpo, &path->fp_dpo);
+		break;		
+	    case FIB_FORW_CHAIN_TYPE_ETHERNET:
+		ASSERT(0);
+		break;
+            }
+            break;
+	case FIB_PATH_TYPE_EXCLUSIVE:
+	    dpo_copy(dpo, &path->exclusive.fp_ex_dpo);
+	    break;
+        case FIB_PATH_TYPE_ATTACHED:
+	case FIB_PATH_TYPE_RECEIVE:
+	case FIB_PATH_TYPE_SPECIAL:
+	    ASSERT(0);
+            break;
+	}
+
+    }
+}
+
+load_balance_path_t *
+fib_path_append_nh_for_multipath_hash (fib_node_index_t path_index,
+				       fib_forward_chain_type_t fct,
+				       load_balance_path_t *hash_key)
+{
+    load_balance_path_t *mnh;
+    fib_path_t *path;
+
+    path = fib_path_get(path_index);
+
+    ASSERT(path);
+
+    if (fib_path_is_resolved(path_index))
+    {
+	vec_add2(hash_key, mnh, 1);
+
+	mnh->path_weight = path->fp_weight;
+	mnh->path_index = path_index;
+	fib_path_contribute_forwarding(path_index, fct, &mnh->path_dpo);
+    }
+
+    return (hash_key);
+}
+
+int
+fib_path_is_recursive (fib_node_index_t path_index)
+{
+    fib_path_t *path;
+
+    path = fib_path_get(path_index);
+
+    return (FIB_PATH_TYPE_RECURSIVE == path->fp_type);
+}
+
+int
+fib_path_is_exclusive (fib_node_index_t path_index)
+{
+    fib_path_t *path;
+
+    path = fib_path_get(path_index);
+
+    return (FIB_PATH_TYPE_EXCLUSIVE == path->fp_type);
+}
+
+int
+fib_path_is_deag (fib_node_index_t path_index)
+{
+    fib_path_t *path;
+
+    path = fib_path_get(path_index);
+
+    return (FIB_PATH_TYPE_DEAG == path->fp_type);
+}
+
+int
+fib_path_is_resolved (fib_node_index_t path_index)
+{
+    fib_path_t *path;
+
+    path = fib_path_get(path_index);
+
+    return (dpo_id_is_valid(&path->fp_dpo) &&
+	    (path->fp_oper_flags & FIB_PATH_OPER_FLAG_RESOLVED) &&
+	    !fib_path_is_looped(path_index) &&
+	    !fib_path_is_permanent_drop(path));
+}
+
+int
+fib_path_is_looped (fib_node_index_t path_index)
+{
+    fib_path_t *path;
+
+    path = fib_path_get(path_index);
+
+    return (path->fp_oper_flags & FIB_PATH_OPER_FLAG_RECURSIVE_LOOP);
+}
+
+int
+fib_path_encode (fib_node_index_t path_list_index,
+		 fib_node_index_t path_index,
+                 void *ctx)
+{
+    fib_route_path_encode_t **api_rpaths = ctx;
+    fib_route_path_encode_t *api_rpath;
+    fib_path_t *path;
+
+    path = fib_path_get(path_index);
+    if (!path)
+      return (0);
+    vec_add2(*api_rpaths, api_rpath, 1);
+    api_rpath->rpath.frp_weight = path->fp_weight;
+    api_rpath->rpath.frp_proto = path->fp_nh_proto;
+    api_rpath->rpath.frp_sw_if_index = ~0;
+    api_rpath->dpo = path->exclusive.fp_ex_dpo;
+    switch (path->fp_type)
+      {
+      case FIB_PATH_TYPE_RECEIVE:
+        api_rpath->rpath.frp_addr = path->receive.fp_addr;
+        api_rpath->rpath.frp_sw_if_index = path->receive.fp_interface;
+        break;
+      case FIB_PATH_TYPE_ATTACHED:
+        api_rpath->rpath.frp_sw_if_index = path->attached.fp_interface;
+        break;
+      case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
+        api_rpath->rpath.frp_sw_if_index = path->attached_next_hop.fp_interface;
+        api_rpath->rpath.frp_addr = path->attached_next_hop.fp_nh;
+        break;
+      case FIB_PATH_TYPE_SPECIAL:
+        break;
+      case FIB_PATH_TYPE_DEAG:
+        break;
+      case FIB_PATH_TYPE_RECURSIVE:
+        api_rpath->rpath.frp_addr = path->recursive.fp_nh.fp_ip;
+        break;
+      default:
+        break;
+      }
+    return (1);
+}
+
+fib_protocol_t
+fib_path_get_proto (fib_node_index_t path_index)
+{
+    fib_path_t *path;
+
+    path = fib_path_get(path_index);
+
+    return (path->fp_nh_proto);
+}
+
+void
+fib_path_module_init (void)
+{
+    fib_node_register_type (FIB_NODE_TYPE_PATH, &fib_path_vft);
+}
+
+static clib_error_t *
+show_fib_path_command (vlib_main_t * vm,
+			unformat_input_t * input,
+			vlib_cli_command_t * cmd)
+{
+    fib_node_index_t pi;
+    fib_path_t *path;
+
+    if (unformat (input, "%d", &pi))
+    {
+	/*
+	 * show one in detail
+	 */
+	if (!pool_is_free_index(fib_path_pool, pi))
+	{
+	    path = fib_path_get(pi);
+	    u8 *s = fib_path_format(pi, NULL);
+	    s = format(s, "children:");
+	    s = fib_node_children_format(path->fp_node.fn_children, s);
+	    vlib_cli_output (vm, "%s", s);
+	    vec_free(s);
+	}
+	else
+	{
+	    vlib_cli_output (vm, "path %d invalid", pi);
+	}
+    }
+    else
+    {
+	vlib_cli_output (vm, "FIB Paths");
+	pool_foreach(path, fib_path_pool,
+	({
+	    vlib_cli_output (vm, "%U", format_fib_path, path);
+	}));
+    }
+
+    return (NULL);
+}
+
+VLIB_CLI_COMMAND (show_fib_path, static) = {
+  .path = "show fib paths",
+  .function = show_fib_path_command,
+  .short_help = "show fib paths",
+};
diff --git a/src/vnet/fib/fib_path.h b/src/vnet/fib/fib_path.h
new file mode 100644
index 00000000000..91f49d09234
--- /dev/null
+++ b/src/vnet/fib/fib_path.h
@@ -0,0 +1,158 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * Given a route of the form;
+ *   q.r.s.t/Y
+ *     via <interface> <next-hop>
+ *
+ * The prefix is: q.r.s.t./Y
+ * the path is: 'via <interface> <next-hop>
+ *
+ * The path is the description of where to send the traffic, and the
+ * the prefix is a description of which traffic to send.
+ * It is the aim of the FIB to resolve the path, i.e. to find the corresponding
+ * adjacency to match the path's description.
+ */
+
+#ifndef __FIB_PATH_H__
+#define __FIB_PATH_H__
+
+#include <vnet/ip/ip.h>
+#include <vnet/dpo/load_balance.h>
+
+#include <vnet/fib/fib_types.h>
+#include <vnet/adj/adj_types.h>
+
+/**
+ * Enurmeration of path configuration attributes
+ */
+typedef enum fib_path_cfg_attribute_t_ {
+    /**
+     * Marker. Add new types after this one.
+     */
+    FIB_PATH_CFG_ATTRIBUTE_FIRST = 0,
+    /**
+     * The path is forced to a drop, whatever the next-hop info says.
+     * something somewhere knows better...
+     */
+    FIB_PATH_CFG_ATTRIBUTE_DROP = FIB_PATH_CFG_ATTRIBUTE_FIRST,
+    /**
+     * The path uses an adj that is exclusive. I.e. it is known only by
+     * the source of the route.
+     */
+    FIB_PATH_CFG_ATTRIBUTE_EXCLUSIVE,
+    /**
+     * Recursion constraint via host
+     */
+    FIB_PATH_CFG_ATTRIBUTE_RESOLVE_HOST,
+    /**
+     * Recursion constraint via attached
+     */
+    FIB_PATH_CFG_ATTRIBUTE_RESOLVE_ATTACHED,
+    /**
+     * The path is a for-us path
+     */
+    FIB_PATH_CFG_ATTRIBUTE_LOCAL,
+    /**
+     * Marker. Add new types before this one, then update it.
+     */
+    FIB_PATH_CFG_ATTRIBUTE_LAST = FIB_PATH_CFG_ATTRIBUTE_LOCAL,
+} __attribute__ ((packed)) fib_path_cfg_attribute_t;
+
+/**
+ * The maximum number of path attributes
+ */
+#define FIB_PATH_CFG_ATTRIBUTE_MAX (FIB_PATH_CFG_ATTRIBUTE_LAST + 1)
+
+#define FIB_PATH_CFG_ATTRIBUTES {			\
+    [FIB_PATH_CFG_ATTRIBUTE_DROP]  = "drop",	        \
+    [FIB_PATH_CFG_ATTRIBUTE_EXCLUSIVE] = "exclusive",	\
+    [FIB_PATH_CFG_ATTRIBUTE_RESOLVE_HOST] = "resolve-host", \
+    [FIB_PATH_CFG_ATTRIBUTE_RESOLVE_ATTACHED] = "resolve-attached", \
+    [FIB_PATH_CFG_ATTRIBUTE_LOCAL] = "local",	        \
+}
+
+#define FOR_EACH_FIB_PATH_CFG_ATTRIBUTE(_item) \
+    for (_item = FIB_PATH_CFG_ATTRIBUTE_FIRST; \
+	 _item <= FIB_PATH_CFG_ATTRIBUTE_LAST; \
+	 _item++)
+
+/**
+ * Path config flags from the attributes
+ */
+typedef enum fib_path_cfg_flags_t_ {
+    FIB_PATH_CFG_FLAG_NONE  = 0,
+    FIB_PATH_CFG_FLAG_DROP  = (1 << FIB_PATH_CFG_ATTRIBUTE_DROP),
+    FIB_PATH_CFG_FLAG_EXCLUSIVE = (1 << FIB_PATH_CFG_ATTRIBUTE_EXCLUSIVE),
+    FIB_PATH_CFG_FLAG_RESOLVE_HOST = (1 << FIB_PATH_CFG_ATTRIBUTE_RESOLVE_HOST),
+    FIB_PATH_CFG_FLAG_RESOLVE_ATTACHED = (1 << FIB_PATH_CFG_ATTRIBUTE_RESOLVE_ATTACHED),
+    FIB_PATH_CFG_FLAG_LOCAL = (1 << FIB_PATH_CFG_ATTRIBUTE_LOCAL),
+} __attribute__ ((packed)) fib_path_cfg_flags_t;
+
+
+extern u8 *fib_path_format(fib_node_index_t pi, u8 *s);
+extern u8 *fib_path_adj_format(fib_node_index_t pi,
+			       u32 indent,
+			       u8 *s);
+
+extern u8 * format_fib_path(u8 * s, va_list * args);
+
+extern fib_node_index_t fib_path_create(fib_node_index_t pl_index,
+					fib_protocol_t nh_proto,
+					fib_path_cfg_flags_t flags,
+					const fib_route_path_t *path);
+extern fib_node_index_t fib_path_create_special(fib_node_index_t pl_index,
+						fib_protocol_t nh_proto,
+						fib_path_cfg_flags_t flags,
+						const dpo_id_t *dpo);
+
+extern int fib_path_cmp(fib_node_index_t path_index1,
+			fib_node_index_t path_index2);
+extern int fib_path_cmp_for_sort(void * a1, void * a2);
+extern int fib_path_cmp_w_route_path(fib_node_index_t path_index,
+				     const fib_route_path_t *rpath);
+extern fib_node_index_t fib_path_copy(fib_node_index_t path_index,
+				      fib_node_index_t path_list_index);
+extern int fib_path_resolve(fib_node_index_t path_index);
+extern int fib_path_is_resolved(fib_node_index_t path_index);
+extern int fib_path_is_recursive(fib_node_index_t path_index);
+extern int fib_path_is_exclusive(fib_node_index_t path_index);
+extern int fib_path_is_deag(fib_node_index_t path_index);
+extern int fib_path_is_looped(fib_node_index_t path_index);
+extern fib_protocol_t fib_path_get_proto(fib_node_index_t path_index);
+extern void fib_path_destroy(fib_node_index_t path_index);
+extern uword fib_path_hash(fib_node_index_t path_index);
+extern load_balance_path_t * fib_path_append_nh_for_multipath_hash(
+    fib_node_index_t path_index,
+    fib_forward_chain_type_t fct,
+    load_balance_path_t *hash_key);
+extern void fib_path_contribute_forwarding(fib_node_index_t path_index,
+					   fib_forward_chain_type_t type,
+					   dpo_id_t *dpo);
+extern void fib_path_contribute_urpf(fib_node_index_t path_index,
+				     index_t urpf);
+extern adj_index_t fib_path_get_adj(fib_node_index_t path_index);
+extern int fib_path_recursive_loop_detect(fib_node_index_t path_index,
+					  fib_node_index_t **entry_indicies);
+extern u32 fib_path_get_resolving_interface(fib_node_index_t fib_entry_index);
+extern int fib_path_get_weight(fib_node_index_t path_index);
+
+extern void fib_path_module_init(void);
+extern int fib_path_encode(fib_node_index_t path_list_index,
+                           fib_node_index_t path_index,
+			   void *ctx);
+
+#endif
diff --git a/src/vnet/fib/fib_path_ext.c b/src/vnet/fib/fib_path_ext.c
new file mode 100644
index 00000000000..f75b5626c04
--- /dev/null
+++ b/src/vnet/fib/fib_path_ext.c
@@ -0,0 +1,231 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vnet/mpls/mpls.h>
+#include <vnet/dpo/mpls_label_dpo.h>
+#include <vnet/dpo/load_balance.h>
+#include <vnet/dpo/drop_dpo.h>
+
+#include <vnet/fib/fib_path_ext.h>
+#include <vnet/fib/fib_entry_src.h>
+#include <vnet/fib/fib_path.h>
+#include <vnet/fib/fib_path_list.h>
+#include <vnet/fib/fib_internal.h>
+
+u8 *
+format_fib_path_ext (u8 * s, va_list * args)
+{
+    fib_path_ext_t *path_ext;
+    u32 ii;
+
+    path_ext = va_arg (*args, fib_path_ext_t *);
+
+    s = format(s, "path:%d labels:",
+	       path_ext->fpe_path_index);
+    for (ii = 0; ii < vec_len(path_ext->fpe_path.frp_label_stack); ii++)
+    {
+	s = format(s, "%U ",
+		   format_mpls_unicast_label,
+		   path_ext->fpe_path.frp_label_stack[ii]);
+    }
+    return (s);
+}
+
+int
+fib_path_ext_cmp (fib_path_ext_t *path_ext,
+		  const fib_route_path_t *rpath)
+{
+    return (fib_route_path_cmp(&path_ext->fpe_path, rpath));
+}
+
+static int
+fib_path_ext_match (fib_node_index_t pl_index,
+		    fib_node_index_t path_index,
+		    void *ctx)
+{
+    fib_path_ext_t *path_ext = ctx;
+
+    if (!fib_path_cmp_w_route_path(path_index,
+				   &path_ext->fpe_path))
+    {
+	path_ext->fpe_path_index = path_index;
+	return (0);
+    }
+    // keep going
+    return (1);
+}
+
+void
+fib_path_ext_resolve (fib_path_ext_t *path_ext,
+		      fib_node_index_t path_list_index)
+{
+    /*
+     * Find the path on the path list that this is an extension for
+     */
+    path_ext->fpe_path_index = FIB_NODE_INDEX_INVALID;
+    fib_path_list_walk(path_list_index,
+		       fib_path_ext_match,
+		       path_ext);
+}
+
+void
+fib_path_ext_init (fib_path_ext_t *path_ext,
+		   fib_node_index_t path_list_index,
+		   const fib_route_path_t *rpath)
+{
+    path_ext->fpe_path = *rpath;
+    path_ext->fpe_path_index = FIB_NODE_INDEX_INVALID;
+
+    fib_path_ext_resolve(path_ext, path_list_index);
+}
+
+/**
+ * @brief Return true if the label stack is implicit null
+ */
+static int
+fib_path_ext_is_imp_null (fib_path_ext_t *path_ext)
+{
+    return ((1 == vec_len(path_ext->fpe_label_stack)) &&
+	    (MPLS_IETF_IMPLICIT_NULL_LABEL == path_ext->fpe_label_stack[0]));
+}
+
+load_balance_path_t *
+fib_path_ext_stack (fib_path_ext_t *path_ext,
+		    const fib_entry_t *entry,
+                    fib_forward_chain_type_t child_fct,
+		    load_balance_path_t *nhs)
+{
+    fib_forward_chain_type_t parent_fct;
+    load_balance_path_t *nh;
+
+    if (!fib_path_is_resolved(path_ext->fpe_path_index))
+	return (nhs);
+
+    /*
+     * Since we are stacking this path-extension, it must have a valid out
+     * label. From the chain type request by the child, determine what
+     * chain type we will request from the parent.
+     */
+    switch (child_fct)
+    {
+    case FIB_FORW_CHAIN_TYPE_MPLS_EOS:
+    {
+	/*
+	 * The EOS chain is a tricky since, when the path has an imp NULL one cannot know
+         * the adjacency to link to without knowing what the packets payload protocol
+	 * will be once the label is popped.
+	 */
+	if (fib_path_ext_is_imp_null(path_ext))
+	{
+            parent_fct = fib_entry_chain_type_fixup(entry, child_fct);
+        }
+        else
+        {
+            /*
+             * we have a label to stack. packets will thus be labelled when
+             * they encounter the child, ergo, non-eos.
+             */
+	    parent_fct = FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS;
+        }
+	break;
+    }
+    case FIB_FORW_CHAIN_TYPE_UNICAST_IP4:
+    case FIB_FORW_CHAIN_TYPE_UNICAST_IP6:
+	if (fib_path_ext_is_imp_null(path_ext))
+	{
+            /*
+             * implicit-null label for the eos or IP chain, need to pick up
+             * the IP adj
+             */
+	    parent_fct = child_fct;
+	}
+        else
+        {
+            /*
+             * we have a label to stack. packets will thus be labelled when
+             * they encounter the child, ergo, non-eos.
+             */
+	    parent_fct = FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS;
+        }
+	break;
+    case FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS:
+        parent_fct = child_fct;
+	break;
+    default:
+        return (nhs);
+	break;
+    }
+
+    dpo_id_t via_dpo = DPO_INVALID;
+
+    /*
+     * The next object in the graph after the imposition of the label
+     * will be the DPO contributed by the path through which the packets
+     * are to be sent. We stack the MPLS Label DPO on this path DPO
+     */
+    fib_path_contribute_forwarding(path_ext->fpe_path_index,
+				   parent_fct,
+				   &via_dpo);
+
+    if (dpo_is_drop(&via_dpo) ||
+	load_balance_is_drop(&via_dpo))
+    {
+	/*
+	 * don't stack a path extension on a drop. doing so will create
+	 * a LB bucket entry on drop, and we will lose a percentage of traffic.
+	 */
+    }
+    else
+    {
+	vec_add2(nhs, nh, 1);
+	nh->path_weight = fib_path_get_weight(path_ext->fpe_path_index);
+	nh->path_index = path_ext->fpe_path_index;
+	dpo_copy(&nh->path_dpo, &via_dpo);
+
+	/*
+	 * The label is stackable for this chain type
+	 * construct the mpls header that will be imposed in the data-path
+	 */
+	if (!fib_path_ext_is_imp_null(path_ext))
+	{
+            /*
+             * we use the parent protocol for the label so that
+             * we pickup the correct MPLS imposition nodes to do
+             * ip[46] processing.
+             */
+            dpo_proto_t chain_proto;
+            mpls_eos_bit_t eos;
+            index_t mldi;
+
+            eos = (child_fct == FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS ?
+                   MPLS_NON_EOS :
+                   MPLS_EOS);
+            chain_proto = fib_forw_chain_type_to_dpo_proto(child_fct);
+
+            mldi = mpls_label_dpo_create(path_ext->fpe_label_stack,
+                                         eos, 255, 0,
+                                         chain_proto,
+                                         &nh->path_dpo);
+
+	    dpo_set(&nh->path_dpo,
+		    DPO_MPLS_LABEL,
+                    chain_proto,
+                    mldi);
+	}
+    }
+    dpo_reset(&via_dpo);
+
+    return (nhs);
+}
diff --git a/src/vnet/fib/fib_path_ext.h b/src/vnet/fib/fib_path_ext.h
new file mode 100644
index 00000000000..cf8f8df00c6
--- /dev/null
+++ b/src/vnet/fib/fib_path_ext.h
@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __FIB_PATH_EXT_H__
+#define __FIB_PATH_EXT_H__
+
+#include <vnet/mpls/mpls.h>
+#include <vnet/fib/fib_types.h>
+
+/**
+ * A path extension is a per-entry addition to the forwarding information
+ * when packets are sent for that entry over that path.
+ *
+ * For example:
+ *    ip route add 1.1.1.1/32 via 10.10.10.10 out-label 100
+ *
+ * The out-going MPLS label value 100 is a path-extension. It is a value sepcific
+ * to the entry 1.1.1.1/32 and valid only when packets are sent via 10.10.10.10.
+ */
+typedef struct fib_path_ext_t_
+{
+    /**
+     * A description of the path that is being extended.
+     * This description is used to match this extension with the [changing]
+     * instance of a fib_path_t that is extended
+     */
+    fib_route_path_t fpe_path;
+#define fpe_label_stack fpe_path.frp_label_stack
+
+    /**
+     * The index of the path. This is the global index, not the path's
+     * position in the path-list.
+     */
+    fib_node_index_t fpe_path_index;
+} fib_path_ext_t;
+
+struct fib_entry_t_;
+
+extern u8 * format_fib_path_ext(u8 * s, va_list * args);
+
+extern void fib_path_ext_init(fib_path_ext_t *path_ext,
+			      fib_node_index_t path_list_index,
+			      const fib_route_path_t *rpath);
+
+extern int fib_path_ext_cmp(fib_path_ext_t *path_ext,
+			    const fib_route_path_t *rpath);
+
+extern void fib_path_ext_resolve(fib_path_ext_t *path_ext,
+				 fib_node_index_t path_list_index);
+
+extern load_balance_path_t *fib_path_ext_stack(fib_path_ext_t *path_ext,
+                                               const struct fib_entry_t_ *entry,
+                                               fib_forward_chain_type_t fct,
+                                               load_balance_path_t *nhs);
+
+#endif
+
diff --git a/src/vnet/fib/fib_path_list.c b/src/vnet/fib/fib_path_list.c
new file mode 100644
index 00000000000..5b35e9b87e7
--- /dev/null
+++ b/src/vnet/fib/fib_path_list.c
@@ -0,0 +1,1223 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vppinfra/mhash.h>
+#include <vnet/ip/ip.h>
+#include <vnet/adj/adj.h>
+#include <vnet/dpo/load_balance.h>
+#include <vnet/dpo/load_balance_map.h>
+
+#include <vnet/fib/fib_path_list.h>
+#include <vnet/fib/fib_internal.h>
+#include <vnet/fib/fib_node_list.h>
+#include <vnet/fib/fib_walk.h>
+#include <vnet/fib/fib_urpf_list.h>
+
+/**
+ * FIB path-list
+ * A representation of the list/set of path trough which a prefix is reachable
+ */
+typedef struct fib_path_list_t_ {
+    /**
+     * A path-list is a node in the FIB graph.
+     */
+    fib_node_t fpl_node;
+
+    /**
+     * Flags on the path-list
+     */
+    fib_path_list_flags_t fpl_flags;
+
+    /**
+     * The next-hop protocol for the paths in this path list.
+     * Note that fixing the proto here means we don't support a mix of
+     * v4 and v6 paths. ho hum.
+     */
+    fib_protocol_t fpl_nh_proto;
+
+    /**
+     * Vector of paths indicies for all configured paths.
+     * For shareable path-lists this list MUST not change.
+     */
+    fib_node_index_t *fpl_paths;
+
+    /**
+     * the RPF list calculated for this path list
+     */
+    fib_node_index_t fpl_urpf;
+} fib_path_list_t;
+
+/*
+ * Array of strings/names for the FIB sources
+ */
+static const char *fib_path_list_attr_names[] = FIB_PATH_LIST_ATTRIBUTES;
+
+/*
+ * The memory pool from which we allocate all the path-lists
+ */
+static fib_path_list_t * fib_path_list_pool;
+
+/*
+ * The data-base of shared path-lists
+ */
+static uword *fib_path_list_db;
+
+/*
+ * Debug macro
+ */
+#ifdef FIB_DEBUG
+#define FIB_PATH_LIST_DBG(_pl, _fmt, _args...)		  \
+{   		            				  \
+    u8 *_tmp = 0;					  \
+    _tmp = fib_path_list_format(			  \
+	fib_path_list_get_index(_pl), _tmp);		  \
+    clib_warning("pl:[%d:%p:%p:%s]:" _fmt,		  \
+		 fib_path_list_get_index(_pl),		  \
+		 _pl, _pl->fpl_paths, _tmp,		  \
+		 ##_args);				  \
+    vec_free(_tmp);					  \
+}
+#else
+#define FIB_PATH_LIST_DBG(_pl, _fmt, _args...)
+#endif
+
+static fib_path_list_t *
+fib_path_list_get (fib_node_index_t index)
+{
+    return (pool_elt_at_index(fib_path_list_pool, index));
+}
+
+static fib_node_t *
+fib_path_list_get_node (fib_node_index_t index)
+{
+    return ((fib_node_t*)fib_path_list_get(index));
+}
+
+static fib_path_list_t*
+fib_path_list_from_fib_node (fib_node_t *node)
+{
+#if CLIB_DEBUG > 0
+    ASSERT(FIB_NODE_TYPE_PATH_LIST == node->fn_type);
+#endif
+    return ((fib_path_list_t*)node);
+}
+
+static fib_node_index_t
+fib_path_list_get_index (fib_path_list_t *path_list)
+{
+    return (path_list - fib_path_list_pool);
+}
+
+static u8 *
+format_fib_path_list (u8 * s, va_list * args)
+{
+    fib_path_list_attribute_t attr;
+    fib_node_index_t *path_index;
+    fib_path_list_t *path_list;
+
+    path_list = va_arg (*args, fib_path_list_t *);
+    
+    s = format (s, "    index:%u", fib_path_list_get_index(path_list));
+    s = format (s, " locks:%u", path_list->fpl_node.fn_locks);
+    s = format (s, " proto:%U", format_fib_protocol, path_list->fpl_nh_proto);
+
+    if (FIB_PATH_LIST_FLAG_NONE != path_list->fpl_flags)
+    {
+	s = format (s, " flags:");
+	FOR_EACH_PATH_LIST_ATTRIBUTE(attr)
+        {
+	    if ((1<<attr) & path_list->fpl_flags)
+            {
+		s = format (s, "%s,", fib_path_list_attr_names[attr]);
+	    }
+	}
+    }
+    s = format (s, " %U\n", format_fib_urpf_list, path_list->fpl_urpf);
+
+    vec_foreach (path_index, path_list->fpl_paths)
+    {
+	s = fib_path_format(*path_index, s);
+	s = format(s, "\n");
+    }
+
+    return (s);
+}
+
+u8 *
+fib_path_list_adjs_format (fib_node_index_t path_list_index,
+			   u32 indent,
+			   u8 * s)
+{
+    fib_path_list_t *path_list;
+    u32 i;
+
+    path_list = fib_path_list_get(path_list_index);
+
+    vec_foreach_index (i, path_list->fpl_paths)
+    {
+	s = fib_path_adj_format(path_list->fpl_paths[i],
+				indent, s);
+    }
+
+    return (s);
+}
+
+
+u8 *
+fib_path_list_format (fib_node_index_t path_list_index,
+		      u8 * s)
+{
+    fib_path_list_t *path_list;
+
+    path_list = fib_path_list_get(path_list_index);
+
+    return (format(s, "%U", format_fib_path_list, path_list));
+}
+
+static uword
+fib_path_list_hash (fib_path_list_t *path_list)
+{
+    uword old_path_list_hash, new_path_list_hash, path_hash;
+    fib_node_index_t *path_index;
+
+    ASSERT(path_list);
+
+    new_path_list_hash = old_path_list_hash = vec_len(path_list->fpl_paths);
+
+    vec_foreach (path_index, path_list->fpl_paths)
+    {
+	path_hash = fib_path_hash(*path_index);
+#if uword_bits == 64
+	hash_mix64(path_hash, old_path_list_hash, new_path_list_hash);
+#else
+	hash_mix32(path_hash, old_path_list_hash, new_path_list_hash);
+#endif
+    }
+
+    return (new_path_list_hash);
+}
+
+always_inline uword
+fib_path_list_db_hash_key_from_index (uword index)
+{
+    return 1 + 2*index;
+}
+
+always_inline uword
+fib_path_list_db_hash_key_is_index (uword key)
+{
+    return key & 1;
+}
+
+always_inline uword
+fib_path_list_db_hash_key_2_index (uword key)
+{
+    ASSERT (fib_path_list_db_hash_key_is_index (key));
+    return key / 2;
+}
+
+static fib_path_list_t*
+fib_path_list_db_get_from_hash_key (uword key)
+{
+    fib_path_list_t *path_list;
+
+    if (fib_path_list_db_hash_key_is_index (key))
+    {
+	fib_node_index_t path_list_index;
+
+	path_list_index = fib_path_list_db_hash_key_2_index(key);
+	path_list = fib_path_list_get(path_list_index);
+    }
+    else
+    {       
+	path_list = uword_to_pointer (key, fib_path_list_t *);
+    }
+
+    return (path_list);
+}
+
+static uword
+fib_path_list_db_hash_key_sum (hash_t * h,
+			       uword key)
+{
+    fib_path_list_t *path_list;
+
+    path_list = fib_path_list_db_get_from_hash_key(key);
+
+    return (fib_path_list_hash(path_list));
+}
+
+static uword
+fib_path_list_db_hash_key_equal (hash_t * h,
+				 uword key1,
+				 uword key2)
+{
+    fib_path_list_t *path_list1, *path_list2;
+
+    path_list1 = fib_path_list_db_get_from_hash_key(key1);
+    path_list2 = fib_path_list_db_get_from_hash_key(key2);
+
+    return (fib_path_list_hash(path_list1) ==
+	    fib_path_list_hash(path_list2));
+}
+
+static fib_node_index_t
+fib_path_list_db_find (fib_path_list_t *path_list)
+{
+    uword *p;
+
+    p = hash_get(fib_path_list_db, path_list);
+
+    if (NULL != p)
+    {
+	return p[0];
+    }
+
+    return (FIB_NODE_INDEX_INVALID);
+}
+
+static void
+fib_path_list_db_insert (fib_node_index_t path_list_index)
+{
+    fib_path_list_t *path_list;
+
+    path_list = fib_path_list_get(path_list_index);
+
+    ASSERT(FIB_NODE_INDEX_INVALID == fib_path_list_db_find(path_list));
+
+    hash_set (fib_path_list_db,
+	      fib_path_list_db_hash_key_from_index(path_list_index),
+	      path_list_index);
+
+    FIB_PATH_LIST_DBG(path_list, "DB-inserted");
+}
+
+static void
+fib_path_list_db_remove (fib_node_index_t path_list_index)
+{
+    fib_path_list_t *path_list;
+
+    path_list = fib_path_list_get(path_list_index);
+
+    ASSERT(FIB_NODE_INDEX_INVALID != fib_path_list_db_find(path_list));
+
+    hash_unset(fib_path_list_db,
+	       fib_path_list_db_hash_key_from_index(path_list_index));
+
+    FIB_PATH_LIST_DBG(path_list, "DB-removed");
+}
+
+static void
+fib_path_list_destroy (fib_path_list_t *path_list)
+{
+    fib_node_index_t *path_index;
+
+    FIB_PATH_LIST_DBG(path_list, "destroy");
+
+    vec_foreach (path_index, path_list->fpl_paths)
+    {
+	fib_path_destroy(*path_index);
+    }
+
+    vec_free(path_list->fpl_paths);
+    fib_urpf_list_unlock(path_list->fpl_urpf);
+
+    fib_node_deinit(&path_list->fpl_node);
+    pool_put(fib_path_list_pool, path_list);
+}
+
+static void
+fib_path_list_last_lock_gone (fib_node_t *node)
+{
+    fib_path_list_t *path_list;
+
+    path_list = fib_path_list_from_fib_node(node);
+
+    FIB_PATH_LIST_DBG(path_list, "last-lock");
+
+    if (path_list->fpl_flags & FIB_PATH_LIST_FLAG_SHARED)
+    {
+	fib_path_list_db_remove(fib_path_list_get_index(path_list));
+    }
+    fib_path_list_destroy(path_list);
+}
+
+/*
+ * fib_path_mk_lb
+ *
+ * update the multipath adj this path-list will contribute to its
+ * children's forwarding.
+ */
+static void
+fib_path_list_mk_lb (fib_path_list_t *path_list,
+		     fib_forward_chain_type_t fct,
+		     dpo_id_t *dpo)
+{
+    load_balance_path_t *hash_key;
+    fib_node_index_t *path_index;
+
+    hash_key  = NULL;
+
+    if (!dpo_id_is_valid(dpo))
+    {
+        /*
+         * first time create
+         */
+        dpo_set(dpo,
+                DPO_LOAD_BALANCE,
+                fib_forw_chain_type_to_dpo_proto(fct),
+                load_balance_create(0,
+				    fib_forw_chain_type_to_dpo_proto(fct),
+				    0 /* FIXME FLOW HASH */));
+    }
+
+    /*
+     * We gather the DPOs from resolved paths.
+     */
+    vec_foreach (path_index, path_list->fpl_paths)
+    {
+	hash_key = fib_path_append_nh_for_multipath_hash(
+	               *path_index,
+		       fct,
+		       hash_key);
+    }
+
+    /*
+     * Path-list load-balances, which if used, would be shared and hence
+     * never need a load-balance map.
+     */
+    load_balance_multipath_update(dpo, hash_key, LOAD_BALANCE_FLAG_NONE);
+
+    FIB_PATH_LIST_DBG(path_list, "mk lb: %d", dpo->dpoi_index);
+
+    vec_free(hash_key);
+}
+
+/**
+ * @brief [re]build the path list's uRPF list
+ */
+static void
+fib_path_list_mk_urpf (fib_path_list_t *path_list)
+{
+    fib_node_index_t *path_index;
+
+    /*
+     * ditch the old one. by iterating through all paths we are going
+     * to re-find all the adjs that were in the old one anyway. If we
+     * keep the old one, then the |sort|uniq requires more work.
+     * All users of the RPF list have their own lock, so we can release
+     * immediately.
+     */
+    fib_urpf_list_unlock(path_list->fpl_urpf);
+    path_list->fpl_urpf = fib_urpf_list_alloc_and_lock();
+
+    vec_foreach (path_index, path_list->fpl_paths)
+    {
+	fib_path_contribute_urpf(*path_index, path_list->fpl_urpf);
+    }
+
+    fib_urpf_list_bake(path_list->fpl_urpf);
+}
+
+/**
+ * @brief Contribute (add) this path list's uRPF list. This allows the child
+ * to construct an aggregate list.
+ */
+void
+fib_path_list_contribute_urpf (fib_node_index_t path_list_index,
+			       index_t urpf)
+{
+    fib_path_list_t *path_list;
+
+    path_list = fib_path_list_get(path_list_index);
+
+    fib_urpf_list_combine(urpf, path_list->fpl_urpf);
+}
+
+/**
+ * @brief Return the the child the RPF list pre-built for this path list
+ */
+index_t
+fib_path_list_get_urpf (fib_node_index_t path_list_index)
+{
+    fib_path_list_t *path_list;
+
+    path_list = fib_path_list_get(path_list_index);
+
+    return (path_list->fpl_urpf);
+}
+
+/*
+ * fib_path_list_back_walk
+ *
+ * Called from one of this path-list's paths to progate
+ * a back walk
+ */
+void
+fib_path_list_back_walk (fib_node_index_t path_list_index,
+			 fib_node_back_walk_ctx_t *ctx)
+{
+    fib_path_list_t *path_list;
+
+    path_list = fib_path_list_get(path_list_index);
+
+    fib_path_list_mk_urpf(path_list);
+
+    /*
+     * propagate the backwalk further
+     */
+    if (32 >= fib_node_list_get_size(path_list->fpl_node.fn_children))
+    {
+        /*
+         * only a few children. continue the walk synchronously
+         */
+	fib_walk_sync(FIB_NODE_TYPE_PATH_LIST, path_list_index, ctx);
+    }
+    else
+    {
+        /*
+         * many children. schedule a async walk
+         */
+        fib_walk_async(FIB_NODE_TYPE_PATH_LIST,
+                       path_list_index,
+                       FIB_WALK_PRIORITY_LOW,
+                       ctx);
+    }
+}
+
+/*
+ * fib_path_list_back_walk_notify
+ *
+ * A back walk has reach this path-list.
+ */
+static fib_node_back_walk_rc_t
+fib_path_list_back_walk_notify (fib_node_t *node,
+				fib_node_back_walk_ctx_t *ctx)
+{
+    /*
+     * the path-list is not a direct child of any other node type
+     * paths, which do not change thier to-list-mapping, save the
+     * list they are a member of, and invoke the BW function directly.
+     */
+    ASSERT(0);
+
+    return (FIB_NODE_BACK_WALK_CONTINUE);
+}
+
+/*
+ * Display the path-list memory usage
+ */
+static void
+fib_path_list_memory_show (void)
+{
+    fib_show_memory_usage("Path-list",
+			  pool_elts(fib_path_list_pool),
+			  pool_len(fib_path_list_pool),
+			  sizeof(fib_path_list_t));
+    fib_urpf_list_show_mem();
+}
+
+/*
+ * The FIB path-list's graph node virtual function table
+ */
+static const fib_node_vft_t fib_path_list_vft = {
+    .fnv_get = fib_path_list_get_node,
+    .fnv_last_lock = fib_path_list_last_lock_gone,
+    .fnv_back_walk = fib_path_list_back_walk_notify,
+    .fnv_mem_show = fib_path_list_memory_show,
+};
+
+static fib_path_list_t *
+fib_path_list_alloc (fib_node_index_t *path_list_index)
+{
+    fib_path_list_t *path_list;
+
+    pool_get(fib_path_list_pool, path_list);
+    memset(path_list, 0, sizeof(*path_list));
+
+    fib_node_init(&path_list->fpl_node,
+		  FIB_NODE_TYPE_PATH_LIST);
+    path_list->fpl_urpf = INDEX_INVALID;
+
+    if (NULL != path_list_index)
+    {
+	*path_list_index = fib_path_list_get_index(path_list);
+    }
+
+    FIB_PATH_LIST_DBG(path_list, "alloc");
+
+    return (path_list);
+}
+
+static fib_path_list_t *
+fib_path_list_resolve (fib_path_list_t *path_list)
+{
+    fib_node_index_t *path_index, *paths, path_list_index;
+
+    ASSERT(!(path_list->fpl_flags & FIB_PATH_LIST_FLAG_RESOLVED));
+
+    /*
+     * resolving a path-list is a recursive action. this means more path
+     * lists can be created during this call, and hence this path-list
+     * can be realloc'd. so we work with copies.
+     * this function is called only once per-path list, so its no great overhead.
+     */
+    path_list_index = fib_path_list_get_index(path_list);
+    paths = vec_dup(path_list->fpl_paths);
+
+    vec_foreach (path_index, paths)
+    {
+	fib_path_resolve(*path_index);
+    }
+
+    vec_free(paths);
+    path_list = fib_path_list_get(path_list_index);
+
+    FIB_PATH_LIST_DBG(path_list, "resovled");
+    fib_path_list_mk_urpf(path_list);
+
+    return (path_list);
+}
+
+u32
+fib_path_list_get_resolving_interface (fib_node_index_t path_list_index)
+{
+    fib_node_index_t *path_index;
+    fib_path_list_t *path_list;
+    u32 sw_if_index;
+
+    path_list = fib_path_list_get(path_list_index);
+
+    sw_if_index = ~0;
+    vec_foreach (path_index, path_list->fpl_paths)
+    {
+	sw_if_index = fib_path_get_resolving_interface(*path_index);
+	if (~0 != sw_if_index)
+	{
+	    return (sw_if_index);
+	}
+    }
+
+    return (sw_if_index);
+}
+
+fib_protocol_t
+fib_path_list_get_proto (fib_node_index_t path_list_index)
+{
+    fib_path_list_t *path_list;
+
+    path_list = fib_path_list_get(path_list_index);
+
+    /*
+     * we don't support a mix of path protocols, so we can return the proto
+     * of the first
+     */
+    return (fib_path_get_proto(path_list->fpl_paths[0]));
+}
+
+int
+fib_path_list_is_looped (fib_node_index_t path_list_index)
+{
+    fib_path_list_t *path_list;
+
+    path_list = fib_path_list_get(path_list_index);
+
+    return (path_list->fpl_flags & FIB_PATH_LIST_FLAG_LOOPED);
+}
+
+static fib_path_cfg_flags_t 
+fib_path_list_flags_2_path_flags (fib_path_list_flags_t plf)
+{
+    fib_path_cfg_flags_t pf = FIB_PATH_CFG_FLAG_NONE;
+
+    if (plf & FIB_PATH_LIST_FLAG_LOCAL)
+    {
+	pf |= FIB_PATH_CFG_FLAG_LOCAL;
+    }
+    if (plf & FIB_PATH_LIST_FLAG_DROP)
+    {
+	pf |= FIB_PATH_CFG_FLAG_DROP;
+    }
+    if (plf & FIB_PATH_LIST_FLAG_EXCLUSIVE)
+    {
+	pf |= FIB_PATH_CFG_FLAG_EXCLUSIVE;
+    }
+
+    return (pf);
+}
+
+static fib_path_list_flags_t
+fib_path_list_flags_fixup (fib_path_list_flags_t flags)
+{
+    /*
+     * we do no share drop nor exclusive path-lists
+     */
+    if (flags & FIB_PATH_LIST_FLAG_DROP ||
+	flags & FIB_PATH_LIST_FLAG_EXCLUSIVE)
+    {
+	flags &= ~FIB_PATH_LIST_FLAG_SHARED;
+    }
+
+    return (flags);
+}
+
+fib_node_index_t
+fib_path_list_create (fib_path_list_flags_t flags,
+		      const fib_route_path_t *rpaths)
+{
+    fib_node_index_t path_list_index, old_path_list_index;
+    fib_path_list_t *path_list;
+    int i;
+
+    flags = fib_path_list_flags_fixup(flags);
+    path_list = fib_path_list_alloc(&path_list_index);
+    path_list->fpl_flags = flags;
+    /*
+     * we'll assume for now all paths are the same next-hop protocol
+     */
+    path_list->fpl_nh_proto = rpaths[0].frp_proto;
+
+    vec_foreach_index(i, rpaths)
+    {
+	vec_add1(path_list->fpl_paths,
+		 fib_path_create(path_list_index,
+				 path_list->fpl_nh_proto,
+				 fib_path_list_flags_2_path_flags(flags),
+				 &rpaths[i]));
+    }
+
+    /*
+     * If a shared path list is requested, consult the DB for a match
+     */
+    if (flags & FIB_PATH_LIST_FLAG_SHARED)
+    {
+	/*
+	 * check for a matching path-list in the DB.
+	 * If we find one then we can return the existing one and destroy the
+	 * new one just created.
+	 */
+	old_path_list_index = fib_path_list_db_find(path_list);
+	if (FIB_NODE_INDEX_INVALID != old_path_list_index)
+	{
+	    fib_path_list_destroy(path_list);
+	
+	    path_list_index = old_path_list_index;
+	}
+	else
+	{
+	    /*
+	     * if there was not a matching path-list, then this
+	     * new one will need inserting into the DB and resolving.
+	     */
+	    fib_path_list_db_insert(path_list_index);
+	    path_list = fib_path_list_resolve(path_list);
+	}
+    }
+    else
+    {
+	/*
+	 * no shared path list requested. resolve and use the one
+	 * just created.
+	 */
+	path_list = fib_path_list_resolve(path_list);
+    }
+
+    return (path_list_index);
+}
+
+fib_node_index_t
+fib_path_list_create_special (fib_protocol_t nh_proto,
+			      fib_path_list_flags_t flags,
+			      const dpo_id_t *dpo)
+{
+    fib_node_index_t path_index, path_list_index;
+    fib_path_list_t *path_list;
+
+    path_list = fib_path_list_alloc(&path_list_index);
+    path_list->fpl_flags = flags;
+    path_list->fpl_nh_proto = nh_proto;
+
+    path_index =
+	fib_path_create_special(path_list_index,
+				path_list->fpl_nh_proto,
+				fib_path_list_flags_2_path_flags(flags),
+				dpo);
+    vec_add1(path_list->fpl_paths, path_index);
+
+    /*
+     * we don't share path-lists. we can do PIC on them so why bother.
+     */
+    path_list = fib_path_list_resolve(path_list);
+
+    return (path_list_index);
+}
+
+/*
+ * fib_path_list_copy_and_path_add
+ *
+ * Create a copy of a path-list and append one more path to it.
+ * The path-list returned could either have been newly created, or
+ * can be a shared path-list from the data-base.
+ */
+fib_node_index_t
+fib_path_list_copy_and_path_add (fib_node_index_t orig_path_list_index,
+				 fib_path_list_flags_t flags,
+				 const fib_route_path_t *rpaths)
+{
+    fib_node_index_t path_index, new_path_index, *orig_path_index;
+    fib_path_list_t *path_list, *orig_path_list;
+    fib_node_index_t path_list_index;
+    fib_node_index_t pi;
+
+    ASSERT(1 == vec_len(rpaths));
+
+    /*
+     * alloc the new list before we retrieve the old one, lest
+     * the alloc result in a realloc
+     */
+    path_list = fib_path_list_alloc(&path_list_index);
+
+    orig_path_list = fib_path_list_get(orig_path_list_index);
+
+    FIB_PATH_LIST_DBG(orig_path_list, "copy-add");
+
+    flags = fib_path_list_flags_fixup(flags);
+    path_list->fpl_flags = flags;
+    path_list->fpl_nh_proto = orig_path_list->fpl_nh_proto;
+    vec_validate(path_list->fpl_paths, vec_len(orig_path_list->fpl_paths));
+    pi = 0;
+
+    new_path_index = fib_path_create(path_list_index,
+                                     path_list->fpl_nh_proto,
+                                     fib_path_list_flags_2_path_flags(flags),
+                                     rpaths);
+
+    vec_foreach (orig_path_index, orig_path_list->fpl_paths)
+    {
+        /*
+         * don't add duplicate paths
+         * In the unlikely event the path is a duplicate, then we'll
+         * find a matching path-list later and this one will be toast.
+         */
+	if (0 != fib_path_cmp(new_path_index, *orig_path_index))
+        {
+            path_index = fib_path_copy(*orig_path_index, path_list_index);
+            path_list->fpl_paths[pi++] = path_index;
+        }
+        else
+        {
+            _vec_len(path_list->fpl_paths) = vec_len(orig_path_list->fpl_paths);
+        }
+    }
+
+    path_list->fpl_paths[pi] = new_path_index;
+
+    /*
+     * we sort the paths since the key for the path-list is
+     * the description of the paths it contains. The paths need to
+     * be sorted else this description will differ.
+     */
+    vec_sort_with_function(path_list->fpl_paths, fib_path_cmp_for_sort);
+
+    FIB_PATH_LIST_DBG(path_list, "path-added");
+
+    /*
+     * If a shared path list is requested, consult the DB for a match
+     */
+    if (path_list->fpl_flags & FIB_PATH_LIST_FLAG_SHARED)
+    {
+	fib_node_index_t exist_path_list_index;
+	/*
+	 * check for a matching path-list in the DB.
+	 * If we find one then we can return the existing one and destroy the
+	 * new one just created.
+	 */
+	exist_path_list_index = fib_path_list_db_find(path_list);
+	if (FIB_NODE_INDEX_INVALID != exist_path_list_index)
+	{
+	    fib_path_list_destroy(path_list);
+	
+	    path_list_index = exist_path_list_index;
+	}
+	else
+	{
+	    /*
+	     * if there was not a matching path-list, then this
+	     * new one will need inserting into the DB and resolving.
+	     */
+	    fib_path_list_db_insert(path_list_index);
+
+	    path_list = fib_path_list_resolve(path_list);
+	}
+    }
+    else
+    {
+	/*
+	 * no shared path list requested. resolve and use the one
+	 * just created.
+	 */
+	path_list = fib_path_list_resolve(path_list);
+    }
+
+    return (path_list_index);
+}
+
+/*
+ * fib_path_list_copy_and_path_remove
+ *
+ * Copy the path-list excluding the path passed.
+ * If the path is the last one, then the index reurned will be invalid.
+ * i.e. the path-list is toast.
+ */
+fib_node_index_t
+fib_path_list_copy_and_path_remove (fib_node_index_t orig_path_list_index,
+				    fib_path_list_flags_t flags,
+				    const fib_route_path_t *rpaths)
+{
+    fib_node_index_t path_index, *orig_path_index, path_list_index, tmp_path_index;
+    fib_path_list_t *path_list,  *orig_path_list;
+    fib_node_index_t pi;
+
+    ASSERT(1 == vec_len(rpaths));
+
+    path_list = fib_path_list_alloc(&path_list_index);
+
+    flags = fib_path_list_flags_fixup(flags);
+    orig_path_list = fib_path_list_get(orig_path_list_index);
+
+    FIB_PATH_LIST_DBG(orig_path_list, "copy-remove");
+
+    path_list->fpl_flags = flags;
+    path_list->fpl_nh_proto = orig_path_list->fpl_nh_proto;
+    /*
+     * allocate as many paths as we might need in one go, rather than
+     * using vec_add to do a few at a time.
+     */
+    if (vec_len(orig_path_list->fpl_paths) > 1)
+    {
+	vec_validate(path_list->fpl_paths, vec_len(orig_path_list->fpl_paths) - 2);
+    }
+    pi = 0;
+
+    /*
+     * create a representation of the path to be removed, so it
+     * can be used as a comparison object during the copy.
+     */
+    tmp_path_index = fib_path_create(path_list_index,
+				     path_list->fpl_nh_proto,
+				     fib_path_list_flags_2_path_flags(flags),
+				     rpaths);
+
+    vec_foreach (orig_path_index, orig_path_list->fpl_paths)
+    {
+	if (0 != fib_path_cmp(tmp_path_index, *orig_path_index)) {
+	    path_index = fib_path_copy(*orig_path_index, path_list_index);
+	    if (pi < vec_len(path_list->fpl_paths))
+	    {
+		path_list->fpl_paths[pi++] = path_index;
+	    }
+	    else
+	    {
+		/*
+		 * this is the unlikely case that the path being
+		 * removed does not match one in the path-list, so
+		 * we end up with as many paths as we started with.
+		 * the paths vector was sized above with the expectation
+		 * that we would have 1 less.
+		 */
+		vec_add1(path_list->fpl_paths, path_index);
+	    }
+	}
+    }
+
+    /*
+     * done with the temporary now
+     */
+    fib_path_destroy(tmp_path_index);
+
+    /*
+     * if there are no paths, then the new path-list is aborted
+     */
+    if (0 == vec_len(path_list->fpl_paths)) {
+	FIB_PATH_LIST_DBG(path_list, "last-path-removed");
+
+	fib_path_list_destroy(path_list);
+
+	path_list_index = FIB_NODE_INDEX_INVALID;
+    } else {
+	/*
+	 * we sort the paths since the key for the path-list is
+	 * the description of the paths it contains. The paths need to
+	 * be sorted else this description will differ.
+	 */
+	vec_sort_with_function(path_list->fpl_paths, fib_path_cmp_for_sort);
+    
+	/*
+	 * If a shared path list is requested, consult the DB for a match
+	 */
+	if (path_list->fpl_flags & FIB_PATH_LIST_FLAG_SHARED)
+	{
+	    fib_node_index_t exist_path_list_index;
+
+            /*
+	     * check for a matching path-list in the DB.
+	     * If we find one then we can return the existing one and destroy the
+	     * new one just created.
+	     */
+	    exist_path_list_index = fib_path_list_db_find(path_list);
+	    if (FIB_NODE_INDEX_INVALID != exist_path_list_index)
+	    {
+		fib_path_list_destroy(path_list);
+	
+		path_list_index = exist_path_list_index;
+	    }
+	    else
+	    {
+		/*
+		 * if there was not a matching path-list, then this
+		 * new one will need inserting into the DB and resolving.
+		 */
+		fib_path_list_db_insert(path_list_index);
+
+		path_list = fib_path_list_resolve(path_list);
+	    }
+	}
+	else
+	{
+	    /*
+	     * no shared path list requested. resolve and use the one
+	     * just created.
+	     */
+	    path_list = fib_path_list_resolve(path_list);
+	}
+    }
+
+    return (path_list_index);
+}
+
+/*
+ * fib_path_list_contribute_forwarding
+ *
+ * Return the index of a load-balance that user of this path-list should
+ * use for forwarding
+ */
+void
+fib_path_list_contribute_forwarding (fib_node_index_t path_list_index,
+				     fib_forward_chain_type_t type,
+				     dpo_id_t *dpo)
+{
+    fib_path_list_t *path_list;
+
+    path_list = fib_path_list_get(path_list_index);
+
+    fib_path_list_mk_lb(path_list, type, dpo);
+}
+
+/*
+ * fib_path_list_get_adj
+ *
+ * Return the index of a adjacency for the first path that user of this
+ * path-list should use for forwarding
+ */
+adj_index_t
+fib_path_list_get_adj (fib_node_index_t path_list_index,
+		       fib_forward_chain_type_t type)
+{
+    fib_path_list_t *path_list;
+
+    path_list = fib_path_list_get(path_list_index);
+    return (fib_path_get_adj(path_list->fpl_paths[0]));
+}
+
+int
+fib_path_list_recursive_loop_detect (fib_node_index_t path_list_index,
+				     fib_node_index_t **entry_indicies)
+{
+    fib_node_index_t *path_index;
+    int is_looped, list_looped;
+    fib_path_list_t *path_list;
+
+    list_looped = 0;
+    path_list = fib_path_list_get(path_list_index);
+
+    vec_foreach (path_index, path_list->fpl_paths)
+    {
+	fib_node_index_t *copy, **copy_ptr;
+
+	/*
+	 * we need a copy of the nodes visited so that when we add entries
+	 * we explore on the nth path and a looped is detected, those entries
+	 * are not again searched for n+1 path and so finding a loop that does
+	 * not exist.
+	 */
+	copy = vec_dup(*entry_indicies);
+	copy_ptr = &copy;
+
+	is_looped  = fib_path_recursive_loop_detect(*path_index, copy_ptr);
+	list_looped += is_looped;
+    }
+
+    FIB_PATH_LIST_DBG(path_list, "loop-detect: eval:%d", eval);
+
+    if (list_looped)
+    {
+	path_list->fpl_flags |= FIB_PATH_LIST_FLAG_LOOPED;
+    }
+    else
+    {
+	path_list->fpl_flags &= ~FIB_PATH_LIST_FLAG_LOOPED;
+    }
+
+    return (list_looped);
+}
+
+u32
+fib_path_list_child_add (fib_node_index_t path_list_index,
+			 fib_node_type_t child_type,
+			 fib_node_index_t child_index)
+{
+    return (fib_node_child_add(FIB_NODE_TYPE_PATH_LIST,
+                               path_list_index,
+                               child_type,
+                               child_index));
+}
+
+void
+fib_path_list_child_remove (fib_node_index_t path_list_index,
+			    u32 si)
+{
+    fib_node_child_remove(FIB_NODE_TYPE_PATH_LIST,
+                          path_list_index,
+                          si);
+}
+
+void
+fib_path_list_lock(fib_node_index_t path_list_index)
+{
+    fib_path_list_t *path_list;
+
+    if (FIB_NODE_INDEX_INVALID != path_list_index)
+    {
+	path_list = fib_path_list_get(path_list_index);
+
+	fib_node_lock(&path_list->fpl_node);
+	FIB_PATH_LIST_DBG(path_list, "lock");
+    }
+}
+
+void
+fib_path_list_unlock (fib_node_index_t path_list_index)
+{
+    fib_path_list_t *path_list;
+
+    if (FIB_NODE_INDEX_INVALID != path_list_index)
+    {
+	path_list = fib_path_list_get(path_list_index);
+	FIB_PATH_LIST_DBG(path_list, "unlock");
+    
+	fib_node_unlock(&path_list->fpl_node);
+    }
+}
+
+u32
+fib_path_list_pool_size (void)
+{
+    return (pool_elts(fib_path_list_pool));    
+}
+
+u32
+fib_path_list_db_size (void)
+{
+    return (hash_elts(fib_path_list_db));
+}
+
+void
+fib_path_list_walk (fib_node_index_t path_list_index,
+		    fib_path_list_walk_fn_t func,
+		    void *ctx)
+{
+    fib_node_index_t *path_index;
+    fib_path_list_t *path_list;
+
+    path_list = fib_path_list_get(path_list_index);
+
+    vec_foreach(path_index, path_list->fpl_paths)
+    {
+	if (!func(path_list_index, *path_index, ctx))
+	    break;
+    }
+}
+
+
+void
+fib_path_list_module_init (void)
+{
+    fib_node_register_type (FIB_NODE_TYPE_PATH_LIST, &fib_path_list_vft);
+
+    fib_path_list_db = hash_create2 (/* elts */ 0,
+    				     /* user */ 0,
+    				     /* value_bytes */ sizeof (fib_node_index_t),
+    				     fib_path_list_db_hash_key_sum,
+    				     fib_path_list_db_hash_key_equal,
+    				     /* format pair/arg */
+    				     0, 0);
+}
+
+static clib_error_t *
+show_fib_path_list_command (vlib_main_t * vm,
+			    unformat_input_t * input,
+			    vlib_cli_command_t * cmd)
+{
+    fib_path_list_t *path_list;
+    fib_node_index_t pli;
+
+    if (unformat (input, "%d", &pli))
+    {
+	/*
+	 * show one in detail
+	 */
+	if (!pool_is_free_index(fib_path_list_pool, pli))
+	{
+	    path_list = fib_path_list_get(pli);
+	    u8 *s = fib_path_list_format(pli, NULL);
+	    s = format(s, "children:");
+	    s = fib_node_children_format(path_list->fpl_node.fn_children, s);
+	    vlib_cli_output (vm, "%s", s);
+	    vec_free(s);
+	}
+	else
+	{
+	    vlib_cli_output (vm, "path list %d invalid", pli);
+	}
+    }
+    else
+    {
+	/*
+	 * show all
+	 */
+	vlib_cli_output (vm, "FIB Path Lists");
+	pool_foreach(path_list, fib_path_list_pool,
+	({
+	    vlib_cli_output (vm, "%U", format_fib_path_list, path_list);
+	}));
+    }
+    return (NULL);
+}
+
+VLIB_CLI_COMMAND (show_fib_path_list, static) = {
+  .path = "show fib path-lists",
+  .function = show_fib_path_list_command,
+  .short_help = "show fib path-lists",
+};
diff --git a/src/vnet/fib/fib_path_list.h b/src/vnet/fib/fib_path_list.h
new file mode 100644
index 00000000000..8bc1b20b6bf
--- /dev/null
+++ b/src/vnet/fib/fib_path_list.h
@@ -0,0 +1,158 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __FIB_PATH_LIST_H__
+#define __FIB_PATH_LIST_H__
+
+#include <vlib/vlib.h>
+#include <vnet/adj/adj.h>
+
+#include "fib_node.h"
+#include "fib_path.h"
+
+/**
+ * Enumeration of path-list flags.
+ */
+typedef enum fib_path_list_attribute_t_ {
+    /**
+     * Marker. Add new flags after this one.
+     */
+    FIB_PATH_LIST_ATTRIBUTE_FIRST = 0,
+    /**
+     * This path list is shareable. Shareable path-lists
+     * are inserted into the path-list data-base.
+     * All path-list are inherently shareable, the reason we share some and
+     * not others is to limit the size of the path-list database. This DB must
+     * be searched for each route update.
+     */
+    FIB_PATH_LIST_ATTRIBUTE_SHARED = FIB_PATH_LIST_ATTRIBUTE_FIRST,
+    /**
+     * explicit drop path-list. Used when the entry source needs to 
+     * force a drop, despite the fact the path info is present.
+     */
+    FIB_PATH_LIST_ATTRIBUTE_DROP,
+    /**
+     * explicit local path-list.
+     */
+    FIB_PATH_LIST_ATTRIBUTE_LOCAL,
+    /**
+     * exclusive path-list. Exclusive means the path will resolve via the
+     * exclusive (user provided) adj.
+     */
+    FIB_PATH_LIST_ATTRIBUTE_EXCLUSIVE,
+    /**
+     * resolved path-list
+     */
+    FIB_PATH_LIST_ATTRIBUTE_RESOLVED,
+    /**
+     * looped path-list. one path looped implies the whole list is
+     */
+    FIB_PATH_LIST_ATTRIBUTE_LOOPED,
+    /**
+     * Marher. Add new flags before this one, and then update it.
+     */
+    FIB_PATH_LIST_ATTRIBUTE_LAST = FIB_PATH_LIST_ATTRIBUTE_LOOPED,
+} fib_path_list_attribute_t;
+
+typedef enum fib_path_list_flags_t_ {
+    FIB_PATH_LIST_FLAG_NONE      = 0,
+    FIB_PATH_LIST_FLAG_SHARED    = (1 << FIB_PATH_LIST_ATTRIBUTE_SHARED),
+    FIB_PATH_LIST_FLAG_DROP      = (1 << FIB_PATH_LIST_ATTRIBUTE_DROP),
+    FIB_PATH_LIST_FLAG_LOCAL     = (1 << FIB_PATH_LIST_ATTRIBUTE_LOCAL),
+    FIB_PATH_LIST_FLAG_EXCLUSIVE = (1 << FIB_PATH_LIST_ATTRIBUTE_EXCLUSIVE),
+    FIB_PATH_LIST_FLAG_RESOLVED  = (1 << FIB_PATH_LIST_ATTRIBUTE_RESOLVED),
+    FIB_PATH_LIST_FLAG_LOOPED    = (1 << FIB_PATH_LIST_ATTRIBUTE_LOOPED),
+} fib_path_list_flags_t;
+
+#define FIB_PATH_LIST_ATTRIBUTES {       		 \
+    [FIB_PATH_LIST_ATTRIBUTE_SHARED]    = "shared",	 \
+    [FIB_PATH_LIST_ATTRIBUTE_RESOLVED]  = "resolved",	 \
+    [FIB_PATH_LIST_ATTRIBUTE_DROP]      = "drop",	 \
+    [FIB_PATH_LIST_ATTRIBUTE_EXCLUSIVE] = "exclusive",   \
+    [FIB_PATH_LIST_ATTRIBUTE_LOCAL]     = "local",	 \
+    [FIB_PATH_LIST_ATTRIBUTE_LOOPED]     = "looped",	 \
+}
+
+#define FOR_EACH_PATH_LIST_ATTRIBUTE(_item)		\
+    for (_item = FIB_PATH_LIST_ATTRIBUTE_FIRST;		\
+	 _item <= FIB_PATH_LIST_ATTRIBUTE_LAST;		\
+	 _item++)
+
+extern fib_node_index_t fib_path_list_create(fib_path_list_flags_t flags,
+					     const fib_route_path_t *paths);
+extern fib_node_index_t fib_path_list_create_special(fib_protocol_t nh_proto,
+						     fib_path_list_flags_t flags,
+						     const dpo_id_t *dpo);
+
+extern fib_node_index_t fib_path_list_copy_and_path_add(
+    fib_node_index_t pl_index,
+    fib_path_list_flags_t flags,
+    const fib_route_path_t *path);
+extern fib_node_index_t fib_path_list_copy_and_path_remove(
+    fib_node_index_t pl_index,
+    fib_path_list_flags_t flags,
+    const fib_route_path_t *path);
+extern void fib_path_list_contribute_forwarding(fib_node_index_t path_list_index,
+						fib_forward_chain_type_t type,
+						dpo_id_t *dpo);
+extern void fib_path_list_contribute_urpf(fib_node_index_t path_index,
+					  index_t urpf);
+extern index_t fib_path_list_get_urpf(fib_node_index_t path_list_index);
+extern index_t fib_path_list_get_adj(fib_node_index_t path_list_index,
+				     fib_forward_chain_type_t type);
+
+extern u32 fib_path_list_child_add(fib_node_index_t pl_index,
+				   fib_node_type_t type,
+				   fib_node_index_t child_index);
+extern void fib_path_list_child_remove(fib_node_index_t pl_index,
+				       fib_node_index_t sibling_index);
+extern void fib_path_list_back_walk(fib_node_index_t pl_index,
+				    fib_node_back_walk_ctx_t *ctx);
+extern void fib_path_list_lock(fib_node_index_t pl_index);
+extern void fib_path_list_unlock(fib_node_index_t pl_index);
+extern int fib_path_list_recursive_loop_detect(fib_node_index_t path_list_index,
+					       fib_node_index_t **entry_indicies);
+extern u32 fib_path_list_get_resolving_interface(fib_node_index_t path_list_index);
+extern int fib_path_list_is_looped(fib_node_index_t path_list_index);
+extern fib_protocol_t fib_path_list_get_proto(fib_node_index_t path_list_index);
+extern u8 * fib_path_list_format(fib_node_index_t pl_index,
+				 u8 * s);
+extern u8 * fib_path_list_adjs_format(fib_node_index_t pl_index,
+				      u32 indent,
+				      u8 * s);
+extern index_t fib_path_list_lb_map_add_or_lock(fib_node_index_t pl_index,
+                                                const fib_node_index_t *pis);
+/**
+ * A callback function type for walking a path-list's paths
+ */
+typedef int (*fib_path_list_walk_fn_t)(fib_node_index_t pl_index,
+				       fib_node_index_t path_index,
+				       void *ctx);
+
+extern void fib_path_list_walk(fib_node_index_t pl_index,
+			       fib_path_list_walk_fn_t func,
+			       void *ctx);
+
+extern void fib_path_list_module_init(void);
+
+extern void fib_path_list_module_init(void);
+
+/*
+ * functions for testing.
+ */
+u32 fib_path_list_pool_size(void);
+u32 fib_path_list_db_size(void);
+
+#endif
diff --git a/src/vnet/fib/fib_table.c b/src/vnet/fib/fib_table.c
new file mode 100644
index 00000000000..76db42d0ec7
--- /dev/null
+++ b/src/vnet/fib/fib_table.c
@@ -0,0 +1,1104 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vlib/vlib.h>
+#include <vnet/dpo/drop_dpo.h>
+
+#include <vnet/fib/fib_table.h>
+#include <vnet/fib/fib_entry_cover.h>
+#include <vnet/fib/fib_internal.h>
+#include <vnet/fib/ip4_fib.h>
+#include <vnet/fib/ip6_fib.h>
+#include <vnet/fib/mpls_fib.h>
+
+fib_table_t *
+fib_table_get (fib_node_index_t index,
+	       fib_protocol_t proto)
+{
+    switch (proto)
+    {
+    case FIB_PROTOCOL_IP4:
+	return (pool_elt_at_index(ip4_main.fibs, index));
+    case FIB_PROTOCOL_IP6:
+	return (pool_elt_at_index(ip6_main.fibs, index));
+    case FIB_PROTOCOL_MPLS:
+	return (pool_elt_at_index(mpls_main.fibs, index));
+    }
+    ASSERT(0);
+    return (NULL);
+}
+
+static inline fib_node_index_t
+fib_table_lookup_i (fib_table_t *fib_table,
+		    const fib_prefix_t *prefix)
+{
+    switch (prefix->fp_proto)
+    {
+    case FIB_PROTOCOL_IP4:
+	return (ip4_fib_table_lookup(&fib_table->v4,
+				     &prefix->fp_addr.ip4,
+				     prefix->fp_len));
+    case FIB_PROTOCOL_IP6:
+	return (ip6_fib_table_lookup(fib_table->ft_index,
+				     &prefix->fp_addr.ip6,
+				     prefix->fp_len));
+    case FIB_PROTOCOL_MPLS:
+	return (mpls_fib_table_lookup(&fib_table->mpls,
+				      prefix->fp_label,
+				      prefix->fp_eos));
+    }
+    return (FIB_NODE_INDEX_INVALID);
+}
+
+fib_node_index_t
+fib_table_lookup (u32 fib_index,
+		  const fib_prefix_t *prefix)
+{
+    return (fib_table_lookup_i(fib_table_get(fib_index, prefix->fp_proto), prefix));
+}
+
+static inline fib_node_index_t
+fib_table_lookup_exact_match_i (const fib_table_t *fib_table,
+				const fib_prefix_t *prefix)
+{
+    switch (prefix->fp_proto)
+    {
+    case FIB_PROTOCOL_IP4:
+	return (ip4_fib_table_lookup_exact_match(&fib_table->v4,
+						 &prefix->fp_addr.ip4,
+						 prefix->fp_len));
+    case FIB_PROTOCOL_IP6:
+	return (ip6_fib_table_lookup_exact_match(fib_table->ft_index,
+						 &prefix->fp_addr.ip6,
+						 prefix->fp_len));
+    case FIB_PROTOCOL_MPLS:
+	return (mpls_fib_table_lookup(&fib_table->mpls,
+				      prefix->fp_label,
+				      prefix->fp_eos));
+    }
+    return (FIB_NODE_INDEX_INVALID);
+}
+
+fib_node_index_t
+fib_table_lookup_exact_match (u32 fib_index,
+			      const fib_prefix_t *prefix)
+{
+    return (fib_table_lookup_exact_match_i(fib_table_get(fib_index,
+							 prefix->fp_proto),
+					   prefix));
+}
+
+static fib_node_index_t
+fib_table_get_less_specific_i (fib_table_t *fib_table,
+			       const fib_prefix_t *prefix)
+{
+    fib_prefix_t pfx;
+
+    pfx = *prefix;
+
+    if (FIB_PROTOCOL_MPLS == pfx.fp_proto)
+    {
+	return (FIB_NODE_INDEX_INVALID);
+    }
+
+    /*
+     * in the absence of a tree structure for the table that allows for an O(1)
+     * parent get, a cheeky way to find the cover is to LPM for the prefix with
+     * mask-1.
+     * there should always be a cover, though it may be the default route. the
+     * default route's cover is the default route.
+     */
+    if (pfx.fp_len != 0) {
+	pfx.fp_len -= 1;
+    }
+
+    return (fib_table_lookup_i(fib_table, &pfx));    
+}
+
+fib_node_index_t
+fib_table_get_less_specific (u32 fib_index,
+			     const fib_prefix_t *prefix)
+{
+    return (fib_table_get_less_specific_i(fib_table_get(fib_index,
+							prefix->fp_proto),
+					  prefix));
+}
+
+static void
+fib_table_entry_remove (fib_table_t *fib_table,
+			const fib_prefix_t *prefix,
+			fib_node_index_t fib_entry_index)
+{
+    vlib_smp_unsafe_warning();
+
+    fib_table->ft_total_route_counts--;
+
+    switch (prefix->fp_proto)
+    {
+    case FIB_PROTOCOL_IP4:
+	ip4_fib_table_entry_remove(&fib_table->v4,
+				   &prefix->fp_addr.ip4,
+				   prefix->fp_len);
+	break;
+    case FIB_PROTOCOL_IP6:
+	ip6_fib_table_entry_remove(fib_table->ft_index,
+				   &prefix->fp_addr.ip6,
+				   prefix->fp_len);
+	break;
+    case FIB_PROTOCOL_MPLS:
+	mpls_fib_table_entry_remove(&fib_table->mpls,
+				    prefix->fp_label,
+				    prefix->fp_eos);
+	break;
+    }
+
+    fib_entry_unlock(fib_entry_index);
+}
+
+static void
+fib_table_post_insert_actions (fib_table_t *fib_table,
+			       const fib_prefix_t *prefix,
+			       fib_node_index_t fib_entry_index)
+{
+    fib_node_index_t fib_entry_cover_index;
+
+    /*
+     * no cover relationships in the MPLS FIB
+     */
+    if (FIB_PROTOCOL_MPLS == prefix->fp_proto)
+	return;
+
+    /*
+     * find and inform the covering entry that a new more specific
+     * has been inserted beneath it
+     */
+    fib_entry_cover_index = fib_table_get_less_specific_i(fib_table, prefix);
+    /*
+     * the indicies are the same when the default route is first added
+     */
+    if (fib_entry_cover_index != fib_entry_index)
+    {
+	fib_entry_cover_change_notify(fib_entry_cover_index,
+				      fib_entry_index);
+    }
+}
+
+static void
+fib_table_entry_insert (fib_table_t *fib_table,
+			const fib_prefix_t *prefix,
+			fib_node_index_t fib_entry_index)
+{
+    vlib_smp_unsafe_warning();
+
+    fib_entry_lock(fib_entry_index);
+    fib_table->ft_total_route_counts++;
+
+    switch (prefix->fp_proto)
+    {
+    case FIB_PROTOCOL_IP4:
+	ip4_fib_table_entry_insert(&fib_table->v4,
+				   &prefix->fp_addr.ip4,
+				   prefix->fp_len,
+				   fib_entry_index);
+	break;
+    case FIB_PROTOCOL_IP6:
+	ip6_fib_table_entry_insert(fib_table->ft_index,
+				   &prefix->fp_addr.ip6,
+				   prefix->fp_len,
+				   fib_entry_index);
+	break;
+    case FIB_PROTOCOL_MPLS:
+	mpls_fib_table_entry_insert(&fib_table->mpls,
+				    prefix->fp_label,
+				    prefix->fp_eos,
+				    fib_entry_index);
+	break;
+    }
+
+    fib_table_post_insert_actions(fib_table, prefix, fib_entry_index);
+}
+
+void
+fib_table_fwding_dpo_update (u32 fib_index,
+			     const fib_prefix_t *prefix,
+			     const dpo_id_t *dpo)
+{
+    vlib_smp_unsafe_warning();
+
+    switch (prefix->fp_proto)
+    {
+    case FIB_PROTOCOL_IP4:
+	return (ip4_fib_table_fwding_dpo_update(ip4_fib_get(fib_index),
+						&prefix->fp_addr.ip4,
+						prefix->fp_len,
+						dpo));
+    case FIB_PROTOCOL_IP6:
+	return (ip6_fib_table_fwding_dpo_update(fib_index,
+						&prefix->fp_addr.ip6,
+						prefix->fp_len,
+						dpo));
+    case FIB_PROTOCOL_MPLS:
+	return (mpls_fib_forwarding_table_update(mpls_fib_get(fib_index),
+						 prefix->fp_label,
+						 prefix->fp_eos,
+						 dpo));
+    }
+}
+
+void
+fib_table_fwding_dpo_remove (u32 fib_index,
+			     const fib_prefix_t *prefix,
+			     const dpo_id_t *dpo)
+{
+    vlib_smp_unsafe_warning();
+
+    switch (prefix->fp_proto)
+    {
+    case FIB_PROTOCOL_IP4:
+	return (ip4_fib_table_fwding_dpo_remove(ip4_fib_get(fib_index),
+						&prefix->fp_addr.ip4,
+						prefix->fp_len,
+						dpo));
+    case FIB_PROTOCOL_IP6:
+	return (ip6_fib_table_fwding_dpo_remove(fib_index,
+						&prefix->fp_addr.ip6,
+						prefix->fp_len,
+						dpo));
+    case FIB_PROTOCOL_MPLS:
+	return (mpls_fib_forwarding_table_reset(mpls_fib_get(fib_index),
+						prefix->fp_label,
+						prefix->fp_eos));
+    }
+}
+
+
+fib_node_index_t
+fib_table_entry_special_dpo_add (u32 fib_index,
+                                 const fib_prefix_t *prefix,
+                                 fib_source_t source,
+                                 fib_entry_flag_t flags,
+                                 const dpo_id_t *dpo)
+{
+    fib_node_index_t fib_entry_index;
+    fib_table_t *fib_table;
+
+    fib_table = fib_table_get(fib_index, prefix->fp_proto);
+    fib_entry_index = fib_table_lookup_exact_match_i(fib_table, prefix);
+
+    if (FIB_NODE_INDEX_INVALID == fib_entry_index)
+    {
+	fib_entry_index = fib_entry_create_special(fib_index, prefix,
+						   source, flags,
+						   dpo);
+
+	fib_table_entry_insert(fib_table, prefix, fib_entry_index);
+        fib_table->ft_src_route_counts[source]++;
+    }
+    else
+    {
+        int was_sourced;
+
+        was_sourced = fib_entry_is_sourced(fib_entry_index, source);
+	fib_entry_special_add(fib_entry_index, source, flags, dpo);
+
+        if (was_sourced != fib_entry_is_sourced(fib_entry_index, source))
+        {
+            fib_table->ft_src_route_counts[source]++;
+        }
+    }
+
+
+    return (fib_entry_index);
+}
+
+fib_node_index_t
+fib_table_entry_special_dpo_update (u32 fib_index,
+				    const fib_prefix_t *prefix,
+				    fib_source_t source,
+				    fib_entry_flag_t flags,
+				    const dpo_id_t *dpo)
+{
+    fib_node_index_t fib_entry_index;
+    fib_table_t *fib_table;
+
+    fib_table = fib_table_get(fib_index, prefix->fp_proto);
+    fib_entry_index = fib_table_lookup_exact_match_i(fib_table, prefix);
+
+    if (FIB_NODE_INDEX_INVALID == fib_entry_index)
+    {
+	fib_entry_index = fib_entry_create_special(fib_index, prefix,
+						   source, flags,
+						   dpo);
+
+	fib_table_entry_insert(fib_table, prefix, fib_entry_index);
+        fib_table->ft_src_route_counts[source]++;
+    }
+    else
+    {
+        int was_sourced;
+
+        was_sourced = fib_entry_is_sourced(fib_entry_index, source);
+
+	if (was_sourced)
+	    fib_entry_special_update(fib_entry_index, source, flags, dpo);
+	else
+	    fib_entry_special_add(fib_entry_index, source, flags, dpo);
+
+        if (was_sourced != fib_entry_is_sourced(fib_entry_index, source))
+        {
+            fib_table->ft_src_route_counts[source]++;
+        }
+    }
+
+    return (fib_entry_index);
+}
+
+fib_node_index_t
+fib_table_entry_special_add (u32 fib_index,
+			     const fib_prefix_t *prefix,
+			     fib_source_t source,
+			     fib_entry_flag_t flags,
+			     adj_index_t adj_index)
+{
+    fib_node_index_t fib_entry_index;
+    dpo_id_t tmp_dpo = DPO_INVALID;
+
+    if (ADJ_INDEX_INVALID != adj_index)
+    {
+        dpo_set(&tmp_dpo,
+                DPO_ADJACENCY,
+                FIB_PROTOCOL_MAX,
+                adj_index);
+    }
+    else
+    {
+        dpo_copy(&tmp_dpo, drop_dpo_get(fib_proto_to_dpo(prefix->fp_proto)));
+    }
+ 
+    fib_entry_index = fib_table_entry_special_dpo_add(fib_index, prefix, source,
+                                                      flags, &tmp_dpo);
+
+    dpo_unlock(&tmp_dpo);
+
+    return (fib_entry_index);
+}
+
+void
+fib_table_entry_special_remove (u32 fib_index,
+				const fib_prefix_t *prefix,
+				fib_source_t source)
+{
+    /*
+     * 1 is it present
+     *   yes => remove source
+     *    2 - is it still sourced?
+     *      no => cover walk
+     */
+    fib_node_index_t fib_entry_index;
+    fib_table_t *fib_table;
+
+    fib_table = fib_table_get(fib_index, prefix->fp_proto);
+    fib_entry_index = fib_table_lookup_exact_match_i(fib_table, prefix);
+
+    if (FIB_NODE_INDEX_INVALID == fib_entry_index)
+    {
+	/*
+	 * removing an etry that does not exist. i'll allow it.
+	 */
+    }
+    else
+    {
+	fib_entry_src_flag_t src_flag;
+        int was_sourced;
+
+	/*
+	 * don't nobody go nowhere
+	 */
+	fib_entry_lock(fib_entry_index);
+        was_sourced = fib_entry_is_sourced(fib_entry_index, source);
+
+	src_flag = fib_entry_special_remove(fib_entry_index, source);
+
+	if (!(FIB_ENTRY_SRC_FLAG_ADDED & src_flag))
+	{
+	    /*
+	     * last source gone. remove from the table
+	     */
+	    fib_table_entry_remove(fib_table, prefix, fib_entry_index);
+
+	    /*
+	     * now the entry is no longer in the table, we can
+	     * inform the entries that it covers to re-calculate their cover
+	     */
+	    fib_entry_cover_change_notify(fib_entry_index,
+					  FIB_NODE_INDEX_INVALID);
+	}
+	/*
+	 * else
+	 *   still has sources, leave it be.
+	 */
+        if (was_sourced != fib_entry_is_sourced(fib_entry_index, source))
+        {
+            fib_table->ft_src_route_counts[source]--;
+        }
+
+	fib_entry_unlock(fib_entry_index);
+    }
+}
+
+/**
+ * fib_table_route_path_fixup
+ *
+ * Convert attached hosts to attached next-hops.
+ * 
+ * This special case is required because an attached path will link to a
+ * glean, and the FIB entry will have the interface or API/CLI source. When
+ * the ARP/ND process is completes then that source (which will provide a
+ * complete adjacency) will be lower priority and so the FIB entry will
+ * remain linked to a glean and traffic will never reach the hosts. For
+ * an ATTAHCED_HOST path we can link the path directly to the [incomplete]
+ * adjacency.
+ */
+static void
+fib_table_route_path_fixup (const fib_prefix_t *prefix,
+			    fib_route_path_t *path)
+{
+    if (fib_prefix_is_host(prefix) &&
+	ip46_address_is_zero(&path->frp_addr) &&
+	path->frp_sw_if_index != ~0)
+    {
+	path->frp_addr = prefix->fp_addr;
+    }
+}		  
+
+fib_node_index_t
+fib_table_entry_path_add (u32 fib_index,
+			  const fib_prefix_t *prefix,
+			  fib_source_t source,
+			  fib_entry_flag_t flags,
+			  fib_protocol_t next_hop_proto,
+			  const ip46_address_t *next_hop,
+			  u32 next_hop_sw_if_index,
+			  u32 next_hop_fib_index,
+			  u32 next_hop_weight,
+			  mpls_label_t *next_hop_labels,
+			  fib_route_path_flags_t path_flags)
+{
+    fib_route_path_t path = {
+	.frp_proto = next_hop_proto,
+	.frp_addr = (NULL == next_hop? zero_addr : *next_hop),
+	.frp_sw_if_index = next_hop_sw_if_index,
+	.frp_fib_index = next_hop_fib_index,
+	.frp_weight = next_hop_weight,
+	.frp_flags = path_flags,
+	.frp_label_stack = next_hop_labels,
+    };
+    fib_node_index_t fib_entry_index;
+    fib_route_path_t *paths = NULL;
+
+    vec_add1(paths, path);
+
+    fib_entry_index = fib_table_entry_path_add2(fib_index, prefix,
+						source, flags, paths);
+
+    vec_free(paths);
+    return (fib_entry_index);
+}
+
+fib_node_index_t
+fib_table_entry_path_add2 (u32 fib_index,
+			   const fib_prefix_t *prefix,
+			   fib_source_t source,
+			   fib_entry_flag_t flags,
+			   fib_route_path_t *rpath)
+{
+    fib_node_index_t fib_entry_index;
+    fib_table_t *fib_table;
+    u32 ii;
+
+    fib_table = fib_table_get(fib_index, prefix->fp_proto);
+    fib_entry_index = fib_table_lookup_exact_match_i(fib_table, prefix);
+
+    for (ii = 0; ii < vec_len(rpath); ii++)
+    {
+	fib_table_route_path_fixup(prefix, &rpath[ii]);
+    }
+
+    if (FIB_NODE_INDEX_INVALID == fib_entry_index)
+    {
+	fib_entry_index = fib_entry_create(fib_index, prefix,
+					   source, flags,
+					   rpath);
+
+	fib_table_entry_insert(fib_table, prefix, fib_entry_index);
+        fib_table->ft_src_route_counts[source]++;
+    }
+    else
+    {
+        int was_sourced;
+
+        was_sourced = fib_entry_is_sourced(fib_entry_index, source);
+	fib_entry_path_add(fib_entry_index, source, flags, rpath);;
+
+        if (was_sourced != fib_entry_is_sourced(fib_entry_index, source))
+        {
+            fib_table->ft_src_route_counts[source]++;
+        }
+    }
+
+    return (fib_entry_index);
+}
+
+void
+fib_table_entry_path_remove2 (u32 fib_index,
+			      const fib_prefix_t *prefix,
+			      fib_source_t source,
+			      fib_route_path_t *rpath)
+{
+    /*
+     * 1 is it present
+     *   yes => remove source
+     *    2 - is it still sourced?
+     *      no => cover walk
+     */
+    fib_node_index_t fib_entry_index;
+    fib_table_t *fib_table;
+    u32 ii;
+
+    fib_table = fib_table_get(fib_index, prefix->fp_proto);
+    fib_entry_index = fib_table_lookup_exact_match_i(fib_table, prefix);
+
+    for (ii = 0; ii < vec_len(rpath); ii++)
+    {
+	fib_table_route_path_fixup(prefix, &rpath[ii]);
+    }
+
+    if (FIB_NODE_INDEX_INVALID == fib_entry_index)
+    {
+	/*
+	 * removing an etry that does not exist. i'll allow it.
+	 */
+    }
+    else
+    {
+	fib_entry_src_flag_t src_flag;
+        int was_sourced;
+
+	/*
+	 * don't nobody go nowhere
+	 */
+	fib_entry_lock(fib_entry_index);
+        was_sourced = fib_entry_is_sourced(fib_entry_index, source);
+
+	src_flag = fib_entry_path_remove(fib_entry_index, source, rpath);
+
+	if (!(FIB_ENTRY_SRC_FLAG_ADDED & src_flag))
+	{
+	    /*
+	     * last source gone. remove from the table
+	     */
+	    fib_table_entry_remove(fib_table, prefix, fib_entry_index);
+
+	    /*
+	     * now the entry is no longer in the table, we can
+	     * inform the entries that it covers to re-calculate their cover
+	     */
+	    fib_entry_cover_change_notify(fib_entry_index,
+					  FIB_NODE_INDEX_INVALID);
+	}
+	/*
+	 * else
+	 *   still has sources, leave it be.
+	 */
+        if (was_sourced != fib_entry_is_sourced(fib_entry_index, source))
+        {
+            fib_table->ft_src_route_counts[source]--;
+        }
+
+	fib_entry_unlock(fib_entry_index);
+    }
+}
+
+void
+fib_table_entry_path_remove (u32 fib_index,
+			     const fib_prefix_t *prefix,
+			     fib_source_t source,
+			     fib_protocol_t next_hop_proto,
+			     const ip46_address_t *next_hop,
+			     u32 next_hop_sw_if_index,
+			     u32 next_hop_fib_index,
+			     u32 next_hop_weight,
+			     fib_route_path_flags_t path_flags)
+{
+    /*
+     * 1 is it present
+     *   yes => remove source
+     *    2 - is it still sourced?
+     *      no => cover walk
+     */
+    fib_route_path_t path = {
+	.frp_proto = next_hop_proto,
+	.frp_addr = (NULL == next_hop? zero_addr : *next_hop),
+	.frp_sw_if_index = next_hop_sw_if_index,
+	.frp_fib_index = next_hop_fib_index,
+	.frp_weight = next_hop_weight,
+	.frp_flags = path_flags,
+    };
+    fib_route_path_t *paths = NULL;
+
+    fib_table_route_path_fixup(prefix, &path);
+    vec_add1(paths, path);
+
+    fib_table_entry_path_remove2(fib_index, prefix, source, paths);
+
+    vec_free(paths);
+}
+
+static int
+fib_route_path_cmp_for_sort (void * v1,
+			     void * v2)
+{
+    return (fib_route_path_cmp(v1, v2));
+}
+
+fib_node_index_t
+fib_table_entry_update (u32 fib_index,
+			const fib_prefix_t *prefix,
+			fib_source_t source,
+			fib_entry_flag_t flags,
+			fib_route_path_t *paths)
+{
+    fib_node_index_t fib_entry_index;
+    fib_table_t *fib_table;
+    u32 ii;
+
+    fib_table = fib_table_get(fib_index, prefix->fp_proto);
+    fib_entry_index = fib_table_lookup_exact_match_i(fib_table, prefix);
+
+    for (ii = 0; ii < vec_len(paths); ii++)
+    {
+	fib_table_route_path_fixup(prefix, &paths[ii]);
+    }
+    /*
+     * sort the paths provided by the control plane. this means
+     * the paths and the extension on the entry will be sorted.
+     */
+    vec_sort_with_function(paths, fib_route_path_cmp_for_sort);
+
+    if (FIB_NODE_INDEX_INVALID == fib_entry_index)
+    {
+    	fib_entry_index = fib_entry_create(fib_index, prefix,
+    					   source, flags,
+					   paths);
+
+    	fib_table_entry_insert(fib_table, prefix, fib_entry_index);
+        fib_table->ft_src_route_counts[source]++;
+    }
+    else
+    {
+        int was_sourced;
+
+        was_sourced = fib_entry_is_sourced(fib_entry_index, source);
+    	fib_entry_update(fib_entry_index, source, flags, paths);
+
+        if (was_sourced != fib_entry_is_sourced(fib_entry_index, source))
+        {
+            fib_table->ft_src_route_counts[source]++;
+        }
+    }
+
+    return (fib_entry_index);
+}
+
+fib_node_index_t
+fib_table_entry_update_one_path (u32 fib_index,
+				 const fib_prefix_t *prefix,
+				 fib_source_t source,
+				 fib_entry_flag_t flags,
+				 fib_protocol_t next_hop_proto,
+				 const ip46_address_t *next_hop,
+				 u32 next_hop_sw_if_index,
+				 u32 next_hop_fib_index,
+				 u32 next_hop_weight,
+				 mpls_label_t *next_hop_labels,
+				 fib_route_path_flags_t path_flags)
+{
+    fib_node_index_t fib_entry_index;
+    fib_route_path_t path = {
+	.frp_proto = next_hop_proto,
+	.frp_addr = (NULL == next_hop? zero_addr : *next_hop),
+	.frp_sw_if_index = next_hop_sw_if_index,
+	.frp_fib_index = next_hop_fib_index,
+	.frp_weight = next_hop_weight,
+	.frp_flags = path_flags,
+	.frp_label_stack = next_hop_labels,
+    };
+    fib_route_path_t *paths = NULL;
+
+    fib_table_route_path_fixup(prefix, &path);
+    vec_add1(paths, path);
+
+    fib_entry_index = 
+	fib_table_entry_update(fib_index, prefix, source, flags, paths);
+
+    vec_free(paths);
+
+    return (fib_entry_index);
+}
+
+static void
+fib_table_entry_delete_i (u32 fib_index,
+			  fib_node_index_t fib_entry_index,
+			  const fib_prefix_t *prefix,
+			  fib_source_t source)
+{
+    fib_entry_src_flag_t src_flag;
+    fib_table_t *fib_table;
+    int was_sourced;
+
+    fib_table = fib_table_get(fib_index, prefix->fp_proto);
+    was_sourced = fib_entry_is_sourced(fib_entry_index, source);
+
+    /*
+     * don't nobody go nowhere
+     */
+    fib_entry_lock(fib_entry_index);
+
+    src_flag = fib_entry_delete(fib_entry_index, source);
+
+    if (!(FIB_ENTRY_SRC_FLAG_ADDED & src_flag))
+    {
+	/*
+	 * last source gone. remove from the table
+	 */
+	fib_table_entry_remove(fib_table, prefix, fib_entry_index);
+
+	/*
+	 * now the entry is no longer in the table, we can
+	 * inform the entries that it covers to re-calculate their cover
+	 */
+	fib_entry_cover_change_notify(fib_entry_index,
+				      FIB_NODE_INDEX_INVALID);
+    }
+    /*
+     * else
+     *   still has sources, leave it be.
+     */
+    if (was_sourced != fib_entry_is_sourced(fib_entry_index, source))
+    {
+        fib_table->ft_src_route_counts[source]--;
+    }
+
+    fib_entry_unlock(fib_entry_index);
+}
+
+void
+fib_table_entry_delete (u32 fib_index,
+			const fib_prefix_t *prefix,
+			fib_source_t source)
+{
+    fib_node_index_t fib_entry_index;
+
+    fib_entry_index = fib_table_lookup_exact_match(fib_index, prefix);
+
+    if (FIB_NODE_INDEX_INVALID == fib_entry_index)
+    {
+	/*
+	 * removing an etry that does not exist.
+	 * i'll allow it, but i won't like it.
+	 */
+	clib_warning("%U not in FIB", format_fib_prefix, prefix);
+    }
+    else
+    {
+	fib_table_entry_delete_i(fib_index, fib_entry_index, prefix, source);
+    }
+}
+
+void
+fib_table_entry_delete_index (fib_node_index_t fib_entry_index,
+			      fib_source_t source)
+{
+    fib_prefix_t prefix;
+
+    fib_entry_get_prefix(fib_entry_index, &prefix);
+
+    fib_table_entry_delete_i(fib_entry_get_fib_index(fib_entry_index),
+                             fib_entry_index, &prefix, source);
+}
+
+fib_node_index_t
+fib_table_entry_local_label_add (u32 fib_index,
+				 const fib_prefix_t *prefix,
+				 mpls_label_t label)
+{
+    fib_node_index_t fib_entry_index;
+ 
+    fib_entry_index = fib_table_lookup_exact_match(fib_index, prefix);
+
+    if (FIB_NODE_INDEX_INVALID == fib_entry_index ||
+	!fib_entry_is_sourced(fib_entry_index, FIB_SOURCE_MPLS))
+    {
+	/*
+	 * only source the prefix once. this allows the label change
+	 * operation to work
+	 */
+	fib_entry_index = fib_table_entry_special_dpo_add(fib_index, prefix,
+							  FIB_SOURCE_MPLS,
+							  FIB_ENTRY_FLAG_NONE,
+							  NULL);
+    }
+
+    fib_entry_set_source_data(fib_entry_index, FIB_SOURCE_MPLS, &label);
+
+    return (fib_entry_index);
+}
+
+void
+fib_table_entry_local_label_remove (u32 fib_index,
+				    const fib_prefix_t *prefix,
+				    mpls_label_t label)
+{
+    fib_node_index_t fib_entry_index;
+    const void *data;
+    mpls_label_t pl;
+
+    fib_entry_index = fib_table_lookup_exact_match(fib_index, prefix);
+
+    if (FIB_NODE_INDEX_INVALID == fib_entry_index)
+        return;
+
+    data = fib_entry_get_source_data(fib_entry_index, FIB_SOURCE_MPLS);
+
+    if (NULL == data)
+        return;
+
+    pl = *(mpls_label_t*)data;
+
+    if (pl != label)
+        return;
+
+    pl = MPLS_LABEL_INVALID;
+
+    fib_entry_set_source_data(fib_entry_index, FIB_SOURCE_MPLS, &pl);
+    fib_table_entry_special_remove(fib_index,
+				   prefix,
+				   FIB_SOURCE_MPLS);
+}
+
+u32
+fib_table_get_index_for_sw_if_index (fib_protocol_t proto,
+				     u32 sw_if_index)
+{
+    switch (proto)
+    {
+    case FIB_PROTOCOL_IP4:
+	return (ip4_fib_table_get_index_for_sw_if_index(sw_if_index));
+    case FIB_PROTOCOL_IP6:
+	return (ip6_fib_table_get_index_for_sw_if_index(sw_if_index));
+    case FIB_PROTOCOL_MPLS:
+	return (mpls_fib_table_get_index_for_sw_if_index(sw_if_index));
+    }
+    return (~0);
+}
+
+flow_hash_config_t
+fib_table_get_flow_hash_config (u32 fib_index,
+				fib_protocol_t proto)
+{
+    switch (proto)
+    {
+    case FIB_PROTOCOL_IP4:
+	return (ip4_fib_table_get_flow_hash_config(fib_index));
+    case FIB_PROTOCOL_IP6:
+	return (ip6_fib_table_get_flow_hash_config(fib_index));
+    case FIB_PROTOCOL_MPLS:
+	return (mpls_fib_table_get_flow_hash_config(fib_index));
+    }
+    return (0);
+}
+
+
+u32
+fib_table_get_table_id_for_sw_if_index (fib_protocol_t proto,
+					u32 sw_if_index)
+{
+    fib_table_t *fib_table;
+
+    fib_table = fib_table_get(fib_table_get_index_for_sw_if_index(
+				  proto, sw_if_index),
+			      proto);
+
+    return ((NULL != fib_table ? fib_table->ft_table_id : ~0));
+}
+
+u32
+fib_table_find (fib_protocol_t proto,
+		u32 table_id)
+{
+    switch (proto)
+    {
+    case FIB_PROTOCOL_IP4:
+	return (ip4_fib_index_from_table_id(table_id));
+    case FIB_PROTOCOL_IP6:
+	return (ip6_fib_index_from_table_id(table_id));
+    case FIB_PROTOCOL_MPLS:
+	return (mpls_fib_index_from_table_id(table_id));
+    }
+    return (~0);
+}
+
+u32
+fib_table_find_or_create_and_lock (fib_protocol_t proto,
+				   u32 table_id)
+{
+    fib_table_t *fib_table;
+    fib_node_index_t fi;
+
+    switch (proto)
+    {
+    case FIB_PROTOCOL_IP4:
+	fi = ip4_fib_table_find_or_create_and_lock(table_id);
+        break;
+    case FIB_PROTOCOL_IP6:
+	fi = ip6_fib_table_find_or_create_and_lock(table_id);
+        break;
+    case FIB_PROTOCOL_MPLS:
+	fi = mpls_fib_table_find_or_create_and_lock(table_id);
+        break;
+    default:
+        return (~0);        
+    }
+
+    fib_table = fib_table_get(fi, proto);
+
+    fib_table->ft_desc = format(NULL, "%U-VRF:%d",
+                                format_fib_protocol, proto,
+                                table_id);
+
+    return (fi);
+}
+
+u32
+fib_table_create_and_lock (fib_protocol_t proto,
+                           const char *const fmt,
+                           ...)
+{
+    fib_table_t *fib_table;
+    fib_node_index_t fi;
+    va_list ap;
+
+    va_start(ap, fmt);
+
+    switch (proto)
+    {
+    case FIB_PROTOCOL_IP4:
+	fi = ip4_fib_table_create_and_lock();
+        break;
+    case FIB_PROTOCOL_IP6:
+	fi = ip6_fib_table_create_and_lock();
+        break;
+     case FIB_PROTOCOL_MPLS:
+	fi = mpls_fib_table_create_and_lock();
+        break;
+   default:
+        return (~0);        
+    }
+
+    fib_table = fib_table_get(fi, proto);
+
+    fib_table->ft_desc = va_format(fib_table->ft_desc, fmt, &ap);
+
+    va_end(ap);
+    return (fi);
+}
+
+static void
+fib_table_destroy (fib_table_t *fib_table)
+{
+    vec_free(fib_table->ft_desc);
+
+    switch (fib_table->ft_proto)
+    {
+    case FIB_PROTOCOL_IP4:
+	ip4_fib_table_destroy(&fib_table->v4);
+	break;
+    case FIB_PROTOCOL_IP6:
+	ip6_fib_table_destroy(fib_table->ft_index);
+	break;
+    case FIB_PROTOCOL_MPLS:
+	mpls_fib_table_destroy(&fib_table->mpls);
+	break;
+    }
+}
+
+void
+fib_table_unlock (u32 fib_index,
+		  fib_protocol_t proto)
+{
+    fib_table_t *fib_table;
+
+    fib_table = fib_table_get(fib_index, proto);
+    fib_table->ft_locks--;
+
+    if (0 == fib_table->ft_locks)
+    {
+	fib_table_destroy(fib_table);
+    }
+}
+void
+fib_table_lock (u32 fib_index,
+		fib_protocol_t proto)
+{
+    fib_table_t *fib_table;
+
+    fib_table = fib_table_get(fib_index, proto);
+    fib_table->ft_locks++;
+}
+
+u32
+fib_table_get_num_entries (u32 fib_index,
+			   fib_protocol_t proto,
+			   fib_source_t source)
+{
+    fib_table_t *fib_table;
+
+    fib_table = fib_table_get(fib_index, proto);
+
+    return (fib_table->ft_src_route_counts[source]);
+}
+
+u8*
+format_fib_table_name (u8* s, va_list ap)
+{
+    fib_node_index_t fib_index = va_arg(ap, fib_node_index_t);
+    fib_protocol_t proto = va_arg(ap, int); // int promotion
+    fib_table_t *fib_table;
+
+    fib_table = fib_table_get(fib_index, proto);
+
+    s = format(s, "%v", fib_table->ft_desc);
+
+    return (s);
+}
+
+void
+fib_table_flush (u32 fib_index,
+		 fib_protocol_t proto,
+		 fib_source_t source)
+{
+    // FIXME
+    ASSERT(0);
+}
diff --git a/src/vnet/fib/fib_table.h b/src/vnet/fib/fib_table.h
new file mode 100644
index 00000000000..cfec516de1a
--- /dev/null
+++ b/src/vnet/fib/fib_table.h
@@ -0,0 +1,732 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __FIB_TABLE_H__
+#define __FIB_TABLE_H__
+
+#include <vnet/ip/ip.h>
+#include <vnet/adj/adj.h>
+#include <vnet/fib/fib_entry.h>
+#include <vnet/mpls/mpls.h>
+#include <vnet/mpls/packet.h>
+
+/**
+ * @brief 
+ *   A protocol Independent FIB table
+ */
+typedef struct fib_table_t_
+{
+    /**
+     * A union of the protocol specific FIBs that provide the
+     * underlying LPM mechanism.
+     * This element is first in the struct so that it is in the
+     * first cache line.
+     */
+    union {
+	ip4_fib_t v4;
+	ip6_fib_t v6;
+	mpls_fib_t mpls;
+    };
+
+    /**
+     * Which protocol this table serves. Used to switch on the union above.
+     */
+    fib_protocol_t ft_proto;
+
+    /**
+     * number of locks on the table
+     */
+    u16 ft_locks;
+
+    /**
+     * Table ID (hash key) for this FIB.
+     */
+    u32 ft_table_id;
+
+    /**
+     * Index into FIB vector.
+     */
+    fib_node_index_t ft_index;
+
+    /**
+     * flow hash configuration
+     */
+    u32 ft_flow_hash_config;
+
+    /**
+     * Per-source route counters
+     */
+    u32 ft_src_route_counts[FIB_SOURCE_MAX];
+
+    /**
+     * Total route counters
+     */
+    u32 ft_total_route_counts;
+
+    /**
+     * Table description
+     */
+    u8* ft_desc;
+} fib_table_t;
+
+/**
+ * @brief
+ *  Format the description/name of the table
+ */
+extern u8* format_fib_table_name(u8* s, va_list ap);
+
+/**
+ * @brief
+ *  Perfom a longest prefix match in the non-forwarding table
+ *
+ * @param fib_index
+ *  The index of the FIB
+ *
+ * @param prefix
+ *  The prefix to lookup
+ *
+ * @return
+ *  The index of the fib_entry_t for the best match, which may be the default route
+ */
+extern fib_node_index_t fib_table_lookup(u32 fib_index,
+					 const fib_prefix_t *prefix);
+
+/**
+ * @brief
+ *  Perfom an exact match in the non-forwarding table
+ *
+ * @param fib_index
+ *  The index of the FIB
+ *
+ * @param prefix
+ *  The prefix to lookup
+ *
+ * @return
+ *  The index of the fib_entry_t for the exact match, or INVALID
+ *  is there is no match.
+ */
+extern fib_node_index_t fib_table_lookup_exact_match(u32 fib_index,
+						     const fib_prefix_t *prefix);
+
+/**
+ * @brief
+ *  Get the less specific (covering) prefix
+ *
+ * @param fib_index
+ *  The index of the FIB
+ *
+ * @param prefix
+ *  The prefix to lookup
+ *
+ * @return
+ *  The index of the less specific fib_entry_t.
+ */
+extern fib_node_index_t fib_table_get_less_specific(u32 fib_index,
+						    const fib_prefix_t *prefix);
+
+/**
+ * @brief
+ *  Add a 'special' entry to the FIB that links to the adj passed
+ *  A special entry is an entry that the FIB is not expect to resolve
+ *  via the usual mechanisms (i.e. recurisve or neighbour adj DB lookup).
+ *  Instead the client/source provides the adj to link to.
+ *  This add is reference counting per-source. So n 'removes' are required
+ *  for n 'adds', if the entry is no longer required.
+ *
+  * @param fib_index
+ *  The index of the FIB
+ *
+ * @param prefix
+ *  The prefix to add
+ *
+ * @param source
+ *  The ID of the client/source adding the entry.
+ *
+ * @param flags
+ *  Flags for the entry.
+ *
+ * @param adj_index
+ *  The adjacency to link to.
+ *
+ * @return
+ *  the index of the fib_entry_t that is created (or exists already).
+ */
+extern fib_node_index_t fib_table_entry_special_add(u32 fib_index,
+						    const fib_prefix_t *prefix,
+						    fib_source_t source,
+						    fib_entry_flag_t flags,
+						    adj_index_t adj_index);
+
+/**
+ * @brief
+ *  Add a 'special' entry to the FIB that links to the DPO passed
+ *  A special entry is an entry that the FIB is not expect to resolve
+ *  via the usual mechanisms (i.e. recurisve or neighbour adj DB lookup).
+ *  Instead the client/source provides the DPO to link to.
+ *  This add is reference counting per-source. So n 'removes' are required
+ *  for n 'adds', if the entry is no longer required.
+ *
+  * @param fib_index
+ *  The index of the FIB
+ *
+ * @param prefix
+ *  The prefix to add
+ *
+ * @param source
+ *  The ID of the client/source adding the entry.
+ *
+ * @param flags
+ *  Flags for the entry.
+ *
+ * @param dpo
+ *  The DPO to link to.
+ *
+ * @return
+ *  the index of the fib_entry_t that is created (or existed already).
+ */
+extern fib_node_index_t fib_table_entry_special_dpo_add(u32 fib_index,
+                                                        const fib_prefix_t *prefix,
+                                                        fib_source_t source,
+                                                        fib_entry_flag_t stype,
+                                                        const dpo_id_t *dpo);
+
+/**
+ * @brief
+ *  Update a 'special' entry to the FIB that links to the DPO passed
+ *  A special entry is an entry that the FIB is not expect to resolve
+ *  via the usual mechanisms (i.e. recurisve or neighbour adj DB lookup).
+ *  Instead the client/source provides the DPO to link to.
+ *  Special entries are add/remove reference counted per-source. So n
+ * 'removes' are required for n 'adds', if the entry is no longer required.
+ *  An 'update' is an 'add' if no 'add' has already been called, otherwise an 'add'
+ * is therefore assumed to act on the reference instance of that add.
+ *
+ * @param fib_entry_index
+ *  The index of the FIB entry to update
+ *
+ * @param source
+ *  The ID of the client/source adding the entry.
+ *
+ * @param flags
+ *  Flags for the entry.
+ *
+ * @param dpo
+ *  The DPO to link to.
+ *
+ * @return
+ *  the index of the fib_entry_t that is created (or existed already).
+ */
+extern fib_node_index_t fib_table_entry_special_dpo_update (u32 fib_index,
+							    const fib_prefix_t *prefix,
+							    fib_source_t source,
+							    fib_entry_flag_t stype,
+							    const dpo_id_t *dpo);
+
+/**
+ * @brief
+ *  Remove a 'special' entry from the FIB.
+ *  This add is reference counting per-source. So n 'removes' are required
+ *  for n 'adds', if the entry is no longer required.
+ *
+ * @param fib_index
+ *  The index of the FIB
+ *
+ * @param prefix
+ *  The prefix to remove
+ *
+ * @param source
+ *  The ID of the client/source adding the entry.
+ *
+ */
+extern void fib_table_entry_special_remove(u32 fib_index,
+					   const fib_prefix_t *prefix,
+					   fib_source_t source);
+
+/**
+ * @brief
+ *  Add one path to an entry (aka route) in the FIB. If the entry does not
+ *  exist, it will be created.
+ * See the documentation for fib_route_path_t for more descirptions of
+ * the path parameters.
+ *
+ * @param fib_index
+ *  The index of the FIB
+ *
+ * @param prefix
+ *  The prefix for the entry to add
+ *
+ * @param source
+ *  The ID of the client/source adding the entry.
+ *
+ * @param flags
+ *  Flags for the entry.
+ *
+ * @paran next_hop_proto
+ *  The protocol of the next hop. This cannot be derived in the event that
+ * the next hop is all zeros.
+ *
+ * @param next_hop
+ *  The address of the next-hop.
+ *
+ * @param sw_if_index
+ *  The index of the interface.
+ *
+ * @param next_hop_fib_index,
+ *  The fib index of the next-hop for recursive resolution
+ *
+ * @param next_hop_weight
+ *  [un]equal cost path weight
+ *
+ * @param  next_hop_label_stack
+ *  The path's out-going label stack. NULL is there is none.
+ *
+ * @param  pf
+ *  Flags for the path
+ *
+ * @return
+ *  the index of the fib_entry_t that is created (or existed already).
+ */
+extern fib_node_index_t fib_table_entry_path_add(u32 fib_index,
+						 const fib_prefix_t *prefix,
+						 fib_source_t source,
+						 fib_entry_flag_t flags,
+						 fib_protocol_t next_hop_proto,
+						 const ip46_address_t *next_hop,
+						 u32 next_hop_sw_if_index,
+						 u32 next_hop_fib_index,
+						 u32 next_hop_weight,
+						 mpls_label_t *next_hop_label_stack,
+						 fib_route_path_flags_t pf);
+/**
+ * @brief
+ *  Add n paths to an entry (aka route) in the FIB. If the entry does not
+ *  exist, it will be created.
+ * See the documentation for fib_route_path_t for more descirptions of
+ * the path parameters.
+ *
+ * @param fib_index
+ *  The index of the FIB
+ *
+ * @param prefix
+ *  The prefix for the entry to add
+ *
+ * @param source
+ *  The ID of the client/source adding the entry.
+ *
+ * @param flags
+ *  Flags for the entry.
+ *
+ * @param rpaths
+ *  A vector of paths. Not const since they may be modified.
+ *
+ * @return
+ *  the index of the fib_entry_t that is created (or existed already).
+ */
+extern fib_node_index_t fib_table_entry_path_add2(u32 fib_index,
+						  const fib_prefix_t *prefix,
+						  fib_source_t source,
+						  fib_entry_flag_t flags,
+						  fib_route_path_t *rpath);
+
+/**
+ * @brief
+ * remove one path to an entry (aka route) in the FIB. If this is the entry's
+ * last path, then the entry will be removed, unless it has other sources.
+ * See the documentation for fib_route_path_t for more descirptions of
+ * the path parameters.
+ *
+ * @param fib_index
+ *  The index of the FIB
+ *
+ * @param prefix
+ *  The prefix for the entry to add
+ *
+ * @param source
+ *  The ID of the client/source adding the entry.
+ *
+ * @paran next_hop_proto
+ *  The protocol of the next hop. This cannot be derived in the event that
+ * the next hop is all zeros.
+ *
+ * @param next_hop
+ *  The address of the next-hop.
+ *
+ * @param sw_if_index
+ *  The index of the interface.
+ *
+ * @param next_hop_fib_index,
+ *  The fib index of the next-hop for recursive resolution
+ *
+ * @param next_hop_weight
+ *  [un]equal cost path weight
+ *
+ * @param  pf
+ *  Flags for the path
+ */
+extern void fib_table_entry_path_remove(u32 fib_index,
+					const fib_prefix_t *prefix,
+					fib_source_t source,
+					fib_protocol_t next_hop_proto,
+					const ip46_address_t *next_hop,
+					u32 next_hop_sw_if_index,
+					u32 next_hop_fib_index,
+					u32 next_hop_weight,
+					fib_route_path_flags_t pf);
+
+/**
+ * @brief
+ * Remove n paths to an entry (aka route) in the FIB. If this is the entry's
+ * last path, then the entry will be removed, unless it has other sources.
+ * See the documentation for fib_route_path_t for more descirptions of
+ * the path parameters.
+ *
+ * @param fib_index
+ *  The index of the FIB
+ *
+ * @param prefix
+ *  The prefix for the entry to add
+ *
+ * @param source
+ *  The ID of the client/source adding the entry.
+ *
+ * @param rpaths
+ *  A vector of paths.
+ */
+extern void fib_table_entry_path_remove2(u32 fib_index,
+					 const fib_prefix_t *prefix,
+					 fib_source_t source,
+					 fib_route_path_t *paths);
+
+/**
+ * @brief
+ *  Update an entry to have a new set of paths. If the entry does not
+ *  exist, it will be created.
+ * The difference between an 'path-add' and an update, is that path-add is
+ * an incremental addition of paths, whereas an update is a wholesale swap.
+ *
+ * @param fib_index
+ *  The index of the FIB
+ *
+ * @param prefix
+ *  The prefix for the entry to add
+ *
+ * @param source
+ *  The ID of the client/source adding the entry.
+ *
+ * @param rpaths
+ *  A vector of paths. Not const since they may be modified.
+ *
+ * @return
+ *  the index of the fib_entry_t that is created (or existed already).
+ */
+extern fib_node_index_t fib_table_entry_update(u32 fib_index,
+					       const fib_prefix_t *prefix,
+					       fib_source_t source,
+					       fib_entry_flag_t flags,
+					       fib_route_path_t *paths);
+
+/**
+ * @brief
+ *  Update the entry to have just one path. If the entry does not
+ *  exist, it will be created.
+ * See the documentation for fib_route_path_t for more descirptions of
+ * the path parameters.
+ *
+ * @param fib_index
+ *  The index of the FIB
+ *
+ * @param prefix
+ *  The prefix for the entry to add
+ *
+ * @param source
+ *  The ID of the client/source adding the entry.
+ *
+ * @param flags
+ *  Flags for the entry.
+ *
+ * @paran next_hop_proto
+ *  The protocol of the next hop. This cannot be derived in the event that
+ * the next hop is all zeros.
+ *
+ * @param next_hop
+ *  The address of the next-hop.
+ *
+ * @param sw_if_index
+ *  The index of the interface.
+ *
+ * @param next_hop_fib_index,
+ *  The fib index of the next-hop for recursive resolution
+ *
+ * @param next_hop_weight
+ *  [un]equal cost path weight
+ *
+ * @param  next_hop_label_stack
+ *  The path's out-going label stack. NULL is there is none.
+ *
+ * @param  pf
+ *  Flags for the path
+ *
+ * @return
+ *  the index of the fib_entry_t that is created (or existed already).
+ */
+extern fib_node_index_t fib_table_entry_update_one_path(u32 fib_index,
+							const fib_prefix_t *prefix,
+							fib_source_t source,
+							fib_entry_flag_t flags,
+							fib_protocol_t next_hop_proto,
+							const ip46_address_t *next_hop,
+							u32 next_hop_sw_if_index,
+							u32 next_hop_fib_index,
+							u32 next_hop_weight,
+							mpls_label_t *next_hop_label_stack,
+							fib_route_path_flags_t pf);
+
+/**
+ * @brief
+ *  Add a MPLS local label for the prefix/route. If the entry does not
+ *  exist, it will be created. In theory more than one local label can be
+ *  added, but this is not yet supported.
+ *
+ * @param fib_index
+ *  The index of the FIB
+ *
+ * @param prefix
+ *  The prefix for the entry to which to add the label
+ *
+ * @param label
+ *  The MPLS label to add
+ *
+ * @return
+ *  the index of the fib_entry_t that is created (or existed already).
+ */
+extern fib_node_index_t fib_table_entry_local_label_add(u32 fib_index,
+							const fib_prefix_t *prefix,
+							mpls_label_t label);
+/**
+ * @brief
+ *  remove a MPLS local label for the prefix/route.
+ *
+ * @param fib_index
+ *  The index of the FIB
+ *
+ * @param prefix
+ *  The prefix for the entry to which to add the label
+ *
+ * @param label
+ *  The MPLS label to add
+ */
+extern void fib_table_entry_local_label_remove(u32 fib_index,
+					       const fib_prefix_t *prefix,
+					       mpls_label_t label);
+
+/**
+ * @brief
+ *  Delete a FIB entry. If the entry has no more sources, then it is
+ * removed from the table.
+ *
+ * @param fib_index
+ *  The index of the FIB
+ *
+ * @param prefix
+ *  The prefix for the entry to remove
+ *
+ * @param source
+ *  The ID of the client/source adding the entry.
+ */
+extern void fib_table_entry_delete(u32 fib_index,
+				   const fib_prefix_t *prefix,
+				   fib_source_t source);
+
+/**
+ * @brief
+ *  Delete a FIB entry. If the entry has no more sources, then it is
+ * removed from the table.
+ *
+ * @param entry_index
+ *  The index of the FIB entry
+ *
+ * @param source
+ *  The ID of the client/source adding the entry.
+ */
+extern void fib_table_entry_delete_index(fib_node_index_t entry_index,
+					 fib_source_t source);
+
+/**
+ * @brief
+ *  Flush all entries from a table for the source
+ *
+ * @param fib_index
+ *  The index of the FIB
+ *
+ * @paran proto
+ *  The protocol of the entries in the table
+ *
+ * @param source
+ *  the source to flush
+ */
+extern void fib_table_flush(u32 fib_index,
+			    fib_protocol_t proto,
+			    fib_source_t source);
+
+/**
+ * @brief
+ *  Get the index of the FIB bound to the interface
+ *
+ * @paran proto
+ *  The protocol of the FIB (and thus the entries therein)
+ *
+ * @param sw_if_index
+ *  The interface index
+ *
+ * @return fib_index
+ *  The index of the FIB
+ */
+extern u32 fib_table_get_index_for_sw_if_index(fib_protocol_t proto,
+					       u32 sw_if_index);
+
+/**
+ * @brief
+ *  Get the Table-ID of the FIB bound to the interface
+ *
+ * @paran proto
+ *  The protocol of the FIB (and thus the entries therein)
+ *
+ * @param sw_if_index
+ *  The interface index
+ *
+ * @return fib_index
+ *  The tableID of the FIB
+ */
+extern u32 fib_table_get_table_id_for_sw_if_index(fib_protocol_t proto,
+						  u32 sw_if_index);
+
+/**
+ * @brief
+ *  Get the index of the FIB for a Table-ID. This DOES NOT create the
+ * FIB if it does not exist.
+ *
+ * @paran proto
+ *  The protocol of the FIB (and thus the entries therein)
+ *
+ * @param table-id
+ *  The Table-ID
+ *
+ * @return fib_index
+ *  The index of the FIB, which may be INVALID.
+ */
+extern u32 fib_table_find(fib_protocol_t proto, u32 table_id);
+
+
+/**
+ * @brief
+ *  Get the index of the FIB for a Table-ID. This DOES create the
+ * FIB if it does not exist.
+ *
+ * @paran proto
+ *  The protocol of the FIB (and thus the entries therein)
+ *
+ * @param table-id
+ *  The Table-ID
+ *
+ * @return fib_index
+ *  The index of the FIB
+ */
+extern u32 fib_table_find_or_create_and_lock(fib_protocol_t proto,
+					     u32 table_id);
+
+/**
+ * @brief
+ *  Create a new table with no table ID. This means it does not get
+ * added to the hash-table and so can only be found by using the index returned.
+ *
+ * @paran proto
+ *  The protocol of the FIB (and thus the entries therein)
+ *
+ * @param fmt
+ *  A string to describe the table
+ *
+ * @return fib_index
+ *  The index of the FIB
+ */
+extern u32 fib_table_create_and_lock(fib_protocol_t proto,
+                                     const char *const fmt,
+                                     ...);
+
+/**
+ * @brief
+ *  Get the flow hash configured used by the table
+ *
+ * @param fib_index
+ *  The index of the FIB
+ *
+ * @paran proto
+ *  The protocol of the FIB (and thus the entries therein)
+ *
+ * @return The flow hash config
+ */
+extern flow_hash_config_t fib_table_get_flow_hash_config(u32 fib_index,
+							 fib_protocol_t proto);
+
+/**
+ * @brief
+ * Take a reference counting lock on the table
+ *
+ * @param fib_index
+ *  The index of the FIB
+ *
+ * @paran proto
+ *  The protocol of the FIB (and thus the entries therein)
+ */ 
+extern void fib_table_unlock(u32 fib_index,
+			     fib_protocol_t proto);
+
+/**
+ * @brief
+ * Release a reference counting lock on the table. When the last lock
+ * has gone. the FIB is deleted.
+ *
+ * @param fib_index
+ *  The index of the FIB
+ *
+ * @paran proto
+ *  The protocol of the FIB (and thus the entries therein)
+ */ 
+extern void fib_table_lock(u32 fib_index,
+			   fib_protocol_t proto);
+
+/**
+ * @brief
+ * Return the number of entries in the FIB added by a given source.
+ *
+ * @param fib_index
+ *  The index of the FIB
+ *
+ * @paran proto
+ *  The protocol of the FIB (and thus the entries therein)
+ *
+ * @return number of sourced entries.
+ */ 
+extern u32 fib_table_get_num_entries(u32 fib_index,
+				     fib_protocol_t proto,
+				     fib_source_t source);
+
+/**
+ * @brief
+ * Get a pointer to a FIB table
+ */
+extern fib_table_t *fib_table_get(fib_node_index_t index,
+				  fib_protocol_t proto);
+
+#endif
diff --git a/src/vnet/fib/fib_test.c b/src/vnet/fib/fib_test.c
new file mode 100644
index 00000000000..5083db26872
--- /dev/null
+++ b/src/vnet/fib/fib_test.c
@@ -0,0 +1,7112 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vnet/fib/ip6_fib.h>
+#include <vnet/fib/ip4_fib.h>
+#include <vnet/fib/mpls_fib.h>
+#include <vnet/adj/adj.h>
+#include <vnet/dpo/load_balance.h>
+#include <vnet/dpo/load_balance_map.h>
+#include <vnet/dpo/mpls_label_dpo.h>
+#include <vnet/dpo/lookup_dpo.h>
+#include <vnet/dpo/drop_dpo.h>
+#include <vnet/dpo/receive_dpo.h>
+#include <vnet/dpo/ip_null_dpo.h>
+
+#include <vnet/mpls/mpls.h>
+
+#include <vnet/fib/fib_path_list.h>
+#include <vnet/fib/fib_entry_src.h>
+#include <vnet/fib/fib_walk.h>
+#include <vnet/fib/fib_node_list.h>
+#include <vnet/fib/fib_urpf_list.h>
+
+#define FIB_TEST_I(_cond, _comment, _args...)			\
+({								\
+    int _evald = (_cond);					\
+    if (!(_evald)) {						\
+	fformat(stderr, "FAIL:%d: " _comment "\n",		\
+		__LINE__, ##_args);				\
+    } else {							\
+	fformat(stderr, "PASS:%d: " _comment "\n",		\
+		__LINE__, ##_args);				\
+    }								\
+    _evald;							\
+})
+#define FIB_TEST(_cond, _comment, _args...)			\
+{								\
+    if (!FIB_TEST_I(_cond, _comment, ##_args)) {		\
+	return 1;                                               \
+	ASSERT(!("FAIL: " _comment));				\
+    }								\
+}
+
+/**
+ * A 'i'm not fussed is this is not efficient' store of test data
+ */
+typedef struct test_main_t_ {
+    /**
+     * HW if indicies
+     */
+    u32 hw_if_indicies[4];
+    /**
+     * HW interfaces
+     */
+    vnet_hw_interface_t * hw[4];
+
+} test_main_t;
+static test_main_t test_main;
+
+/* fake ethernet device class, distinct from "fake-ethX" */
+static u8 * format_test_interface_name (u8 * s, va_list * args)
+{
+  u32 dev_instance = va_arg (*args, u32);
+  return format (s, "test-eth%d", dev_instance);
+}
+
+static uword dummy_interface_tx (vlib_main_t * vm,
+				 vlib_node_runtime_t * node,
+				 vlib_frame_t * frame)
+{
+  clib_warning ("you shouldn't be here, leaking buffers...");
+  return frame->n_vectors;
+}
+
+static clib_error_t *
+test_interface_admin_up_down (vnet_main_t * vnm,
+                              u32 hw_if_index,
+                              u32 flags)
+{
+  u32 hw_flags = (flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP) ?
+    VNET_HW_INTERFACE_FLAG_LINK_UP : 0;
+  vnet_hw_interface_set_flags (vnm, hw_if_index, hw_flags);
+  return 0;
+}
+
+VNET_DEVICE_CLASS (test_interface_device_class,static) = {
+  .name = "Test interface",
+  .format_device_name = format_test_interface_name,
+  .tx_function = dummy_interface_tx,
+  .admin_up_down_function = test_interface_admin_up_down,
+};
+
+static u8 *hw_address;
+
+static int
+fib_test_mk_intf (u32 ninterfaces)
+{
+    clib_error_t * error = NULL;
+    test_main_t *tm = &test_main;
+    u8 byte;
+    u32 i;
+
+    ASSERT(ninterfaces <= ARRAY_LEN(tm->hw_if_indicies));
+
+    for (i=0; i<6; i++)
+    {
+	byte = 0xd0+i;
+	vec_add1(hw_address, byte);
+    }
+
+    for (i = 0; i < ninterfaces; i++)
+    {
+	hw_address[5] = i;
+
+	error = ethernet_register_interface(vnet_get_main(),
+                                            test_interface_device_class.index,
+					    i /* instance */,
+					    hw_address,
+					    &tm->hw_if_indicies[i], 
+					    /* flag change */ 0);
+
+	FIB_TEST((NULL == error), "ADD interface %d", i);
+      
+        error = vnet_hw_interface_set_flags(vnet_get_main(),
+                                            tm->hw_if_indicies[i],
+                                            VNET_HW_INTERFACE_FLAG_LINK_UP);
+        tm->hw[i] = vnet_get_hw_interface(vnet_get_main(),
+					  tm->hw_if_indicies[i]);
+	vec_validate (ip4_main.fib_index_by_sw_if_index,
+                      tm->hw[i]->sw_if_index);
+	vec_validate (ip6_main.fib_index_by_sw_if_index,
+                      tm->hw[i]->sw_if_index);
+	ip4_main.fib_index_by_sw_if_index[tm->hw[i]->sw_if_index] = 0;
+	ip6_main.fib_index_by_sw_if_index[tm->hw[i]->sw_if_index] = 0;
+
+	error = vnet_sw_interface_set_flags(vnet_get_main(),
+					    tm->hw[i]->sw_if_index,
+					    VNET_SW_INTERFACE_FLAG_ADMIN_UP);
+	FIB_TEST((NULL == error), "UP interface %d", i);
+    }
+    /*
+     * re-eval after the inevitable realloc
+     */
+    for (i = 0; i < ninterfaces; i++)
+    {
+	tm->hw[i] = vnet_get_hw_interface(vnet_get_main(),
+					  tm->hw_if_indicies[i]);
+    }
+
+    return (0);
+}
+
+#define FIB_TEST_REC_FORW(_rec_prefix, _via_prefix, _bucket)		\
+{                                                                       \
+    const dpo_id_t *_rec_dpo = fib_entry_contribute_ip_forwarding(      \
+        fib_table_lookup_exact_match(fib_index, (_rec_prefix)));        \
+    const dpo_id_t *_via_dpo = fib_entry_contribute_ip_forwarding(      \
+        fib_table_lookup(fib_index, (_via_prefix)));                    \
+    FIB_TEST(!dpo_cmp(_via_dpo,                                         \
+                      load_balance_get_bucket(_rec_dpo->dpoi_index,	\
+					      _bucket)),		\
+             "%U is recursive via %U",                                  \
+             format_fib_prefix, (_rec_prefix),                          \
+             format_fib_prefix, _via_prefix);                           \
+}
+
+#define FIB_TEST_LB_BUCKET_VIA_ADJ(_prefix, _bucket, _ai)               \
+{                                                                       \
+    const dpo_id_t *_dpo = fib_entry_contribute_ip_forwarding(          \
+        fib_table_lookup_exact_match(fib_index, (_prefix)));            \
+    const dpo_id_t *_dpo1 =                                             \
+        load_balance_get_bucket(_dpo->dpoi_index, _bucket);             \
+    FIB_TEST(DPO_ADJACENCY == _dpo1->dpoi_type, "type is %U",           \
+             format_dpo_type, _dpo1->dpoi_type);                        \
+    FIB_TEST((_ai == _dpo1->dpoi_index),                                \
+	     "%U bucket %d resolves via %U",                            \
+             format_fib_prefix, (_prefix),                              \
+             _bucket,                                                   \
+             format_dpo_id, _dpo1, 0);                                  \
+}
+
+#define FIB_TEST_RPF(_cond, _comment, _args...)			\
+{								\
+    if (!FIB_TEST_I(_cond, _comment, ##_args)) {		\
+	return (0);						\
+    }								\
+}
+
+static int
+fib_test_urpf_is_equal (fib_node_index_t fei,
+		       fib_forward_chain_type_t fct,
+		       u32 num, ...)
+{
+    dpo_id_t dpo = DPO_INVALID;
+    fib_urpf_list_t *urpf;
+    index_t ui;
+    va_list ap;
+    int ii;
+
+    va_start(ap, num);
+
+    fib_entry_contribute_forwarding(fei, fct, &dpo);
+    ui = load_balance_get_urpf(dpo.dpoi_index);
+
+    urpf = fib_urpf_list_get(ui);
+
+    FIB_TEST_RPF(num == vec_len(urpf->furpf_itfs),
+		 "RPF:%U len %d == %d",
+		 format_fib_urpf_list, ui,
+		 num, vec_len(urpf->furpf_itfs));
+    FIB_TEST_RPF(num == fib_urpf_check_size(ui),
+		 "RPF:%U check-size %d == %d",
+		 format_fib_urpf_list, ui,
+		 num, vec_len(urpf->furpf_itfs));
+
+    for (ii = 0; ii < num; ii++)
+    {
+	adj_index_t ai = va_arg(ap, adj_index_t);
+
+	FIB_TEST_RPF(ai == urpf->furpf_itfs[ii],
+		     "RPF:%d item:%d - %d == %d",
+		     ui, ii, ai, urpf->furpf_itfs[ii]);
+	FIB_TEST_RPF(fib_urpf_check(ui, ai),
+		     "RPF:%d %d found",
+		     ui, ai);
+    }
+
+    dpo_reset(&dpo);
+
+    va_end(ap);
+
+    return (1);
+}
+
+static u8*
+fib_test_build_rewrite (u8 *eth_addr)
+{
+    u8* rewrite = NULL;
+
+    vec_validate(rewrite, 13);
+
+    memcpy(rewrite, eth_addr, 6);
+    memcpy(rewrite+6, eth_addr, 6);
+
+    return (rewrite);
+}
+
+typedef enum fib_test_lb_bucket_type_t_ {
+    FT_LB_LABEL_O_ADJ,
+    FT_LB_LABEL_STACK_O_ADJ,
+    FT_LB_LABEL_O_LB,
+    FT_LB_O_LB,
+    FT_LB_SPECIAL,
+    FT_LB_ADJ,
+} fib_test_lb_bucket_type_t;
+
+typedef struct fib_test_lb_bucket_t_ {
+    fib_test_lb_bucket_type_t type;
+
+    union
+    {
+	struct
+	{
+	    mpls_eos_bit_t eos;
+	    mpls_label_t label;
+	    u8 ttl;
+	    adj_index_t adj;
+	} label_o_adj;
+	struct
+	{
+	    mpls_eos_bit_t eos;
+	    mpls_label_t label_stack[8];
+	    u8 label_stack_size;
+	    u8 ttl;
+	    adj_index_t adj;
+	} label_stack_o_adj;
+	struct
+	{
+	    mpls_eos_bit_t eos;
+	    mpls_label_t label;
+	    u8 ttl;
+	    index_t lb;
+	} label_o_lb;
+	struct
+	{
+	    index_t adj;
+	} adj;
+	struct
+	{
+	    index_t lb;
+	} lb;
+	struct
+	{
+	    index_t adj;
+	} special;
+    };
+} fib_test_lb_bucket_t;
+
+#define FIB_TEST_LB(_cond, _comment, _args...)			\
+{								\
+    if (!FIB_TEST_I(_cond, _comment, ##_args)) {		\
+	return (0);						\
+    }								\
+}
+
+static int
+fib_test_validate_lb_v (const load_balance_t *lb,
+			u16 n_buckets,
+			va_list ap)
+{
+    const dpo_id_t *dpo;
+    int bucket;
+
+    FIB_TEST_LB((n_buckets == lb->lb_n_buckets), "n_buckets = %d", lb->lb_n_buckets);
+
+    for (bucket = 0; bucket < n_buckets; bucket++)
+    {
+	const fib_test_lb_bucket_t *exp;
+
+	exp = va_arg(ap, fib_test_lb_bucket_t*);
+	dpo = load_balance_get_bucket_i(lb, bucket);
+
+	switch (exp->type)
+	{
+	case FT_LB_LABEL_STACK_O_ADJ:
+	    {
+		const mpls_label_dpo_t *mld;
+                mpls_label_t hdr;
+		u32 ii;
+
+		FIB_TEST_LB((DPO_MPLS_LABEL == dpo->dpoi_type),
+			   "bucket %d stacks on %U",
+			   bucket,
+			   format_dpo_type, dpo->dpoi_type);
+	    
+		mld = mpls_label_dpo_get(dpo->dpoi_index);
+
+		FIB_TEST_LB(exp->label_stack_o_adj.label_stack_size == mld->mld_n_labels,
+			    "label stack size",
+			    mld->mld_n_labels);
+
+		for (ii = 0; ii < mld->mld_n_labels; ii++)
+		{
+		    hdr = clib_net_to_host_u32(mld->mld_hdr[ii].label_exp_s_ttl);
+		    FIB_TEST_LB((vnet_mpls_uc_get_label(hdr) ==
+				 exp->label_stack_o_adj.label_stack[ii]),
+				"bucket %d stacks on label %d",
+				bucket,
+				exp->label_stack_o_adj.label_stack[ii]);
+
+		    if (ii == mld->mld_n_labels-1)
+		    {
+			FIB_TEST_LB((vnet_mpls_uc_get_s(hdr) ==
+				     exp->label_o_adj.eos),
+				    "bucket %d stacks on label %d %U!=%U",
+				    bucket,
+				    exp->label_stack_o_adj.label_stack[ii],
+				    format_mpls_eos_bit, exp->label_o_adj.eos,
+				    format_mpls_eos_bit, vnet_mpls_uc_get_s(hdr));
+		    }
+		    else
+		    {
+			FIB_TEST_LB((vnet_mpls_uc_get_s(hdr) == MPLS_NON_EOS),
+				    "bucket %d stacks on label %d %U",
+				    bucket,
+				    exp->label_stack_o_adj.label_stack[ii],
+				    format_mpls_eos_bit, vnet_mpls_uc_get_s(hdr));
+		    }
+		}
+
+		FIB_TEST_LB((DPO_ADJACENCY_INCOMPLETE == mld->mld_dpo.dpoi_type),
+			    "bucket %d label stacks on %U",
+			    bucket,
+			    format_dpo_type, mld->mld_dpo.dpoi_type);
+
+		FIB_TEST_LB((exp->label_stack_o_adj.adj == mld->mld_dpo.dpoi_index),
+			    "bucket %d label stacks on adj %d",
+			    bucket,
+			    exp->label_stack_o_adj.adj);
+	    }
+	    break;
+	case FT_LB_LABEL_O_ADJ:
+	    {
+		const mpls_label_dpo_t *mld;
+                mpls_label_t hdr;
+		FIB_TEST_LB((DPO_MPLS_LABEL == dpo->dpoi_type),
+			   "bucket %d stacks on %U",
+			   bucket,
+			   format_dpo_type, dpo->dpoi_type);
+	    
+		mld = mpls_label_dpo_get(dpo->dpoi_index);
+                hdr = clib_net_to_host_u32(mld->mld_hdr[0].label_exp_s_ttl);
+
+		FIB_TEST_LB((vnet_mpls_uc_get_label(hdr) ==
+			     exp->label_o_adj.label),
+			    "bucket %d stacks on label %d",
+			    bucket,
+			    exp->label_o_adj.label);
+
+		FIB_TEST_LB((vnet_mpls_uc_get_s(hdr) ==
+			     exp->label_o_adj.eos),
+			    "bucket %d stacks on label %d %U",
+			    bucket,
+			    exp->label_o_adj.label,
+			    format_mpls_eos_bit, exp->label_o_adj.eos);
+
+		FIB_TEST_LB((DPO_ADJACENCY_INCOMPLETE == mld->mld_dpo.dpoi_type),
+			    "bucket %d label stacks on %U",
+			    bucket,
+			    format_dpo_type, mld->mld_dpo.dpoi_type);
+
+		FIB_TEST_LB((exp->label_o_adj.adj == mld->mld_dpo.dpoi_index),
+			    "bucket %d label stacks on adj %d",
+			    bucket,
+			    exp->label_o_adj.adj);
+	    }
+	    break;
+	case FT_LB_LABEL_O_LB:
+	    {
+		const mpls_label_dpo_t *mld;
+                mpls_label_t hdr;
+
+		FIB_TEST_LB((DPO_MPLS_LABEL == dpo->dpoi_type),
+			   "bucket %d stacks on %U",
+			   bucket,
+			   format_dpo_type, dpo->dpoi_type);
+	    
+		mld = mpls_label_dpo_get(dpo->dpoi_index);
+                hdr = clib_net_to_host_u32(mld->mld_hdr[0].label_exp_s_ttl);
+
+		FIB_TEST_LB(1 == mld->mld_n_labels, "label stack size",
+			    mld->mld_n_labels);
+		FIB_TEST_LB((vnet_mpls_uc_get_label(hdr) ==
+			     exp->label_o_lb.label),
+			    "bucket %d stacks on label %d",
+			    bucket,
+			    exp->label_o_lb.label);
+
+		FIB_TEST_LB((vnet_mpls_uc_get_s(hdr) ==
+			     exp->label_o_lb.eos),
+			    "bucket %d stacks on label %d %U",
+			    bucket,
+			    exp->label_o_lb.label,
+			    format_mpls_eos_bit, exp->label_o_lb.eos);
+
+		FIB_TEST_LB((DPO_LOAD_BALANCE == mld->mld_dpo.dpoi_type),
+			    "bucket %d label stacks on %U",
+			    bucket,
+			    format_dpo_type, mld->mld_dpo.dpoi_type);
+
+		FIB_TEST_LB((exp->label_o_lb.lb == mld->mld_dpo.dpoi_index),
+			    "bucket %d label stacks on LB %d",
+			    bucket,
+			    exp->label_o_lb.lb);
+	    }
+	    break;
+	case FT_LB_ADJ:
+	    FIB_TEST_I(((DPO_ADJACENCY == dpo->dpoi_type) ||
+			(DPO_ADJACENCY_INCOMPLETE == dpo->dpoi_type)),
+		       "bucket %d stacks on %U",
+		       bucket,
+		       format_dpo_type, dpo->dpoi_type);
+	    FIB_TEST_LB((exp->adj.adj == dpo->dpoi_index),
+			"bucket %d stacks on adj %d",
+			bucket,
+			exp->adj.adj);
+	    break;
+	case FT_LB_O_LB:
+	    FIB_TEST_I((DPO_LOAD_BALANCE == dpo->dpoi_type),
+                       "bucket %d stacks on %U",
+                       bucket,
+                       format_dpo_type, dpo->dpoi_type);
+	    FIB_TEST_LB((exp->lb.lb == dpo->dpoi_index),
+			"bucket %d stacks on lb %d",
+			bucket,
+			exp->lb.lb);
+	    break;
+	case FT_LB_SPECIAL:
+	    FIB_TEST_I((DPO_DROP == dpo->dpoi_type),
+		       "bucket %d stacks on %U",
+		       bucket,
+		       format_dpo_type, dpo->dpoi_type);
+	    FIB_TEST_LB((exp->special.adj == dpo->dpoi_index),
+			"bucket %d stacks on drop %d",
+			bucket,
+			exp->special.adj);
+	    break;
+	}
+    }
+    return (!0);
+}
+
+static int
+fib_test_validate_entry (fib_node_index_t fei,
+			 fib_forward_chain_type_t fct,
+			 u16 n_buckets,
+			 ...)
+{
+    dpo_id_t dpo = DPO_INVALID;
+    const load_balance_t *lb;
+    fib_prefix_t pfx;
+    index_t fw_lbi;
+    u32 fib_index;
+    va_list ap;
+    int res;
+
+    va_start(ap, n_buckets);
+
+    fib_entry_get_prefix(fei, &pfx);
+    fib_index = fib_entry_get_fib_index(fei);
+    fib_entry_contribute_forwarding(fei, fct, &dpo);
+
+    FIB_TEST_LB((DPO_LOAD_BALANCE == dpo.dpoi_type),
+		"Entry links to %U",
+		format_dpo_type, dpo.dpoi_type);
+    lb = load_balance_get(dpo.dpoi_index);
+
+    res = fib_test_validate_lb_v(lb, n_buckets, ap);
+
+    /*
+     * ensure that the LB contributed by the entry is the
+     * same as the LB in the forwarding tables
+     */
+    if (fct == fib_entry_get_default_chain_type(fib_entry_get(fei)))
+    {
+        switch (pfx.fp_proto)
+        {
+        case FIB_PROTOCOL_IP4:
+            fw_lbi = ip4_fib_forwarding_lookup(fib_index, &pfx.fp_addr.ip4);
+            break;
+        case FIB_PROTOCOL_IP6:
+            fw_lbi = ip6_fib_table_fwding_lookup(&ip6_main, fib_index, &pfx.fp_addr.ip6);
+            break;
+        case FIB_PROTOCOL_MPLS:
+            {
+                mpls_unicast_header_t hdr = {
+                    .label_exp_s_ttl = 0,
+                };
+
+                vnet_mpls_uc_set_label(&hdr.label_exp_s_ttl, pfx.fp_label);
+                vnet_mpls_uc_set_s(&hdr.label_exp_s_ttl, pfx.fp_eos);
+                hdr.label_exp_s_ttl = clib_host_to_net_u32(hdr.label_exp_s_ttl);
+
+                fw_lbi = mpls_fib_table_forwarding_lookup(fib_index, &hdr);
+                break;
+            }
+        default:
+            fw_lbi = 0;
+        }
+        FIB_TEST_LB((fw_lbi == dpo.dpoi_index),
+                    "Contributed LB = FW LB: %U\n %U",
+                    format_load_balance, fw_lbi, 0,
+                    format_load_balance, dpo.dpoi_index, 0);
+    }
+
+    dpo_reset(&dpo);
+
+    va_end(ap);
+
+    return (res);
+}
+
+static int
+fib_test_v4 (void)
+{
+    /*
+     * In the default table check for the presence and correct forwarding
+     * of the special entries
+     */
+    fib_node_index_t dfrt, fei, ai, ai2, locked_ai, ai_01, ai_02, ai_03;
+    const dpo_id_t *dpo, *dpo1, *dpo2, *dpo_drop;
+    const ip_adjacency_t *adj;
+    const load_balance_t *lb;
+    test_main_t *tm;
+    u32 fib_index;
+    int ii;
+
+    /* via 10.10.10.1 */
+    ip46_address_t nh_10_10_10_1 = {
+	.ip4.as_u32 = clib_host_to_net_u32(0x0a0a0a01),
+    };
+    /* via 10.10.10.2 */
+    ip46_address_t nh_10_10_10_2 = {
+	.ip4.as_u32 = clib_host_to_net_u32(0x0a0a0a02),
+    };
+
+    tm = &test_main;
+
+    /* Find or create FIB table 11 */
+    fib_index = fib_table_find_or_create_and_lock(FIB_PROTOCOL_IP4, 11);
+
+    for (ii = 0; ii < 4; ii++)
+    {
+	ip4_main.fib_index_by_sw_if_index[tm->hw[ii]->sw_if_index] = fib_index;
+    }
+
+    fib_prefix_t pfx_0_0_0_0_s_0 = {
+	.fp_len = 0,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    .ip4 = {
+		{0}
+	    },
+	},
+    };
+
+    fib_prefix_t pfx = {
+	.fp_len = 0,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    .ip4 = {
+		{0}
+	    },
+	},
+    };
+
+    dpo_drop = drop_dpo_get(DPO_PROTO_IP4);
+
+    dfrt = fib_table_lookup(fib_index, &pfx_0_0_0_0_s_0);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != dfrt), "default route present");
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(dfrt)),
+	     "Default route is DROP");
+
+    pfx.fp_len = 32;
+    fei = fib_table_lookup(fib_index, &pfx);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "all zeros route present");
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(fei)),
+	     "all 0s route is DROP");
+
+    pfx.fp_addr.ip4.as_u32 = clib_host_to_net_u32(0xffffffff);
+    pfx.fp_len = 32;
+    fei = fib_table_lookup(fib_index, &pfx);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "all ones route present");
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(fei)),
+	     "all 1s route is DROP");
+
+    pfx.fp_addr.ip4.as_u32 = clib_host_to_net_u32(0xe0000000);
+    pfx.fp_len = 8;
+    fei = fib_table_lookup(fib_index, &pfx);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "all-mcast route present");
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(fei)),
+	     "all-mcast route is DROP");
+
+    pfx.fp_addr.ip4.as_u32 = clib_host_to_net_u32(0xf0000000);
+    pfx.fp_len = 8;
+    fei = fib_table_lookup(fib_index, &pfx);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "class-e route present");
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(fei)),
+	     "class-e route is DROP");
+
+    /*
+     * at this stage there are 5 entries in the test FIB (plus 5 in the default),
+     * all of which are special sourced and so none of which share path-lists.
+     * There are also 6 entries, and 6 non-shared path-lists, in the v6 default
+     * table
+     */
+#define NBR (5+5+6)
+    FIB_TEST((0 == fib_path_list_db_size()),   "path list DB is empty");
+    FIB_TEST((NBR == fib_path_list_pool_size()), "path list pool size is %d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NBR == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    /*
+     * add interface routes.
+     *  validate presence of /24 attached and /32 recieve.
+     *  test for the presence of the receive address in the glean and local adj
+     */
+    fib_prefix_t local_pfx = {
+	.fp_len = 24,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    .ip4 = {
+		.as_u32 = clib_host_to_net_u32(0x0a0a0a0a),
+	    },
+	},
+    };
+
+    fib_table_entry_update_one_path(fib_index, &local_pfx,
+				    FIB_SOURCE_INTERFACE,
+				    (FIB_ENTRY_FLAG_CONNECTED |
+				     FIB_ENTRY_FLAG_ATTACHED),
+				    FIB_PROTOCOL_IP4,
+				    NULL,
+				    tm->hw[0]->sw_if_index,
+				    ~0, // invalid fib index
+				    1, // weight
+				    NULL,
+				    FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup(fib_index, &local_pfx);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "attached interface route present");
+    FIB_TEST(((FIB_ENTRY_FLAG_ATTACHED | FIB_ENTRY_FLAG_CONNECTED) ==
+	      fib_entry_get_flags(fei)),
+	     "Flags set on attached interface");
+
+    ai = fib_entry_get_adj(fei);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != ai), "attached interface route adj present");
+    adj = adj_get(ai);
+    FIB_TEST((IP_LOOKUP_NEXT_GLEAN == adj->lookup_next_index),
+	     "attached interface adj is glean");
+    FIB_TEST((0 == ip46_address_cmp(&local_pfx.fp_addr,
+				    &adj->sub_type.glean.receive_addr)),
+	      "attached interface adj is receive ok");
+
+    local_pfx.fp_len = 32;
+    fib_table_entry_update_one_path(fib_index, &local_pfx,
+				    FIB_SOURCE_INTERFACE,
+				    (FIB_ENTRY_FLAG_CONNECTED |
+				     FIB_ENTRY_FLAG_LOCAL),
+				    FIB_PROTOCOL_IP4,
+				    NULL,
+				    tm->hw[0]->sw_if_index,
+				    ~0, // invalid fib index
+				    1, // weight
+				    NULL,
+				    FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup(fib_index, &local_pfx);
+    FIB_TEST(((FIB_ENTRY_FLAG_LOCAL | FIB_ENTRY_FLAG_CONNECTED) ==
+	      fib_entry_get_flags(fei)),
+	     "Flags set on local interface");
+
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "local interface route present");
+
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    FIB_TEST(fib_test_urpf_is_equal(fei, FIB_FORW_CHAIN_TYPE_UNICAST_IP4, 0),
+	     "RPF list for local length 0");
+    dpo = load_balance_get_bucket(dpo->dpoi_index, 0);
+    FIB_TEST((DPO_RECEIVE == dpo->dpoi_type),
+	     "local interface adj is local");
+    receive_dpo_t *rd = receive_dpo_get(dpo->dpoi_index);
+
+    FIB_TEST((0 == ip46_address_cmp(&local_pfx.fp_addr,
+				    &rd->rd_addr)),
+	      "local interface adj is receive ok");
+
+    FIB_TEST((2 == fib_table_get_num_entries(fib_index,
+                                             FIB_PROTOCOL_IP4,
+                                             FIB_SOURCE_INTERFACE)),
+             "2 Interface Source'd prefixes");
+
+    /*
+     * +2 interface routes +2 non-shared path-lists
+     */
+    FIB_TEST((0 == fib_path_list_db_size()),   "path list DB is empty");
+    FIB_TEST((NBR+2 == fib_path_list_pool_size()), "path list pool size is%d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NBR+2 == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    /*
+     * Modify the default route to be via an adj not yet known.
+     * this sources the defalut route with the API source, which is
+     * a higher preference to the DEFAULT_ROUTE source
+     */
+    pfx.fp_addr.ip4.as_u32 = 0;
+    pfx.fp_len = 0;
+    fib_table_entry_path_add(fib_index, &pfx,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+			     &nh_10_10_10_1,
+			     tm->hw[0]->sw_if_index,
+			     ~0, // invalid fib index
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup(fib_index, &pfx);
+    FIB_TEST((FIB_ENTRY_FLAG_NONE == fib_entry_get_flags(fei)),
+	     "Flags set on API route");
+
+    FIB_TEST((fei == dfrt), "default route same index");
+    ai = fib_entry_get_adj(fei);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != ai), "default route adj present");
+    adj = adj_get(ai);
+    FIB_TEST((IP_LOOKUP_NEXT_ARP == adj->lookup_next_index),
+	     "adj is incomplete");
+    FIB_TEST((0 == ip46_address_cmp(&nh_10_10_10_1, &adj->sub_type.nbr.next_hop)),
+	      "adj nbr next-hop ok");
+    FIB_TEST((1 == fib_table_get_num_entries(fib_index,
+                                             FIB_PROTOCOL_IP4,
+                                             FIB_SOURCE_API)),
+             "1 API Source'd prefixes");
+
+    /*
+     * find the adj in the shared db
+     */
+    locked_ai = adj_nbr_add_or_lock(FIB_PROTOCOL_IP4,
+				    VNET_LINK_IP4,
+				    &nh_10_10_10_1,
+				    tm->hw[0]->sw_if_index);
+    FIB_TEST((locked_ai == ai), "ADJ NBR DB find");
+    adj_unlock(locked_ai);
+
+    /*
+     * +1 shared path-list
+     */
+    FIB_TEST((1 == fib_path_list_db_size()),   "path list DB population:%d",
+	     fib_path_list_db_size());
+    FIB_TEST((NBR+3 == fib_path_list_pool_size()), "path list pool size is%d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NBR+2 == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    /*
+     * remove the API source from the default route. We expected
+     * the route to remain, sourced by DEFAULT_ROUTE, and hence a DROP
+     */
+    pfx.fp_addr.ip4.as_u32 = 0;
+    pfx.fp_len = 0;
+    fib_table_entry_path_remove(fib_index, &pfx,
+				FIB_SOURCE_API,
+				FIB_PROTOCOL_IP4,
+				&nh_10_10_10_1,
+				tm->hw[0]->sw_if_index,
+				~0, // non-recursive path, so no FIB index
+				1,
+				FIB_ROUTE_PATH_FLAG_NONE);
+
+    fei = fib_table_lookup(fib_index, &pfx);
+
+    FIB_TEST((fei == dfrt), "default route same index");
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(fei)),
+	     "Default route is DROP");
+
+    /*
+     * -1 shared-path-list
+     */
+    FIB_TEST((0 == fib_path_list_db_size()),   "path list DB is empty");
+    FIB_TEST((NBR+2 == fib_path_list_pool_size()), "path list pool size is%d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NBR+2 == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    /*
+     * Add an 2 ARP entry => a complete ADJ plus adj-fib.
+     */
+    fib_prefix_t pfx_10_10_10_1_s_32 = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    /* 10.10.10.1 */
+	    .ip4.as_u32 = clib_host_to_net_u32(0x0a0a0a01),
+	},
+    };
+    fib_prefix_t pfx_10_10_10_2_s_32 = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    /* 10.10.10.2 */
+	    .ip4.as_u32 = clib_host_to_net_u32(0x0a0a0a02),
+	},
+    };
+    fib_prefix_t pfx_11_11_11_11_s_32 = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    /* 11.11.11.11 */
+	    .ip4.as_u32 = clib_host_to_net_u32(0x0b0b0b0b),
+	},
+    };
+    u8 eth_addr[] = {
+	0xde, 0xde, 0xde, 0xba, 0xba, 0xba,
+    };
+
+    ip46_address_t nh_12_12_12_12 = {
+	.ip4.as_u32 = clib_host_to_net_u32(0x0c0c0c0c),
+    };
+    adj_index_t ai_12_12_12_12;
+
+    /*
+     * Add a route via an incomplete ADJ. then complete the ADJ
+     * Expect the route LB is updated to use complete adj type.
+     */
+    fei = fib_table_entry_update_one_path(fib_index,
+                                          &pfx_11_11_11_11_s_32,
+                                          FIB_SOURCE_API,
+                                          FIB_ENTRY_FLAG_ATTACHED,
+					  FIB_PROTOCOL_IP4,
+                                          &pfx_10_10_10_1_s_32.fp_addr,
+                                          tm->hw[0]->sw_if_index,
+                                          ~0, // invalid fib index
+                                          1,
+                                          NULL,
+                                          FIB_ROUTE_PATH_FLAG_NONE);
+
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    dpo1 = load_balance_get_bucket(dpo->dpoi_index, 0);
+    FIB_TEST(DPO_ADJACENCY_INCOMPLETE == dpo1->dpoi_type,
+             "11.11.11.11/32 via incomplete adj");
+
+    ai_01 = adj_nbr_add_or_lock(FIB_PROTOCOL_IP4,
+				VNET_LINK_IP4,
+				&pfx_10_10_10_1_s_32.fp_addr,
+				tm->hw[0]->sw_if_index);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != ai_01), "adj created");
+    adj = adj_get(ai_01);
+    FIB_TEST((IP_LOOKUP_NEXT_ARP == adj->lookup_next_index),
+	     "adj is incomplete");
+    FIB_TEST((0 == ip46_address_cmp(&pfx_10_10_10_1_s_32.fp_addr,
+				    &adj->sub_type.nbr.next_hop)),
+	      "adj nbr next-hop ok");
+
+    adj_nbr_update_rewrite(ai_01, ADJ_NBR_REWRITE_FLAG_COMPLETE,
+			   fib_test_build_rewrite(eth_addr));
+    FIB_TEST((IP_LOOKUP_NEXT_REWRITE == adj->lookup_next_index),
+	     "adj is complete");
+    FIB_TEST((0 == ip46_address_cmp(&pfx_10_10_10_1_s_32.fp_addr,
+				    &adj->sub_type.nbr.next_hop)),
+	      "adj nbr next-hop ok");
+    ai = fib_entry_get_adj(fei);
+    FIB_TEST((ai_01 == ai), "ADJ-FIB resolves via adj");
+
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    dpo1 = load_balance_get_bucket(dpo->dpoi_index, 0);
+    FIB_TEST(DPO_ADJACENCY == dpo1->dpoi_type,
+             "11.11.11.11/32 via complete adj");
+    FIB_TEST(fib_test_urpf_is_equal(fei, FIB_FORW_CHAIN_TYPE_UNICAST_IP4, 1,
+				    tm->hw[0]->sw_if_index),
+	     "RPF list for adj-fib contains adj");
+
+    ai_12_12_12_12 = adj_nbr_add_or_lock(FIB_PROTOCOL_IP4,
+					 VNET_LINK_IP4,
+					 &nh_12_12_12_12,
+					 tm->hw[1]->sw_if_index);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != ai_12_12_12_12), "adj created");
+    adj = adj_get(ai_12_12_12_12);
+    FIB_TEST((IP_LOOKUP_NEXT_ARP == adj->lookup_next_index),
+	     "adj is incomplete");
+    FIB_TEST((0 == ip46_address_cmp(&nh_12_12_12_12,
+				    &adj->sub_type.nbr.next_hop)),
+	      "adj nbr next-hop ok");
+    adj_nbr_update_rewrite(ai_12_12_12_12, ADJ_NBR_REWRITE_FLAG_COMPLETE,
+			   fib_test_build_rewrite(eth_addr));
+    FIB_TEST((IP_LOOKUP_NEXT_REWRITE == adj->lookup_next_index),
+	     "adj is complete");
+
+    /*
+     * add the adj fib
+     */
+    fei = fib_table_entry_update_one_path(fib_index,
+                                          &pfx_10_10_10_1_s_32,
+                                          FIB_SOURCE_ADJ,
+                                          FIB_ENTRY_FLAG_ATTACHED,
+					  FIB_PROTOCOL_IP4,
+                                          &pfx_10_10_10_1_s_32.fp_addr,
+                                          tm->hw[0]->sw_if_index,
+                                          ~0, // invalid fib index
+                                          1,
+                                          NULL,
+                                          FIB_ROUTE_PATH_FLAG_NONE);
+    FIB_TEST((FIB_ENTRY_FLAG_ATTACHED  == fib_entry_get_flags(fei)),
+	     "Flags set on adj-fib");
+    ai = fib_entry_get_adj(fei);
+    FIB_TEST((ai_01 == ai), "ADJ-FIB resolves via adj");
+
+    fib_table_entry_path_remove(fib_index,
+                                &pfx_11_11_11_11_s_32,
+                                FIB_SOURCE_API,
+				FIB_PROTOCOL_IP4,
+                                &pfx_10_10_10_1_s_32.fp_addr,
+                                tm->hw[0]->sw_if_index,
+                                ~0, // invalid fib index
+                                1,
+                                FIB_ROUTE_PATH_FLAG_NONE);
+
+    eth_addr[5] = 0xb2;
+
+    ai_02 = adj_nbr_add_or_lock(FIB_PROTOCOL_IP4,
+				VNET_LINK_IP4,
+				&pfx_10_10_10_2_s_32.fp_addr,
+				tm->hw[0]->sw_if_index);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != ai_02), "adj created");
+    adj = adj_get(ai_02);
+    FIB_TEST((IP_LOOKUP_NEXT_ARP == adj->lookup_next_index),
+	     "adj is incomplete");
+    FIB_TEST((0 == ip46_address_cmp(&pfx_10_10_10_2_s_32.fp_addr,
+				    &adj->sub_type.nbr.next_hop)),
+	      "adj nbr next-hop ok");
+
+    adj_nbr_update_rewrite(ai_02, ADJ_NBR_REWRITE_FLAG_COMPLETE,
+			   fib_test_build_rewrite(eth_addr));
+    FIB_TEST((IP_LOOKUP_NEXT_REWRITE == adj->lookup_next_index),
+	     "adj is complete");
+    FIB_TEST((0 == ip46_address_cmp(&pfx_10_10_10_2_s_32.fp_addr,
+				    &adj->sub_type.nbr.next_hop)),
+	      "adj nbr next-hop ok");
+    FIB_TEST((ai_01 != ai_02), "ADJs are different");
+
+    fib_table_entry_update_one_path(fib_index,
+				    &pfx_10_10_10_2_s_32,
+				    FIB_SOURCE_ADJ,
+				    FIB_ENTRY_FLAG_ATTACHED,
+				    FIB_PROTOCOL_IP4,
+				    &pfx_10_10_10_2_s_32.fp_addr,
+				    tm->hw[0]->sw_if_index,
+				    ~0, // invalid fib index
+				    1,
+				    NULL,
+				    FIB_ROUTE_PATH_FLAG_NONE);
+
+    fei = fib_table_lookup(fib_index, &pfx_10_10_10_2_s_32);
+    ai = fib_entry_get_adj(fei);
+    FIB_TEST((ai_02 == ai), "ADJ-FIB resolves via adj");
+
+    /*
+     * +2 adj-fibs, and their non-shared path-lists
+     */
+    FIB_TEST((0 == fib_path_list_db_size()),   "path list DB is empty");
+    FIB_TEST((NBR+4 == fib_path_list_pool_size()), "path list pool size is %d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NBR+4 == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    /*
+     * Add 2 routes via the first ADJ. ensure path-list sharing
+     */
+    fib_prefix_t pfx_1_1_1_1_s_32 = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    /* 1.1.1.1/32 */
+	    .ip4.as_u32 = clib_host_to_net_u32(0x01010101),
+	},
+    };
+
+    fib_table_entry_path_add(fib_index,
+			     &pfx_1_1_1_1_s_32,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+			     &nh_10_10_10_1,
+			     tm->hw[0]->sw_if_index,
+			     ~0, // invalid fib index
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup(fib_index, &pfx_1_1_1_1_s_32);
+    ai = fib_entry_get_adj(fei);
+    FIB_TEST((ai_01 == ai), "1.1.1.1 resolves via 10.10.10.1");
+
+    /*
+     * +1 entry and a shared path-list
+     */
+    FIB_TEST((1 == fib_path_list_db_size()),   "path list DB is empty");
+    FIB_TEST((NBR+5 == fib_path_list_pool_size()), "path list pool size is %d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NBR+5 == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    /* 1.1.2.0/24 */
+    fib_prefix_t pfx_1_1_2_0_s_24 = {
+	.fp_len = 24,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    .ip4.as_u32 = clib_host_to_net_u32(0x01010200),
+	}
+    };
+
+    fib_table_entry_path_add(fib_index,
+			     &pfx_1_1_2_0_s_24,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+			     &nh_10_10_10_1,
+			     tm->hw[0]->sw_if_index,
+			     ~0, // invalid fib index
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup(fib_index, &pfx_1_1_2_0_s_24);
+    ai = fib_entry_get_adj(fei);
+    FIB_TEST((ai_01 == ai), "1.1.2.0/24 resolves via 10.10.10.1");
+
+    /*
+     * +1 entry only
+     */
+    FIB_TEST((1 == fib_path_list_db_size()),   "path list DB is empty");
+    FIB_TEST((NBR+5 == fib_path_list_pool_size()), "path list pool size is %d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NBR+6 == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    /*
+     * modify 1.1.2.0/24 to use multipath.
+     */
+    fib_table_entry_path_add(fib_index,
+			     &pfx_1_1_2_0_s_24,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+			     &nh_10_10_10_2,
+			     tm->hw[0]->sw_if_index,
+			     ~0, // invalid fib index
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup(fib_index, &pfx_1_1_2_0_s_24);
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    FIB_TEST(fib_test_urpf_is_equal(fei, FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+				    1, tm->hw[0]->sw_if_index),
+	     "RPF list for 1.1.2.0/24 contains both adjs");
+
+    dpo1 = load_balance_get_bucket(dpo->dpoi_index, 0);
+    FIB_TEST(DPO_ADJACENCY == dpo1->dpoi_type, "type is %d", dpo1->dpoi_type);
+    FIB_TEST((ai_01 == dpo1->dpoi_index),
+	     "1.1.2.0/24 bucket 0 resolves via 10.10.10.1 (%d=%d)",
+             ai_01, dpo1->dpoi_index);
+
+    dpo1 = load_balance_get_bucket(dpo->dpoi_index, 1);
+    FIB_TEST(DPO_ADJACENCY == dpo1->dpoi_type, "type is %d", dpo1->dpoi_type);
+    FIB_TEST((ai_02 == dpo1->dpoi_index),
+	     "1.1.2.0/24 bucket 1 resolves via 10.10.10.2");
+
+    /*
+     * +1 shared-pathlist
+     */
+    FIB_TEST((2 == fib_path_list_db_size()),   "path list DB is empty");
+    FIB_TEST((NBR+6 == fib_path_list_pool_size()), "path list pool size is %d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NBR+6 == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    /*
+     * revert the modify
+     */
+    fib_table_entry_path_remove(fib_index,
+				&pfx_1_1_2_0_s_24,
+				FIB_SOURCE_API,
+				FIB_PROTOCOL_IP4,
+				&nh_10_10_10_2,
+				tm->hw[0]->sw_if_index,
+				~0,
+				1,
+				FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup(fib_index, &pfx_1_1_2_0_s_24);
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    FIB_TEST(fib_test_urpf_is_equal(fei, FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+				   1, tm->hw[0]->sw_if_index),
+	     "RPF list for 1.1.2.0/24 contains one adj");
+
+    ai = fib_entry_get_adj(fei);
+    FIB_TEST((ai_01 == ai), "1.1.2.0/24 resolves via 10.10.10.1");
+
+    /*
+     * +1 shared-pathlist
+     */
+    FIB_TEST((1 == fib_path_list_db_size()),   "path list DB is %d",
+	     fib_path_list_db_size());
+    FIB_TEST((NBR+5 == fib_path_list_pool_size()), "path list pool size is %d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NBR+6 == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    /*
+     * Add 2 recursive routes:
+     *   100.100.100.100/32 via 1.1.1.1/32  => the via entry is installed.
+     *   100.100.100.101/32 via 1.1.1.1/32  => the via entry is installed.
+     */
+    fib_prefix_t bgp_100_pfx = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    /* 100.100.100.100/32 */
+	    .ip4.as_u32 = clib_host_to_net_u32(0x64646464),
+	},
+    };
+    /* via 1.1.1.1 */
+    ip46_address_t nh_1_1_1_1 = {
+	.ip4.as_u32 = clib_host_to_net_u32(0x01010101),
+    };
+
+    fei = fib_table_entry_path_add(fib_index,
+				   &bgp_100_pfx,
+				   FIB_SOURCE_API,
+				   FIB_ENTRY_FLAG_NONE,
+				   FIB_PROTOCOL_IP4,
+				   &nh_1_1_1_1,
+				   ~0, // no index provided.
+				   fib_index, // nexthop in same fib as route
+				   1,
+				   NULL,
+				   FIB_ROUTE_PATH_FLAG_NONE);
+
+    FIB_TEST_REC_FORW(&bgp_100_pfx, &pfx_1_1_1_1_s_32, 0);
+    FIB_TEST(fib_test_urpf_is_equal(fei, FIB_FORW_CHAIN_TYPE_UNICAST_IP4, 1,
+				    tm->hw[0]->sw_if_index),
+	     "RPF list for adj-fib contains adj");
+
+    /*
+     * +1 entry and +1 shared-path-list
+     */
+    FIB_TEST((2  == fib_path_list_db_size()),   "path list DB population:%d",
+	     fib_path_list_db_size());
+    FIB_TEST((NBR+6 == fib_path_list_pool_size()), "path list pool size is %d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NBR+7 == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    fib_prefix_t bgp_101_pfx = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    /* 100.100.100.101/32 */
+	    .ip4.as_u32 = clib_host_to_net_u32(0x64646465),
+	},
+    };
+
+    fib_table_entry_path_add(fib_index,
+			     &bgp_101_pfx,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+			     &nh_1_1_1_1,
+			     ~0, // no index provided.
+			     fib_index, // nexthop in same fib as route
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_FLAG_NONE);
+
+    FIB_TEST_REC_FORW(&bgp_101_pfx, &pfx_1_1_1_1_s_32, 0);
+    FIB_TEST(fib_test_urpf_is_equal(fei, FIB_FORW_CHAIN_TYPE_UNICAST_IP4, 1,
+				    tm->hw[0]->sw_if_index),
+	     "RPF list for adj-fib contains adj");
+
+    /*
+     * +1 entry, but the recursive path-list is shared.
+     */
+    FIB_TEST((2  == fib_path_list_db_size()),   "path list DB population:%d",
+	     fib_path_list_db_size());
+    FIB_TEST((NBR+6 == fib_path_list_pool_size()), "path list pool size is %d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NBR+8 == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    /*
+     * An EXCLUSIVE route; one where the user (me) provides the exclusive
+     * adjacency through which the route will resovle
+     */
+    fib_prefix_t ex_pfx = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    /* 4.4.4.4/32 */
+	    .ip4.as_u32 = clib_host_to_net_u32(0x04040404),
+	},
+    };
+
+    fib_table_entry_special_add(fib_index,
+				&ex_pfx,
+				FIB_SOURCE_SPECIAL,
+				FIB_ENTRY_FLAG_EXCLUSIVE,
+				locked_ai);
+    fei = fib_table_lookup_exact_match(fib_index, &ex_pfx);
+    FIB_TEST((ai == fib_entry_get_adj(fei)),
+	     "Exclusive route links to user adj");
+
+    fib_table_entry_special_remove(fib_index,
+				   &ex_pfx,
+				   FIB_SOURCE_SPECIAL);
+    FIB_TEST(FIB_NODE_INDEX_INVALID ==
+	     fib_table_lookup_exact_match(fib_index, &ex_pfx),
+	     "Exclusive reoute removed");
+
+    /*
+     * An EXCLUSIVE route; one where the user (me) provides the exclusive
+     * adjacency through which the route will resovle
+     */
+    dpo_id_t ex_dpo = DPO_INVALID;
+
+    lookup_dpo_add_or_lock_w_fib_index(fib_index,
+                                       DPO_PROTO_IP4,
+                                       LOOKUP_INPUT_DST_ADDR,
+                                       LOOKUP_TABLE_FROM_CONFIG,
+                                       &ex_dpo);
+
+    fib_table_entry_special_dpo_add(fib_index,
+                                    &ex_pfx,
+                                    FIB_SOURCE_SPECIAL,
+                                    FIB_ENTRY_FLAG_EXCLUSIVE,
+                                    &ex_dpo);
+    fei = fib_table_lookup_exact_match(fib_index, &ex_pfx);
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    FIB_TEST(!dpo_cmp(&ex_dpo, load_balance_get_bucket(dpo->dpoi_index, 0)),
+	     "exclusive remote uses lookup DPO");
+
+    /*
+     * update the exclusive to use a different DPO
+     */
+    ip_null_dpo_add_and_lock(DPO_PROTO_IP4,
+			     IP_NULL_ACTION_SEND_ICMP_UNREACH,
+			     &ex_dpo);
+    fib_table_entry_special_dpo_update(fib_index,
+				       &ex_pfx,
+				       FIB_SOURCE_SPECIAL,
+				       FIB_ENTRY_FLAG_EXCLUSIVE,
+				       &ex_dpo);
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    FIB_TEST(!dpo_cmp(&ex_dpo, load_balance_get_bucket(dpo->dpoi_index, 0)),
+	     "exclusive remote uses now uses NULL DPO");
+
+    fib_table_entry_special_remove(fib_index,
+				   &ex_pfx,
+				   FIB_SOURCE_SPECIAL);
+    FIB_TEST(FIB_NODE_INDEX_INVALID ==
+	     fib_table_lookup_exact_match(fib_index, &ex_pfx),
+	     "Exclusive reoute removed");
+    dpo_reset(&ex_dpo);
+
+    /*
+     * Add a recursive route:
+     *   200.200.200.200/32 via 1.1.1.2/32  => the via entry is NOT installed.
+     */
+    fib_prefix_t bgp_200_pfx = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    /* 200.200.200.200/32 */
+	    .ip4.as_u32 = clib_host_to_net_u32(0xc8c8c8c8),
+	},
+    };
+    /* via 1.1.1.2 */
+    fib_prefix_t pfx_1_1_1_2_s_32 = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    .ip4.as_u32 = clib_host_to_net_u32(0x01010102),
+	},
+    };
+
+    fib_table_entry_path_add(fib_index,
+			     &bgp_200_pfx,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+			     &pfx_1_1_1_2_s_32.fp_addr,
+			     ~0, // no index provided.
+			     fib_index, // nexthop in same fib as route
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_FLAG_NONE);
+
+    FIB_TEST_REC_FORW(&bgp_200_pfx, &pfx_1_1_1_2_s_32, 0);
+
+    /*
+     * the adj should be recursive via drop, since the route resolves via
+     * the default route, which is itself a DROP 
+     */
+    fei = fib_table_lookup(fib_index, &pfx_1_1_1_2_s_32);
+    dpo1 = fib_entry_contribute_ip_forwarding(fei);
+    FIB_TEST(load_balance_is_drop(dpo1), "1.1.1.2/32 is drop");
+    FIB_TEST(fib_test_urpf_is_equal(fei, FIB_FORW_CHAIN_TYPE_UNICAST_IP4, 0),
+	     "RPF list for 1.1.1.2/32 contains 0 adjs");
+
+    /*
+     * +2 entry and +1 shared-path-list
+     */
+    FIB_TEST((3  == fib_path_list_db_size()),   "path list DB population:%d",
+	     fib_path_list_db_size());
+    FIB_TEST((NBR+7 == fib_path_list_pool_size()), "path list pool size is %d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NBR+10 == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    /*
+     * Unequal Cost load-balance. 3:1 ratio. fits in a 4 bucket LB
+     * The paths are sort by NH first. in this case the the path with greater
+     * weight is first in the set. This ordering is to test the RPF sort|uniq logic
+     */
+    fib_prefix_t pfx_1_2_3_4_s_32 = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    .ip4.as_u32 = clib_host_to_net_u32(0x01020304),
+	},
+    };
+    fib_table_entry_path_add(fib_index,
+			     &pfx_1_2_3_4_s_32,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+                             &nh_10_10_10_1,
+                             tm->hw[0]->sw_if_index,
+                             ~0,
+                             1,
+                             NULL,
+                             FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_entry_path_add(fib_index,
+                                   &pfx_1_2_3_4_s_32,
+                                   FIB_SOURCE_API,
+                                   FIB_ENTRY_FLAG_NONE,
+				   FIB_PROTOCOL_IP4,
+                                   &nh_12_12_12_12,
+                                   tm->hw[1]->sw_if_index,
+                                   ~0,
+                                   3,
+                                   NULL,
+                                   FIB_ROUTE_PATH_FLAG_NONE);
+
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "1.2.3.4/32 presnet");
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    lb = load_balance_get(dpo->dpoi_index);
+    FIB_TEST((lb->lb_n_buckets == 4),
+             "1.2.3.4/32 LB has %d bucket",
+             lb->lb_n_buckets);
+
+    FIB_TEST_LB_BUCKET_VIA_ADJ(&pfx_1_2_3_4_s_32, 0, ai_12_12_12_12);
+    FIB_TEST_LB_BUCKET_VIA_ADJ(&pfx_1_2_3_4_s_32, 1, ai_12_12_12_12);
+    FIB_TEST_LB_BUCKET_VIA_ADJ(&pfx_1_2_3_4_s_32, 2, ai_12_12_12_12);
+    FIB_TEST_LB_BUCKET_VIA_ADJ(&pfx_1_2_3_4_s_32, 3, ai_01);
+
+    FIB_TEST(fib_test_urpf_is_equal(fei, FIB_FORW_CHAIN_TYPE_UNICAST_IP4, 2,
+				    tm->hw[0]->sw_if_index,
+				    tm->hw[1]->sw_if_index),
+	     "RPF list for 1.2.3.4/32 contains both adjs");
+
+
+    /*
+     * Unequal Cost load-balance. 4:1 ratio.
+     *  fits in a 16 bucket LB with ratio 13:3
+     */
+    fib_prefix_t pfx_1_2_3_5_s_32 = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    .ip4.as_u32 = clib_host_to_net_u32(0x01020305),
+	},
+    };
+    fib_table_entry_path_add(fib_index,
+			     &pfx_1_2_3_5_s_32,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+                             &nh_12_12_12_12,
+                             tm->hw[1]->sw_if_index,
+                             ~0,
+                             1,
+                             NULL,
+                             FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_entry_path_add(fib_index,
+                                   &pfx_1_2_3_5_s_32,
+                                   FIB_SOURCE_API,
+                                   FIB_ENTRY_FLAG_NONE,
+				   FIB_PROTOCOL_IP4,
+                                   &nh_10_10_10_1,
+                                   tm->hw[0]->sw_if_index,
+                                   ~0,
+                                   4,
+                                   NULL,
+                                   FIB_ROUTE_PATH_FLAG_NONE);
+
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "1.2.3.5/32 presnet");
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    lb = load_balance_get(dpo->dpoi_index);
+    FIB_TEST((lb->lb_n_buckets == 16),
+             "1.2.3.5/32 LB has %d bucket",
+             lb->lb_n_buckets);
+
+    FIB_TEST_LB_BUCKET_VIA_ADJ(&pfx_1_2_3_5_s_32, 0, ai_01);
+    FIB_TEST_LB_BUCKET_VIA_ADJ(&pfx_1_2_3_5_s_32, 1, ai_01);
+    FIB_TEST_LB_BUCKET_VIA_ADJ(&pfx_1_2_3_5_s_32, 2, ai_01);
+    FIB_TEST_LB_BUCKET_VIA_ADJ(&pfx_1_2_3_5_s_32, 3, ai_01);
+    FIB_TEST_LB_BUCKET_VIA_ADJ(&pfx_1_2_3_5_s_32, 4, ai_01);
+    FIB_TEST_LB_BUCKET_VIA_ADJ(&pfx_1_2_3_5_s_32, 5, ai_01);
+    FIB_TEST_LB_BUCKET_VIA_ADJ(&pfx_1_2_3_5_s_32, 6, ai_01);
+    FIB_TEST_LB_BUCKET_VIA_ADJ(&pfx_1_2_3_5_s_32, 7, ai_01);
+    FIB_TEST_LB_BUCKET_VIA_ADJ(&pfx_1_2_3_5_s_32, 8, ai_01);
+    FIB_TEST_LB_BUCKET_VIA_ADJ(&pfx_1_2_3_5_s_32, 9, ai_01);
+    FIB_TEST_LB_BUCKET_VIA_ADJ(&pfx_1_2_3_5_s_32, 10, ai_01);
+    FIB_TEST_LB_BUCKET_VIA_ADJ(&pfx_1_2_3_5_s_32, 11, ai_01);
+    FIB_TEST_LB_BUCKET_VIA_ADJ(&pfx_1_2_3_5_s_32, 12, ai_01);
+    FIB_TEST_LB_BUCKET_VIA_ADJ(&pfx_1_2_3_5_s_32, 13, ai_12_12_12_12);
+    FIB_TEST_LB_BUCKET_VIA_ADJ(&pfx_1_2_3_5_s_32, 14, ai_12_12_12_12);
+    FIB_TEST_LB_BUCKET_VIA_ADJ(&pfx_1_2_3_5_s_32, 15, ai_12_12_12_12);
+
+    FIB_TEST(fib_test_urpf_is_equal(fei, FIB_FORW_CHAIN_TYPE_UNICAST_IP4, 2,
+				    tm->hw[0]->sw_if_index,
+				    tm->hw[1]->sw_if_index),
+	     "RPF list for 1.2.3.4/32 contains both adjs");
+
+    /*
+     * Test UCMP with a large weight skew - this produces load-balance objects with large
+     * numbers of buckets to accommodate the skew. By updating said load-balances we are
+     * laso testing the LB in placce modify code when number of buckets is large.
+     */
+    fib_prefix_t pfx_6_6_6_6_s_32 = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    /* 1.1.1.1/32 */
+	    .ip4.as_u32 = clib_host_to_net_u32(0x06060606),
+	},
+    };
+    fib_test_lb_bucket_t ip_6_6_6_6_o_10_10_10_1 = {
+	.type = FT_LB_ADJ,
+	.adj = {
+	    .adj = ai_01,
+	},
+    };
+    fib_test_lb_bucket_t ip_6_6_6_6_o_10_10_10_2 = {
+        .type = FT_LB_ADJ,
+        .adj = {
+            .adj = ai_02,
+        },
+    };
+    fib_test_lb_bucket_t ip_6_6_6_6_o_12_12_12_12 = {
+        .type = FT_LB_ADJ,
+        .adj = {
+            .adj = ai_12_12_12_12,
+        },
+    };
+    fib_table_entry_update_one_path(fib_index,
+				    &pfx_6_6_6_6_s_32,
+				    FIB_SOURCE_API,
+				    FIB_ENTRY_FLAG_NONE,
+				    FIB_PROTOCOL_IP4,
+				    &nh_10_10_10_1,
+				    tm->hw[0]->sw_if_index,
+				    ~0, // invalid fib index
+				    0,  // zero weigth
+				    NULL,
+				    FIB_ROUTE_PATH_FLAG_NONE);
+
+    fei = fib_table_lookup(fib_index, &pfx_6_6_6_6_s_32);
+    FIB_TEST(fib_test_validate_entry(fei,
+				     FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+				     1,
+				     &ip_6_6_6_6_o_10_10_10_1),
+	     "6.6.6.6/32 via 10.10.10.1");
+
+    fib_table_entry_path_add(fib_index,
+                             &pfx_6_6_6_6_s_32,
+                             FIB_SOURCE_API,
+                             FIB_ENTRY_FLAG_NONE,
+                             FIB_PROTOCOL_IP4,
+                             &nh_10_10_10_2,
+                             tm->hw[0]->sw_if_index,
+                             ~0, // invalid fib index
+                             100,
+                             NULL,
+                             FIB_ROUTE_PATH_FLAG_NONE);
+
+    fei = fib_table_lookup(fib_index, &pfx_6_6_6_6_s_32);
+    FIB_TEST(fib_test_validate_entry(fei,
+				     FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+				     64,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_1),
+	     "6.6.6.6/32 via 10.10.10.1 and 10.10.10.2 in 63:1 ratio");
+
+    fib_table_entry_path_add(fib_index,
+                             &pfx_6_6_6_6_s_32,
+                             FIB_SOURCE_API,
+                             FIB_ENTRY_FLAG_NONE,
+                             FIB_PROTOCOL_IP4,
+                             &nh_12_12_12_12,
+                             tm->hw[1]->sw_if_index,
+                             ~0, // invalid fib index
+                             100,
+                             NULL,
+                             FIB_ROUTE_PATH_FLAG_NONE);
+
+    fei = fib_table_lookup(fib_index, &pfx_6_6_6_6_s_32);
+    FIB_TEST(fib_test_validate_entry(fei,
+				     FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+				     128,
+				     &ip_6_6_6_6_o_10_10_10_1,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12,
+				     &ip_6_6_6_6_o_12_12_12_12),
+	     "6.6.6.6/32 via 10.10.10.1 and 10.10.10.2 in 63:1 ratio");
+
+    fib_table_entry_path_remove(fib_index,
+                                &pfx_6_6_6_6_s_32,
+                                FIB_SOURCE_API,
+                                FIB_PROTOCOL_IP4,
+                                &nh_12_12_12_12,
+                                tm->hw[1]->sw_if_index,
+                                ~0, // invalid fib index
+                                100,
+                                FIB_ROUTE_PATH_FLAG_NONE);
+
+    fei = fib_table_lookup(fib_index, &pfx_6_6_6_6_s_32);
+    FIB_TEST(fib_test_validate_entry(fei,
+				     FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+				     64,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_2,
+				     &ip_6_6_6_6_o_10_10_10_1),
+	     "6.6.6.6/32 via 10.10.10.1 and 10.10.10.2 in 63:1 ratio");
+
+    fib_table_entry_path_remove(fib_index,
+                                &pfx_6_6_6_6_s_32,
+                                FIB_SOURCE_API,
+                                FIB_PROTOCOL_IP4,
+                                &nh_10_10_10_2,
+                                tm->hw[0]->sw_if_index,
+                                ~0, // invalid fib index
+                                100,
+                                FIB_ROUTE_PATH_FLAG_NONE);
+
+    fei = fib_table_lookup(fib_index, &pfx_6_6_6_6_s_32);
+    FIB_TEST(fib_test_validate_entry(fei,
+				     FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+				     1,
+				     &ip_6_6_6_6_o_10_10_10_1),
+	     "6.6.6.6/32 via 10.10.10.1");
+
+    fib_table_entry_delete(fib_index, &pfx_6_6_6_6_s_32, FIB_SOURCE_API);
+
+    /*
+     * A recursive via the two unequal cost entries
+     */
+    fib_prefix_t bgp_44_s_32 = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    /* 200.200.200.201/32 */
+	    .ip4.as_u32 = clib_host_to_net_u32(0x44444444),
+	},
+    };
+    fei = fib_table_entry_path_add(fib_index,
+                                   &bgp_44_s_32,
+                                   FIB_SOURCE_API,
+                                   FIB_ENTRY_FLAG_NONE,
+				   FIB_PROTOCOL_IP4,
+				   &pfx_1_2_3_4_s_32.fp_addr,
+                                   ~0,
+                                   fib_index,
+                                   1,
+                                   NULL,
+                                   FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_entry_path_add(fib_index,
+                                   &bgp_44_s_32,
+                                   FIB_SOURCE_API,
+                                   FIB_ENTRY_FLAG_NONE,
+				   FIB_PROTOCOL_IP4,
+				   &pfx_1_2_3_5_s_32.fp_addr,
+                                   ~0,
+                                   fib_index,
+                                   1,
+                                   NULL,
+                                   FIB_ROUTE_PATH_FLAG_NONE);
+
+    FIB_TEST_REC_FORW(&bgp_44_s_32, &pfx_1_2_3_4_s_32, 0);
+    FIB_TEST_REC_FORW(&bgp_44_s_32, &pfx_1_2_3_5_s_32, 1);
+    FIB_TEST(fib_test_urpf_is_equal(fei, FIB_FORW_CHAIN_TYPE_UNICAST_IP4, 2,
+				    tm->hw[0]->sw_if_index,
+				    tm->hw[1]->sw_if_index),
+	     "RPF list for 1.2.3.4/32 contains both adjs");
+
+    /*
+     * test the uRPF check functions
+     */
+    dpo_id_t dpo_44 = DPO_INVALID;
+    index_t urpfi;
+
+    fib_entry_contribute_forwarding(fei, FIB_FORW_CHAIN_TYPE_UNICAST_IP4, &dpo_44);
+    urpfi = load_balance_get_urpf(dpo_44.dpoi_index);
+
+    FIB_TEST(fib_urpf_check(urpfi, tm->hw[0]->sw_if_index),
+	     "uRPF check for 68.68.68.68/32 on %d OK",
+	     tm->hw[0]->sw_if_index);
+    FIB_TEST(fib_urpf_check(urpfi, tm->hw[1]->sw_if_index),
+	     "uRPF check for 68.68.68.68/32 on %d OK",
+	     tm->hw[1]->sw_if_index);
+    FIB_TEST(!fib_urpf_check(urpfi, 99),
+	     "uRPF check for 68.68.68.68/32 on 99 not-OK",
+	     99);
+    dpo_reset(&dpo_44);
+
+    fib_table_entry_delete(fib_index,
+                           &bgp_44_s_32,
+                           FIB_SOURCE_API);
+    fib_table_entry_delete(fib_index,
+                           &pfx_1_2_3_5_s_32,
+                           FIB_SOURCE_API);
+    fib_table_entry_delete(fib_index,
+                           &pfx_1_2_3_4_s_32,
+                           FIB_SOURCE_API);
+
+    /*
+     * Add a recursive route:
+     *   200.200.200.201/32 via 1.1.1.200/32  => the via entry is NOT installed.
+     */
+    fib_prefix_t bgp_201_pfx = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    /* 200.200.200.201/32 */
+	    .ip4.as_u32 = clib_host_to_net_u32(0xc8c8c8c9),
+	},
+    };
+    /* via 1.1.1.200 */
+    fib_prefix_t pfx_1_1_1_200_s_32 = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    .ip4.as_u32 = clib_host_to_net_u32(0x010101c8),
+	},
+    };
+
+    fib_table_entry_path_add(fib_index,
+			     &bgp_201_pfx,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+			     &pfx_1_1_1_200_s_32.fp_addr,
+			     ~0, // no index provided.
+			     fib_index, // nexthop in same fib as route
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_FLAG_NONE);
+
+    FIB_TEST_REC_FORW(&bgp_201_pfx, &pfx_1_1_1_200_s_32, 0);
+
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_1_1_1_200_s_32);
+    FIB_TEST((FIB_ENTRY_FLAG_NONE == fib_entry_get_flags(fei)),
+	     "Flags set on RR via non-attached");
+    FIB_TEST(fib_test_urpf_is_equal(fei, FIB_FORW_CHAIN_TYPE_UNICAST_IP4, 0),
+	     "RPF list for BGP route empty");
+
+    /*
+     * +2 entry (BGP & RR) and +1 shared-path-list
+     */
+    FIB_TEST((4  == fib_path_list_db_size()),   "path list DB population:%d",
+	     fib_path_list_db_size());
+    FIB_TEST((NBR+8 == fib_path_list_pool_size()), "path list pool size is %d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NBR+12 == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    /*
+     * insert a route that covers the missing 1.1.1.2/32. we epxect
+     * 200.200.200.200/32 and 200.200.200.201/32 to resolve through it.
+     */
+    fib_prefix_t pfx_1_1_1_0_s_24 = {
+	.fp_len = 24,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    /* 1.1.1.0/24 */
+	    .ip4.as_u32 = clib_host_to_net_u32(0x01010100),
+	},
+    };
+
+    fib_table_entry_path_add(fib_index,
+			     &pfx_1_1_1_0_s_24,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+			     &nh_10_10_10_1,
+			     tm->hw[0]->sw_if_index,
+			     ~0, // invalid fib index
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup(fib_index, &pfx_1_1_1_0_s_24);
+    dpo1 = fib_entry_contribute_ip_forwarding(fei);
+    ai = fib_entry_get_adj(fei);
+    FIB_TEST((ai_01 == ai), "1.1.1.0/24 resolves via 10.10.10.1");
+    fei = fib_table_lookup(fib_index, &pfx_1_1_1_2_s_32);
+    dpo1 = fib_entry_contribute_ip_forwarding(fei);
+    ai = fib_entry_get_adj(fei);
+    FIB_TEST((ai_01 == ai), "1.1.1.2/32 resolves via 10.10.10.1");
+    fei = fib_table_lookup(fib_index, &pfx_1_1_1_200_s_32);
+    dpo1 = fib_entry_contribute_ip_forwarding(fei);
+    ai = fib_entry_get_adj(fei);
+    FIB_TEST((ai_01 == ai), "1.1.1.200/24 resolves via 10.10.10.1");
+
+    /*
+     * +1 entry. 1.1.1.1/32 already uses 10.10.10.1 so no new pah-list
+     */
+    FIB_TEST((4  == fib_path_list_db_size()),   "path list DB population:%d",
+	     fib_path_list_db_size());
+    FIB_TEST((NBR+8 == fib_path_list_pool_size()), "path list pool size is %d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NBR+13 == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    /*
+     * the recursive adj for 200.200.200.200 should be updated.
+     */
+    FIB_TEST_REC_FORW(&bgp_201_pfx, &pfx_1_1_1_200_s_32, 0);
+    FIB_TEST_REC_FORW(&bgp_200_pfx, &pfx_1_1_1_2_s_32, 0);
+    fei = fib_table_lookup(fib_index, &bgp_200_pfx);
+    FIB_TEST(fib_test_urpf_is_equal(fei, FIB_FORW_CHAIN_TYPE_UNICAST_IP4, 1,
+				    tm->hw[0]->sw_if_index),
+	     "RPF list for BGP route has itf index 0");
+
+    /*
+     * insert a more specific route than 1.1.1.0/24 that also covers the
+     * missing 1.1.1.2/32, but not 1.1.1.200/32. we epxect
+     * 200.200.200.200 to resolve through it.
+     */
+    fib_prefix_t pfx_1_1_1_0_s_28 = {
+	.fp_len = 28,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    /* 1.1.1.0/24 */
+	    .ip4.as_u32 = clib_host_to_net_u32(0x01010100),
+	},
+    };
+
+    fib_table_entry_path_add(fib_index,
+			     &pfx_1_1_1_0_s_28,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+			     &nh_10_10_10_2,
+			     tm->hw[0]->sw_if_index,
+			     ~0, // invalid fib index
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup(fib_index, &pfx_1_1_1_0_s_28);
+    dpo2 = fib_entry_contribute_ip_forwarding(fei);
+    ai = fib_entry_get_adj(fei);
+    FIB_TEST((ai_02 == ai), "1.1.1.0/24 resolves via 10.10.10.2");
+
+    /*
+     * +1 entry. +1 shared path-list
+     */
+    FIB_TEST((5  == fib_path_list_db_size()),   "path list DB population:%d",
+	     fib_path_list_db_size());
+    FIB_TEST((NBR+9 == fib_path_list_pool_size()), "path list pool size is %d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NBR+14 == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    /*
+     * the recursive adj for 200.200.200.200 should be updated.
+     * 200.200.200.201 remains unchanged.
+     */
+    FIB_TEST_REC_FORW(&bgp_201_pfx, &pfx_1_1_1_200_s_32, 0);
+    FIB_TEST_REC_FORW(&bgp_200_pfx, &pfx_1_1_1_2_s_32, 0);
+
+    /*
+     * remove this /28. 200.200.200.200/32 should revert back to via 1.1.1.0/24
+     */
+    fib_table_entry_path_remove(fib_index,
+				&pfx_1_1_1_0_s_28,
+				FIB_SOURCE_API,
+				FIB_PROTOCOL_IP4,
+				&nh_10_10_10_2,
+				tm->hw[0]->sw_if_index,
+				~0,
+				1,
+				FIB_ROUTE_PATH_FLAG_NONE);
+    FIB_TEST((fib_table_lookup_exact_match(fib_index, &pfx_1_1_1_0_s_28) == 
+	      FIB_NODE_INDEX_INVALID),
+	     "1.1.1.0/28 removed");
+    FIB_TEST((fib_table_lookup(fib_index, &pfx_1_1_1_0_s_28) == 
+	      fib_table_lookup(fib_index, &pfx_1_1_1_0_s_24)),
+	     "1.1.1.0/28 lookup via /24");
+    FIB_TEST_REC_FORW(&bgp_201_pfx, &pfx_1_1_1_200_s_32, 0);
+    FIB_TEST_REC_FORW(&bgp_200_pfx, &pfx_1_1_1_2_s_32, 0);
+
+    /*
+     * -1 entry. -1 shared path-list
+     */
+    FIB_TEST((4  == fib_path_list_db_size()),   "path list DB population:%d",
+	     fib_path_list_db_size());
+    FIB_TEST((NBR+8 == fib_path_list_pool_size()), "path list pool size is %d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NBR+13 == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    /*
+     * remove 1.1.1.0/24. 200.200.200.200/32 should revert back to via 0.0.0.0/0
+     */
+    fib_table_entry_path_remove(fib_index,
+				&pfx_1_1_1_0_s_24,
+				FIB_SOURCE_API,
+				FIB_PROTOCOL_IP4,
+				&nh_10_10_10_1,
+				tm->hw[0]->sw_if_index,
+				~0,
+				1,
+				FIB_ROUTE_PATH_FLAG_NONE);
+    FIB_TEST((fib_table_lookup_exact_match(fib_index, &pfx_1_1_1_0_s_24) == 
+	      FIB_NODE_INDEX_INVALID),
+	     "1.1.1.0/24 removed");
+
+    fei = fib_table_lookup(fib_index, &pfx_1_1_1_2_s_32);
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(fei)),
+	     "1.1.1.2/32 route is DROP");
+    fei = fib_table_lookup(fib_index, &pfx_1_1_1_200_s_32);
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(fei)),
+	     "1.1.1.200/32 route is DROP");
+
+    FIB_TEST_REC_FORW(&bgp_201_pfx, &pfx_1_1_1_200_s_32, 0);
+    FIB_TEST_REC_FORW(&bgp_200_pfx, &pfx_1_1_1_2_s_32, 0);
+
+    /*
+     * -1 entry
+     */
+    FIB_TEST((4  == fib_path_list_db_size()),   "path list DB population:%d",
+	fib_path_list_db_size());
+    FIB_TEST((NBR+8 == fib_path_list_pool_size()), "path list pool size is %d",
+	fib_path_list_pool_size());
+    FIB_TEST((NBR+12 == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    /*
+     * insert the missing 1.1.1.2/32
+     */
+    fei = fib_table_entry_path_add(fib_index,
+	                           &pfx_1_1_1_2_s_32,
+				   FIB_SOURCE_API,
+				   FIB_ENTRY_FLAG_NONE,
+				   FIB_PROTOCOL_IP4,
+				   &nh_10_10_10_1,
+				   tm->hw[0]->sw_if_index,
+				   ~0, // invalid fib index
+				   1,
+				   NULL,
+				   FIB_ROUTE_PATH_FLAG_NONE);
+    dpo1 = fib_entry_contribute_ip_forwarding(fei);
+    ai = fib_entry_get_adj(fei);
+    FIB_TEST((ai = ai_01), "1.1.1.2/32 resolves via 10.10.10.1");
+
+    FIB_TEST_REC_FORW(&bgp_201_pfx, &pfx_1_1_1_200_s_32, 0);
+    FIB_TEST_REC_FORW(&bgp_200_pfx, &pfx_1_1_1_2_s_32, 0);
+
+    /*
+     * no change. 1.1.1.2/32 was already there RR sourced.
+     */
+    FIB_TEST((4  == fib_path_list_db_size()),   "path list DB population:%d",
+	     fib_path_list_db_size());
+    FIB_TEST((NBR+8 == fib_path_list_pool_size()), "path list pool size is %d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NBR+12 == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    /*
+     * remove 200.200.200.201/32 which does not have a valid via FIB
+     */
+    fib_table_entry_path_remove(fib_index,
+				&bgp_201_pfx,
+				FIB_SOURCE_API,
+				FIB_PROTOCOL_IP4,
+				&pfx_1_1_1_200_s_32.fp_addr,
+				~0, // no index provided.
+				fib_index,
+				1,
+				FIB_ROUTE_PATH_FLAG_NONE);
+
+    /*
+     * -2 entries (BGP and RR). -1 shared path-list;
+     */
+    FIB_TEST((fib_table_lookup_exact_match(fib_index, &bgp_201_pfx) == 
+	      FIB_NODE_INDEX_INVALID),
+	     "200.200.200.201/32 removed");
+    FIB_TEST((fib_table_lookup_exact_match(fib_index, &pfx_1_1_1_200_s_32) == 
+	      FIB_NODE_INDEX_INVALID),
+	     "1.1.1.200/32 removed");
+
+    FIB_TEST((3  == fib_path_list_db_size()),   "path list DB population:%d",
+	     fib_path_list_db_size());
+    FIB_TEST((NBR+7 == fib_path_list_pool_size()), "path list pool size is %d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NBR+10 == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    /*
+     * remove 200.200.200.200/32 which does have a valid via FIB
+     */
+    fib_table_entry_path_remove(fib_index,
+				&bgp_200_pfx,
+				FIB_SOURCE_API,
+				FIB_PROTOCOL_IP4,
+				&pfx_1_1_1_2_s_32.fp_addr,
+				~0, // no index provided.
+				fib_index,
+				1,
+				FIB_ROUTE_PATH_FLAG_NONE);
+
+    FIB_TEST((fib_table_lookup_exact_match(fib_index, &bgp_200_pfx) == 
+	      FIB_NODE_INDEX_INVALID),
+	     "200.200.200.200/32 removed");
+    FIB_TEST((fib_table_lookup_exact_match(fib_index, &pfx_1_1_1_2_s_32) != 
+	      FIB_NODE_INDEX_INVALID),
+	     "1.1.1.2/32 still present");
+
+    /*
+     * -1 entry (BGP, the RR source is also API sourced). -1 shared path-list;
+     */
+    FIB_TEST((2  == fib_path_list_db_size()),   "path list DB population:%d",
+	     fib_path_list_db_size());
+    FIB_TEST((NBR+6 == fib_path_list_pool_size()), "path list pool size is %d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NBR+9 == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    /*
+     * A recursive prefix that has a 2 path  load-balance.
+     * It also shares a next-hop with other BGP prefixes and hence
+     * test the ref counting of RR sourced prefixes and 2 level LB.
+     */
+    const fib_prefix_t bgp_102 = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    /* 100.100.100.101/32 */
+	    .ip4.as_u32 = clib_host_to_net_u32(0x64646466),
+	},
+    };
+    fib_table_entry_path_add(fib_index,
+			     &bgp_102,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+			     &pfx_1_1_1_1_s_32.fp_addr,
+			     ~0, // no index provided.
+			     fib_index, // same as route
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_FLAG_NONE);
+    fib_table_entry_path_add(fib_index,
+			     &bgp_102,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+			     &pfx_1_1_1_2_s_32.fp_addr,
+			     ~0, // no index provided.
+			     fib_index, // same as route's FIB
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup_exact_match(fib_index, &bgp_102);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "100.100.100.102/32 presnet");
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+
+    fei  = fib_table_lookup_exact_match(fib_index, &pfx_1_1_1_1_s_32);
+    dpo1 = fib_entry_contribute_ip_forwarding(fei);
+    fei  = fib_table_lookup_exact_match(fib_index, &pfx_1_1_1_2_s_32);
+    dpo2 = fib_entry_contribute_ip_forwarding(fei);
+
+    lb = load_balance_get(dpo->dpoi_index);
+    FIB_TEST((lb->lb_n_buckets == 2), "Recursive LB has %d bucket", lb->lb_n_buckets);
+    FIB_TEST(!dpo_cmp(dpo1, load_balance_get_bucket(dpo->dpoi_index, 0)),
+	     "First via 10.10.10.1");
+    FIB_TEST(!dpo_cmp(dpo2, load_balance_get_bucket(dpo->dpoi_index, 1)),
+	     "Second via 10.10.10.1");
+
+    fib_table_entry_path_remove(fib_index,
+				&bgp_102,
+				FIB_SOURCE_API,
+				FIB_PROTOCOL_IP4,
+				&pfx_1_1_1_1_s_32.fp_addr,
+				~0, // no index provided.
+				fib_index, // same as route's FIB
+				1,
+				FIB_ROUTE_PATH_FLAG_NONE);
+    fib_table_entry_path_remove(fib_index,
+				&bgp_102,
+				FIB_SOURCE_API,
+				FIB_PROTOCOL_IP4,
+				&pfx_1_1_1_2_s_32.fp_addr,
+				~0, // no index provided.
+				fib_index, // same as route's FIB
+				1,
+				FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup_exact_match(fib_index, &bgp_102);
+    FIB_TEST((FIB_NODE_INDEX_INVALID == fei), "100.100.100.102/32 removed");
+
+    /*
+     * remove the remaining recursives
+     */
+    fib_table_entry_path_remove(fib_index,
+				&bgp_100_pfx,
+				FIB_SOURCE_API,
+				FIB_PROTOCOL_IP4,
+				&pfx_1_1_1_1_s_32.fp_addr,
+				~0, // no index provided.
+				fib_index, // same as route's FIB
+				1,
+				FIB_ROUTE_PATH_FLAG_NONE);
+    fib_table_entry_path_remove(fib_index,
+				&bgp_101_pfx,
+				FIB_SOURCE_API,
+				FIB_PROTOCOL_IP4,
+				&pfx_1_1_1_1_s_32.fp_addr,
+				~0, // no index provided.
+				fib_index, // same as route's FIB
+				1,
+				FIB_ROUTE_PATH_FLAG_NONE);
+    FIB_TEST((fib_table_lookup_exact_match(fib_index, &bgp_100_pfx) == 
+	      FIB_NODE_INDEX_INVALID),
+	     "100.100.100.100/32 removed");
+    FIB_TEST((fib_table_lookup_exact_match(fib_index, &bgp_101_pfx) == 
+	      FIB_NODE_INDEX_INVALID),
+	     "100.100.100.101/32 removed");
+
+    /*
+     * -2 entry (2*BGP, the RR source is also API sourced). -1 shared path-list;
+     */
+    FIB_TEST((1  == fib_path_list_db_size()),   "path list DB population:%d",
+	     fib_path_list_db_size());
+    FIB_TEST((NBR+5 == fib_path_list_pool_size()), "path list pool size is %d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NBR+7 == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    /*
+     * Add a recursive route via a connected cover, using an adj-fib that does exist
+     */
+    fib_table_entry_path_add(fib_index,
+			     &bgp_200_pfx,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+			     &nh_10_10_10_1,
+			     ~0, // no index provided.
+			     fib_index, // Same as route's FIB
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_FLAG_NONE);
+
+    /*
+     * +1 entry. +1 shared path-list (recursive via 10.10.10.1)
+     */
+    FIB_TEST((2  == fib_path_list_db_size()),   "path list DB population:%d",
+	     fib_path_list_db_size());
+    FIB_TEST((NBR+6 == fib_path_list_pool_size()), "path list pool size is %d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NBR+8 == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    fei = fib_table_lookup_exact_match(fib_index, &bgp_200_pfx);
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+
+    fei  = fib_table_lookup_exact_match(fib_index, &pfx_10_10_10_1_s_32);
+    dpo1 = fib_entry_contribute_ip_forwarding(fei);
+
+    FIB_TEST(!dpo_cmp(dpo1, load_balance_get_bucket(dpo->dpoi_index, 0)),
+	     "200.200.200.200/32 is recursive via adj for 10.10.10.1");
+
+    FIB_TEST((FIB_ENTRY_FLAG_ATTACHED  == fib_entry_get_flags(fei)),
+	     "Flags set on RR via existing attached");
+
+    /*
+     * Add a recursive route via a connected cover, using and adj-fib that does
+     * not exist
+     */
+    ip46_address_t nh_10_10_10_3 = {
+	.ip4.as_u32 = clib_host_to_net_u32(0x0a0a0a03),
+    };
+    fib_prefix_t pfx_10_10_10_3 = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = nh_10_10_10_3,
+    };
+
+    fib_table_entry_path_add(fib_index,
+			     &bgp_201_pfx,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+			     &nh_10_10_10_3,
+			     ~0, // no index provided.
+			     fib_index,
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_FLAG_NONE);
+
+    /*
+     * +2 entries (BGP and RR). +1 shared path-list (recursive via 10.10.10.3) and
+     * one unshared non-recursive via 10.10.10.3
+     */
+    FIB_TEST((3  == fib_path_list_db_size()),   "path list DB population:%d",
+	     fib_path_list_db_size());
+    FIB_TEST((NBR+8 == fib_path_list_pool_size()), "path list pool size is %d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NBR+10 == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    ai_03 = adj_nbr_add_or_lock(FIB_PROTOCOL_IP4,
+				VNET_LINK_IP4,
+				&nh_10_10_10_3,
+				tm->hw[0]->sw_if_index);
+
+    fei  = fib_table_lookup_exact_match(fib_index, &bgp_201_pfx);
+    dpo  = fib_entry_contribute_ip_forwarding(fei);
+    fei  = fib_table_lookup_exact_match(fib_index, &pfx_10_10_10_3);
+    dpo1 = fib_entry_contribute_ip_forwarding(fei);
+
+    ai = fib_entry_get_adj(fei);
+    FIB_TEST((ai == ai_03), "adj for 10.10.10.3/32 is via adj for 10.10.10.3");
+    FIB_TEST(((FIB_ENTRY_FLAG_ATTACHED | FIB_ENTRY_FLAG_CONNECTED) ==
+	      fib_entry_get_flags(fei)),
+	     "Flags set on RR via non-existing attached");
+
+    FIB_TEST(!dpo_cmp(dpo1, load_balance_get_bucket(dpo->dpoi_index, 0)),
+	     "adj for 200.200.200.200/32 is recursive via adj for 10.10.10.3");
+
+    adj_unlock(ai_03);
+
+    /*
+     * remove the recursives
+     */
+    fib_table_entry_path_remove(fib_index,
+    				&bgp_200_pfx,
+    				FIB_SOURCE_API,
+				FIB_PROTOCOL_IP4,
+    				&nh_10_10_10_1,
+    				~0, // no index provided.
+				fib_index, // same as route's FIB
+				1,
+				FIB_ROUTE_PATH_FLAG_NONE);
+    fib_table_entry_path_remove(fib_index,
+    				&bgp_201_pfx,
+    				FIB_SOURCE_API,
+				FIB_PROTOCOL_IP4,
+    				&nh_10_10_10_3,
+    				~0, // no index provided.
+				fib_index, // same as route's FIB
+				1,
+				FIB_ROUTE_PATH_FLAG_NONE);
+
+    FIB_TEST((fib_table_lookup_exact_match(fib_index, &bgp_201_pfx) ==
+    	      FIB_NODE_INDEX_INVALID),
+    	     "200.200.200.201/32 removed");
+    FIB_TEST((fib_table_lookup_exact_match(fib_index, &bgp_200_pfx) ==
+    	      FIB_NODE_INDEX_INVALID),
+    	     "200.200.200.200/32 removed");
+    FIB_TEST((fib_table_lookup_exact_match(fib_index, &pfx_10_10_10_3) ==
+    	      FIB_NODE_INDEX_INVALID),
+    	     "10.10.10.3/32 removed");
+
+    /*
+     * -3 entries (2*BGP and RR). -2 shared path-list (recursive via 10.10.10.3 &
+     *  10.10.10.1) and one unshared non-recursive via 10.10.10.3
+     */
+    FIB_TEST((1  == fib_path_list_db_size()),   "path list DB population:%d",
+    	     fib_path_list_db_size());
+    FIB_TEST((NBR+5 == fib_path_list_pool_size()), "path list pool size is %d",
+    	     fib_path_list_pool_size());
+    FIB_TEST((NBR+7 == fib_entry_pool_size()), "entry pool size is %d",
+    	     fib_entry_pool_size());
+
+
+    /*
+     * RECURSION LOOPS
+     *  Add 5.5.5.5/32 -> 5.5.5.6/32 -> 5.5.5.7/32 -> 5.5.5.5/32
+     */
+    fib_prefix_t pfx_5_5_5_5_s_32 = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    .ip4.as_u32 = clib_host_to_net_u32(0x05050505),
+	},
+    };
+    fib_prefix_t pfx_5_5_5_6_s_32 = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    .ip4.as_u32 = clib_host_to_net_u32(0x05050506),
+	},
+    };
+    fib_prefix_t pfx_5_5_5_7_s_32 = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    .ip4.as_u32 = clib_host_to_net_u32(0x05050507),
+	},
+    };
+
+    fib_table_entry_path_add(fib_index,
+			     &pfx_5_5_5_5_s_32,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+			     &pfx_5_5_5_6_s_32.fp_addr,
+			     ~0, // no index provided.
+			     fib_index,
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_FLAG_NONE);
+    fib_table_entry_path_add(fib_index,
+			     &pfx_5_5_5_6_s_32,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+			     &pfx_5_5_5_7_s_32.fp_addr,
+			     ~0, // no index provided.
+			     fib_index,
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_FLAG_NONE);
+    fib_table_entry_path_add(fib_index,
+			     &pfx_5_5_5_7_s_32,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+			     &pfx_5_5_5_5_s_32.fp_addr,
+			     ~0, // no index provided.
+			     fib_index,
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_FLAG_NONE);
+    /*
+     * +3 entries, +3 shared path-list
+     */
+    FIB_TEST((4  == fib_path_list_db_size()),   "path list DB population:%d",
+    	     fib_path_list_db_size());
+    FIB_TEST((NBR+8 == fib_path_list_pool_size()), "path list pool size is %d",
+    	     fib_path_list_pool_size());
+    FIB_TEST((NBR+10 == fib_entry_pool_size()), "entry pool size is %d",
+    	     fib_entry_pool_size());
+
+    /*
+     * All the entries have only looped paths, so they are all drop
+     */
+    fei = fib_table_lookup(fib_index, &pfx_5_5_5_7_s_32);
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(fei)),
+	     "LB for 5.5.5.7/32 is via adj for DROP");
+    fei = fib_table_lookup(fib_index, &pfx_5_5_5_5_s_32);
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(fei)),
+	     "LB for 5.5.5.5/32 is via adj for DROP");
+    fei = fib_table_lookup(fib_index, &pfx_5_5_5_6_s_32);
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(fei)),
+	     "LB for 5.5.5.6/32 is via adj for DROP");
+
+    /*
+     * provide 5.5.5.6/32 with alternate path.
+     * this will allow only 5.5.5.6/32 to forward with this path, the others
+     * are still drop since the loop is still present.
+     */
+    fib_table_entry_path_add(fib_index,
+			     &pfx_5_5_5_6_s_32,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+			     &nh_10_10_10_1,
+			     tm->hw[0]->sw_if_index,
+			     ~0,
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_FLAG_NONE);
+
+
+    fei = fib_table_lookup(fib_index, &pfx_5_5_5_6_s_32);
+    dpo1 = fib_entry_contribute_ip_forwarding(fei);
+
+    lb = load_balance_get(dpo1->dpoi_index);
+    FIB_TEST((lb->lb_n_buckets == 1), "5.5.5.6 LB has %d bucket", lb->lb_n_buckets);
+
+    dpo2 = load_balance_get_bucket(dpo1->dpoi_index, 0);
+    FIB_TEST(DPO_ADJACENCY == dpo2->dpoi_type, "type is %d", dpo2->dpoi_type);
+    FIB_TEST((ai_01 == dpo2->dpoi_index),
+	     "5.5.5.6 bucket 0 resolves via 10.10.10.2");
+
+    fei = fib_table_lookup(fib_index, &pfx_5_5_5_7_s_32);
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(fei)),
+	     "LB for 5.5.5.7/32 is via adj for DROP");
+    fei = fib_table_lookup(fib_index, &pfx_5_5_5_5_s_32);
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(fei)),
+	     "LB for 5.5.5.5/32 is via adj for DROP");
+
+    /*
+     * remove the alternate path for 5.5.5.6/32
+     * back to all drop
+     */
+    fib_table_entry_path_remove(fib_index,
+				&pfx_5_5_5_6_s_32,
+				FIB_SOURCE_API,
+				FIB_PROTOCOL_IP4,
+				&nh_10_10_10_1,
+				tm->hw[0]->sw_if_index,
+				~0,
+				1,
+				FIB_ROUTE_PATH_FLAG_NONE);
+
+    fei = fib_table_lookup(fib_index, &pfx_5_5_5_7_s_32);
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(fei)),
+	     "LB for 5.5.5.7/32 is via adj for DROP");
+    fei = fib_table_lookup(fib_index, &pfx_5_5_5_5_s_32);
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(fei)),
+	     "LB for 5.5.5.5/32 is via adj for DROP");
+    fei = fib_table_lookup(fib_index, &pfx_5_5_5_6_s_32);
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(fei)),
+	     "LB for 5.5.5.6/32 is via adj for DROP");
+
+    /*
+     * break the loop by giving 5.5.5.5/32 a new set of paths
+     * expect all to forward via this new path.
+     */
+    fib_table_entry_update_one_path(fib_index,
+				    &pfx_5_5_5_5_s_32,
+				    FIB_SOURCE_API,
+				    FIB_ENTRY_FLAG_NONE,
+				    FIB_PROTOCOL_IP4,
+				    &nh_10_10_10_1,
+				    tm->hw[0]->sw_if_index,
+				    ~0, // invalid fib index
+				    1,
+				    NULL,
+				    FIB_ROUTE_PATH_FLAG_NONE);
+
+    fei = fib_table_lookup(fib_index, &pfx_5_5_5_5_s_32);
+    dpo1 = fib_entry_contribute_ip_forwarding(fei);
+    lb = load_balance_get(dpo1->dpoi_index);
+    FIB_TEST((lb->lb_n_buckets == 1), "5.5.5.5 LB has %d bucket", lb->lb_n_buckets);
+
+    dpo2 = load_balance_get_bucket(dpo1->dpoi_index, 0);
+    FIB_TEST(DPO_ADJACENCY == dpo2->dpoi_type, "type is %d", dpo2->dpoi_type);
+    FIB_TEST((ai_01 == dpo2->dpoi_index),
+	     "5.5.5.5 bucket 0 resolves via 10.10.10.2");
+
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_5_5_5_7_s_32);
+    dpo2 = fib_entry_contribute_ip_forwarding(fei);
+
+    lb = load_balance_get(dpo2->dpoi_index);
+    FIB_TEST((lb->lb_n_buckets == 1), "Recursive LB has %d bucket", lb->lb_n_buckets);
+    FIB_TEST(!dpo_cmp(dpo1, load_balance_get_bucket(dpo2->dpoi_index, 0)),
+	     "5.5.5.5.7 via 5.5.5.5");
+
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_5_5_5_6_s_32);
+    dpo1 = fib_entry_contribute_ip_forwarding(fei);
+
+    lb = load_balance_get(dpo1->dpoi_index);
+    FIB_TEST((lb->lb_n_buckets == 1), "Recursive LB has %d bucket", lb->lb_n_buckets);
+    FIB_TEST(!dpo_cmp(dpo2, load_balance_get_bucket(dpo1->dpoi_index, 0)),
+	     "5.5.5.5.6 via 5.5.5.7");
+
+    /*
+     * revert back to the loop. so we can remove the prefixes with
+     * the loop intact
+     */
+    fib_table_entry_update_one_path(fib_index,
+				    &pfx_5_5_5_5_s_32,
+				    FIB_SOURCE_API,
+				    FIB_ENTRY_FLAG_NONE,
+				    FIB_PROTOCOL_IP4,
+				    &pfx_5_5_5_6_s_32.fp_addr,
+				    ~0, // no index provided.
+				    fib_index,
+				    1,
+				    NULL,
+				    FIB_ROUTE_PATH_FLAG_NONE);
+
+    fei = fib_table_lookup(fib_index, &pfx_5_5_5_7_s_32);
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(fei)),
+	     "LB for 5.5.5.7/32 is via adj for DROP");
+    fei = fib_table_lookup(fib_index, &pfx_5_5_5_5_s_32);
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(fei)),
+	     "LB for 5.5.5.5/32 is via adj for DROP");
+    fei = fib_table_lookup(fib_index, &pfx_5_5_5_6_s_32);
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(fei)),
+	     "LB for 5.5.5.6/32 is via adj for DROP");
+
+    /*
+     * remove all the 5.5.5.x/32 prefixes
+     */
+    fib_table_entry_path_remove(fib_index,
+				&pfx_5_5_5_5_s_32,
+				FIB_SOURCE_API,
+				FIB_PROTOCOL_IP4,
+				&pfx_5_5_5_6_s_32.fp_addr,
+				~0, // no index provided.
+				fib_index, // same as route's FIB
+				1,
+				FIB_ROUTE_PATH_FLAG_NONE);
+    fib_table_entry_path_remove(fib_index,
+				&pfx_5_5_5_6_s_32,
+				FIB_SOURCE_API,
+				FIB_PROTOCOL_IP4,
+				&pfx_5_5_5_7_s_32.fp_addr,
+				~0, // no index provided.
+				fib_index, // same as route's FIB
+				1,
+				FIB_ROUTE_PATH_FLAG_NONE);
+    fib_table_entry_path_remove(fib_index,
+				&pfx_5_5_5_7_s_32,
+				FIB_SOURCE_API,
+				FIB_PROTOCOL_IP4,
+				&pfx_5_5_5_5_s_32.fp_addr,
+				~0, // no index provided.
+				fib_index, // same as route's FIB
+				1,
+				FIB_ROUTE_PATH_FLAG_NONE);
+    fib_table_entry_path_remove(fib_index,
+				&pfx_5_5_5_6_s_32,
+				FIB_SOURCE_API,
+				FIB_PROTOCOL_IP4,
+				&nh_10_10_10_2,
+				~0, // no index provided.
+				fib_index, // same as route's FIB
+				1,
+				FIB_ROUTE_PATH_FLAG_NONE);
+
+    /*
+     * -3 entries, -3 shared path-list
+     */
+    FIB_TEST((1  == fib_path_list_db_size()),   "path list DB population:%d",
+    	     fib_path_list_db_size());
+    FIB_TEST((NBR+5 == fib_path_list_pool_size()), "path list pool size is %d",
+    	     fib_path_list_pool_size());
+    FIB_TEST((NBR+7 == fib_entry_pool_size()), "entry pool size is %d",
+    	     fib_entry_pool_size());
+
+    /*
+     * Single level loop 5.5.5.5/32 via 5.5.5.5/32
+     */
+    fib_table_entry_path_add(fib_index,
+			     &pfx_5_5_5_6_s_32,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+			     &pfx_5_5_5_6_s_32.fp_addr,
+			     ~0, // no index provided.
+			     fib_index,
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup(fib_index, &pfx_5_5_5_6_s_32);
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(fei)),
+	     "1-level 5.5.5.6/32 loop is via adj for DROP");
+ 
+    fib_table_entry_path_remove(fib_index,
+				&pfx_5_5_5_6_s_32,
+				FIB_SOURCE_API,
+				FIB_PROTOCOL_IP4,
+				&pfx_5_5_5_6_s_32.fp_addr,
+				~0, // no index provided.
+				fib_index, // same as route's FIB
+				1,
+				FIB_ROUTE_PATH_FLAG_NONE);
+    FIB_TEST(FIB_NODE_INDEX_INVALID ==
+	     fib_table_lookup_exact_match(fib_index, &pfx_5_5_5_6_s_32),
+	     "1-level 5.5.5.6/32 loop is removed");
+
+    /*
+     * A recursive route whose next-hop is covered by the prefix.
+     * This would mean the via-fib, which inherits forwarding from its
+     * cover, thus picks up forwarding from the prfix, which is via the
+     * via-fib, and we have a loop.
+     */
+    fib_prefix_t pfx_23_23_23_0_s_24 = {
+	.fp_len = 24,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    .ip4.as_u32 = clib_host_to_net_u32(0x17171700),
+	},
+    };
+    fib_prefix_t pfx_23_23_23_23_s_32 = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+            .ip4.as_u32 = clib_host_to_net_u32(0x17171717),
+        },
+    };
+    fei = fib_table_entry_path_add(fib_index,
+				   &pfx_23_23_23_0_s_24,
+				   FIB_SOURCE_API,
+				   FIB_ENTRY_FLAG_NONE,
+				   FIB_PROTOCOL_IP4,
+				   &pfx_23_23_23_23_s_32.fp_addr,
+				   ~0, // recursive
+				   fib_index,
+				   1,
+				   NULL,
+				   FIB_ROUTE_PATH_FLAG_NONE);
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    FIB_TEST(load_balance_is_drop(dpo),
+	     "23.23.23.0/24 via covered is DROP");
+    fib_table_entry_delete_index(fei, FIB_SOURCE_API);
+
+    /*
+     * add-remove test. no change.
+     */
+    FIB_TEST((1  == fib_path_list_db_size()),   "path list DB population:%d",
+    	     fib_path_list_db_size());
+    FIB_TEST((NBR+5 == fib_path_list_pool_size()), "path list pool size is %d",
+    	     fib_path_list_pool_size());
+    FIB_TEST((NBR+7 == fib_entry_pool_size()), "entry pool size is %d",
+    	     fib_entry_pool_size());
+
+    /*
+     * A recursive route with recursion constraints.
+     *  200.200.200.200/32 via 1.1.1.1 is recurse via host constrained
+     */
+    fib_table_entry_path_add(fib_index,
+			     &bgp_200_pfx,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+			     &nh_1_1_1_1,
+			     ~0,
+			     fib_index,
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_RESOLVE_VIA_HOST);
+
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_1_1_1_1_s_32);
+    dpo2 = fib_entry_contribute_ip_forwarding(fei);
+
+    fei = fib_table_lookup_exact_match(fib_index, &bgp_200_pfx);
+    dpo1 = fib_entry_contribute_ip_forwarding(fei);
+
+    FIB_TEST(!dpo_cmp(dpo2, load_balance_get_bucket(dpo1->dpoi_index, 0)),
+	     "adj for 200.200.200.200/32 is recursive via adj for 1.1.1.1");
+
+    /*
+     * save the load-balance. we expect it to be inplace modified
+     */
+    lb = load_balance_get(dpo1->dpoi_index);
+
+    /*
+     * add a covering prefix for the via fib that would otherwise serve
+     * as the resolving route when the host is removed
+     */
+    fib_table_entry_path_add(fib_index,
+			     &pfx_1_1_1_0_s_28,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+			     &nh_10_10_10_1,
+			     tm->hw[0]->sw_if_index,
+			     ~0, // invalid fib index
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_1_1_1_0_s_28);
+    ai = fib_entry_get_adj(fei);
+    FIB_TEST((ai == ai_01),
+	     "adj for 1.1.1.0/28 is via adj for 1.1.1.1");
+
+    /*
+     * remove the host via FIB - expect the BGP prefix to be drop
+     */
+    fib_table_entry_path_remove(fib_index,
+				&pfx_1_1_1_1_s_32,
+				FIB_SOURCE_API,
+				FIB_PROTOCOL_IP4,
+				&nh_10_10_10_1,
+				tm->hw[0]->sw_if_index,
+				~0, // invalid fib index
+				1,
+				FIB_ROUTE_PATH_FLAG_NONE);
+
+    FIB_TEST(!dpo_cmp(dpo_drop, load_balance_get_bucket(dpo1->dpoi_index, 0)),
+	     "adj for 200.200.200.200/32 is recursive via adj for DROP");
+
+    /*
+     * add the via-entry host reoute back. expect to resolve again
+     */
+    fib_table_entry_path_add(fib_index,
+			     &pfx_1_1_1_1_s_32,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+			     &nh_10_10_10_1,
+			     tm->hw[0]->sw_if_index,
+			     ~0, // invalid fib index
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_FLAG_NONE);
+    FIB_TEST(!dpo_cmp(dpo2, load_balance_get_bucket(dpo1->dpoi_index, 0)),
+	     "adj for 200.200.200.200/32 is recursive via adj for 1.1.1.1");
+
+    /*
+     * add another path for the recursive. it will then have 2.
+     */
+    fib_prefix_t pfx_1_1_1_3_s_32 = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    .ip4.as_u32 = clib_host_to_net_u32(0x01010103),
+	},
+    };
+    fib_table_entry_path_add(fib_index,
+			     &pfx_1_1_1_3_s_32,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+			     &nh_10_10_10_2,
+			     tm->hw[0]->sw_if_index,
+			     ~0, // invalid fib index
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_FLAG_NONE);
+
+    fib_table_entry_path_add(fib_index,
+			     &bgp_200_pfx,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+			     &pfx_1_1_1_3_s_32.fp_addr,
+			     ~0,
+			     fib_index,
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_RESOLVE_VIA_HOST);
+
+    fei = fib_table_lookup_exact_match(fib_index, &bgp_200_pfx);
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_1_1_1_1_s_32);
+    dpo2 = fib_entry_contribute_ip_forwarding(fei);
+    FIB_TEST(!dpo_cmp(dpo2, load_balance_get_bucket(dpo->dpoi_index, 0)),
+	     "adj for 200.200.200.200/32 is recursive via adj for 1.1.1.1");
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_1_1_1_3_s_32);
+    dpo1 = fib_entry_contribute_ip_forwarding(fei);
+    FIB_TEST(!dpo_cmp(dpo1, load_balance_get_bucket(dpo->dpoi_index, 1)),
+	     "adj for 200.200.200.200/32 is recursive via adj for 1.1.1.3");
+
+    /*
+     * expect the lb-map used by the recursive's load-balance is using both buckets
+     */
+    load_balance_map_t *lbm;
+    index_t lbmi;
+
+    lb = load_balance_get(dpo->dpoi_index);
+    lbmi = lb->lb_map;
+    load_balance_map_lock(lbmi);
+    lbm = load_balance_map_get(lbmi);
+
+    FIB_TEST(lbm->lbm_buckets[0] == 0,
+             "LB maps's bucket 0 is %d",
+             lbm->lbm_buckets[0]);
+    FIB_TEST(lbm->lbm_buckets[1] == 1,
+             "LB maps's bucket 1 is %d",
+             lbm->lbm_buckets[1]);
+
+    /*
+     * withdraw one of the /32 via-entrys.
+     * that ECMP path will be unresolved and forwarding should continue on the
+     * other available path. this is an iBGP PIC edge failover.
+     * Test the forwarding changes without re-fetching the adj from the
+     * recursive entry. this ensures its the same one that is updated; i.e. an
+     * inplace-modify.
+     */
+    fib_table_entry_path_remove(fib_index,
+				&pfx_1_1_1_1_s_32,
+				FIB_SOURCE_API,
+				FIB_PROTOCOL_IP4,
+				&nh_10_10_10_1,
+				tm->hw[0]->sw_if_index,
+				~0, // invalid fib index
+				1,
+				FIB_ROUTE_PATH_FLAG_NONE);
+
+    fei = fib_table_lookup_exact_match(fib_index, &bgp_200_pfx);
+    FIB_TEST(!dpo_cmp(dpo, fib_entry_contribute_ip_forwarding(fei)),
+	     "post PIC 200.200.200.200/32 was inplace modified");
+
+    FIB_TEST(!dpo_cmp(dpo1, load_balance_get_bucket_i(lb, 0)),
+	     "post PIC adj for 200.200.200.200/32 is recursive"
+	     " via adj for 1.1.1.3");
+
+    /*
+     * the LB maps that was locked above should have been modified to remove
+     * the path that was down, and thus its bucket points to a path that is
+     * still up.
+     */
+    FIB_TEST(lbm->lbm_buckets[0] == 1,
+             "LB maps's bucket 0 is %d",
+             lbm->lbm_buckets[0]);
+    FIB_TEST(lbm->lbm_buckets[1] == 1,
+             "LB maps's bucket 1 is %d",
+             lbm->lbm_buckets[1]);
+
+    load_balance_map_unlock(lb->lb_map);
+
+    /*
+     * add it back. again 
+     */
+    fib_table_entry_path_add(fib_index,
+			     &pfx_1_1_1_1_s_32,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+			     &nh_10_10_10_1,
+			     tm->hw[0]->sw_if_index,
+			     ~0, // invalid fib index
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_FLAG_NONE);
+
+    FIB_TEST(!dpo_cmp(dpo2, load_balance_get_bucket_i(lb, 0)),
+	     "post PIC recovery adj for 200.200.200.200/32 is recursive "
+	     "via adj for 1.1.1.1");
+    FIB_TEST(!dpo_cmp(dpo1, load_balance_get_bucket_i(lb, 1)),
+	     "post PIC recovery adj for 200.200.200.200/32 is recursive "
+	     "via adj for 1.1.1.3");
+
+    fei = fib_table_lookup_exact_match(fib_index, &bgp_200_pfx);
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    FIB_TEST(lb == load_balance_get(dpo->dpoi_index),
+	     "post PIC 200.200.200.200/32 was inplace modified");
+
+    /*
+     * add a 3rd path. this makes the LB 16 buckets. 
+     */
+    fib_table_entry_path_add(fib_index,
+			     &bgp_200_pfx,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+			     &pfx_1_1_1_2_s_32.fp_addr,
+			     ~0,
+			     fib_index,
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_RESOLVE_VIA_HOST);
+
+    fei = fib_table_lookup_exact_match(fib_index, &bgp_200_pfx);
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    FIB_TEST(lb == load_balance_get(dpo->dpoi_index),
+	     "200.200.200.200/32 was inplace modified for 3rd path");
+    FIB_TEST(16 == lb->lb_n_buckets,
+	     "200.200.200.200/32 was inplace modified for 3rd path to 16 buckets");
+
+    lbmi = lb->lb_map;
+    load_balance_map_lock(lbmi);
+    lbm = load_balance_map_get(lbmi);
+
+    for (ii = 0; ii < 16; ii++)
+    {
+        FIB_TEST(lbm->lbm_buckets[ii] == ii,
+                 "LB Map for 200.200.200.200/32 at %d is %d",
+                 ii, lbm->lbm_buckets[ii]);
+    }
+
+    /*
+     * trigger PIC by removing the first via-entry
+     * the first 6 buckets of the map should map to the next 6
+     */
+    fib_table_entry_path_remove(fib_index,
+				&pfx_1_1_1_1_s_32,
+				FIB_SOURCE_API,
+				FIB_PROTOCOL_IP4,
+				&nh_10_10_10_1,
+				tm->hw[0]->sw_if_index,
+				~0,
+				1,
+				FIB_ROUTE_PATH_FLAG_NONE);
+
+    fei = fib_table_lookup_exact_match(fib_index, &bgp_200_pfx);
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    FIB_TEST(lb == load_balance_get(dpo->dpoi_index),
+	     "200.200.200.200/32 was inplace modified for 3rd path");
+    FIB_TEST(2 == lb->lb_n_buckets,
+	     "200.200.200.200/32 was inplace modified for 3rd path remove to 2 buckets");
+
+    for (ii = 0; ii < 6; ii++)
+    {
+        FIB_TEST(lbm->lbm_buckets[ii] == ii+6,
+                 "LB Map for 200.200.200.200/32 at %d is %d",
+                 ii, lbm->lbm_buckets[ii]);
+    }
+    for (ii = 6; ii < 16; ii++)
+    {
+        FIB_TEST(lbm->lbm_buckets[ii] == ii,
+                 "LB Map for 200.200.200.200/32 at %d is %d",
+                 ii, lbm->lbm_buckets[ii]);
+    }
+
+
+    /*
+     * tidy up
+     */
+    fib_table_entry_path_add(fib_index,
+                             &pfx_1_1_1_1_s_32,
+                             FIB_SOURCE_API,
+                             FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+                             &nh_10_10_10_1,
+                             tm->hw[0]->sw_if_index,
+                             ~0,
+                             1,
+                             NULL,
+                             FIB_ROUTE_PATH_FLAG_NONE);
+
+    fib_table_entry_path_remove(fib_index,
+                                &bgp_200_pfx,
+                                FIB_SOURCE_API,
+				FIB_PROTOCOL_IP4,
+                                &pfx_1_1_1_2_s_32.fp_addr,
+                                ~0,
+                                fib_index,
+                                1,
+                                MPLS_LABEL_INVALID);
+    fib_table_entry_path_remove(fib_index,
+				&bgp_200_pfx,
+				FIB_SOURCE_API,
+				FIB_PROTOCOL_IP4,
+				&nh_1_1_1_1,
+				~0,
+				fib_index,
+				1,
+				FIB_ROUTE_PATH_RESOLVE_VIA_HOST);
+    fib_table_entry_path_remove(fib_index,
+				&bgp_200_pfx,
+				FIB_SOURCE_API,
+				FIB_PROTOCOL_IP4,
+				&pfx_1_1_1_3_s_32.fp_addr,
+				~0,
+				fib_index,
+				1,
+				FIB_ROUTE_PATH_RESOLVE_VIA_HOST);
+    fib_table_entry_delete(fib_index,
+			   &pfx_1_1_1_3_s_32,
+			   FIB_SOURCE_API);
+    fib_table_entry_delete(fib_index,
+			   &pfx_1_1_1_0_s_28,
+			   FIB_SOURCE_API);
+    FIB_TEST((FIB_NODE_INDEX_INVALID ==
+	      fib_table_lookup_exact_match(fib_index, &pfx_1_1_1_0_s_28)),
+	     "1.1.1.1/28 removed");
+    FIB_TEST((FIB_NODE_INDEX_INVALID ==
+	      fib_table_lookup_exact_match(fib_index, &pfx_1_1_1_3_s_32)),
+	     "1.1.1.3/32 removed");
+    FIB_TEST((FIB_NODE_INDEX_INVALID ==
+	      fib_table_lookup_exact_match(fib_index, &bgp_200_pfx)),
+	     "200.200.200.200/32 removed");
+
+    /*
+     * add-remove test. no change.
+     */
+    FIB_TEST((1  == fib_path_list_db_size()),   "path list DB population:%d",
+    	     fib_path_list_db_size());
+    FIB_TEST((NBR+5 == fib_path_list_pool_size()), "path list pool size is %d",
+    	     fib_path_list_pool_size());
+    FIB_TEST((NBR+7 == fib_entry_pool_size()), "entry pool size is %d",
+    	     fib_entry_pool_size());
+
+    /*
+     * A route whose paths are built up iteratively and then removed
+     * all at once
+     */
+    fib_prefix_t pfx_4_4_4_4_s_32 = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    /* 4.4.4.4/32 */
+	    .ip4.as_u32 = clib_host_to_net_u32(0x04040404),
+	},
+    };
+
+    fib_table_entry_path_add(fib_index,
+			     &pfx_4_4_4_4_s_32,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+			     &nh_10_10_10_1,
+			     tm->hw[0]->sw_if_index,
+			     ~0,
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_FLAG_NONE);
+    fib_table_entry_path_add(fib_index,
+			     &pfx_4_4_4_4_s_32,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+			     &nh_10_10_10_2,
+			     tm->hw[0]->sw_if_index,
+			     ~0,
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_FLAG_NONE);
+    fib_table_entry_path_add(fib_index,
+			     &pfx_4_4_4_4_s_32,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+			     &nh_10_10_10_3,
+			     tm->hw[0]->sw_if_index,
+			     ~0,
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_FLAG_NONE);
+    FIB_TEST(FIB_NODE_INDEX_INVALID !=
+	     fib_table_lookup_exact_match(fib_index, &pfx_4_4_4_4_s_32),
+	     "4.4.4.4/32 present");
+
+    fib_table_entry_delete(fib_index,
+			   &pfx_4_4_4_4_s_32,
+			   FIB_SOURCE_API);
+    FIB_TEST(FIB_NODE_INDEX_INVALID ==
+	     fib_table_lookup_exact_match(fib_index, &pfx_4_4_4_4_s_32),
+	     "4.4.4.4/32 removed");
+
+    /*
+     * add-remove test. no change.
+     */
+    FIB_TEST((1  == fib_path_list_db_size()),   "path list DB population:%d",
+    	     fib_path_list_db_size());
+    FIB_TEST((NBR+5 == fib_path_list_pool_size()), "path list pool size is %d",
+    	     fib_path_list_pool_size());
+    FIB_TEST((NBR+7 == fib_entry_pool_size()), "entry pool size is %d",
+    	     fib_entry_pool_size());
+
+    /*
+     * A route with multiple paths at once
+     */
+    fib_route_path_t *r_paths = NULL;
+
+    for (ii = 0; ii < 4; ii++)
+    {
+	fib_route_path_t r_path = {
+	    .frp_proto = FIB_PROTOCOL_IP4,
+	    .frp_addr = {
+		.ip4.as_u32 = clib_host_to_net_u32(0x0a0a0a02 + ii),
+	    },
+	    .frp_sw_if_index = tm->hw[0]->sw_if_index,
+	    .frp_weight = 1,
+	    .frp_fib_index = ~0,
+	};
+	vec_add1(r_paths, r_path);
+    }
+
+    fib_table_entry_update(fib_index,
+			   &pfx_4_4_4_4_s_32,
+			   FIB_SOURCE_API,
+			   FIB_ENTRY_FLAG_NONE,
+			   r_paths);
+
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_4_4_4_4_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "4.4.4.4/32 present");
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+
+    lb = load_balance_get(dpo->dpoi_index);
+    FIB_TEST((lb->lb_n_buckets == 4), "4.4.4.4/32 lb over %d paths", lb->lb_n_buckets);
+
+    fib_table_entry_delete(fib_index,
+			   &pfx_4_4_4_4_s_32,
+			   FIB_SOURCE_API);
+    FIB_TEST(FIB_NODE_INDEX_INVALID ==
+	     fib_table_lookup_exact_match(fib_index, &pfx_4_4_4_4_s_32),
+	     "4.4.4.4/32 removed");
+    vec_free(r_paths);
+
+    /*
+     * add-remove test. no change.
+     */
+    FIB_TEST((1  == fib_path_list_db_size()),   "path list DB population:%d",
+    	     fib_path_list_db_size());
+    FIB_TEST((NBR+5 == fib_path_list_pool_size()), "path list pool size is %d",
+    	     fib_path_list_pool_size());
+    FIB_TEST((NBR+7 == fib_entry_pool_size()), "entry pool size is %d",
+    	     fib_entry_pool_size());
+
+    /*
+     * A route deag route
+     */
+    fib_table_entry_path_add(fib_index,
+			     &pfx_4_4_4_4_s_32,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+			     &zero_addr,
+			     ~0,
+			     fib_index,
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_FLAG_NONE);
+
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_4_4_4_4_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "4.4.4.4/32 present");
+
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    dpo = load_balance_get_bucket(dpo->dpoi_index, 0);
+    lookup_dpo_t *lkd = lookup_dpo_get(dpo->dpoi_index);
+
+    FIB_TEST((fib_index == lkd->lkd_fib_index),
+	     "4.4.4.4/32 is deag in %d %U",
+             lkd->lkd_fib_index,
+             format_dpo_id, dpo, 0);
+
+    fib_table_entry_delete(fib_index,
+			   &pfx_4_4_4_4_s_32,
+			   FIB_SOURCE_API);
+    FIB_TEST(FIB_NODE_INDEX_INVALID ==
+	     fib_table_lookup_exact_match(fib_index, &pfx_4_4_4_4_s_32),
+	     "4.4.4.4/32 removed");
+    vec_free(r_paths);
+
+    /*
+     * add-remove test. no change.
+     */
+    FIB_TEST((1  == fib_path_list_db_size()),   "path list DB population:%d",
+    	     fib_path_list_db_size());
+    FIB_TEST((NBR+5 == fib_path_list_pool_size()), "path list pool size is %d",
+    	     fib_path_list_pool_size());
+    FIB_TEST((NBR+7 == fib_entry_pool_size()), "entry pool size is %d",
+    	     fib_entry_pool_size());
+
+    /*
+     * Duplicate paths:
+     *  add a recursive with duplicate paths. Expect the duplicate to be ignored.
+     */
+    fib_prefix_t pfx_34_1_1_1_s_32 = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    .ip4.as_u32 = clib_host_to_net_u32(0x22010101),
+	},
+    };
+    fib_prefix_t pfx_34_34_1_1_s_32 = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    .ip4.as_u32 = clib_host_to_net_u32(0x22220101),
+	},
+    };
+    fei = fib_table_entry_path_add(fib_index,
+                                   &pfx_34_1_1_1_s_32,
+                                   FIB_SOURCE_API,
+                                   FIB_ENTRY_FLAG_NONE,
+                                   FIB_PROTOCOL_IP4,
+                                   &pfx_34_34_1_1_s_32.fp_addr,
+                                   ~0,
+                                   fib_index,
+                                   1,
+                                   NULL,
+                                   FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_entry_path_add(fib_index,
+                                   &pfx_34_1_1_1_s_32,
+                                   FIB_SOURCE_API,
+                                   FIB_ENTRY_FLAG_NONE,
+                                   FIB_PROTOCOL_IP4,
+                                   &pfx_34_34_1_1_s_32.fp_addr,
+                                   ~0,
+                                   fib_index,
+                                   1,
+                                   NULL,
+                                   FIB_ROUTE_PATH_FLAG_NONE);
+    FIB_TEST_REC_FORW(&pfx_34_1_1_1_s_32, &pfx_34_34_1_1_s_32, 0);
+    fib_table_entry_delete_index(fei, FIB_SOURCE_API);
+
+    /*
+     * CLEANUP
+     *   remove: 1.1.1.2/32, 1.1.2.0/24 and 1.1.1.1/32
+     *           all of which are via 10.10.10.1, Itf1
+     */
+    fib_table_entry_path_remove(fib_index,
+				&pfx_1_1_1_2_s_32,
+				FIB_SOURCE_API,
+				FIB_PROTOCOL_IP4,
+				&nh_10_10_10_1,
+				tm->hw[0]->sw_if_index,
+				~0,
+				1,
+				FIB_ROUTE_PATH_FLAG_NONE);
+    fib_table_entry_path_remove(fib_index,
+				&pfx_1_1_1_1_s_32,
+				FIB_SOURCE_API,
+				FIB_PROTOCOL_IP4,
+				&nh_10_10_10_1,
+				tm->hw[0]->sw_if_index,
+				~0,
+				1,
+				FIB_ROUTE_PATH_FLAG_NONE);
+    fib_table_entry_path_remove(fib_index,
+				&pfx_1_1_2_0_s_24,
+				FIB_SOURCE_API,
+				FIB_PROTOCOL_IP4,
+				&nh_10_10_10_1,
+				tm->hw[0]->sw_if_index,
+				~0,
+				1,
+				FIB_ROUTE_PATH_FLAG_NONE);
+
+    FIB_TEST(FIB_NODE_INDEX_INVALID ==
+	     fib_table_lookup_exact_match(fib_index, &pfx_1_1_1_1_s_32),
+	     "1.1.1.1/32 removed");
+    FIB_TEST(FIB_NODE_INDEX_INVALID ==
+	     fib_table_lookup_exact_match(fib_index, &pfx_1_1_1_2_s_32),
+	     "1.1.1.2/32 removed");
+    FIB_TEST(FIB_NODE_INDEX_INVALID ==
+	     fib_table_lookup_exact_match(fib_index, &pfx_1_1_2_0_s_24),
+	     "1.1.2.0/24 removed");
+
+    /*
+     * -3 entries and -1 shared path-list
+     */
+    FIB_TEST((0  == fib_path_list_db_size()),   "path list DB population:%d",
+    	     fib_path_list_db_size());
+    FIB_TEST((NBR+4 == fib_path_list_pool_size()), "path list pool size is %d",
+    	     fib_path_list_pool_size());
+    FIB_TEST((NBR+4 == fib_entry_pool_size()), "entry pool size is %d",
+    	     fib_entry_pool_size());
+
+    /*
+     * An attached-host route. Expect to link to the incomplete adj
+     */
+    fib_prefix_t pfx_4_1_1_1_s_32 = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    /* 4.1.1.1/32 */
+	    .ip4.as_u32 = clib_host_to_net_u32(0x04010101),
+	},
+    };
+    fib_table_entry_path_add(fib_index,
+			     &pfx_4_1_1_1_s_32,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+			     &zero_addr,
+			     tm->hw[0]->sw_if_index,
+			     fib_index,
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_FLAG_NONE);
+
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_4_1_1_1_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "4.1.1.1/32 present");
+    ai = fib_entry_get_adj(fei);
+
+    ai2 = adj_nbr_add_or_lock(FIB_PROTOCOL_IP4,
+			      VNET_LINK_IP4,
+			      &pfx_4_1_1_1_s_32.fp_addr,
+			      tm->hw[0]->sw_if_index);
+    FIB_TEST((ai == ai2), "Attached-host link to incomplete ADJ");
+    adj_unlock(ai2);
+
+    /*
+     * +1 entry and +1 shared path-list
+     */
+    FIB_TEST((1  == fib_path_list_db_size()),   "path list DB population:%d",
+    	     fib_path_list_db_size());
+    FIB_TEST((NBR+5 == fib_path_list_pool_size()), "path list pool size is %d",
+    	     fib_path_list_pool_size());
+    FIB_TEST((NBR+5 == fib_entry_pool_size()), "entry pool size is %d",
+    	     fib_entry_pool_size());
+
+    fib_table_entry_delete(fib_index,
+			   &pfx_4_1_1_1_s_32,
+			   FIB_SOURCE_API);
+
+    FIB_TEST((0  == fib_path_list_db_size()),   "path list DB population:%d",
+    	     fib_path_list_db_size());
+    FIB_TEST((NBR+4 == fib_path_list_pool_size()), "path list pool size is %d",
+    	     fib_path_list_pool_size());
+    FIB_TEST((NBR+4 == fib_entry_pool_size()), "entry pool size is %d",
+    	     fib_entry_pool_size());
+
+    /*
+     * add a v6 prefix via v4 next-hops
+     */
+    fib_prefix_t pfx_2001_s_64 = {
+	.fp_len = 64,
+	.fp_proto = FIB_PROTOCOL_IP6,
+	.fp_addr = {
+	    .ip6.as_u64[0] = clib_host_to_net_u64(0x2001000000000000),
+	},
+    };
+    fei = fib_table_entry_path_add(0, //default v6 table
+				   &pfx_2001_s_64,
+				   FIB_SOURCE_API,
+				   FIB_ENTRY_FLAG_NONE,
+				   FIB_PROTOCOL_IP4,
+				   &nh_10_10_10_1,
+				   tm->hw[0]->sw_if_index,
+				   fib_index,
+				   1,
+				   NULL,
+				   FIB_ROUTE_PATH_FLAG_NONE);
+
+    fei = fib_table_lookup_exact_match(0, &pfx_2001_s_64);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "2001::/64 present");
+    ai = fib_entry_get_adj(fei);
+    adj = adj_get(ai);
+    FIB_TEST((adj->lookup_next_index == IP_LOOKUP_NEXT_ARP),
+	     "2001::/64 via ARP-adj");
+    FIB_TEST((adj->ia_link == VNET_LINK_IP6),
+	     "2001::/64 is link type v6");
+    FIB_TEST((adj->ia_nh_proto == FIB_PROTOCOL_IP4),
+	     "2001::/64 ADJ-adj is NH proto v4");
+    fib_table_entry_delete(0, &pfx_2001_s_64, FIB_SOURCE_API);
+
+    /*
+     * add a uRPF exempt prefix:
+     *  test:
+     *   - it's forwarding is drop
+     *   - it's uRPF list is not empty
+     *   - the uRPF list for the default route (it's cover) is empty
+     */
+    fei = fib_table_entry_special_add(fib_index,
+				      &pfx_4_1_1_1_s_32,
+				      FIB_SOURCE_URPF_EXEMPT,
+				      FIB_ENTRY_FLAG_DROP,
+				      ADJ_INDEX_INVALID);
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    FIB_TEST(load_balance_is_drop(dpo),
+	     "uRPF exempt 4.1.1.1/32 DROP");
+    FIB_TEST(fib_test_urpf_is_equal(fei, FIB_FORW_CHAIN_TYPE_UNICAST_IP4, 1, 0),
+	     "uRPF list for exempt prefix has itf index 0");
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_0_0_0_0_s_0);
+    FIB_TEST(fib_test_urpf_is_equal(fei, FIB_FORW_CHAIN_TYPE_UNICAST_IP4, 0),
+	     "uRPF list for 0.0.0.0/0 empty");
+
+    fib_table_entry_delete(fib_index, &pfx_4_1_1_1_s_32, FIB_SOURCE_URPF_EXEMPT);
+
+    /*
+     * CLEANUP
+     *    remove adj-fibs: 
+     */
+    fib_table_entry_delete(fib_index,
+			   &pfx_10_10_10_1_s_32,
+			   FIB_SOURCE_ADJ);
+    fib_table_entry_delete(fib_index,
+			   &pfx_10_10_10_2_s_32,
+			   FIB_SOURCE_ADJ);
+    FIB_TEST(FIB_NODE_INDEX_INVALID ==
+	     fib_table_lookup_exact_match(fib_index, &pfx_10_10_10_1_s_32),
+	     "10.10.10.1/32 adj-fib removed");
+    FIB_TEST(FIB_NODE_INDEX_INVALID ==
+	     fib_table_lookup_exact_match(fib_index, &pfx_10_10_10_2_s_32),
+	     "10.10.10.2/32 adj-fib removed");
+
+    /*
+     * -2 entries and -2 non-shared path-list
+     */
+    FIB_TEST((0  == fib_path_list_db_size()),   "path list DB population:%d",
+    	     fib_path_list_db_size());
+    FIB_TEST((NBR+2 == fib_path_list_pool_size()), "path list pool size is %d",
+    	     fib_path_list_pool_size());
+    FIB_TEST((NBR+2 == fib_entry_pool_size()), "entry pool size is %d",
+    	     fib_entry_pool_size());
+
+    /*
+     * unlock the adjacencies for which this test provided a rewrite.
+     * These are the last locks on these adjs. they should thus go away.
+     */
+    adj_unlock(ai_02);
+    adj_unlock(ai_01);
+    adj_unlock(ai_12_12_12_12);
+
+    FIB_TEST((0 == adj_nbr_db_size()), "ADJ DB size is %d",
+	     adj_nbr_db_size());
+
+    /*
+     * CLEANUP
+     *   remove the interface prefixes
+     */
+    local_pfx.fp_len = 32;
+    fib_table_entry_special_remove(fib_index, &local_pfx,
+				   FIB_SOURCE_INTERFACE);
+    fei = fib_table_lookup(fib_index, &local_pfx);
+
+    FIB_TEST(FIB_NODE_INDEX_INVALID ==
+	     fib_table_lookup_exact_match(fib_index, &local_pfx),
+	     "10.10.10.10/32 adj-fib removed");
+
+    local_pfx.fp_len = 24;
+    fib_table_entry_delete(fib_index, &local_pfx,
+			   FIB_SOURCE_INTERFACE);
+
+    FIB_TEST(FIB_NODE_INDEX_INVALID ==
+	     fib_table_lookup_exact_match(fib_index, &local_pfx),
+	     "10.10.10.10/24 adj-fib removed");
+
+    /*
+     * -2 entries and -2 non-shared path-list
+     */
+    FIB_TEST((0  == fib_path_list_db_size()),   "path list DB population:%d",
+    	     fib_path_list_db_size());
+    FIB_TEST((NBR == fib_path_list_pool_size()), "path list pool size is %d",
+    	     fib_path_list_pool_size());
+    FIB_TEST((NBR == fib_entry_pool_size()), "entry pool size is %d",
+    	     fib_entry_pool_size());
+
+    /*
+     * Last but not least, remove the VRF
+     */
+    FIB_TEST((0 == fib_table_get_num_entries(fib_index,
+                                             FIB_PROTOCOL_IP4,
+                                             FIB_SOURCE_API)),
+             "NO API Source'd prefixes");
+    FIB_TEST((0 == fib_table_get_num_entries(fib_index,
+                                             FIB_PROTOCOL_IP4,
+                                             FIB_SOURCE_RR)),
+             "NO RR Source'd prefixes");
+    FIB_TEST((0 == fib_table_get_num_entries(fib_index,
+                                             FIB_PROTOCOL_IP4,
+                                             FIB_SOURCE_INTERFACE)),
+             "NO INterface Source'd prefixes");
+
+    fib_table_unlock(fib_index, FIB_PROTOCOL_IP4);
+
+    FIB_TEST((0  == fib_path_list_db_size()), "path list DB population:%d",
+    	     fib_path_list_db_size());
+    FIB_TEST((NBR-5 == fib_path_list_pool_size()), "path list pool size is %d",
+    	     fib_path_list_pool_size());
+    FIB_TEST((NBR-5 == fib_entry_pool_size()), "entry pool size is %d",
+    	     fib_entry_pool_size());
+    FIB_TEST((NBR-5 == pool_elts(fib_urpf_list_pool)), "uRPF pool size is %d",
+    	     pool_elts(fib_urpf_list_pool));
+
+    return 0;
+}
+
+static int
+fib_test_v6 (void)
+{
+    /*
+     * In the default table check for the presence and correct forwarding
+     * of the special entries
+     */
+    fib_node_index_t dfrt, fei, ai, locked_ai, ai_01, ai_02;
+    const dpo_id_t *dpo, *dpo_drop;
+    const ip_adjacency_t *adj;
+    const receive_dpo_t *rd;
+    test_main_t *tm;
+    u32 fib_index;
+    int ii;
+
+    FIB_TEST((0 == adj_nbr_db_size()), "ADJ DB size is %d",
+	     adj_nbr_db_size());
+
+    /* via 2001:0:0:1::2 */
+    ip46_address_t nh_2001_2 = {
+	.ip6 = {
+	    .as_u64 = {
+		[0] = clib_host_to_net_u64(0x2001000000000001),
+		[1] = clib_host_to_net_u64(0x0000000000000002),
+	    },
+	},
+    };
+
+    tm = &test_main;
+
+    dpo_drop = drop_dpo_get(DPO_PROTO_IP6);
+
+    /* Find or create FIB table 11 */
+    fib_index = fib_table_find_or_create_and_lock(FIB_PROTOCOL_IP6, 11);
+
+    for (ii = 0; ii < 4; ii++)
+    {
+	ip6_main.fib_index_by_sw_if_index[tm->hw[ii]->sw_if_index] = fib_index;
+    }
+
+    fib_prefix_t pfx_0_0 = {
+	.fp_len = 0,
+	.fp_proto = FIB_PROTOCOL_IP6,
+	.fp_addr = {
+	    .ip6 = {
+		{0, 0},
+	    },
+	},
+    };
+
+    dfrt = fib_table_lookup(fib_index, &pfx_0_0);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != dfrt), "default route present");
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(dfrt)),
+	     "Default route is DROP");
+
+    dpo = fib_entry_contribute_ip_forwarding(dfrt);
+    FIB_TEST((dpo->dpoi_index == ip6_fib_table_fwding_lookup(
+		                     &ip6_main,
+				     1,
+				     &pfx_0_0.fp_addr.ip6)),
+	     "default-route; fwd and non-fwd tables match");
+
+    // FIXME - check specials.
+
+    /*
+     * At this stage there is one v4 FIB with 5 routes and two v6 FIBs
+     * each with 6 entries. All entries are special so no path-list sharing.
+     */
+#define NPS (5+6+6)
+    FIB_TEST((0 == fib_path_list_db_size()),   "path list DB is empty");
+    FIB_TEST((NPS == fib_path_list_pool_size()), "path list pool size is %d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NPS == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    /*
+     * add interface routes.
+     *  validate presence of /64 attached and /128 recieve.
+     *  test for the presence of the receive address in the glean and local adj
+     *
+     * receive on 2001:0:0:1::1/128
+     */
+    fib_prefix_t local_pfx = {
+	.fp_len = 64,
+	.fp_proto = FIB_PROTOCOL_IP6,
+	.fp_addr = {
+	    .ip6 = {
+		.as_u64 = {
+		    [0] = clib_host_to_net_u64(0x2001000000000001),
+		    [1] = clib_host_to_net_u64(0x0000000000000001),
+		},
+	    },
+	}
+    };
+
+    fib_table_entry_update_one_path(fib_index, &local_pfx,
+				    FIB_SOURCE_INTERFACE,
+				    (FIB_ENTRY_FLAG_CONNECTED |
+				     FIB_ENTRY_FLAG_ATTACHED),
+				    FIB_PROTOCOL_IP6,
+				    NULL,
+				    tm->hw[0]->sw_if_index,
+				    ~0,
+				    1,
+				    NULL,
+				    FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup_exact_match(fib_index, &local_pfx);
+
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "attached interface route present");
+
+    ai = fib_entry_get_adj(fei);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != ai), "attached interface route adj present");
+    adj = adj_get(ai);
+    FIB_TEST((IP_LOOKUP_NEXT_GLEAN == adj->lookup_next_index),
+	     "attached interface adj is glean");
+    FIB_TEST((0 == ip46_address_cmp(&local_pfx.fp_addr,
+				    &adj->sub_type.glean.receive_addr)),
+	      "attached interface adj is receive ok");
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    FIB_TEST((dpo->dpoi_index == ip6_fib_table_fwding_lookup(
+		                     &ip6_main,
+				     1,
+				     &local_pfx.fp_addr.ip6)),
+	     "attached-route; fwd and non-fwd tables match");
+
+    local_pfx.fp_len = 128;
+    fib_table_entry_update_one_path(fib_index, &local_pfx,
+				    FIB_SOURCE_INTERFACE,
+				    (FIB_ENTRY_FLAG_CONNECTED |
+				     FIB_ENTRY_FLAG_LOCAL),
+				    FIB_PROTOCOL_IP6,
+				    NULL,
+				    tm->hw[0]->sw_if_index,
+				    ~0, // invalid fib index
+				    1,
+				    NULL,
+				    FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup(fib_index, &local_pfx);
+
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "local interface route present");
+
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    dpo = load_balance_get_bucket(dpo->dpoi_index, 0);
+    FIB_TEST((DPO_RECEIVE == dpo->dpoi_type),
+	     "local interface adj is local");
+    rd = receive_dpo_get(dpo->dpoi_index);
+
+    FIB_TEST((0 == ip46_address_cmp(&local_pfx.fp_addr,
+				    &rd->rd_addr)),
+	      "local interface adj is receive ok");
+
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    FIB_TEST((dpo->dpoi_index == ip6_fib_table_fwding_lookup(
+		                     &ip6_main,
+				     1,
+				     &local_pfx.fp_addr.ip6)),
+	     "local-route; fwd and non-fwd tables match");
+
+    /*
+     * +2 entries. +2 unshared path-lists
+     */
+    FIB_TEST((0 == fib_path_list_db_size()),   "path list DB is empty");
+    FIB_TEST((NPS+2 == fib_path_list_pool_size()), "path list pool size is%d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NPS+2 == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    /*
+     * Modify the default route to be via an adj not yet known.
+     * this sources the defalut route with the API source, which is
+     * a higher preference to the DEFAULT_ROUTE source
+     */
+    fib_table_entry_path_add(fib_index, &pfx_0_0,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP6,
+			     &nh_2001_2,
+			     tm->hw[0]->sw_if_index,
+			     ~0,
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup(fib_index, &pfx_0_0);
+
+    FIB_TEST((fei == dfrt), "default route same index");
+    ai = fib_entry_get_adj(fei);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != ai), "default route adj present");
+    adj = adj_get(ai);
+    FIB_TEST((IP_LOOKUP_NEXT_ARP == adj->lookup_next_index),
+	     "adj is incomplete");
+    FIB_TEST((0 == ip46_address_cmp(&nh_2001_2, &adj->sub_type.nbr.next_hop)),
+	      "adj nbr next-hop ok");
+
+    /*
+     * find the adj in the shared db
+     */
+    locked_ai = adj_nbr_add_or_lock(FIB_PROTOCOL_IP6,
+				    VNET_LINK_IP6,
+				    &nh_2001_2,
+				    tm->hw[0]->sw_if_index);
+    FIB_TEST((locked_ai == ai), "ADJ NBR DB find");
+    adj_unlock(locked_ai);
+
+    /*
+     * no more entires. +1 shared path-list
+     */
+    FIB_TEST((1 == fib_path_list_db_size()),   "path list DB population:%d",
+	     fib_path_list_db_size());
+    FIB_TEST((NPS+3 == fib_path_list_pool_size()), "path list pool size is%d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NPS+2 == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    /*
+     * remove the API source from the default route. We expected
+     * the route to remain, sourced by DEFAULT_ROUTE, and hence a DROP
+     */
+    fib_table_entry_path_remove(fib_index, &pfx_0_0,
+				FIB_SOURCE_API,	
+				FIB_PROTOCOL_IP6,
+				&nh_2001_2,
+				tm->hw[0]->sw_if_index,
+				~0,
+				1,
+				FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup(fib_index, &pfx_0_0);
+
+    FIB_TEST((fei == dfrt), "default route same index");
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(dfrt)),
+	     "Default route is DROP");
+
+    /*
+     * no more entires. -1 shared path-list
+     */
+    FIB_TEST((0 == fib_path_list_db_size()),   "path list DB population:%d",
+	     fib_path_list_db_size());
+    FIB_TEST((NPS+2 == fib_path_list_pool_size()), "path list pool size is%d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NPS+2 == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    /*
+     * Add an 2 ARP entry => a complete ADJ plus adj-fib.
+     */
+    fib_prefix_t pfx_2001_1_2_s_128 = {
+	.fp_len   = 128,
+	.fp_proto = FIB_PROTOCOL_IP6,
+	.fp_addr  = {
+	    .ip6 = {
+		.as_u64 = {
+		    [0] = clib_host_to_net_u64(0x2001000000000001),
+		    [1] = clib_host_to_net_u64(0x0000000000000002),
+		},
+	    },
+	}
+    };
+    fib_prefix_t pfx_2001_1_3_s_128 = {
+	.fp_len   = 128,
+	.fp_proto = FIB_PROTOCOL_IP6,
+	.fp_addr  = {
+	    .ip6 = {
+		.as_u64 = {
+		    [0] = clib_host_to_net_u64(0x2001000000000001),
+		    [1] = clib_host_to_net_u64(0x0000000000000003),
+		},
+	    },
+	}
+    };
+    u8 eth_addr[] = {
+	0xde, 0xde, 0xde, 0xba, 0xba, 0xba,
+    };
+
+    ai_01 = adj_nbr_add_or_lock(FIB_PROTOCOL_IP6,
+				VNET_LINK_IP6,
+				&pfx_2001_1_2_s_128.fp_addr,
+				tm->hw[0]->sw_if_index);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != ai_01), "adj created");
+    adj = adj_get(ai_01);
+    FIB_TEST((IP_LOOKUP_NEXT_ARP == adj->lookup_next_index),
+	     "adj is incomplete");
+    FIB_TEST((0 == ip46_address_cmp(&pfx_2001_1_2_s_128.fp_addr,
+				    &adj->sub_type.nbr.next_hop)),
+	      "adj nbr next-hop ok");
+
+    adj_nbr_update_rewrite(ai_01, ADJ_NBR_REWRITE_FLAG_COMPLETE,
+			   fib_test_build_rewrite(eth_addr));
+    FIB_TEST((IP_LOOKUP_NEXT_REWRITE == adj->lookup_next_index),
+	     "adj is complete");
+    FIB_TEST((0 == ip46_address_cmp(&pfx_2001_1_2_s_128.fp_addr,
+				    &adj->sub_type.nbr.next_hop)),
+	      "adj nbr next-hop ok");
+
+    fib_table_entry_update_one_path(fib_index,
+				    &pfx_2001_1_2_s_128,
+				    FIB_SOURCE_ADJ,
+				    FIB_ENTRY_FLAG_ATTACHED,
+				    FIB_PROTOCOL_IP6,
+				    &pfx_2001_1_2_s_128.fp_addr,
+				    tm->hw[0]->sw_if_index,
+				    ~0,
+				    1,
+				    NULL,
+				    FIB_ROUTE_PATH_FLAG_NONE);
+
+    fei = fib_table_lookup(fib_index, &pfx_2001_1_2_s_128);
+    ai = fib_entry_get_adj(fei);
+    FIB_TEST((ai_01 == ai), "ADJ-FIB resolves via adj");
+
+    eth_addr[5] = 0xb2;
+
+    ai_02 = adj_nbr_add_or_lock(FIB_PROTOCOL_IP6,
+				VNET_LINK_IP6,
+				&pfx_2001_1_3_s_128.fp_addr,
+				tm->hw[0]->sw_if_index);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != ai_02), "adj created");
+    adj = adj_get(ai_02);
+    FIB_TEST((IP_LOOKUP_NEXT_ARP == adj->lookup_next_index),
+	     "adj is incomplete");
+    FIB_TEST((0 == ip46_address_cmp(&pfx_2001_1_3_s_128.fp_addr,
+				    &adj->sub_type.nbr.next_hop)),
+	      "adj nbr next-hop ok");
+
+    adj_nbr_update_rewrite(ai_02, ADJ_NBR_REWRITE_FLAG_COMPLETE,
+			   fib_test_build_rewrite(eth_addr));
+    FIB_TEST((IP_LOOKUP_NEXT_REWRITE == adj->lookup_next_index),
+	     "adj is complete");
+    FIB_TEST((0 == ip46_address_cmp(&pfx_2001_1_3_s_128.fp_addr,
+				    &adj->sub_type.nbr.next_hop)),
+	      "adj nbr next-hop ok");
+    FIB_TEST((ai_01 != ai_02), "ADJs are different");
+
+    fib_table_entry_update_one_path(fib_index,
+				    &pfx_2001_1_3_s_128,
+				    FIB_SOURCE_ADJ,
+				    FIB_ENTRY_FLAG_ATTACHED,
+				    FIB_PROTOCOL_IP6,
+				    &pfx_2001_1_3_s_128.fp_addr,
+				    tm->hw[0]->sw_if_index,
+				    ~0,
+				    1,
+				    NULL,
+				    FIB_ROUTE_PATH_FLAG_NONE);
+
+    fei = fib_table_lookup(fib_index, &pfx_2001_1_3_s_128);
+    ai = fib_entry_get_adj(fei);
+    FIB_TEST((ai_02 == ai), "ADJ-FIB resolves via adj");
+
+    /*
+     * +2 entries, +2 unshread path-lists.
+     */
+    FIB_TEST((0 == fib_path_list_db_size()),   "path list DB population:%d",
+	     fib_path_list_db_size());
+    FIB_TEST((NPS+4 == fib_path_list_pool_size()), "path list pool size is%d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NPS+4 == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    /*
+     * Add a 2 routes via the first ADJ. ensure path-list sharing
+     */
+    fib_prefix_t pfx_2001_a_s_64 = {
+	.fp_len   = 64,
+	.fp_proto = FIB_PROTOCOL_IP6,
+	.fp_addr  = {
+	    .ip6 = {
+		.as_u64 = {
+		    [0] = clib_host_to_net_u64(0x200100000000000a),
+		    [1] = clib_host_to_net_u64(0x0000000000000000),
+		},
+	    },
+	}
+    };
+    fib_prefix_t pfx_2001_b_s_64 = {
+	.fp_len   = 64,
+	.fp_proto = FIB_PROTOCOL_IP6,
+	.fp_addr  = {
+	    .ip6 = {
+		.as_u64 = {
+		    [0] = clib_host_to_net_u64(0x200100000000000b),
+		    [1] = clib_host_to_net_u64(0x0000000000000000),
+		},
+	    },
+	}
+    };
+
+    fib_table_entry_path_add(fib_index,
+			     &pfx_2001_a_s_64,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP6,
+			     &nh_2001_2,
+			     tm->hw[0]->sw_if_index,
+			     ~0,
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup(fib_index, &pfx_2001_a_s_64);
+    ai = fib_entry_get_adj(fei);
+    FIB_TEST((ai_01 == ai), "2001::a/64 resolves via 2001:0:0:1::1");
+    fib_table_entry_path_add(fib_index,
+			     &pfx_2001_b_s_64,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP6,
+			     &nh_2001_2,
+			     tm->hw[0]->sw_if_index,
+			     ~0,
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup(fib_index, &pfx_2001_b_s_64);
+    ai = fib_entry_get_adj(fei);
+    FIB_TEST((ai_01 == ai), "2001::b/64 resolves via 2001:0:0:1::1");
+
+    /*
+     * +2 entries, +1 shared path-list.
+     */
+    FIB_TEST((1 == fib_path_list_db_size()),   "path list DB population:%d",
+	     fib_path_list_db_size());
+    FIB_TEST((NPS+5 == fib_path_list_pool_size()), "path list pool size is%d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NPS+6 == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    /*
+     * add a v4 prefix via a v6 next-hop
+     */
+    fib_prefix_t pfx_1_1_1_1_s_32 = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    .ip4.as_u32 = 0x01010101,
+	},
+    };
+    fei = fib_table_entry_path_add(0, // default table
+				   &pfx_1_1_1_1_s_32,
+				   FIB_SOURCE_API,
+				   FIB_ENTRY_FLAG_NONE,
+				   FIB_PROTOCOL_IP6,
+				   &nh_2001_2,
+				   tm->hw[0]->sw_if_index,
+				   ~0,
+				   1,
+				   NULL,
+				   FIB_ROUTE_PATH_FLAG_NONE);
+    FIB_TEST(fei == fib_table_lookup_exact_match(0, &pfx_1_1_1_1_s_32),
+	     "1.1.1.1/32 o v6 route present");
+    ai = fib_entry_get_adj(fei);
+    adj = adj_get(ai);
+    FIB_TEST((adj->lookup_next_index == IP_LOOKUP_NEXT_ARP),
+	     "1.1.1.1/32 via ARP-adj");
+    FIB_TEST((adj->ia_link == VNET_LINK_IP4),
+	     "1.1.1.1/32 ADJ-adj is link type v4");
+    FIB_TEST((adj->ia_nh_proto == FIB_PROTOCOL_IP6),
+	     "1.1.1.1/32 ADJ-adj is NH proto v6");
+    fib_table_entry_delete(0, &pfx_1_1_1_1_s_32, FIB_SOURCE_API);
+
+    /*
+     * An attached route
+     */
+    fib_prefix_t pfx_2001_c_s_64 = {
+	.fp_len   = 64,
+	.fp_proto = FIB_PROTOCOL_IP6,
+	.fp_addr  = {
+	    .ip6 = {
+		.as_u64 = {
+		    [0] = clib_host_to_net_u64(0x200100000000000c),
+		    [1] = clib_host_to_net_u64(0x0000000000000000),
+		},
+	    },
+	}
+    };
+    fib_table_entry_path_add(fib_index,
+			     &pfx_2001_c_s_64,
+			     FIB_SOURCE_CLI,
+			     FIB_ENTRY_FLAG_ATTACHED,
+			     FIB_PROTOCOL_IP6,
+			     NULL,
+			     tm->hw[0]->sw_if_index,
+			     ~0,
+			     1,
+			     NULL,
+			     FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_2001_c_s_64);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "attached route present");
+    ai = fib_entry_get_adj(fei);
+    adj = adj_get(ai);
+    FIB_TEST((adj->lookup_next_index == IP_LOOKUP_NEXT_GLEAN),
+	     "2001:0:0:c/64 attached resolves via glean");
+
+    fib_table_entry_path_remove(fib_index,
+				&pfx_2001_c_s_64,
+				FIB_SOURCE_CLI,
+				FIB_PROTOCOL_IP6,
+				NULL,
+				tm->hw[0]->sw_if_index,
+				~0,
+				1,
+				FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_2001_c_s_64);
+    FIB_TEST((FIB_NODE_INDEX_INVALID == fei), "attached route removed");
+
+    /*
+     * Shutdown the interface on which we have a connected and through
+     * which the routes are reachable.
+     * This will result in the connected, adj-fibs, and routes linking to drop
+     * The local/for-us prefix continues to receive.
+     */
+    clib_error_t * error;
+
+    error = vnet_sw_interface_set_flags(vnet_get_main(),
+					tm->hw[0]->sw_if_index,
+					~VNET_SW_INTERFACE_FLAG_ADMIN_UP);
+    FIB_TEST((NULL == error), "Interface shutdown OK");
+
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_2001_b_s_64);
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    FIB_TEST(!dpo_cmp(dpo_drop, load_balance_get_bucket(dpo->dpoi_index, 0)),
+	     "2001::b/64 resolves via drop");
+
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_2001_a_s_64);
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    FIB_TEST(!dpo_cmp(dpo_drop, load_balance_get_bucket(dpo->dpoi_index, 0)),
+	     "2001::a/64 resolves via drop");
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_2001_1_3_s_128);
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    FIB_TEST(!dpo_cmp(dpo_drop, load_balance_get_bucket(dpo->dpoi_index, 0)),
+	     "2001:0:0:1::3/64 resolves via drop");
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_2001_1_2_s_128);
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    FIB_TEST(!dpo_cmp(dpo_drop, load_balance_get_bucket(dpo->dpoi_index, 0)),
+	     "2001:0:0:1::2/64 resolves via drop");
+    fei = fib_table_lookup_exact_match(fib_index, &local_pfx);
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    FIB_TEST(dpo_cmp(dpo_drop, load_balance_get_bucket(dpo->dpoi_index, 0)),
+	     "2001:0:0:1::1/128 not drop");
+    local_pfx.fp_len = 64;
+    fei = fib_table_lookup_exact_match(fib_index, &local_pfx);
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    FIB_TEST(!dpo_cmp(dpo_drop, load_balance_get_bucket(dpo->dpoi_index, 0)),
+	     "2001:0:0:1/64 resolves via drop");
+
+    /*
+     * no change
+     */
+    FIB_TEST((1 == fib_path_list_db_size()),   "path list DB population:%d",
+	     fib_path_list_db_size());
+    FIB_TEST((NPS+5 == fib_path_list_pool_size()), "path list pool size is%d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NPS+6 == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    /*
+     * shutdown one of the other interfaces, then add a connected.
+     * and swap one of the routes to it.
+     */
+    error = vnet_sw_interface_set_flags(vnet_get_main(),
+					tm->hw[1]->sw_if_index,
+					~VNET_SW_INTERFACE_FLAG_ADMIN_UP);
+    FIB_TEST((NULL == error), "Interface 1 shutdown OK");
+
+    fib_prefix_t connected_pfx = {
+	.fp_len = 64,
+	.fp_proto = FIB_PROTOCOL_IP6,
+	.fp_addr = {
+	    .ip6 = {
+		/* 2001:0:0:2::1/64 */
+		.as_u64 = {
+		    [0] = clib_host_to_net_u64(0x2001000000000002),
+		    [1] = clib_host_to_net_u64(0x0000000000000001),
+		},
+	    },
+	}
+    };
+    fib_table_entry_update_one_path(fib_index, &connected_pfx,
+				    FIB_SOURCE_INTERFACE,
+				    (FIB_ENTRY_FLAG_CONNECTED |
+				     FIB_ENTRY_FLAG_ATTACHED),
+				    FIB_PROTOCOL_IP6,
+				    NULL,
+				    tm->hw[1]->sw_if_index,
+				    ~0,
+				    1,
+				    NULL,
+				    FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup_exact_match(fib_index, &connected_pfx);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "attached interface route present");
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    dpo = load_balance_get_bucket(dpo->dpoi_index, 0);
+    FIB_TEST(!dpo_cmp(dpo, dpo_drop),
+             "2001:0:0:2/64 not resolves via drop");
+
+    connected_pfx.fp_len = 128;
+    fib_table_entry_update_one_path(fib_index, &connected_pfx,
+				    FIB_SOURCE_INTERFACE,
+				    (FIB_ENTRY_FLAG_CONNECTED |
+				     FIB_ENTRY_FLAG_LOCAL),
+				    FIB_PROTOCOL_IP6,
+				    NULL,
+				    tm->hw[0]->sw_if_index,
+				    ~0, // invalid fib index
+				    1,
+				    NULL,
+				    FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup(fib_index, &connected_pfx);
+
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "local interface route present");
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    dpo = load_balance_get_bucket(dpo->dpoi_index, 0);
+    FIB_TEST((DPO_RECEIVE == dpo->dpoi_type),
+	     "local interface adj is local");
+    rd = receive_dpo_get(dpo->dpoi_index);
+    FIB_TEST((0 == ip46_address_cmp(&connected_pfx.fp_addr,
+				    &rd->rd_addr)),
+	      "local interface adj is receive ok");
+
+    /*
+     * +2 entries, +2 unshared path-lists
+     */
+    FIB_TEST((1 == fib_path_list_db_size()),   "path list DB population:%d",
+	     fib_path_list_db_size());
+    FIB_TEST((NPS+7 == fib_path_list_pool_size()), "path list pool size is%d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NPS+8 == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+
+    /*
+     * bring the interface back up. we expected the routes to return
+     * to normal forwarding.
+     */
+    error = vnet_sw_interface_set_flags(vnet_get_main(),
+					tm->hw[0]->sw_if_index,
+					VNET_SW_INTERFACE_FLAG_ADMIN_UP);
+    FIB_TEST((NULL == error), "Interface bring-up OK");
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_2001_a_s_64);
+    ai = fib_entry_get_adj(fei);
+    FIB_TEST((ai_01 == ai), "2001::a/64 resolves via 2001:0:0:1::1");
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_2001_b_s_64);
+    ai = fib_entry_get_adj(fei);
+    FIB_TEST((ai_01 == ai), "2001::b/64 resolves via 2001:0:0:1::1");
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_2001_1_3_s_128);
+    ai = fib_entry_get_adj(fei);
+    FIB_TEST((ai_02 == ai), "ADJ-FIB resolves via adj");
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_2001_1_2_s_128);
+    ai = fib_entry_get_adj(fei);
+    FIB_TEST((ai_01 == ai), "ADJ-FIB resolves via adj");
+    local_pfx.fp_len = 64;
+    fei = fib_table_lookup_exact_match(fib_index, &local_pfx);
+    ai = fib_entry_get_adj(fei);
+    adj = adj_get(ai);
+    FIB_TEST((IP_LOOKUP_NEXT_GLEAN == adj->lookup_next_index),
+	     "attached interface adj is glean");
+
+    /*
+     * Same test as above, but this time the HW interface goes down
+     */
+    error = vnet_hw_interface_set_flags(vnet_get_main(),
+					tm->hw_if_indicies[0],
+					~VNET_HW_INTERFACE_FLAG_LINK_UP);
+    FIB_TEST((NULL == error), "Interface shutdown OK");
+
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_2001_b_s_64);
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    FIB_TEST(!dpo_cmp(dpo_drop, load_balance_get_bucket(dpo->dpoi_index, 0)),
+	     "2001::b/64 resolves via drop");
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_2001_a_s_64);
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    FIB_TEST(!dpo_cmp(dpo_drop, load_balance_get_bucket(dpo->dpoi_index, 0)),
+	     "2001::a/64 resolves via drop");
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_2001_1_3_s_128);
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    FIB_TEST(!dpo_cmp(dpo_drop, load_balance_get_bucket(dpo->dpoi_index, 0)),
+	     "2001:0:0:1::3/128 resolves via drop");
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_2001_1_2_s_128);
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    FIB_TEST(!dpo_cmp(dpo_drop, load_balance_get_bucket(dpo->dpoi_index, 0)),
+	     "2001:0:0:1::2/128 resolves via drop");
+    local_pfx.fp_len = 128;
+    fei = fib_table_lookup_exact_match(fib_index, &local_pfx);
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    FIB_TEST(dpo_cmp(dpo_drop, load_balance_get_bucket(dpo->dpoi_index, 0)),
+	     "2001:0:0:1::1/128 not drop");
+    local_pfx.fp_len = 64;
+    fei = fib_table_lookup_exact_match(fib_index, &local_pfx);
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    FIB_TEST(!dpo_cmp(dpo_drop, load_balance_get_bucket(dpo->dpoi_index, 0)),
+	     "2001:0:0:1/64 resolves via drop");
+
+    error = vnet_hw_interface_set_flags(vnet_get_main(),
+					tm->hw_if_indicies[0],
+					VNET_HW_INTERFACE_FLAG_LINK_UP);
+    FIB_TEST((NULL == error), "Interface bring-up OK");
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_2001_a_s_64);
+    ai = fib_entry_get_adj(fei);
+    FIB_TEST((ai_01 == ai), "2001::a/64 resolves via 2001:0:0:1::1");
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_2001_b_s_64);
+    ai = fib_entry_get_adj(fei);
+    FIB_TEST((ai_01 == ai), "2001::b/64 resolves via 2001:0:0:1::1");
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_2001_1_3_s_128);
+    ai = fib_entry_get_adj(fei);
+    FIB_TEST((ai_02 == ai), "ADJ-FIB resolves via adj");
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_2001_1_2_s_128);
+    ai = fib_entry_get_adj(fei);
+    FIB_TEST((ai_01 == ai), "ADJ-FIB resolves via adj");
+    local_pfx.fp_len = 64;
+    fei = fib_table_lookup_exact_match(fib_index, &local_pfx);
+    ai = fib_entry_get_adj(fei);
+    adj = adj_get(ai);
+    FIB_TEST((IP_LOOKUP_NEXT_GLEAN == adj->lookup_next_index),
+	     "attached interface adj is glean");
+
+    /*
+     * Delete the interface that the routes reolve through.
+     * Again no routes are removed. They all point to drop.
+     *
+     * This is considered an error case. The control plane should
+     * not remove interfaces through which routes resolve, but
+     * such things can happen. ALL affected routes will drop.
+     */
+    vnet_delete_hw_interface(vnet_get_main(), tm->hw_if_indicies[0]);
+
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_2001_b_s_64);
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(fei)),
+             "2001::b/64 resolves via drop");
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_2001_a_s_64);
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(fei)),
+             "2001::b/64 resolves via drop");
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_2001_1_3_s_128);
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(fei)),
+             "2001:0:0:1::3/64 resolves via drop");
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_2001_1_2_s_128);
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(fei)),
+             "2001:0:0:1::2/64 resolves via drop");
+    fei = fib_table_lookup_exact_match(fib_index, &local_pfx);
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(fei)),
+             "2001:0:0:1::1/128 is drop");
+    local_pfx.fp_len = 64;
+    fei = fib_table_lookup_exact_match(fib_index, &local_pfx);
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(fei)),
+             "2001:0:0:1/64 resolves via drop");
+
+    /*
+     * no change
+     */
+    FIB_TEST((1 == fib_path_list_db_size()),   "path list DB population:%d",
+	     fib_path_list_db_size());
+    FIB_TEST((NPS+7 == fib_path_list_pool_size()), "path list pool size is%d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NPS+8 == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    /*
+     * Add the interface back. routes stay unresolved.
+     */
+    error = ethernet_register_interface(vnet_get_main(),
+					test_interface_device_class.index,
+					0 /* instance */,
+					hw_address,
+					&tm->hw_if_indicies[0],
+					/* flag change */ 0);
+
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_2001_b_s_64);
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(fei)),
+             "2001::b/64 resolves via drop");
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_2001_a_s_64);
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(fei)),
+             "2001::b/64 resolves via drop");
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_2001_1_3_s_128);
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(fei)),
+             "2001:0:0:1::3/64 resolves via drop");
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_2001_1_2_s_128);
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(fei)),
+             "2001:0:0:1::2/64 resolves via drop");
+    fei = fib_table_lookup_exact_match(fib_index, &local_pfx);
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(fei)),
+             "2001:0:0:1::1/128 is drop");
+    local_pfx.fp_len = 64;
+    fei = fib_table_lookup_exact_match(fib_index, &local_pfx);
+    FIB_TEST(load_balance_is_drop(fib_entry_contribute_ip_forwarding(fei)),
+             "2001:0:0:1/64 resolves via drop");
+
+    /*
+     * CLEANUP ALL the routes
+     */
+    fib_table_entry_delete(fib_index,
+			   &pfx_2001_c_s_64,
+			   FIB_SOURCE_API);
+    fib_table_entry_delete(fib_index,
+			   &pfx_2001_a_s_64,
+			   FIB_SOURCE_API);
+    fib_table_entry_delete(fib_index,
+			   &pfx_2001_b_s_64,
+			   FIB_SOURCE_API);
+    fib_table_entry_delete(fib_index,
+			   &pfx_2001_1_3_s_128,
+			   FIB_SOURCE_ADJ);
+    fib_table_entry_delete(fib_index,
+			   &pfx_2001_1_2_s_128,
+			   FIB_SOURCE_ADJ);
+    local_pfx.fp_len = 64;
+    fib_table_entry_delete(fib_index, &local_pfx,
+			   FIB_SOURCE_INTERFACE);
+    local_pfx.fp_len = 128;
+    fib_table_entry_special_remove(fib_index, &local_pfx,
+				   FIB_SOURCE_INTERFACE);
+    connected_pfx.fp_len = 64;
+    fib_table_entry_delete(fib_index, &connected_pfx,
+			   FIB_SOURCE_INTERFACE);
+    connected_pfx.fp_len = 128;
+    fib_table_entry_special_remove(fib_index, &connected_pfx,
+				   FIB_SOURCE_INTERFACE);
+
+    FIB_TEST((FIB_NODE_INDEX_INVALID ==
+	      fib_table_lookup_exact_match(fib_index, &pfx_2001_a_s_64)),
+	     "2001::a/64 removed");
+    FIB_TEST((FIB_NODE_INDEX_INVALID ==
+	      fib_table_lookup_exact_match(fib_index, &pfx_2001_b_s_64)),
+	     "2001::b/64 removed");
+    FIB_TEST((FIB_NODE_INDEX_INVALID ==
+	      fib_table_lookup_exact_match(fib_index, &pfx_2001_1_3_s_128)),
+	     "2001:0:0:1::3/128 removed");
+    FIB_TEST((FIB_NODE_INDEX_INVALID ==
+	      fib_table_lookup_exact_match(fib_index, &pfx_2001_1_2_s_128)),
+	     "2001:0:0:1::3/128 removed");
+    local_pfx.fp_len = 64;
+    FIB_TEST((FIB_NODE_INDEX_INVALID ==
+	      fib_table_lookup_exact_match(fib_index, &local_pfx)),
+	     "2001:0:0:1/64 removed");
+    local_pfx.fp_len = 128;
+    FIB_TEST((FIB_NODE_INDEX_INVALID ==
+	      fib_table_lookup_exact_match(fib_index, &local_pfx)),
+	     "2001:0:0:1::1/128 removed");
+    connected_pfx.fp_len = 64;
+    FIB_TEST((FIB_NODE_INDEX_INVALID ==
+	      fib_table_lookup_exact_match(fib_index, &connected_pfx)),
+	     "2001:0:0:2/64 removed");
+    connected_pfx.fp_len = 128;
+    FIB_TEST((FIB_NODE_INDEX_INVALID ==
+	      fib_table_lookup_exact_match(fib_index, &connected_pfx)),
+	     "2001:0:0:2::1/128 removed");
+
+    /*
+     * -8 entries. -7 path-lists (1 was shared).
+     */
+    FIB_TEST((0 == fib_path_list_db_size()),   "path list DB population:%d",
+	     fib_path_list_db_size());
+    FIB_TEST((NPS == fib_path_list_pool_size()), "path list pool size is%d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NPS == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    /*
+     * now remove the VRF
+     */
+    fib_table_unlock(fib_index, FIB_PROTOCOL_IP6);
+
+    FIB_TEST((0 == fib_path_list_db_size()),   "path list DB population:%d",
+	     fib_path_list_db_size());
+    FIB_TEST((NPS-6 == fib_path_list_pool_size()), "path list pool size is%d",
+	     fib_path_list_pool_size());
+    FIB_TEST((NPS-6 == fib_entry_pool_size()), "entry pool size is %d",
+	     fib_entry_pool_size());
+
+    adj_unlock(ai_02);
+    adj_unlock(ai_01);
+
+    /*
+     * return the interfaces to up state
+     */
+    error = vnet_sw_interface_set_flags(vnet_get_main(),
+					tm->hw[0]->sw_if_index,
+					VNET_SW_INTERFACE_FLAG_ADMIN_UP);
+    error = vnet_sw_interface_set_flags(vnet_get_main(),
+					tm->hw[1]->sw_if_index,
+					VNET_SW_INTERFACE_FLAG_ADMIN_UP);
+
+    FIB_TEST((0 == adj_nbr_db_size()), "ADJ DB size is %d",
+	     adj_nbr_db_size());
+
+    return (0);
+}
+
+/*
+ * Test Attached Exports
+ */
+static int
+fib_test_ae (void)
+{
+    const dpo_id_t *dpo, *dpo_drop;
+    const u32 fib_index = 0;
+    fib_node_index_t fei;
+    test_main_t *tm;
+    ip4_main_t *im;
+
+    tm = &test_main;
+    im = &ip4_main;
+
+    FIB_TEST((0 == adj_nbr_db_size()), "ADJ DB size is %d",
+	     adj_nbr_db_size());
+
+    /*
+     * add interface routes. We'll assume this works. It's more rigorously
+     * tested elsewhere.
+     */
+    fib_prefix_t local_pfx = {
+	.fp_len = 24,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    .ip4 = {
+		/* 10.10.10.10 */
+		.as_u32 = clib_host_to_net_u32(0x0a0a0a0a),
+	    },
+	},
+    };
+
+    vec_validate(im->fib_index_by_sw_if_index, tm->hw[0]->sw_if_index);
+    im->fib_index_by_sw_if_index[tm->hw[0]->sw_if_index] = fib_index;
+
+    dpo_drop = drop_dpo_get(DPO_PROTO_IP4);
+
+    fib_table_entry_update_one_path(fib_index, &local_pfx,
+				    FIB_SOURCE_INTERFACE,
+				    (FIB_ENTRY_FLAG_CONNECTED |
+				     FIB_ENTRY_FLAG_ATTACHED),
+				    FIB_PROTOCOL_IP4,
+				    NULL,
+				    tm->hw[0]->sw_if_index,
+				    ~0,
+				    1,
+				    NULL,
+				    FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup_exact_match(fib_index, &local_pfx);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei),
+	     "attached interface route present");
+
+    local_pfx.fp_len = 32;
+    fib_table_entry_update_one_path(fib_index, &local_pfx,
+				    FIB_SOURCE_INTERFACE,
+				    (FIB_ENTRY_FLAG_CONNECTED |
+				     FIB_ENTRY_FLAG_LOCAL),
+				    FIB_PROTOCOL_IP4,
+				    NULL,
+				    tm->hw[0]->sw_if_index,
+				    ~0, // invalid fib index
+				    1,
+				    NULL,
+				    FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup_exact_match(fib_index, &local_pfx);
+
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei),
+	     "local interface route present");
+
+    /*
+     * Add an 2 ARP entry => a complete ADJ plus adj-fib.
+     */
+    fib_prefix_t pfx_10_10_10_1_s_32 = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    /* 10.10.10.1 */
+	    .ip4.as_u32 = clib_host_to_net_u32(0x0a0a0a01),
+	},
+    };
+    fib_node_index_t ai;
+
+    fib_table_entry_update_one_path(fib_index,
+				    &pfx_10_10_10_1_s_32,
+				    FIB_SOURCE_ADJ,
+				    FIB_ENTRY_FLAG_ATTACHED,
+				    FIB_PROTOCOL_IP4,
+				    &pfx_10_10_10_1_s_32.fp_addr,
+				    tm->hw[0]->sw_if_index,
+				    ~0, // invalid fib index
+				    1,
+				    NULL,
+				    FIB_ROUTE_PATH_FLAG_NONE);
+
+    fei = fib_table_lookup(fib_index, &pfx_10_10_10_1_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "ADJ-fib1 created");
+    ai = fib_entry_get_adj(fei);
+
+    /*
+     * create another FIB table into which routes will be imported
+     */
+    u32 import_fib_index1;
+
+    import_fib_index1 = fib_table_find_or_create_and_lock(FIB_PROTOCOL_IP4, 11);
+
+    /*
+     * Add an attached route in the import FIB
+     */
+    local_pfx.fp_len = 24;
+    fib_table_entry_update_one_path(import_fib_index1,
+				    &local_pfx,
+				    FIB_SOURCE_API,
+				    FIB_ENTRY_FLAG_NONE,
+				    FIB_PROTOCOL_IP4,
+				    NULL,
+				    tm->hw[0]->sw_if_index,
+				    ~0, // invalid fib index
+				    1,
+				    NULL,
+				    FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup_exact_match(import_fib_index1, &local_pfx);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "attached export created");
+
+    /*
+     * check for the presence of the adj-fibs in the import table
+     */
+    fei = fib_table_lookup_exact_match(import_fib_index1, &pfx_10_10_10_1_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "ADJ-fib1 imported");
+    FIB_TEST((ai == fib_entry_get_adj(fei)),
+	     "adj-fib1 Import uses same adj as export");
+
+    /*
+     * check for the presence of the local in the import table
+     */
+    local_pfx.fp_len = 32;
+    fei = fib_table_lookup_exact_match(import_fib_index1, &local_pfx);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "local imported");
+
+    /*
+     * Add another adj-fin in the export table. Expect this
+     * to get magically exported;
+     */
+    fib_prefix_t pfx_10_10_10_2_s_32 = {
+    	.fp_len = 32,
+    	.fp_proto = FIB_PROTOCOL_IP4,
+    	.fp_addr = {
+    	    /* 10.10.10.2 */
+    	    .ip4.as_u32 = clib_host_to_net_u32(0x0a0a0a02),
+    	},
+    };
+
+    fib_table_entry_update_one_path(fib_index,
+				    &pfx_10_10_10_2_s_32,
+				    FIB_SOURCE_ADJ,
+				    FIB_ENTRY_FLAG_ATTACHED,
+				    FIB_PROTOCOL_IP4,
+				    &pfx_10_10_10_2_s_32.fp_addr,
+				    tm->hw[0]->sw_if_index,
+				    ~0, // invalid fib index
+				    1,
+				    NULL,
+				    FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_10_10_10_2_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "ADJ-fib2 present");
+    ai = fib_entry_get_adj(fei);
+
+    fei = fib_table_lookup_exact_match(import_fib_index1, &pfx_10_10_10_2_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "ADJ-fib2 imported");
+    FIB_TEST((ai == fib_entry_get_adj(fei)),
+	     "Import uses same adj as export");
+    FIB_TEST((FIB_ENTRY_FLAG_ATTACHED & fib_entry_get_flags(fei)),
+             "ADJ-fib2 imported flags %d",
+             fib_entry_get_flags(fei));
+
+    /*
+     * create a 2nd FIB table into which routes will be imported
+     */
+    u32 import_fib_index2;
+
+    import_fib_index2 = fib_table_find_or_create_and_lock(FIB_PROTOCOL_IP4, 12);
+
+    /*
+     * Add an attached route in the import FIB
+     */
+    local_pfx.fp_len = 24;
+    fib_table_entry_update_one_path(import_fib_index2,
+				    &local_pfx,
+				    FIB_SOURCE_API,
+				    FIB_ENTRY_FLAG_NONE,
+				    FIB_PROTOCOL_IP4,
+				    NULL,
+				    tm->hw[0]->sw_if_index,
+				    ~0, // invalid fib index
+				    1,
+				    NULL,
+				    FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup_exact_match(import_fib_index1, &local_pfx);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "attached export created");
+
+    /*
+     * check for the presence of all the adj-fibs and local in the import table
+     */
+    fei = fib_table_lookup_exact_match(import_fib_index2, &pfx_10_10_10_1_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "ADJ-fib1 imported");
+    fei = fib_table_lookup_exact_match(import_fib_index2, &pfx_10_10_10_2_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "ADJ-fib2 imported");
+    local_pfx.fp_len = 32;
+    fei = fib_table_lookup_exact_match(import_fib_index2, &local_pfx);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "local imported");
+
+    /*
+     * add a 3rd adj-fib. expect it to be exported to both tables.
+     */
+    fib_prefix_t pfx_10_10_10_3_s_32 = {
+    	.fp_len = 32,
+    	.fp_proto = FIB_PROTOCOL_IP4,
+    	.fp_addr = {
+    	    /* 10.10.10.3 */
+    	    .ip4.as_u32 = clib_host_to_net_u32(0x0a0a0a03),
+    	},
+    };
+
+    fib_table_entry_update_one_path(fib_index,
+				    &pfx_10_10_10_3_s_32,
+				    FIB_SOURCE_ADJ,
+				    FIB_ENTRY_FLAG_ATTACHED,
+				    FIB_PROTOCOL_IP4,
+				    &pfx_10_10_10_3_s_32.fp_addr,
+				    tm->hw[0]->sw_if_index,
+				    ~0, // invalid fib index
+				    1,
+				    NULL,
+				    FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_10_10_10_3_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "ADJ-fib3 present");
+    ai = fib_entry_get_adj(fei);
+
+    fei = fib_table_lookup_exact_match(import_fib_index1, &pfx_10_10_10_3_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "ADJ-fib3 imported to FIB1");
+    FIB_TEST((ai == fib_entry_get_adj(fei)),
+	     "Import uses same adj as export");
+    fei = fib_table_lookup_exact_match(import_fib_index2, &pfx_10_10_10_3_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "ADJ-fib3 imported to FIB2");
+    FIB_TEST((ai == fib_entry_get_adj(fei)),
+	     "Import uses same adj as export");
+
+    /*
+     * remove the 3rd adj fib. we expect it to be removed from both FIBs
+     */
+    fib_table_entry_delete(fib_index,
+			   &pfx_10_10_10_3_s_32,
+			   FIB_SOURCE_ADJ);
+
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_10_10_10_3_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID == fei), "ADJ-fib3 remved");
+
+    fei = fib_table_lookup_exact_match(import_fib_index1, &pfx_10_10_10_3_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID == fei), "ADJ-fib3 removed from FIB1");
+
+    fei = fib_table_lookup_exact_match(import_fib_index2, &pfx_10_10_10_3_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID == fei), "ADJ-fib3 removed from FIB2");
+
+    /*
+     * remove the attached route from the 2nd FIB. expect the imported
+     * entires to be removed
+     */
+    local_pfx.fp_len = 24;
+    fib_table_entry_delete(import_fib_index2,
+			   &local_pfx,
+			   FIB_SOURCE_API);
+    fei = fib_table_lookup_exact_match(import_fib_index2, &local_pfx);
+    FIB_TEST((FIB_NODE_INDEX_INVALID == fei), "attached export removed");
+
+    fei = fib_table_lookup_exact_match(import_fib_index2, &pfx_10_10_10_1_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID == fei), "ADJ-fib1 removed from FIB2");
+    fei = fib_table_lookup_exact_match(import_fib_index2, &pfx_10_10_10_2_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID == fei), "ADJ-fib2 removed from FIB2");
+    local_pfx.fp_len = 32;
+    fei = fib_table_lookup_exact_match(import_fib_index2, &local_pfx);
+    FIB_TEST((FIB_NODE_INDEX_INVALID == fei), "local removed from FIB2");
+
+    fei = fib_table_lookup_exact_match(import_fib_index1, &pfx_10_10_10_1_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "ADJ-fib1 still in FIB1");
+    fei = fib_table_lookup_exact_match(import_fib_index1, &pfx_10_10_10_2_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "ADJ-fib2 still in FIB1");
+    local_pfx.fp_len = 32;
+    fei = fib_table_lookup_exact_match(import_fib_index1, &local_pfx);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "local still in FIB1");
+
+    /*
+     * modify the route in FIB1 so it is no longer attached. expect the imported
+     * entires to be removed
+     */
+    local_pfx.fp_len = 24;
+    fib_table_entry_update_one_path(import_fib_index1,
+				    &local_pfx,
+				    FIB_SOURCE_API,
+				    FIB_ENTRY_FLAG_NONE,
+				    FIB_PROTOCOL_IP4,
+				    &pfx_10_10_10_2_s_32.fp_addr,
+				    tm->hw[0]->sw_if_index,
+				    ~0, // invalid fib index
+				    1,
+				    NULL,
+				    FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup_exact_match(import_fib_index1, &pfx_10_10_10_1_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID == fei), "ADJ-fib1 removed from FIB1");
+    fei = fib_table_lookup_exact_match(import_fib_index1, &pfx_10_10_10_2_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID == fei), "ADJ-fib2 removed from FIB1");
+    local_pfx.fp_len = 32;
+    fei = fib_table_lookup_exact_match(import_fib_index1, &local_pfx);
+    FIB_TEST((FIB_NODE_INDEX_INVALID == fei), "local removed from FIB1");
+
+    /*
+     * modify it back to attached. expect the adj-fibs back
+     */
+    local_pfx.fp_len = 24;
+    fib_table_entry_update_one_path(import_fib_index1,
+				    &local_pfx,
+				    FIB_SOURCE_API,
+				    FIB_ENTRY_FLAG_NONE,
+				    FIB_PROTOCOL_IP4,
+				    NULL,
+				    tm->hw[0]->sw_if_index,
+				    ~0, // invalid fib index
+				    1,
+				    NULL,
+				    FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup_exact_match(import_fib_index1, &pfx_10_10_10_1_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "ADJ-fib1 imported in FIB1");
+    fei = fib_table_lookup_exact_match(import_fib_index1, &pfx_10_10_10_2_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "ADJ-fib2 imported in FIB1");
+    local_pfx.fp_len = 32;
+    fei = fib_table_lookup_exact_match(import_fib_index1, &local_pfx);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "local imported in FIB1");
+
+    /*
+     * add a covering attached next-hop for the interface address, so we have
+     * a valid adj to find when we check the forwarding tables
+     */
+    fib_prefix_t pfx_10_0_0_0_s_8 = {
+    	.fp_len = 8,
+    	.fp_proto = FIB_PROTOCOL_IP4,
+    	.fp_addr = {
+    	    /* 10.0.0.0 */
+    	    .ip4.as_u32 = clib_host_to_net_u32(0x0a000000),
+    	},
+    };
+
+    fei = fib_table_entry_update_one_path(fib_index,
+                                          &pfx_10_0_0_0_s_8,
+                                          FIB_SOURCE_API,
+                                          FIB_ENTRY_FLAG_NONE,
+					  FIB_PROTOCOL_IP4,
+                                          &pfx_10_10_10_3_s_32.fp_addr,
+                                          tm->hw[0]->sw_if_index,
+                                          ~0, // invalid fib index
+                                          1,
+                                          NULL,
+                                          FIB_ROUTE_PATH_FLAG_NONE);
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+
+    /*
+     * remove the route in the export fib. expect the adj-fibs to be removed
+     */
+    local_pfx.fp_len = 24;
+    fib_table_entry_delete(fib_index,
+			   &local_pfx,
+			   FIB_SOURCE_INTERFACE);
+
+    fei = fib_table_lookup_exact_match(import_fib_index1, &pfx_10_10_10_1_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID == fei), "Delete export: ADJ-fib1 removed from FIB1");
+    fei = fib_table_lookup_exact_match(import_fib_index1, &pfx_10_10_10_2_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID == fei), "ADJ-fib2 removed from FIB1");
+    local_pfx.fp_len = 32;
+    fei = fib_table_lookup_exact_match(import_fib_index1, &local_pfx);
+    FIB_TEST((FIB_NODE_INDEX_INVALID == fei), "local removed from FIB1");
+
+    /*
+     * the adj-fibs in the export VRF are present in the FIB table,
+     * but not installed in forwarding, since they have no attached cover.
+     * Consequently a lookup in the MTRIE gives the adj for the covering
+     * route 10.0.0.0/8.
+     */
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_10_10_10_1_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "ADJ-fib1 in export");
+
+    index_t lbi;
+    lbi = ip4_fib_forwarding_lookup(fib_index, &pfx_10_10_10_1_s_32.fp_addr.ip4);
+    FIB_TEST(lbi == dpo->dpoi_index,
+             "10.10.10.1 forwards on \n%U not \n%U",
+             format_load_balance, lbi, 0,
+             format_dpo_id, dpo, 0);
+    lbi = ip4_fib_forwarding_lookup(fib_index, &pfx_10_10_10_2_s_32.fp_addr.ip4);
+    FIB_TEST(lbi == dpo->dpoi_index,
+             "10.10.10.2 forwards on %U", format_dpo_id, dpo, 0);
+    lbi = ip4_fib_forwarding_lookup(fib_index, &pfx_10_10_10_3_s_32.fp_addr.ip4);
+    FIB_TEST(lbi == dpo->dpoi_index,
+             "10.10.10.3 forwards on %U", format_dpo_id, dpo, 0);
+
+    /*
+     * add the export prefix back, but not as attached.
+     * No adj-fibs in export nor import tables
+     */
+    local_pfx.fp_len = 24;
+    fei = fib_table_entry_update_one_path(fib_index,
+                                          &local_pfx,
+                                          FIB_SOURCE_API,
+                                          FIB_ENTRY_FLAG_NONE,
+					  FIB_PROTOCOL_IP4,
+                                          &pfx_10_10_10_1_s_32.fp_addr,
+                                          tm->hw[0]->sw_if_index,
+                                          ~0, // invalid fib index
+                                          1,
+                                          NULL,
+                                          FIB_ROUTE_PATH_FLAG_NONE);
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_10_10_10_1_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "non-attached in export: ADJ-fib1 in export");
+    lbi = ip4_fib_forwarding_lookup(fib_index, &pfx_10_10_10_1_s_32.fp_addr.ip4);
+    FIB_TEST(lbi == dpo->dpoi_index,
+             "10.10.10.1 forwards on %U", format_dpo_id, dpo, 0);
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_10_10_10_1_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "ADJ-fib1 in export");
+    lbi = ip4_fib_forwarding_lookup(fib_index, &pfx_10_10_10_2_s_32.fp_addr.ip4);
+    FIB_TEST(lbi == dpo->dpoi_index,
+             "10.10.10.2 forwards on %U", format_dpo_id, dpo, 0);
+
+    fei = fib_table_lookup_exact_match(import_fib_index1, &pfx_10_10_10_1_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID == fei), "ADJ-fib1 removed from FIB1");
+    fei = fib_table_lookup_exact_match(import_fib_index1, &pfx_10_10_10_2_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID == fei), "ADJ-fib2 removed from FIB1");
+    local_pfx.fp_len = 32;
+    fei = fib_table_lookup_exact_match(import_fib_index1, &local_pfx);
+    FIB_TEST((FIB_NODE_INDEX_INVALID == fei), "local removed from FIB1");
+
+    /*
+     * modify the export prefix so it is attached. expect all covereds to return
+     */
+    local_pfx.fp_len = 24;
+    fib_table_entry_update_one_path(fib_index,
+				    &local_pfx,
+				    FIB_SOURCE_API,
+				    FIB_ENTRY_FLAG_NONE,
+				    FIB_PROTOCOL_IP4,
+				    NULL,
+				    tm->hw[0]->sw_if_index,
+				    ~0, // invalid fib index
+				    1,
+				    NULL,
+				    FIB_ROUTE_PATH_FLAG_NONE);
+
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_10_10_10_1_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "ADJ-fib1 reinstalled in export");
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    FIB_TEST(dpo_cmp(dpo_drop, load_balance_get_bucket(dpo->dpoi_index, 0)),
+	     "Adj-fib1 is not drop in export");
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_10_10_10_2_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "ADJ-fib2 reinstalled in export");
+    local_pfx.fp_len = 32;
+    fei = fib_table_lookup_exact_match(fib_index, &local_pfx);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "local reinstalled in export");
+    fei = fib_table_lookup_exact_match(import_fib_index1, &pfx_10_10_10_1_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "attached in export: ADJ-fib1 imported");
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    FIB_TEST(dpo_cmp(dpo_drop, load_balance_get_bucket(dpo->dpoi_index, 0)),
+	     "Adj-fib1 is not drop in export");
+    fei = fib_table_lookup_exact_match(import_fib_index1, &pfx_10_10_10_1_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "ADJ-fib1 imported");
+    fei = fib_table_lookup_exact_match(import_fib_index1, &pfx_10_10_10_2_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "ADJ-fib2 imported");
+    local_pfx.fp_len = 32;
+    fei = fib_table_lookup_exact_match(import_fib_index1, &local_pfx);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "local imported");
+
+    /*
+     * modify the export prefix so connected. no change.
+     */
+    local_pfx.fp_len = 24;
+    fib_table_entry_update_one_path(fib_index, &local_pfx,
+				    FIB_SOURCE_INTERFACE,
+				    (FIB_ENTRY_FLAG_CONNECTED |
+				     FIB_ENTRY_FLAG_ATTACHED),
+				    FIB_PROTOCOL_IP4,
+				    NULL,
+				    tm->hw[0]->sw_if_index,
+				    ~0,
+				    1,
+				    NULL,
+				    FIB_ROUTE_PATH_FLAG_NONE);
+
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_10_10_10_1_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "ADJ-fib1 reinstalled in export");
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    FIB_TEST(dpo_cmp(dpo_drop, load_balance_get_bucket(dpo->dpoi_index, 0)),
+	     "Adj-fib1 is not drop in export");
+    fei = fib_table_lookup_exact_match(fib_index, &pfx_10_10_10_2_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "ADJ-fib2 reinstalled in export");
+    local_pfx.fp_len = 32;
+    fei = fib_table_lookup_exact_match(fib_index, &local_pfx);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "local reinstalled in export");
+    fei = fib_table_lookup_exact_match(import_fib_index1, &pfx_10_10_10_1_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "attached in export: ADJ-fib1 imported");
+    dpo = fib_entry_contribute_ip_forwarding(fei);
+    FIB_TEST(dpo_cmp(dpo_drop, load_balance_get_bucket(dpo->dpoi_index, 0)),
+	     "Adj-fib1 is not drop in export");
+    fei = fib_table_lookup_exact_match(import_fib_index1, &pfx_10_10_10_2_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "ADJ-fib2 imported");
+    local_pfx.fp_len = 32;
+    fei = fib_table_lookup_exact_match(import_fib_index1, &local_pfx);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "local imported");
+
+    /*
+     * CLEANUP
+     */
+    fib_table_entry_delete(fib_index,
+                           &pfx_10_0_0_0_s_8,
+                           FIB_SOURCE_API);
+    fib_table_entry_delete(fib_index,
+			   &pfx_10_10_10_1_s_32,
+			   FIB_SOURCE_ADJ);
+    fib_table_entry_delete(fib_index,
+			   &pfx_10_10_10_2_s_32,
+			   FIB_SOURCE_ADJ);
+    local_pfx.fp_len = 32;
+    fib_table_entry_delete(fib_index,
+			   &local_pfx,
+			   FIB_SOURCE_INTERFACE);
+    local_pfx.fp_len = 24;
+    fib_table_entry_delete(fib_index,
+			   &local_pfx,
+			   FIB_SOURCE_API);
+    fib_table_entry_delete(fib_index,
+			   &local_pfx,
+			   FIB_SOURCE_INTERFACE);
+    local_pfx.fp_len = 24;
+    fib_table_entry_delete(import_fib_index1,
+			   &local_pfx,
+			   FIB_SOURCE_API);
+
+    fib_table_unlock(import_fib_index1, FIB_PROTOCOL_IP4);
+    fib_table_unlock(import_fib_index2, FIB_PROTOCOL_IP4);
+
+    FIB_TEST((0 == adj_nbr_db_size()), "ADJ DB size is %d",
+	     adj_nbr_db_size());
+
+    return (0);
+}
+
+
+/*
+ * Test the recursive route route handling for GRE tunnels
+ */
+static int
+fib_test_label (void)
+{
+    fib_node_index_t fei, ai_mpls_10_10_10_1, ai_v4_10_10_11_1, ai_v4_10_10_11_2, ai_mpls_10_10_11_2, ai_mpls_10_10_11_1;
+    const u32 fib_index = 0;
+    test_main_t *tm;
+    ip4_main_t *im;
+    int lb_count, ii;
+
+    lb_count = pool_elts(load_balance_pool);
+    tm = &test_main;
+    im = &ip4_main;
+
+    /*
+     * add interface routes. We'll assume this works. It's more rigorously
+     * tested elsewhere.
+     */
+    fib_prefix_t local0_pfx = {
+	.fp_len = 24,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    .ip4 = {
+		/* 10.10.10.10 */
+		.as_u32 = clib_host_to_net_u32(0x0a0a0a0a),
+	    },
+	},
+    };
+
+    FIB_TEST((0 == adj_nbr_db_size()), "ADJ DB size is %d",
+	     adj_nbr_db_size());
+
+    vec_validate(im->fib_index_by_sw_if_index, tm->hw[0]->sw_if_index);
+    im->fib_index_by_sw_if_index[tm->hw[0]->sw_if_index] = fib_index;
+
+    fib_table_entry_update_one_path(fib_index, &local0_pfx,
+				    FIB_SOURCE_INTERFACE,
+				    (FIB_ENTRY_FLAG_CONNECTED |
+				     FIB_ENTRY_FLAG_ATTACHED),
+				    FIB_PROTOCOL_IP4,
+				    NULL,
+				    tm->hw[0]->sw_if_index,
+				    ~0,
+				    1,
+				    NULL,
+				    FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup_exact_match(fib_index, &local0_pfx);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei),
+	     "attached interface route present");
+
+    local0_pfx.fp_len = 32;
+    fib_table_entry_update_one_path(fib_index, &local0_pfx,
+				    FIB_SOURCE_INTERFACE,
+				    (FIB_ENTRY_FLAG_CONNECTED |
+				     FIB_ENTRY_FLAG_LOCAL),
+				    FIB_PROTOCOL_IP4,
+				    NULL,
+				    tm->hw[0]->sw_if_index,
+				    ~0, // invalid fib index
+				    1,
+				    NULL,
+				    FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup_exact_match(fib_index, &local0_pfx);
+
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei),
+	     "local interface route present");
+
+    fib_prefix_t local1_pfx = {
+	.fp_len = 24,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    .ip4 = {
+		/* 10.10.11.10 */
+		.as_u32 = clib_host_to_net_u32(0x0a0a0b0a),
+	    },
+	},
+    };
+
+    vec_validate(im->fib_index_by_sw_if_index, tm->hw[1]->sw_if_index);
+    im->fib_index_by_sw_if_index[tm->hw[1]->sw_if_index] = fib_index;
+
+    fib_table_entry_update_one_path(fib_index, &local1_pfx,
+				    FIB_SOURCE_INTERFACE,
+				    (FIB_ENTRY_FLAG_CONNECTED |
+				     FIB_ENTRY_FLAG_ATTACHED),
+				    FIB_PROTOCOL_IP4,
+				    NULL,
+				    tm->hw[1]->sw_if_index,
+				    ~0,
+				    1,
+				    NULL,
+				    FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup_exact_match(fib_index, &local1_pfx);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei),
+	     "attached interface route present");
+
+    local1_pfx.fp_len = 32;
+    fib_table_entry_update_one_path(fib_index, &local1_pfx,
+				    FIB_SOURCE_INTERFACE,
+				    (FIB_ENTRY_FLAG_CONNECTED |
+				     FIB_ENTRY_FLAG_LOCAL),
+				    FIB_PROTOCOL_IP4,
+				    NULL,
+				    tm->hw[1]->sw_if_index,
+				    ~0, // invalid fib index
+				    1,
+				    NULL,
+				    FIB_ROUTE_PATH_FLAG_NONE);
+    fei = fib_table_lookup_exact_match(fib_index, &local1_pfx);
+
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei),
+	     "local interface route present");
+
+    ip46_address_t nh_10_10_10_1 = {
+	.ip4 = {
+	    .as_u32 = clib_host_to_net_u32(0x0a0a0a01),
+	},
+    };
+    ip46_address_t nh_10_10_11_1 = {
+	.ip4 = {
+	    .as_u32 = clib_host_to_net_u32(0x0a0a0b01),
+	},
+    };
+    ip46_address_t nh_10_10_11_2 = {
+	.ip4 = {
+	    .as_u32 = clib_host_to_net_u32(0x0a0a0b02),
+	},
+    };
+
+    ai_v4_10_10_11_1 = adj_nbr_add_or_lock(FIB_PROTOCOL_IP4,
+                                           VNET_LINK_IP4,
+                                           &nh_10_10_11_1,
+                                           tm->hw[1]->sw_if_index);
+    ai_v4_10_10_11_2 = adj_nbr_add_or_lock(FIB_PROTOCOL_IP4,
+                                           VNET_LINK_IP4,
+                                           &nh_10_10_11_2,
+                                           tm->hw[1]->sw_if_index);
+    ai_mpls_10_10_10_1 = adj_nbr_add_or_lock(FIB_PROTOCOL_IP4,
+                                             VNET_LINK_MPLS,
+                                             &nh_10_10_10_1,
+                                             tm->hw[0]->sw_if_index);
+    ai_mpls_10_10_11_2 = adj_nbr_add_or_lock(FIB_PROTOCOL_IP4,
+                                             VNET_LINK_MPLS,
+                                             &nh_10_10_11_2,
+                                             tm->hw[1]->sw_if_index);
+    ai_mpls_10_10_11_1 = adj_nbr_add_or_lock(FIB_PROTOCOL_IP4,
+                                             VNET_LINK_MPLS,
+                                             &nh_10_10_11_1,
+                                             tm->hw[1]->sw_if_index);
+
+    /*
+     * Add an etry with one path with a real out-going label
+     */
+    fib_prefix_t pfx_1_1_1_1_s_32 = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    .ip4.as_u32 = clib_host_to_net_u32(0x01010101),
+	},
+    };
+    fib_test_lb_bucket_t l99_eos_o_10_10_10_1 = {
+	.type = FT_LB_LABEL_O_ADJ,
+	.label_o_adj = {
+	    .adj = ai_mpls_10_10_10_1,
+	    .label = 99,
+	    .eos = MPLS_EOS,
+	},
+    };
+    fib_test_lb_bucket_t l99_neos_o_10_10_10_1 = {
+	.type = FT_LB_LABEL_O_ADJ,
+	.label_o_adj = {
+	    .adj = ai_mpls_10_10_10_1,
+	    .label = 99,
+	    .eos = MPLS_NON_EOS,
+	},
+    };
+    mpls_label_t *l99 = NULL;
+    vec_add1(l99, 99);
+
+    fib_table_entry_update_one_path(fib_index,
+				    &pfx_1_1_1_1_s_32,
+				    FIB_SOURCE_API,
+				    FIB_ENTRY_FLAG_NONE,
+				    FIB_PROTOCOL_IP4,
+				    &nh_10_10_10_1,
+				    tm->hw[0]->sw_if_index,
+				    ~0, // invalid fib index
+				    1,
+				    l99,
+				    FIB_ROUTE_PATH_FLAG_NONE);
+
+    fei = fib_table_lookup(fib_index, &pfx_1_1_1_1_s_32);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != fei), "1.1.1.1/32 created");
+
+    FIB_TEST(fib_test_validate_entry(fei, 
+				     FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+				     1,
+				     &l99_eos_o_10_10_10_1),
+	     "1.1.1.1/32 LB 1 bucket via label 99 over 10.10.10.1");
+
+    /*
+     * add a path with an implicit NULL label
+     */
+    fib_test_lb_bucket_t a_o_10_10_11_1 = {
+	.type = FT_LB_ADJ,
+	.adj = {
+	    .adj = ai_v4_10_10_11_1,
+	},
+    };
+    fib_test_lb_bucket_t a_mpls_o_10_10_11_1 = {
+	.type = FT_LB_ADJ,
+	.adj = {
+	    .adj = ai_mpls_10_10_11_1,
+	},
+    };
+    mpls_label_t *l_imp_null = NULL;
+    vec_add1(l_imp_null, MPLS_IETF_IMPLICIT_NULL_LABEL);
+
+    fei = fib_table_entry_path_add(fib_index,
+				   &pfx_1_1_1_1_s_32,
+				   FIB_SOURCE_API,
+				   FIB_ENTRY_FLAG_NONE,
+				   FIB_PROTOCOL_IP4,
+				   &nh_10_10_11_1,
+				   tm->hw[1]->sw_if_index,
+				   ~0, // invalid fib index
+				   1,
+				   l_imp_null,
+				   FIB_ROUTE_PATH_FLAG_NONE);
+
+    FIB_TEST(fib_test_validate_entry(fei, 
+				     FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+				     2,
+				     &l99_eos_o_10_10_10_1,
+				     &a_o_10_10_11_1),
+	     "1.1.1.1/32 LB 2 buckets via: "
+	     "label 99 over 10.10.10.1, "
+	     "adj over 10.10.11.1");
+
+    /*
+     * assign the route a local label
+     */
+    fib_table_entry_local_label_add(fib_index,
+				    &pfx_1_1_1_1_s_32,
+				    24001);
+
+    fib_prefix_t pfx_24001_eos = {
+	.fp_proto = FIB_PROTOCOL_MPLS,
+	.fp_label = 24001,
+	.fp_eos = MPLS_EOS,
+    };
+    fib_prefix_t pfx_24001_neos = {
+	.fp_proto = FIB_PROTOCOL_MPLS,
+	.fp_label = 24001,
+	.fp_eos = MPLS_NON_EOS,
+    };
+
+    /*
+     * The EOS entry should link to both the paths,
+     *  and use an ip adj for the imp-null
+     * The NON-EOS entry should link to both the paths,
+     *  and use an mpls adj for the imp-null
+     */
+    fei = fib_table_lookup(MPLS_FIB_DEFAULT_TABLE_ID,
+			   &pfx_24001_eos);
+    FIB_TEST(fib_test_validate_entry(fei, 
+				     FIB_FORW_CHAIN_TYPE_MPLS_EOS,
+				     2,
+				     &l99_eos_o_10_10_10_1,
+				     &a_o_10_10_11_1),
+	     "24001/eos LB 2 buckets via: "
+	     "label 99 over 10.10.10.1, "
+	     "adj over 10.10.11.1");
+
+
+    fei = fib_table_lookup(MPLS_FIB_DEFAULT_TABLE_ID,
+			   &pfx_24001_neos);
+    FIB_TEST(fib_test_validate_entry(fei, 
+				     FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS,
+				     2,
+				     &l99_neos_o_10_10_10_1,
+				     &a_mpls_o_10_10_11_1),
+	     "24001/neos LB 1 bucket via: "
+	     "label 99 over 10.10.10.1 ",
+	     "mpls-adj via 10.10.11.1");
+
+    /*
+     * add an unlabelled path, this is excluded from the neos chains,
+     */
+    fib_test_lb_bucket_t adj_o_10_10_11_2 = {
+	.type = FT_LB_ADJ,
+	.adj = {
+	    .adj = ai_v4_10_10_11_2,
+	},
+    };
+
+    fei = fib_table_entry_path_add(fib_index,
+				   &pfx_1_1_1_1_s_32,
+				   FIB_SOURCE_API,
+				   FIB_ENTRY_FLAG_NONE,
+				   FIB_PROTOCOL_IP4,
+				   &nh_10_10_11_2,
+				   tm->hw[1]->sw_if_index,
+				   ~0, // invalid fib index
+				   1,
+				   NULL,
+				   FIB_ROUTE_PATH_FLAG_NONE);
+
+    FIB_TEST(fib_test_validate_entry(fei, 
+				     FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+				     16, // 3 choices spread over 16 buckets
+				     &l99_eos_o_10_10_10_1,
+				     &l99_eos_o_10_10_10_1,
+				     &l99_eos_o_10_10_10_1,
+				     &l99_eos_o_10_10_10_1,
+				     &l99_eos_o_10_10_10_1,
+				     &l99_eos_o_10_10_10_1,
+				     &a_o_10_10_11_1,
+				     &a_o_10_10_11_1,
+				     &a_o_10_10_11_1,
+				     &a_o_10_10_11_1,
+				     &a_o_10_10_11_1,
+				     &adj_o_10_10_11_2,
+				     &adj_o_10_10_11_2,
+				     &adj_o_10_10_11_2,
+				     &adj_o_10_10_11_2,
+				     &adj_o_10_10_11_2),
+	     "1.1.1.1/32 LB 16 buckets via: "
+	     "label 99 over 10.10.10.1, "
+	     "adj over 10.10.11.1",
+	     "adj over 10.10.11.2");
+
+    /*
+     * get and lock a reference to the non-eos of the via entry 1.1.1.1/32
+     */
+    dpo_id_t non_eos_1_1_1_1 = DPO_INVALID;
+    fib_entry_contribute_forwarding(fei,
+				    FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS,
+				    &non_eos_1_1_1_1);
+
+    /*
+     * n-eos has only the 2 labelled paths
+     */
+    fei = fib_table_lookup(MPLS_FIB_DEFAULT_TABLE_ID,
+			   &pfx_24001_neos);
+
+    FIB_TEST(fib_test_validate_entry(fei,
+				     FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS,
+				     2,
+				     &l99_neos_o_10_10_10_1,
+				     &a_mpls_o_10_10_11_1),
+	     "24001/neos LB 2 buckets via: "
+	     "label 99 over 10.10.10.1, "
+	     "adj-mpls over 10.10.11.2");
+
+    /*
+     * A labelled recursive
+     */
+    fib_prefix_t pfx_2_2_2_2_s_32 = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    .ip4.as_u32 = clib_host_to_net_u32(0x02020202),
+	},
+    };
+    fib_test_lb_bucket_t l1600_eos_o_1_1_1_1 = {
+	.type = FT_LB_LABEL_O_LB,
+	.label_o_lb = {
+	    .lb = non_eos_1_1_1_1.dpoi_index,
+	    .label = 1600,
+	    .eos = MPLS_EOS,
+	},
+    };
+    mpls_label_t *l1600 = NULL;
+    vec_add1(l1600, 1600);
+
+    fib_table_entry_update_one_path(fib_index,
+				    &pfx_2_2_2_2_s_32,
+				    FIB_SOURCE_API,
+				    FIB_ENTRY_FLAG_NONE,
+				    FIB_PROTOCOL_IP4,
+				    &pfx_1_1_1_1_s_32.fp_addr,
+				    ~0,
+				    fib_index,
+				    1,
+				    l1600,
+				    FIB_ROUTE_PATH_FLAG_NONE);
+
+    fei = fib_table_lookup(fib_index, &pfx_2_2_2_2_s_32);
+    FIB_TEST(fib_test_validate_entry(fei, 
+				     FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+				     1,
+				     &l1600_eos_o_1_1_1_1),
+	     "2.2.2.2.2/32 LB 1 buckets via: "
+	     "label 1600 over 1.1.1.1");
+
+    dpo_id_t dpo_44 = DPO_INVALID;
+    index_t urpfi;
+
+    fib_entry_contribute_forwarding(fei, FIB_FORW_CHAIN_TYPE_UNICAST_IP4, &dpo_44);
+    urpfi = load_balance_get_urpf(dpo_44.dpoi_index);
+
+    FIB_TEST(fib_urpf_check(urpfi, tm->hw[0]->sw_if_index),
+	     "uRPF check for 2.2.2.2/32 on %d OK",
+	     tm->hw[0]->sw_if_index);
+    FIB_TEST(fib_urpf_check(urpfi, tm->hw[1]->sw_if_index),
+	     "uRPF check for 2.2.2.2/32 on %d OK",
+	     tm->hw[1]->sw_if_index);
+    FIB_TEST(!fib_urpf_check(urpfi, 99),
+	     "uRPF check for 2.2.2.2/32 on 99 not-OK",
+	     99);
+
+    fib_entry_contribute_forwarding(fei, FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS, &dpo_44);
+    FIB_TEST(urpfi == load_balance_get_urpf(dpo_44.dpoi_index),
+	     "Shared uRPF on IP and non-EOS chain");
+
+    dpo_reset(&dpo_44);
+
+    /*
+     * we are holding a lock on the non-eos LB of the via-entry.
+     * do a PIC-core failover by shutting the link of the via-entry.
+     *
+     * shut down the link with the valid label
+     */
+    vnet_sw_interface_set_flags(vnet_get_main(),
+				tm->hw[0]->sw_if_index,
+				0);
+
+    fei = fib_table_lookup(fib_index, &pfx_1_1_1_1_s_32);
+    FIB_TEST(fib_test_validate_entry(fei, 
+				     FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+				     2,
+				     &a_o_10_10_11_1,
+				     &adj_o_10_10_11_2),
+	     "1.1.1.1/32 LB 2 buckets via: "
+	     "adj over 10.10.11.1, ",
+	     "adj-v4 over 10.10.11.2");
+
+    fei = fib_table_lookup(MPLS_FIB_DEFAULT_TABLE_ID,
+			   &pfx_24001_eos);
+    FIB_TEST(fib_test_validate_entry(fei, 
+				     FIB_FORW_CHAIN_TYPE_MPLS_EOS,
+				     2,
+				     &a_o_10_10_11_1,
+				     &adj_o_10_10_11_2),
+	     "24001/eos LB 2 buckets via: "
+	     "adj over 10.10.11.1, ",
+	     "adj-v4 over 10.10.11.2");
+
+    fei = fib_table_lookup(MPLS_FIB_DEFAULT_TABLE_ID,
+			   &pfx_24001_neos);
+    FIB_TEST(fib_test_validate_entry(fei,
+				     FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS,
+				     1,
+				     &a_mpls_o_10_10_11_1),
+	     "24001/neos LB 1 buckets via: "
+	     "adj-mpls over 10.10.11.2");
+
+    /*
+     * test that the pre-failover load-balance has been in-place
+     * modified
+     */
+    dpo_id_t current = DPO_INVALID;
+    fib_entry_contribute_forwarding(fei,
+				    FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS,
+				    &current);
+
+    FIB_TEST(!dpo_cmp(&non_eos_1_1_1_1,
+                      &current),
+	     "PIC-core LB inplace modified %U %U",
+             format_dpo_id, &non_eos_1_1_1_1, 0,
+             format_dpo_id, &current, 0);
+
+    dpo_reset(&non_eos_1_1_1_1);
+    dpo_reset(&current);
+
+    /*
+     * no-shut the link with the valid label
+     */
+    vnet_sw_interface_set_flags(vnet_get_main(),
+				tm->hw[0]->sw_if_index,
+				VNET_SW_INTERFACE_FLAG_ADMIN_UP);
+
+    fei = fib_table_lookup(fib_index, &pfx_1_1_1_1_s_32);
+    FIB_TEST(fib_test_validate_entry(fei, 
+				     FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+				     16, // 3 choices spread over 16 buckets
+				     &l99_eos_o_10_10_10_1,
+				     &l99_eos_o_10_10_10_1,
+				     &l99_eos_o_10_10_10_1,
+				     &l99_eos_o_10_10_10_1,
+				     &l99_eos_o_10_10_10_1,
+				     &l99_eos_o_10_10_10_1,
+				     &a_o_10_10_11_1,
+				     &a_o_10_10_11_1,
+				     &a_o_10_10_11_1,
+				     &a_o_10_10_11_1,
+				     &a_o_10_10_11_1,
+				     &adj_o_10_10_11_2,
+				     &adj_o_10_10_11_2,
+				     &adj_o_10_10_11_2,
+				     &adj_o_10_10_11_2,
+				     &adj_o_10_10_11_2),
+	     "1.1.1.1/32 LB 16 buckets via: "
+	     "label 99 over 10.10.10.1, "
+	     "adj over 10.10.11.1",
+	     "adj-v4 over 10.10.11.2");
+
+
+    fei = fib_table_lookup(MPLS_FIB_DEFAULT_TABLE_ID,
+			   &pfx_24001_eos);
+    FIB_TEST(fib_test_validate_entry(fei, 
+				     FIB_FORW_CHAIN_TYPE_MPLS_EOS,
+				     16, // 3 choices spread over 16 buckets
+				     &l99_eos_o_10_10_10_1,
+				     &l99_eos_o_10_10_10_1,
+				     &l99_eos_o_10_10_10_1,
+				     &l99_eos_o_10_10_10_1,
+				     &l99_eos_o_10_10_10_1,
+				     &l99_eos_o_10_10_10_1,
+				     &a_o_10_10_11_1,
+				     &a_o_10_10_11_1,
+				     &a_o_10_10_11_1,
+				     &a_o_10_10_11_1,
+				     &a_o_10_10_11_1,
+				     &adj_o_10_10_11_2,
+				     &adj_o_10_10_11_2,
+				     &adj_o_10_10_11_2,
+				     &adj_o_10_10_11_2,
+				     &adj_o_10_10_11_2),
+	     "24001/eos LB 16 buckets via: "
+	     "label 99 over 10.10.10.1, "
+	     "adj over 10.10.11.1",
+	     "adj-v4 over 10.10.11.2");
+
+    fei = fib_table_lookup(MPLS_FIB_DEFAULT_TABLE_ID,
+			   &pfx_24001_neos);
+    FIB_TEST(fib_test_validate_entry(fei, 
+				     FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS,
+				     2,
+				     &l99_neos_o_10_10_10_1,
+				     &a_mpls_o_10_10_11_1),
+	     "24001/neos LB 2 buckets via: "
+	     "label 99 over 10.10.10.1, "
+	     "adj-mpls over 10.10.11.2");
+
+    /*
+     * remove the first path with the valid label
+     */
+    fib_table_entry_path_remove(fib_index,
+				&pfx_1_1_1_1_s_32,
+				FIB_SOURCE_API,
+				FIB_PROTOCOL_IP4,
+				&nh_10_10_10_1,
+				tm->hw[0]->sw_if_index,
+				~0, // invalid fib index
+				1,
+				FIB_ROUTE_PATH_FLAG_NONE);
+
+    fei = fib_table_lookup(fib_index, &pfx_1_1_1_1_s_32);
+    FIB_TEST(fib_test_validate_entry(fei, 
+				     FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+				     2,
+				     &a_o_10_10_11_1,
+				     &adj_o_10_10_11_2),
+	     "1.1.1.1/32 LB 2 buckets via: "
+	     "adj over 10.10.11.1",
+	     "adj-v4 over 10.10.11.2");
+
+    fei = fib_table_lookup(MPLS_FIB_DEFAULT_TABLE_ID,
+			   &pfx_24001_eos);
+    FIB_TEST(fib_test_validate_entry(fei, 
+				     FIB_FORW_CHAIN_TYPE_MPLS_EOS,
+				     2,
+				     &a_o_10_10_11_1,
+				     &adj_o_10_10_11_2),
+	     "24001/eos LB 2 buckets via: "
+	     "adj over 10.10.11.1",
+	     "adj-v4 over 10.10.11.2");
+
+    fei = fib_table_lookup(MPLS_FIB_DEFAULT_TABLE_ID,
+			   &pfx_24001_neos);
+
+    FIB_TEST(fib_test_validate_entry(fei, 
+				     FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS,
+				     1,
+				     &a_mpls_o_10_10_11_1),
+	     "24001/neos LB 1 buckets via: "
+	     "adj-mpls over 10.10.11.2");
+
+    /*
+     * remove the other path with a valid label
+     */
+    fib_test_lb_bucket_t bucket_drop = {
+	.type = FT_LB_SPECIAL,
+	.special = {
+	    .adj = DPO_PROTO_IP4,
+	},
+    };
+
+    fib_table_entry_path_remove(fib_index,
+				&pfx_1_1_1_1_s_32,
+				FIB_SOURCE_API,
+				FIB_PROTOCOL_IP4,
+				&nh_10_10_11_1,
+				tm->hw[1]->sw_if_index,
+				~0, // invalid fib index
+				1,
+				FIB_ROUTE_PATH_FLAG_NONE);
+
+    fei = fib_table_lookup(fib_index, &pfx_1_1_1_1_s_32);
+    FIB_TEST(fib_test_validate_entry(fei, 
+				     FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+				     1,
+				     &adj_o_10_10_11_2),
+	     "1.1.1.1/32 LB 1 buckets via: "
+	     "adj over 10.10.11.2");
+
+    fei = fib_table_lookup(MPLS_FIB_DEFAULT_TABLE_ID,
+			   &pfx_24001_eos);
+    FIB_TEST(fib_test_validate_entry(fei, 
+				     FIB_FORW_CHAIN_TYPE_MPLS_EOS,
+				     1,
+				     &adj_o_10_10_11_2),
+	     "24001/eos LB 1 buckets via: "
+	     "adj over 10.10.11.2");
+
+    fei = fib_table_lookup(MPLS_FIB_DEFAULT_TABLE_ID,
+			   &pfx_24001_neos);
+    FIB_TEST(fib_test_validate_entry(fei, 
+				     FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS,
+				      1,
+				      &bucket_drop),
+	     "24001/eos LB 1 buckets via: DROP");
+
+    /*
+     * add back the path with the valid label
+     */
+    l99 = NULL;
+    vec_add1(l99, 99);
+
+    fib_table_entry_path_add(fib_index,
+			     &pfx_1_1_1_1_s_32,
+			     FIB_SOURCE_API,
+			     FIB_ENTRY_FLAG_NONE,
+			     FIB_PROTOCOL_IP4,
+			     &nh_10_10_10_1,
+			     tm->hw[0]->sw_if_index,
+			     ~0, // invalid fib index
+			     1,
+			     l99,
+			     FIB_ROUTE_PATH_FLAG_NONE);
+
+    fei = fib_table_lookup(fib_index, &pfx_1_1_1_1_s_32);
+    FIB_TEST(fib_test_validate_entry(fei,
+				     FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+				     2,
+				     &l99_eos_o_10_10_10_1,
+				     &adj_o_10_10_11_2),
+	     "1.1.1.1/32 LB 2 buckets via: "
+	     "label 99 over 10.10.10.1, "
+	     "adj over 10.10.11.2");
+
+    fei = fib_table_lookup(MPLS_FIB_DEFAULT_TABLE_ID,
+			   &pfx_24001_eos);
+    FIB_TEST(fib_test_validate_entry(fei, 
+				     FIB_FORW_CHAIN_TYPE_MPLS_EOS,
+				     2,
+				     &l99_eos_o_10_10_10_1,
+				     &adj_o_10_10_11_2),
+	     "24001/eos LB 2 buckets via: "
+	     "label 99 over 10.10.10.1, "
+	     "adj over 10.10.11.2");
+
+    fei = fib_table_lookup(MPLS_FIB_DEFAULT_TABLE_ID,
+			   &pfx_24001_neos);
+    FIB_TEST(fib_test_validate_entry(fei, 
+				     FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS,
+				     1,
+				     &l99_neos_o_10_10_10_1),
+	     "24001/neos LB 1 buckets via: "
+	     "label 99 over 10.10.10.1");
+
+    /*
+     * change the local label
+     */
+    fib_table_entry_local_label_add(fib_index,
+				    &pfx_1_1_1_1_s_32,
+				    25005);
+
+    fib_prefix_t pfx_25005_eos = {
+	.fp_proto = FIB_PROTOCOL_MPLS,
+	.fp_label = 25005,
+	.fp_eos = MPLS_EOS,
+    };
+    fib_prefix_t pfx_25005_neos = {
+	.fp_proto = FIB_PROTOCOL_MPLS,
+	.fp_label = 25005,
+	.fp_eos = MPLS_NON_EOS,
+    };
+
+    FIB_TEST((FIB_NODE_INDEX_INVALID ==
+	      fib_table_lookup(fib_index, &pfx_24001_eos)),
+	     "24001/eos removed after label change");
+    FIB_TEST((FIB_NODE_INDEX_INVALID ==
+	      fib_table_lookup(fib_index, &pfx_24001_neos)),
+	     "24001/eos removed after label change");
+
+    fei = fib_table_lookup(MPLS_FIB_DEFAULT_TABLE_ID,
+			   &pfx_25005_eos);
+    FIB_TEST(fib_test_validate_entry(fei,
+				     FIB_FORW_CHAIN_TYPE_MPLS_EOS,
+				     2,
+				     &l99_eos_o_10_10_10_1,
+				     &adj_o_10_10_11_2),
+	     "25005/eos LB 2 buckets via: "
+	     "label 99 over 10.10.10.1, "
+	     "adj over 10.10.11.2");
+
+    fei = fib_table_lookup(MPLS_FIB_DEFAULT_TABLE_ID,
+			   &pfx_25005_neos);
+    FIB_TEST(fib_test_validate_entry(fei,
+				     FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS,
+				     1,
+				     &l99_neos_o_10_10_10_1),
+	     "25005/neos LB 1 buckets via: "
+	     "label 99 over 10.10.10.1");
+
+    /*
+     * remove the local label.
+     * the check that the MPLS entries are gone is done by the fact the
+     * MPLS table is no longer present.
+     */
+    fib_table_entry_local_label_remove(fib_index,
+				       &pfx_1_1_1_1_s_32,
+				       25005);
+
+    fei = fib_table_lookup(fib_index, &pfx_1_1_1_1_s_32);
+    FIB_TEST(fib_test_validate_entry(fei, 
+				     FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+				     2,
+				     &l99_eos_o_10_10_10_1,
+				     &adj_o_10_10_11_2),
+	     "24001/eos LB 2 buckets via: "
+	     "label 99 over 10.10.10.1, "
+	     "adj over 10.10.11.2");
+
+    FIB_TEST((FIB_NODE_INDEX_INVALID ==
+	      mpls_fib_index_from_table_id(MPLS_FIB_DEFAULT_TABLE_ID)),
+	     "No more MPLS FIB entries => table removed");
+
+    /*
+     * add another via-entry for the recursive
+     */
+    fib_prefix_t pfx_1_1_1_2_s_32 = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    .ip4.as_u32 = clib_host_to_net_u32(0x01010102),
+	},
+    };
+    fib_test_lb_bucket_t l101_eos_o_10_10_10_1 = {
+	.type = FT_LB_LABEL_O_ADJ,
+	.label_o_adj = {
+	    .adj = ai_mpls_10_10_10_1,
+	    .label = 101,
+	    .eos = MPLS_EOS,
+	},
+    };
+    mpls_label_t *l101 = NULL;
+    vec_add1(l101, 101);
+
+    fei = fib_table_entry_update_one_path(fib_index,
+					  &pfx_1_1_1_2_s_32,
+					  FIB_SOURCE_API,
+					  FIB_ENTRY_FLAG_NONE,
+					  FIB_PROTOCOL_IP4,
+					  &nh_10_10_10_1,
+					  tm->hw[0]->sw_if_index,
+					  ~0, // invalid fib index
+					  1,
+					  l101,
+					  FIB_ROUTE_PATH_FLAG_NONE);
+
+    FIB_TEST(fib_test_validate_entry(fei,
+				     FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+				     1,
+				     &l101_eos_o_10_10_10_1),
+	     "1.1.1.2/32 LB 1 buckets via: "
+	     "label 101 over 10.10.10.1");
+
+    dpo_id_t non_eos_1_1_1_2 = DPO_INVALID;
+    fib_entry_contribute_forwarding(fib_table_lookup(fib_index,
+						     &pfx_1_1_1_1_s_32),
+				    FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS,
+				    &non_eos_1_1_1_1);
+    fib_entry_contribute_forwarding(fib_table_lookup(fib_index,
+						     &pfx_1_1_1_2_s_32),
+				    FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS,
+				    &non_eos_1_1_1_2);
+
+    fib_test_lb_bucket_t l1601_eos_o_1_1_1_2 = {
+    	.type = FT_LB_LABEL_O_LB,
+    	.label_o_lb = {
+    	    .lb = non_eos_1_1_1_2.dpoi_index,
+    	    .label = 1601,
+    	    .eos = MPLS_EOS,
+    	},
+    };
+    mpls_label_t *l1601 = NULL;
+    vec_add1(l1601, 1601);
+
+    l1600_eos_o_1_1_1_1.label_o_lb.lb = non_eos_1_1_1_1.dpoi_index;
+
+    fei = fib_table_entry_path_add(fib_index,
+				   &pfx_2_2_2_2_s_32,
+				   FIB_SOURCE_API,
+				   FIB_ENTRY_FLAG_NONE,
+				   FIB_PROTOCOL_IP4,
+				   &pfx_1_1_1_2_s_32.fp_addr,
+				   ~0,
+				   fib_index,
+				   1,
+				   l1601,
+				   FIB_ROUTE_PATH_FLAG_NONE);
+
+    FIB_TEST(fib_test_validate_entry(fei, 
+				     FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+				     2,
+				     &l1600_eos_o_1_1_1_1,
+				     &l1601_eos_o_1_1_1_2),
+	     "2.2.2.2/32 LB 2 buckets via: "
+	     "label 1600 via 1.1,1.1, "
+	     "label 16001 via 1.1.1.2");
+
+    /*
+     * update the via-entry so it no longer has an imp-null path.
+     * the LB for the recursive can use an imp-null
+     */
+    l_imp_null = NULL;
+    vec_add1(l_imp_null, MPLS_IETF_IMPLICIT_NULL_LABEL);
+
+    fei = fib_table_entry_update_one_path(fib_index,
+					  &pfx_1_1_1_2_s_32,
+					  FIB_SOURCE_API,
+					  FIB_ENTRY_FLAG_NONE,
+					  FIB_PROTOCOL_IP4,
+					  &nh_10_10_11_1,
+					  tm->hw[1]->sw_if_index,
+					  ~0, // invalid fib index
+					  1,
+					  l_imp_null,
+					  FIB_ROUTE_PATH_FLAG_NONE);
+
+    FIB_TEST(fib_test_validate_entry(fei,
+				     FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+				     1,
+				     &a_o_10_10_11_1),
+	     "1.1.1.2/32 LB 1 buckets via: "
+	     "adj 10.10.11.1");
+ 
+    fei = fib_table_lookup(fib_index, &pfx_2_2_2_2_s_32);
+    FIB_TEST(fib_test_validate_entry(fei, 
+				     FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+				     2,
+				     &l1600_eos_o_1_1_1_1,
+				     &l1601_eos_o_1_1_1_2),
+	     "2.2.2.2/32 LB 2 buckets via: "
+	     "label 1600 via 1.1,1.1, "
+	     "label 16001 via 1.1.1.2");
+
+    /*
+     * update the via-entry so it no longer has labelled paths.
+     * the LB for the recursive should exclue this via form its LB
+     */
+    fei = fib_table_entry_update_one_path(fib_index,
+					  &pfx_1_1_1_2_s_32,
+					  FIB_SOURCE_API,
+					  FIB_ENTRY_FLAG_NONE,
+					  FIB_PROTOCOL_IP4,
+					  &nh_10_10_11_1,
+					  tm->hw[1]->sw_if_index,
+					  ~0, // invalid fib index
+					  1,
+					  NULL,
+					  FIB_ROUTE_PATH_FLAG_NONE);
+
+    FIB_TEST(fib_test_validate_entry(fei,
+				     FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+				     1,
+				     &a_o_10_10_11_1),
+	     "1.1.1.2/32 LB 1 buckets via: "
+	     "adj 10.10.11.1");
+ 
+    fei = fib_table_lookup(fib_index, &pfx_2_2_2_2_s_32);
+    FIB_TEST(fib_test_validate_entry(fei, 
+				     FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+				     1,
+				     &l1600_eos_o_1_1_1_1),
+	     "2.2.2.2/32 LB 1 buckets via: "
+	     "label 1600 via 1.1,1.1");
+
+    dpo_reset(&non_eos_1_1_1_1);
+    dpo_reset(&non_eos_1_1_1_2);
+
+    /*
+     * Add a recursive with no out-labels. We expect to use the IP of the via
+     */
+    fib_prefix_t pfx_2_2_2_3_s_32 = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    .ip4.as_u32 = clib_host_to_net_u32(0x02020203),
+	},
+    };
+    dpo_id_t ip_1_1_1_1 = DPO_INVALID;
+
+    fib_table_entry_update_one_path(fib_index,
+				    &pfx_2_2_2_3_s_32,
+				    FIB_SOURCE_API,
+				    FIB_ENTRY_FLAG_NONE,
+				    FIB_PROTOCOL_IP4,
+				    &pfx_1_1_1_1_s_32.fp_addr,
+				    ~0,
+				    fib_index,
+				    1,
+				    NULL,
+				    FIB_ROUTE_PATH_FLAG_NONE);
+
+    fib_entry_contribute_forwarding(fib_table_lookup(fib_index,
+						     &pfx_1_1_1_1_s_32),
+				    FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+				    &ip_1_1_1_1);
+
+    fib_test_lb_bucket_t ip_o_1_1_1_1 = {
+	.type = FT_LB_O_LB,
+	.lb = {
+	    .lb = ip_1_1_1_1.dpoi_index,
+	},
+    };
+
+    fei = fib_table_lookup(fib_index, &pfx_2_2_2_3_s_32);
+    FIB_TEST(fib_test_validate_entry(fei, 
+				     FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+				     1,
+				     &ip_o_1_1_1_1),
+	     "2.2.2.2.3/32 LB 1 buckets via: "
+	     "ip 1.1.1.1");
+
+    /*
+     * Add a recursive with an imp-null out-label. 
+     * We expect to use the IP of the via
+     */
+    fib_prefix_t pfx_2_2_2_4_s_32 = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    .ip4.as_u32 = clib_host_to_net_u32(0x02020204),
+	},
+    };
+
+    fib_table_entry_update_one_path(fib_index,
+				    &pfx_2_2_2_4_s_32,
+				    FIB_SOURCE_API,
+				    FIB_ENTRY_FLAG_NONE,
+				    FIB_PROTOCOL_IP4,
+				    &pfx_1_1_1_1_s_32.fp_addr,
+				    ~0,
+				    fib_index,
+				    1,
+				    NULL,
+				    FIB_ROUTE_PATH_FLAG_NONE);
+
+    fei = fib_table_lookup(fib_index, &pfx_2_2_2_4_s_32);
+    FIB_TEST(fib_test_validate_entry(fei, 
+				     FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+				     1,
+				     &ip_o_1_1_1_1),
+	     "2.2.2.2.4/32 LB 1 buckets via: "
+	     "ip 1.1.1.1");
+
+    dpo_reset(&ip_1_1_1_1);
+
+    /*
+     * Create an entry with a deep label stack
+     */
+    fib_prefix_t pfx_2_2_5_5_s_32 = {
+	.fp_len = 32,
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_addr = {
+	    .ip4.as_u32 = clib_host_to_net_u32(0x02020505),
+	},
+    };
+    fib_test_lb_bucket_t ls_eos_o_10_10_10_1 = {
+	.type = FT_LB_LABEL_STACK_O_ADJ,
+	.label_stack_o_adj = {
+	    .adj = ai_mpls_10_10_11_1,
+	    .label_stack_size = 8,
+	    .label_stack = {
+		200, 201, 202, 203, 204, 205, 206, 207
+	    },
+	    .eos = MPLS_EOS,
+	},
+    };
+    mpls_label_t *label_stack = NULL;
+    vec_validate(label_stack, 7);
+    for (ii = 0; ii < 8; ii++)
+    {
+	label_stack[ii] = ii + 200;
+    }
+
+    fei = fib_table_entry_update_one_path(fib_index,
+					  &pfx_2_2_5_5_s_32,
+					  FIB_SOURCE_API,
+					  FIB_ENTRY_FLAG_NONE,
+					  FIB_PROTOCOL_IP4,
+					  &nh_10_10_11_1,
+					  tm->hw[1]->sw_if_index,
+					  ~0, // invalid fib index
+					  1,
+					  label_stack,
+					  FIB_ROUTE_PATH_FLAG_NONE);
+
+    FIB_TEST(fib_test_validate_entry(fei,
+				     FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+				     1,
+				     &ls_eos_o_10_10_10_1),
+	     "2.2.5.5/32 LB 1 buckets via: "
+	     "adj 10.10.11.1");
+    fib_table_entry_delete_index(fei, FIB_SOURCE_API);
+
+    /*
+     * cleanup
+     */
+    fib_table_entry_delete(fib_index,
+			   &pfx_1_1_1_2_s_32,
+			   FIB_SOURCE_API);
+
+    fei = fib_table_lookup(fib_index, &pfx_2_2_2_2_s_32);
+    FIB_TEST(fib_test_validate_entry(fei, 
+				     FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+				     1,
+				     &l1600_eos_o_1_1_1_1),
+	     "2.2.2.2/32 LB 1 buckets via: "
+	     "label 1600 via 1.1,1.1");
+
+    fib_table_entry_delete(fib_index,
+			   &pfx_1_1_1_1_s_32,
+			   FIB_SOURCE_API);
+
+    FIB_TEST(fib_test_validate_entry(fei, 
+				     FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+				     1,
+				     &bucket_drop),
+	     "2.2.2.2/32 LB 1 buckets via: DROP");
+
+    fib_table_entry_delete(fib_index,
+			   &pfx_2_2_2_2_s_32,
+			   FIB_SOURCE_API);
+    fib_table_entry_delete(fib_index,
+			   &pfx_2_2_2_3_s_32,
+			   FIB_SOURCE_API);
+    fib_table_entry_delete(fib_index,
+			   &pfx_2_2_2_4_s_32,
+			   FIB_SOURCE_API);
+
+    adj_unlock(ai_mpls_10_10_10_1);
+    adj_unlock(ai_mpls_10_10_11_2);
+    adj_unlock(ai_v4_10_10_11_1);
+    adj_unlock(ai_v4_10_10_11_2);
+    adj_unlock(ai_mpls_10_10_11_1);
+
+    FIB_TEST((0 == adj_nbr_db_size()), "ADJ DB size is %d",
+	     adj_nbr_db_size());
+
+    local0_pfx.fp_len = 32;
+    fib_table_entry_delete(fib_index,
+			   &local0_pfx,
+			   FIB_SOURCE_INTERFACE);
+    local0_pfx.fp_len = 24;
+    fib_table_entry_delete(fib_index,
+			   &local0_pfx,
+			   FIB_SOURCE_INTERFACE);
+    local1_pfx.fp_len = 32;
+    fib_table_entry_delete(fib_index,
+			   &local1_pfx,
+			   FIB_SOURCE_INTERFACE);
+    local1_pfx.fp_len = 24;
+    fib_table_entry_delete(fib_index,
+			   &local1_pfx,
+			   FIB_SOURCE_INTERFACE);
+
+    /*
+     * +1 for the drop LB in the MPLS tables.
+     */
+    FIB_TEST(lb_count+1 == pool_elts(load_balance_pool),
+	     "Load-balance resources freed %d of %d",
+             lb_count+1, pool_elts(load_balance_pool));
+
+    return (0);
+}
+
+#define N_TEST_CHILDREN 4
+#define PARENT_INDEX 0
+
+typedef struct fib_node_test_t_
+{
+    fib_node_t node;
+    u32 sibling;
+    u32 index;
+    fib_node_back_walk_ctx_t *ctxs;
+    u32 destroyed;
+} fib_node_test_t;
+
+static fib_node_test_t fib_test_nodes[N_TEST_CHILDREN+1];
+
+#define PARENT() (&fib_test_nodes[PARENT_INDEX].node)
+
+#define FOR_EACH_TEST_CHILD(_tc)                     \
+    for (ii = 1, (_tc) = &fib_test_nodes[1];         \
+         ii < N_TEST_CHILDREN+1;                     \
+         ii++, (_tc) = &fib_test_nodes[ii])
+
+static fib_node_t *
+fib_test_child_get_node (fib_node_index_t index)
+{
+    return (&fib_test_nodes[index].node);
+}
+
+static int fib_test_walk_spawns_walks;
+
+static fib_node_back_walk_rc_t
+fib_test_child_back_walk_notify (fib_node_t *node,
+                                 fib_node_back_walk_ctx_t *ctx)
+{
+    fib_node_test_t *tc = (fib_node_test_t*) node;
+
+    vec_add1(tc->ctxs, *ctx);
+
+    if (1 == fib_test_walk_spawns_walks)
+        fib_walk_sync(FIB_NODE_TYPE_TEST, tc->index, ctx);
+    if (2 == fib_test_walk_spawns_walks)
+        fib_walk_async(FIB_NODE_TYPE_TEST, tc->index,
+                       FIB_WALK_PRIORITY_HIGH, ctx);
+
+    return (FIB_NODE_BACK_WALK_CONTINUE);
+}
+
+static void
+fib_test_child_last_lock_gone (fib_node_t *node)
+{
+    fib_node_test_t *tc = (fib_node_test_t *)node;
+
+    tc->destroyed = 1;
+}
+
+/**
+ * The FIB walk's graph node virtual function table
+ */
+static const fib_node_vft_t fib_test_child_vft = {
+    .fnv_get = fib_test_child_get_node,
+    .fnv_last_lock = fib_test_child_last_lock_gone,
+    .fnv_back_walk = fib_test_child_back_walk_notify,
+};
+
+/*
+ * the function (that should have been static but isn't so I can do this)
+ * that processes the walk from the async queue,
+ */
+f64 fib_walk_process_queues(vlib_main_t * vm,
+                            const f64 quota);
+u32 fib_walk_queue_get_size(fib_walk_priority_t prio);
+
+static int
+fib_test_walk (void)
+{
+    fib_node_back_walk_ctx_t high_ctx = {}, low_ctx = {};
+    fib_node_test_t *tc;
+    vlib_main_t *vm;
+    u32 ii;
+
+    vm = vlib_get_main();
+    fib_node_register_type(FIB_NODE_TYPE_TEST, &fib_test_child_vft);
+
+    /*
+     * init a fake node on which we will add children
+     */
+    fib_node_init(&fib_test_nodes[PARENT_INDEX].node,
+                  FIB_NODE_TYPE_TEST);
+
+    FOR_EACH_TEST_CHILD(tc)
+    {
+        fib_node_init(&tc->node, FIB_NODE_TYPE_TEST);
+        fib_node_lock(&tc->node);
+        tc->ctxs = NULL;
+        tc->index = ii;
+        tc->sibling = fib_node_child_add(FIB_NODE_TYPE_TEST,
+                                         PARENT_INDEX,
+                                         FIB_NODE_TYPE_TEST, ii);
+    }
+
+    /*
+     * enqueue a walk across the parents children.
+     */
+    high_ctx.fnbw_reason = FIB_NODE_BW_REASON_FLAG_RESOLVE;
+
+    fib_walk_async(FIB_NODE_TYPE_TEST, PARENT_INDEX,
+                   FIB_WALK_PRIORITY_HIGH, &high_ctx);
+    FIB_TEST(N_TEST_CHILDREN+1 == fib_node_list_get_size(PARENT()->fn_children),
+             "Parent has %d children pre-walk",
+             fib_node_list_get_size(PARENT()->fn_children));
+
+    /*
+     * give the walk a large amount of time so it gets to the end
+     */
+    fib_walk_process_queues(vm, 1);
+
+    FOR_EACH_TEST_CHILD(tc)
+    {
+        FIB_TEST(1 == vec_len(tc->ctxs),
+                 "%d child visitsed %d times",
+                 ii, vec_len(tc->ctxs));
+        vec_free(tc->ctxs);
+    }
+    FIB_TEST(0 == fib_walk_queue_get_size(FIB_WALK_PRIORITY_HIGH),
+             "Queue is empty post walk");
+    FIB_TEST(N_TEST_CHILDREN == fib_node_list_get_size(PARENT()->fn_children),
+             "Parent has %d children post walk",
+             fib_node_list_get_size(PARENT()->fn_children));
+
+    /*
+     * walk again. should be no increase in the number of visits, since
+     * the walk will have terminated.
+     */
+    fib_walk_process_queues(vm, 1);
+
+    FOR_EACH_TEST_CHILD(tc)
+    {
+        FIB_TEST(0 == vec_len(tc->ctxs),
+                 "%d child visitsed %d times",
+                 ii, vec_len(tc->ctxs));
+    }
+
+    /*
+     * schedule a low and hig priority walk. expect the high to be performed
+     * before the low.
+     * schedule the high prio walk first so that it is further from the head
+     * of the dependency list. that way it won't merge with the low one.
+     */
+    high_ctx.fnbw_reason = FIB_NODE_BW_REASON_FLAG_RESOLVE;
+    low_ctx.fnbw_reason = FIB_NODE_BW_REASON_FLAG_ADJ_UPDATE;
+
+    fib_walk_async(FIB_NODE_TYPE_TEST, PARENT_INDEX,
+                   FIB_WALK_PRIORITY_HIGH, &high_ctx);
+    fib_walk_async(FIB_NODE_TYPE_TEST, PARENT_INDEX,
+                   FIB_WALK_PRIORITY_LOW, &low_ctx);
+
+    fib_walk_process_queues(vm, 1);
+
+    FOR_EACH_TEST_CHILD(tc)
+    {
+        FIB_TEST(high_ctx.fnbw_reason == tc->ctxs[0].fnbw_reason,
+                 "%d child visitsed by high prio walk", ii);
+        FIB_TEST(low_ctx.fnbw_reason  == tc->ctxs[1].fnbw_reason,
+                 "%d child visitsed by low prio walk", ii);
+        vec_free(tc->ctxs);
+    }
+    FIB_TEST(0 == fib_walk_queue_get_size(FIB_WALK_PRIORITY_HIGH),
+             "Queue is empty post prio walk");
+    FIB_TEST(N_TEST_CHILDREN == fib_node_list_get_size(PARENT()->fn_children),
+             "Parent has %d children post prio walk",
+             fib_node_list_get_size(PARENT()->fn_children));
+
+    /*
+     * schedule 2 walks of the same priority that can be megred.
+     * expect that each child is thus visited only once.
+     */
+    high_ctx.fnbw_reason = FIB_NODE_BW_REASON_FLAG_RESOLVE;
+    low_ctx.fnbw_reason  = FIB_NODE_BW_REASON_FLAG_RESOLVE;
+
+    fib_walk_async(FIB_NODE_TYPE_TEST, PARENT_INDEX,
+                   FIB_WALK_PRIORITY_HIGH, &high_ctx);
+    fib_walk_async(FIB_NODE_TYPE_TEST, PARENT_INDEX,
+                   FIB_WALK_PRIORITY_HIGH, &low_ctx);
+
+    fib_walk_process_queues(vm, 1);
+
+    FOR_EACH_TEST_CHILD(tc)
+    {
+        FIB_TEST(1 == vec_len(tc->ctxs),
+                 "%d child visitsed %d times during merge walk",
+                 ii, vec_len(tc->ctxs));
+        vec_free(tc->ctxs);
+    }
+    FIB_TEST(0 == fib_walk_queue_get_size(FIB_WALK_PRIORITY_HIGH),
+             "Queue is empty post merge walk");
+    FIB_TEST(N_TEST_CHILDREN == fib_node_list_get_size(PARENT()->fn_children),
+             "Parent has %d children post merge walk",
+             fib_node_list_get_size(PARENT()->fn_children));
+
+    /*
+     * schedule 2 walks of the same priority that cannot be megred.
+     * expect that each child is thus visited twice and in the order
+     * in which the walks were scheduled.
+     */
+    high_ctx.fnbw_reason = FIB_NODE_BW_REASON_FLAG_RESOLVE;
+    low_ctx.fnbw_reason  = FIB_NODE_BW_REASON_FLAG_ADJ_UPDATE;
+
+    fib_walk_async(FIB_NODE_TYPE_TEST, PARENT_INDEX,
+                   FIB_WALK_PRIORITY_HIGH, &high_ctx);
+    fib_walk_async(FIB_NODE_TYPE_TEST, PARENT_INDEX,
+                   FIB_WALK_PRIORITY_HIGH, &low_ctx);
+
+    fib_walk_process_queues(vm, 1);
+
+    FOR_EACH_TEST_CHILD(tc)
+    {
+        FIB_TEST(high_ctx.fnbw_reason == tc->ctxs[0].fnbw_reason,
+                 "%d child visitsed by high prio walk", ii);
+        FIB_TEST(low_ctx.fnbw_reason  == tc->ctxs[1].fnbw_reason,
+                 "%d child visitsed by low prio walk", ii);
+        vec_free(tc->ctxs);
+    }
+    FIB_TEST(0 == fib_walk_queue_get_size(FIB_WALK_PRIORITY_HIGH),
+             "Queue is empty post no-merge walk");
+    FIB_TEST(N_TEST_CHILDREN == fib_node_list_get_size(PARENT()->fn_children),
+             "Parent has %d children post no-merge walk",
+             fib_node_list_get_size(PARENT()->fn_children));
+
+    /*
+     * schedule a walk that makes one one child progress.
+     * we do this by giving the queue draining process zero
+     * time quanta. it's a do..while loop, so it does something.
+     */
+    high_ctx.fnbw_reason = FIB_NODE_BW_REASON_FLAG_RESOLVE;
+
+    fib_walk_async(FIB_NODE_TYPE_TEST, PARENT_INDEX,
+                   FIB_WALK_PRIORITY_HIGH, &high_ctx);
+    fib_walk_process_queues(vm, 0);
+
+    FOR_EACH_TEST_CHILD(tc)
+    {
+        if (ii == N_TEST_CHILDREN)
+        {
+            FIB_TEST(1 == vec_len(tc->ctxs),
+                     "%d child visitsed %d times in zero quanta walk",
+                     ii, vec_len(tc->ctxs));
+        }
+        else
+        {
+            FIB_TEST(0 == vec_len(tc->ctxs),
+                     "%d child visitsed %d times in 0 quanta walk",
+                     ii, vec_len(tc->ctxs));
+        }
+    }
+    FIB_TEST(1 == fib_walk_queue_get_size(FIB_WALK_PRIORITY_HIGH),
+             "Queue is not empty post zero quanta walk");
+    FIB_TEST(N_TEST_CHILDREN+1 == fib_node_list_get_size(PARENT()->fn_children),
+             "Parent has %d children post zero qunta walk",
+             fib_node_list_get_size(PARENT()->fn_children));
+
+    /*
+     * another one step
+     */
+    fib_walk_process_queues(vm, 0);
+
+    FOR_EACH_TEST_CHILD(tc)
+    {
+        if (ii >= N_TEST_CHILDREN-1)
+        {
+            FIB_TEST(1 == vec_len(tc->ctxs),
+                     "%d child visitsed %d times in 2nd zero quanta walk",
+                     ii, vec_len(tc->ctxs));
+        }
+        else
+        {
+            FIB_TEST(0 == vec_len(tc->ctxs),
+                     "%d child visitsed %d times in 2nd 0 quanta walk",
+                     ii, vec_len(tc->ctxs));
+        }
+    }
+    FIB_TEST(1 == fib_walk_queue_get_size(FIB_WALK_PRIORITY_HIGH),
+             "Queue is not empty post zero quanta walk");
+    FIB_TEST(N_TEST_CHILDREN+1 == fib_node_list_get_size(PARENT()->fn_children),
+             "Parent has %d children post zero qunta walk",
+             fib_node_list_get_size(PARENT()->fn_children));
+
+    /*
+     * schedule another walk that will catch-up and merge.
+     */
+    fib_walk_async(FIB_NODE_TYPE_TEST, PARENT_INDEX,
+                   FIB_WALK_PRIORITY_HIGH, &high_ctx);
+    fib_walk_process_queues(vm, 1);
+
+    FOR_EACH_TEST_CHILD(tc)
+    {
+        if (ii >= N_TEST_CHILDREN-1)
+        {
+            FIB_TEST(2 == vec_len(tc->ctxs),
+                     "%d child visitsed %d times in 2nd zero quanta merge walk",
+                     ii, vec_len(tc->ctxs));
+            vec_free(tc->ctxs);
+        }
+        else
+        {
+            FIB_TEST(1 == vec_len(tc->ctxs),
+                     "%d child visitsed %d times in 2nd 0 quanta merge walk",
+                     ii, vec_len(tc->ctxs));
+            vec_free(tc->ctxs);
+        }
+    }
+    FIB_TEST(0 == fib_walk_queue_get_size(FIB_WALK_PRIORITY_HIGH),
+             "Queue is not empty post 2nd zero quanta merge walk");
+    FIB_TEST(N_TEST_CHILDREN == fib_node_list_get_size(PARENT()->fn_children),
+             "Parent has %d children post 2nd zero qunta merge walk",
+             fib_node_list_get_size(PARENT()->fn_children));
+
+    /*
+     * park a async walk in the middle of the list, then have an sync walk catch
+     * it. same expectations as async catches async.
+     */
+    high_ctx.fnbw_reason = FIB_NODE_BW_REASON_FLAG_RESOLVE;
+
+    fib_walk_async(FIB_NODE_TYPE_TEST, PARENT_INDEX,
+                   FIB_WALK_PRIORITY_HIGH, &high_ctx);
+
+    fib_walk_process_queues(vm, 0);
+    fib_walk_process_queues(vm, 0);
+
+    fib_walk_sync(FIB_NODE_TYPE_TEST, PARENT_INDEX, &high_ctx);
+
+    FOR_EACH_TEST_CHILD(tc)
+    {
+        if (ii >= N_TEST_CHILDREN-1)
+        {
+            FIB_TEST(2 == vec_len(tc->ctxs),
+                     "%d child visitsed %d times in sync catches async walk",
+                     ii, vec_len(tc->ctxs));
+            vec_free(tc->ctxs);
+        }
+        else
+        {
+            FIB_TEST(1 == vec_len(tc->ctxs),
+                     "%d child visitsed %d times in sync catches async walk",
+                     ii, vec_len(tc->ctxs));
+            vec_free(tc->ctxs);
+        }
+    }
+    FIB_TEST(0 == fib_walk_queue_get_size(FIB_WALK_PRIORITY_HIGH),
+             "Queue is not empty post 2nd zero quanta merge walk");
+    FIB_TEST(N_TEST_CHILDREN == fib_node_list_get_size(PARENT()->fn_children),
+             "Parent has %d children post 2nd zero qunta merge walk",
+             fib_node_list_get_size(PARENT()->fn_children));
+
+    /*
+     * make the parent a child of one of its children, thus inducing a routing loop.
+     */
+    fib_test_nodes[PARENT_INDEX].sibling =
+        fib_node_child_add(FIB_NODE_TYPE_TEST,
+                           1, // the first child
+                           FIB_NODE_TYPE_TEST,
+                           PARENT_INDEX);
+
+    /*
+     * execute a sync walk from the parent. each child visited spawns more sync
+     * walks. we expect the walk to terminate.
+     */
+    fib_test_walk_spawns_walks = 1;
+
+    fib_walk_sync(FIB_NODE_TYPE_TEST, PARENT_INDEX, &high_ctx);
+
+    FOR_EACH_TEST_CHILD(tc)
+    {
+        /*
+         * child 1 - which is last in the list - has the loop.
+         * the other children a re thus visitsed first. the we meet
+         * child 1. we go round the loop again, visting the other children.
+         * then we meet the walk in the dep list and bail. child 1 is not visitsed
+         * again.
+         */
+        if (1 == ii)
+        {
+            FIB_TEST(1 == vec_len(tc->ctxs),
+                     "child %d visitsed %d times during looped sync walk",
+                     ii, vec_len(tc->ctxs));
+        }
+        else
+        {
+            FIB_TEST(2 == vec_len(tc->ctxs),
+                     "child %d visitsed %d times during looped sync walk",
+                     ii, vec_len(tc->ctxs));
+        }
+        vec_free(tc->ctxs);
+    }
+    FIB_TEST(N_TEST_CHILDREN == fib_node_list_get_size(PARENT()->fn_children),
+             "Parent has %d children post sync loop walk",
+             fib_node_list_get_size(PARENT()->fn_children));
+
+    /*
+     * the walk doesn't reach the max depth because the infra knows that sync
+     * meets sync implies a loop and bails early.
+     */
+    FIB_TEST(high_ctx.fnbw_depth == 9,
+             "Walk context depth %d post sync loop walk",
+             high_ctx.fnbw_depth);
+
+    /*
+     * execute an async walk of the graph loop, with each child spawns sync walks
+     */
+    high_ctx.fnbw_depth = 0;
+    fib_walk_async(FIB_NODE_TYPE_TEST, PARENT_INDEX,
+                   FIB_WALK_PRIORITY_HIGH, &high_ctx);
+
+    fib_walk_process_queues(vm, 1);
+
+    FOR_EACH_TEST_CHILD(tc)
+    {
+        /*
+         * we don't really care how many times the children are visisted, as long as
+         * it is more than once.
+         */
+        FIB_TEST(1 <= vec_len(tc->ctxs),
+                 "child %d visitsed %d times during looped aync spawns sync walk",
+                 ii, vec_len(tc->ctxs));
+        vec_free(tc->ctxs);
+    }
+
+    /*
+     * execute an async walk of the graph loop, with each child spawns async walks
+     */
+    fib_test_walk_spawns_walks = 2;
+    high_ctx.fnbw_depth = 0;
+    fib_walk_async(FIB_NODE_TYPE_TEST, PARENT_INDEX,
+                   FIB_WALK_PRIORITY_HIGH, &high_ctx);
+
+    fib_walk_process_queues(vm, 1);
+
+    FOR_EACH_TEST_CHILD(tc)
+    {
+        /*
+         * we don't really care how many times the children are visisted, as long as
+         * it is more than once.
+         */
+        FIB_TEST(1 <= vec_len(tc->ctxs),
+                 "child %d visitsed %d times during looped async spawns async walk",
+                 ii, vec_len(tc->ctxs));
+                vec_free(tc->ctxs);
+    }
+
+
+    fib_node_child_remove(FIB_NODE_TYPE_TEST,
+                          1, // the first child
+                          fib_test_nodes[PARENT_INDEX].sibling);
+
+    /*
+     * cleanup
+     */
+    FOR_EACH_TEST_CHILD(tc)
+    {
+        fib_node_child_remove(FIB_NODE_TYPE_TEST, PARENT_INDEX,
+                              tc->sibling);
+        fib_node_deinit(&tc->node);
+        fib_node_unlock(&tc->node);
+    }
+    fib_node_deinit(PARENT());
+
+    /*
+     * The parent will be destroyed when the last lock on it goes.
+     * this test ensures all the walk objects are unlocking it.
+     */
+    FIB_TEST((1 == fib_test_nodes[PARENT_INDEX].destroyed),
+             "Parent was destroyed");
+
+    return (0);
+}
+
+static int
+lfib_test (void)
+{
+    const mpls_label_t deag_label = 50;
+    const u32 lfib_index = 0;
+    const u32 fib_index = 0;
+    dpo_id_t dpo = DPO_INVALID;
+    const dpo_id_t *dpo1;
+    fib_node_index_t lfe;
+    lookup_dpo_t *lkd;
+    test_main_t *tm;
+    int lb_count;
+    adj_index_t ai_mpls_10_10_10_1;
+
+    tm = &test_main;
+    lb_count = pool_elts(load_balance_pool);
+
+    FIB_TEST((0 == adj_nbr_db_size()), "ADJ DB size is %d",
+	     adj_nbr_db_size());
+
+    /*
+     * MPLS enable an interface so we get the MPLS table created
+     */
+    mpls_sw_interface_enable_disable(&mpls_main,
+                                     tm->hw[0]->sw_if_index,
+                                     1);
+
+    ip46_address_t nh_10_10_10_1 = {
+	.ip4.as_u32 = clib_host_to_net_u32(0x0a0a0a01),
+    };
+    ai_mpls_10_10_10_1 = adj_nbr_add_or_lock(FIB_PROTOCOL_IP4,
+                                             VNET_LINK_MPLS,
+                                             &nh_10_10_10_1,
+                                             tm->hw[0]->sw_if_index);
+
+    /*
+     * Test the specials stack properly.
+     */
+    fib_prefix_t exp_null_v6_pfx = {
+	.fp_proto = FIB_PROTOCOL_MPLS,
+	.fp_eos = MPLS_EOS,
+	.fp_label = MPLS_IETF_IPV6_EXPLICIT_NULL_LABEL,
+	.fp_payload_proto = DPO_PROTO_IP6,
+    };
+    lfe = fib_table_lookup(lfib_index, &exp_null_v6_pfx);
+    FIB_TEST((FIB_NODE_INDEX_INVALID != lfe),
+	     "%U/%U present",
+	     format_mpls_unicast_label, MPLS_IETF_IPV6_EXPLICIT_NULL_LABEL,
+	     format_mpls_eos_bit, MPLS_EOS);
+    fib_entry_contribute_forwarding(lfe,
+				    FIB_FORW_CHAIN_TYPE_MPLS_EOS,
+				    &dpo);
+    dpo1 = load_balance_get_bucket(dpo.dpoi_index, 0);
+    lkd = lookup_dpo_get(dpo1->dpoi_index);
+
+    FIB_TEST((fib_index == lkd->lkd_fib_index),
+              "%U/%U is deag in %d %U",
+             format_mpls_unicast_label, deag_label,
+             format_mpls_eos_bit, MPLS_EOS,
+             lkd->lkd_fib_index,
+             format_dpo_id, &dpo, 0);
+    FIB_TEST((LOOKUP_INPUT_DST_ADDR == lkd->lkd_input),
+             "%U/%U is dst deag",
+             format_mpls_unicast_label, deag_label,
+             format_mpls_eos_bit, MPLS_EOS);
+    FIB_TEST((LOOKUP_TABLE_FROM_INPUT_INTERFACE == lkd->lkd_table),
+             "%U/%U is lookup in interface's table",
+             format_mpls_unicast_label, deag_label,
+             format_mpls_eos_bit, MPLS_EOS);
+    FIB_TEST((DPO_PROTO_IP6 == lkd->lkd_proto),
+             "%U/%U is %U dst deag",
+             format_mpls_unicast_label, deag_label,
+             format_mpls_eos_bit, MPLS_EOS,
+             format_dpo_proto, lkd->lkd_proto);
+
+
+    /*
+     * A route deag route for EOS
+     */
+    fib_prefix_t pfx = {
+	.fp_proto = FIB_PROTOCOL_MPLS,
+	.fp_eos = MPLS_EOS,
+	.fp_label = deag_label,
+	.fp_payload_proto = DPO_PROTO_IP4,
+    };
+    lfe = fib_table_entry_path_add(lfib_index,
+				   &pfx,
+				   FIB_SOURCE_CLI,
+				   FIB_ENTRY_FLAG_NONE,
+				   FIB_PROTOCOL_IP4,
+				   &zero_addr,
+				   ~0,
+				   fib_index,
+				   1,
+				   NULL,
+				   FIB_ROUTE_PATH_FLAG_NONE);
+
+    FIB_TEST((lfe == fib_table_lookup(lfib_index, &pfx)),
+              "%U/%U present",
+              format_mpls_unicast_label, deag_label,
+              format_mpls_eos_bit, MPLS_EOS);
+
+    fib_entry_contribute_forwarding(lfe,
+				    FIB_FORW_CHAIN_TYPE_MPLS_EOS,
+				    &dpo);
+    dpo1 = load_balance_get_bucket(dpo.dpoi_index, 0);
+    lkd = lookup_dpo_get(dpo1->dpoi_index);
+
+    FIB_TEST((fib_index == lkd->lkd_fib_index),
+              "%U/%U is deag in %d %U",
+             format_mpls_unicast_label, deag_label,
+             format_mpls_eos_bit, MPLS_EOS,
+             lkd->lkd_fib_index,
+             format_dpo_id, &dpo, 0);
+    FIB_TEST((LOOKUP_INPUT_DST_ADDR == lkd->lkd_input),
+             "%U/%U is dst deag",
+             format_mpls_unicast_label, deag_label,
+             format_mpls_eos_bit, MPLS_EOS);
+    FIB_TEST((DPO_PROTO_IP4 == lkd->lkd_proto),
+             "%U/%U is %U dst deag",
+             format_mpls_unicast_label, deag_label,
+             format_mpls_eos_bit, MPLS_EOS,
+             format_dpo_proto, lkd->lkd_proto);
+
+    fib_table_entry_delete_index(lfe, FIB_SOURCE_CLI);
+
+    FIB_TEST((FIB_NODE_INDEX_INVALID == fib_table_lookup(lfib_index,
+							 &pfx)),
+              "%U/%U not present",
+              format_mpls_unicast_label, deag_label,
+              format_mpls_eos_bit, MPLS_EOS);
+
+    /*
+     * A route deag route for non-EOS
+     */
+    pfx.fp_eos = MPLS_NON_EOS;
+    lfe = fib_table_entry_path_add(lfib_index,
+				   &pfx,
+				   FIB_SOURCE_CLI,
+				   FIB_ENTRY_FLAG_NONE,
+				   FIB_PROTOCOL_IP4,
+				   &zero_addr,
+				   ~0,
+				   lfib_index,
+				   1,
+				   NULL,
+				   FIB_ROUTE_PATH_FLAG_NONE);
+
+    FIB_TEST((lfe == fib_table_lookup(lfib_index, &pfx)),
+              "%U/%U present",
+              format_mpls_unicast_label, deag_label,
+              format_mpls_eos_bit, MPLS_NON_EOS);
+
+    fib_entry_contribute_forwarding(lfe,
+				    FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS,
+				    &dpo);
+    dpo1 = load_balance_get_bucket(dpo.dpoi_index, 0);
+    lkd = lookup_dpo_get(dpo1->dpoi_index);
+
+    FIB_TEST((fib_index == lkd->lkd_fib_index),
+              "%U/%U is deag in %d %U",
+             format_mpls_unicast_label, deag_label,
+             format_mpls_eos_bit, MPLS_NON_EOS,
+             lkd->lkd_fib_index,
+             format_dpo_id, &dpo, 0);
+    FIB_TEST((LOOKUP_INPUT_DST_ADDR == lkd->lkd_input),
+             "%U/%U is dst deag",
+             format_mpls_unicast_label, deag_label,
+             format_mpls_eos_bit, MPLS_NON_EOS);
+
+    FIB_TEST((DPO_PROTO_MPLS == lkd->lkd_proto),
+             "%U/%U is %U dst deag",
+             format_mpls_unicast_label, deag_label,
+             format_mpls_eos_bit, MPLS_NON_EOS,
+             format_dpo_proto, lkd->lkd_proto);
+
+    fib_table_entry_delete_index(lfe, FIB_SOURCE_CLI);
+
+    FIB_TEST((FIB_NODE_INDEX_INVALID == fib_table_lookup(lfib_index,
+							 &pfx)),
+              "%U/%U not present",
+              format_mpls_unicast_label, deag_label,
+              format_mpls_eos_bit, MPLS_EOS);
+
+    dpo_reset(&dpo);
+
+    /*
+     * An MPLS x-connect
+     */
+    fib_prefix_t pfx_1200 = {
+	.fp_len = 21,
+	.fp_proto = FIB_PROTOCOL_MPLS,
+	.fp_label = 1200,
+	.fp_eos = MPLS_NON_EOS,
+    };
+    fib_test_lb_bucket_t neos_o_10_10_10_1 = {
+	.type = FT_LB_LABEL_STACK_O_ADJ,
+	.label_stack_o_adj = {
+	    .adj = ai_mpls_10_10_10_1,
+	    .label_stack_size = 4,
+	    .label_stack = {
+		200, 300, 400, 500,
+	    },
+	    .eos = MPLS_NON_EOS,
+	},
+    };
+    dpo_id_t neos_1200 = DPO_INVALID;
+    dpo_id_t ip_1200 = DPO_INVALID;
+    mpls_label_t *l200 = NULL;
+    vec_add1(l200, 200);
+    vec_add1(l200, 300);
+    vec_add1(l200, 400);
+    vec_add1(l200, 500);
+
+    lfe = fib_table_entry_update_one_path(fib_index,
+					  &pfx_1200,
+					  FIB_SOURCE_API,
+					  FIB_ENTRY_FLAG_NONE,
+					  FIB_PROTOCOL_IP4,
+					  &nh_10_10_10_1,
+					  tm->hw[0]->sw_if_index,
+					  ~0, // invalid fib index
+					  1,
+					  l200,
+					  FIB_ROUTE_PATH_FLAG_NONE);
+
+    FIB_TEST(fib_test_validate_entry(lfe,
+				     FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS,
+				     1,
+				     &neos_o_10_10_10_1),
+	     "1200/0 LB 1 buckets via: "
+	     "adj 10.10.11.1");
+
+    /*
+     * A recursive route via the MPLS x-connect
+     */
+    fib_prefix_t pfx_2_2_2_3_s_32 = {
+    	.fp_len = 32,
+    	.fp_proto = FIB_PROTOCOL_IP4,
+    	.fp_addr = {
+    	    .ip4.as_u32 = clib_host_to_net_u32(0x02020203),
+    	},
+    };
+    fib_route_path_t *rpaths = NULL, rpath = {
+    	.frp_proto = FIB_PROTOCOL_MPLS,
+    	.frp_local_label = 1200,
+    	.frp_sw_if_index = ~0, // recurive
+    	.frp_fib_index = 0, // Default MPLS fib
+    	.frp_weight = 1,
+    	.frp_flags = FIB_ROUTE_PATH_FLAG_NONE,
+    	.frp_label_stack = NULL,
+    };
+    vec_add1(rpaths, rpath);
+
+    fib_table_entry_path_add2(fib_index,
+    			      &pfx_2_2_2_3_s_32,
+    			      FIB_SOURCE_API,
+    			      FIB_ENTRY_FLAG_NONE,
+    			      rpaths);
+
+    /*
+     * A labelled recursive route via the MPLS x-connect
+     */
+    fib_prefix_t pfx_2_2_2_4_s_32 = {
+    	.fp_len = 32,
+    	.fp_proto = FIB_PROTOCOL_IP4,
+    	.fp_addr = {
+    	    .ip4.as_u32 = clib_host_to_net_u32(0x02020204),
+    	},
+    };
+    mpls_label_t *l999 = NULL;
+    vec_add1(l999, 999);
+    rpaths[0].frp_label_stack = l999,
+
+    fib_table_entry_path_add2(fib_index,
+    			      &pfx_2_2_2_4_s_32,
+    			      FIB_SOURCE_API,
+    			      FIB_ENTRY_FLAG_NONE,
+    			      rpaths);
+
+    fib_entry_contribute_forwarding(fib_table_lookup(fib_index, &pfx_1200),
+    				    FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+    				    &ip_1200);
+    fib_entry_contribute_forwarding(fib_table_lookup(fib_index, &pfx_1200),
+    				    FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS,
+    				    &neos_1200);
+
+    fib_test_lb_bucket_t ip_o_1200 = {
+    	.type = FT_LB_O_LB,
+    	.lb = {
+    	    .lb = ip_1200.dpoi_index,
+    	},
+    };
+    fib_test_lb_bucket_t mpls_o_1200 = {
+	.type = FT_LB_LABEL_O_LB,
+	.label_o_lb = {
+    	    .lb = neos_1200.dpoi_index,
+	    .label = 999,
+	    .eos = MPLS_EOS,
+	},
+    };
+
+    lfe = fib_table_lookup(fib_index, &pfx_2_2_2_3_s_32);
+    FIB_TEST(fib_test_validate_entry(lfe,
+    				     FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+    				     1,
+    				     &ip_o_1200),
+    	     "2.2.2.2.3/32 LB 1 buckets via: label 1200 EOS");
+    lfe = fib_table_lookup(fib_index, &pfx_2_2_2_4_s_32);
+    FIB_TEST(fib_test_validate_entry(lfe,
+    				     FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+    				     1,
+    				     &mpls_o_1200),
+    	     "2.2.2.2.4/32 LB 1 buckets via: label 1200 non-EOS");
+
+    fib_table_entry_delete(fib_index, &pfx_1200, FIB_SOURCE_API);
+    fib_table_entry_delete(fib_index, &pfx_2_2_2_3_s_32, FIB_SOURCE_API);
+    fib_table_entry_delete(fib_index, &pfx_2_2_2_4_s_32, FIB_SOURCE_API);
+
+    dpo_reset(&neos_1200);
+    dpo_reset(&ip_1200);
+
+    /*
+     * A recursive via a label that does not exist
+     */
+    fib_test_lb_bucket_t bucket_drop = {
+	.type = FT_LB_SPECIAL,
+	.special = {
+	    .adj = DPO_PROTO_MPLS,
+	},
+    };
+
+    rpaths[0].frp_label_stack = NULL;
+    lfe = fib_table_entry_path_add2(fib_index,
+				    &pfx_2_2_2_4_s_32,
+				    FIB_SOURCE_API,
+				    FIB_ENTRY_FLAG_NONE,
+				    rpaths);
+
+    fib_entry_contribute_forwarding(fib_table_lookup(fib_index, &pfx_1200),
+    				    FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+    				    &ip_1200);
+    ip_o_1200.lb.lb = ip_1200.dpoi_index;
+
+    FIB_TEST(fib_test_validate_entry(lfe,
+    				     FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+    				     1,
+    				     &ip_o_1200),
+    	     "2.2.2.2.4/32 LB 1 buckets via: label 1200 EOS");
+    lfe = fib_table_lookup(fib_index, &pfx_1200);
+    FIB_TEST(fib_test_validate_entry(lfe,
+				     FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+				     1,
+				     &bucket_drop),
+	     "2.2.2.4/32 LB 1 buckets via: ip4-DROP");
+
+    fib_table_entry_delete(fib_index, &pfx_2_2_2_4_s_32, FIB_SOURCE_API);
+
+    dpo_reset(&ip_1200);
+
+    /*
+     * cleanup
+     */
+    mpls_sw_interface_enable_disable(&mpls_main,
+                                     tm->hw[0]->sw_if_index,
+                                     0);
+
+    FIB_TEST(lb_count == pool_elts(load_balance_pool),
+	     "Load-balance resources freed %d of %d",
+             lb_count, pool_elts(load_balance_pool));
+
+    return (0);
+}
+
+static clib_error_t *
+fib_test (vlib_main_t * vm, 
+	  unformat_input_t * input,
+	  vlib_cli_command_t * cmd_arg)
+{
+    int res;
+
+    res = 0;
+    fib_test_mk_intf(4);
+
+    if (unformat (input, "ip"))
+    {
+	res += fib_test_v4();
+	res += fib_test_v6();
+    }
+    else if (unformat (input, "label"))
+    {
+	res += fib_test_label();
+    }
+    else if (unformat (input, "ae"))
+    {
+	res += fib_test_ae();
+    }
+    else if (unformat (input, "lfib"))
+    {
+	res += lfib_test();
+    }
+    else if (unformat (input, "walk"))
+    {
+	res += fib_test_walk();
+    }
+    else
+    {
+        /*
+         * These walk UT aren't run as part of the full suite, since the
+         * fib-walk process must be disabled in order for the tests to work
+         *
+         * fib_test_walk();
+         */
+	res += fib_test_v4();
+	res += fib_test_v6();
+	res += fib_test_ae();
+	res += fib_test_label();
+	res += lfib_test();
+    }
+
+    if (res)
+    {
+        return clib_error_return(0, "FIB Unit Test Failed");
+    }
+    else
+    {
+        return (NULL);
+    }
+}
+
+VLIB_CLI_COMMAND (test_fib_command, static) = {
+    .path = "test fib",
+    .short_help = "fib unit tests - DO NOT RUN ON A LIVE SYSTEM",
+    .function = fib_test,
+};
+
+clib_error_t *
+fib_test_init (vlib_main_t *vm)
+{
+    return 0;
+}
+
+VLIB_INIT_FUNCTION (fib_test_init);
diff --git a/src/vnet/fib/fib_types.c b/src/vnet/fib/fib_types.c
new file mode 100644
index 00000000000..b66e71940a5
--- /dev/null
+++ b/src/vnet/fib/fib_types.c
@@ -0,0 +1,326 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vnet/ip/ip.h>
+
+#include <vnet/fib/fib_types.h>
+#include <vnet/fib/fib_internal.h>
+#include <vnet/mpls/mpls.h>
+
+/*
+ * arrays of protocol and link names
+ */
+static const char* fib_protocol_names[] = FIB_PROTOCOLS;
+static const char* vnet_link_names[] = VNET_LINKS;
+static const char* fib_forw_chain_names[] = FIB_FORW_CHAINS;
+
+u8 *
+format_fib_protocol (u8 * s, va_list ap)
+{
+    fib_protocol_t proto = va_arg(ap, int); // fib_protocol_t promotion
+
+    return (format (s, "%s", fib_protocol_names[proto]));
+}
+
+u8 *
+format_vnet_link (u8 * s, va_list ap)
+{
+    vnet_link_t link = va_arg(ap, int); // vnet_link_t promotion
+
+    return (format (s, "%s", vnet_link_names[link]));
+}
+
+u8 *
+format_fib_forw_chain_type (u8 * s, va_list * args)
+{
+    fib_forward_chain_type_t fct = va_arg(*args, int);
+
+    return (format (s, "%s", fib_forw_chain_names[fct]));
+}
+
+void
+fib_prefix_from_ip46_addr (const ip46_address_t *addr,
+			   fib_prefix_t *pfx)
+{
+    ASSERT(!ip46_address_is_zero(addr));
+
+    pfx->fp_proto = ((ip46_address_is_ip4(addr) ?
+		      FIB_PROTOCOL_IP4 :
+		      FIB_PROTOCOL_IP6));
+    pfx->fp_len = ((ip46_address_is_ip4(addr) ?
+		    32 : 128));
+    pfx->fp_addr = *addr;
+}
+
+void
+fib_prefix_from_mpls_label (mpls_label_t label,
+			    fib_prefix_t *pfx)
+{
+    pfx->fp_proto = FIB_PROTOCOL_MPLS;
+    pfx->fp_len = 21;
+    pfx->fp_label = label;
+    pfx->fp_eos = MPLS_NON_EOS;
+}
+
+int
+fib_prefix_cmp (const fib_prefix_t *p1,
+		const fib_prefix_t *p2)
+{
+    int res;
+
+    res = (p1->fp_proto - p2->fp_proto);
+
+    if (0 == res)
+    {
+	switch (p1->fp_proto)
+	{
+	case FIB_PROTOCOL_IP4:
+	case FIB_PROTOCOL_IP6:
+	    res = (p1->fp_len - p2->fp_len);
+
+	    if (0 == res)
+	    {
+		res = ip46_address_cmp(&p1->fp_addr, &p2->fp_addr);
+	    }
+	    break;
+	case FIB_PROTOCOL_MPLS:
+	    res = (p1->fp_label - p2->fp_label);
+
+	    if (0 == res)
+	    {
+		res = (p1->fp_eos - p2->fp_eos);
+	    }
+	    break;
+	}
+    }
+
+    return (res);
+}
+
+int
+fib_prefix_is_cover (const fib_prefix_t *p1,
+		     const fib_prefix_t *p2)
+{
+    switch (p1->fp_proto)
+    {
+    case FIB_PROTOCOL_IP4:
+	return (ip4_destination_matches_route(&ip4_main,
+					      &p1->fp_addr.ip4,
+					      &p2->fp_addr.ip4,
+					      p1->fp_len));
+    case FIB_PROTOCOL_IP6:
+	return (ip6_destination_matches_route(&ip6_main,
+					      &p1->fp_addr.ip6,
+					      &p2->fp_addr.ip6,
+					      p1->fp_len));
+    case FIB_PROTOCOL_MPLS:
+	break;
+    }
+    return (0);
+}
+
+int
+fib_prefix_is_host (const fib_prefix_t *prefix)
+{
+    switch (prefix->fp_proto)
+    {
+    case FIB_PROTOCOL_IP4:
+	return (prefix->fp_len == 32);
+    case FIB_PROTOCOL_IP6:
+	return (prefix->fp_len == 128);
+    case FIB_PROTOCOL_MPLS:
+	return (!0);
+    }
+    return (0);
+}
+
+u8 *
+format_fib_prefix (u8 * s, va_list * args)
+{
+    fib_prefix_t *fp = va_arg (*args, fib_prefix_t *);
+
+    /*
+     * protocol specific so it prints ::/0 correctly.
+     */
+    switch (fp->fp_proto)
+    {
+    case FIB_PROTOCOL_IP6:
+    {
+	ip6_address_t p6 = fp->fp_addr.ip6;
+
+	ip6_address_mask(&p6, &(ip6_main.fib_masks[fp->fp_len]));
+	s = format (s, "%U", format_ip6_address, &p6);
+	break;
+    }
+    case FIB_PROTOCOL_IP4:
+    {
+	ip4_address_t p4 = fp->fp_addr.ip4;
+	p4.as_u32 &= ip4_main.fib_masks[fp->fp_len];
+
+	s = format (s, "%U", format_ip4_address, &p4);
+	break;
+    }
+    case FIB_PROTOCOL_MPLS:
+	s = format (s, "%U:%U",
+		    format_mpls_unicast_label, fp->fp_label,
+		    format_mpls_eos_bit, fp->fp_eos);
+	break;
+    }
+    s = format (s, "/%d", fp->fp_len);
+
+    return (s);
+}
+
+int
+fib_route_path_cmp (const fib_route_path_t *rpath1,
+		    const fib_route_path_t *rpath2)
+{
+    int res;
+
+    res = ip46_address_cmp(&rpath1->frp_addr,
+			   &rpath2->frp_addr);
+
+    if (0 != res) return (res);
+
+    if (~0 != rpath1->frp_sw_if_index &&
+        ~0 != rpath2->frp_sw_if_index)
+    {
+        res = vnet_sw_interface_compare(vnet_get_main(),
+                                        rpath1->frp_sw_if_index,
+                                        rpath2->frp_sw_if_index);
+    }
+    else
+    {
+        res = rpath1->frp_sw_if_index - rpath2->frp_sw_if_index;
+    }
+
+    if (0 != res) return (res);
+
+    if (ip46_address_is_zero(&rpath1->frp_addr))
+    {
+	res = rpath1->frp_fib_index - rpath2->frp_fib_index;
+    }
+
+    return (res);
+}
+
+dpo_proto_t
+fib_proto_to_dpo (fib_protocol_t fib_proto)
+{
+    switch (fib_proto)
+    {
+    case FIB_PROTOCOL_IP6:
+        return (DPO_PROTO_IP6);
+    case FIB_PROTOCOL_IP4:
+        return (DPO_PROTO_IP4);
+    case FIB_PROTOCOL_MPLS:
+        return (DPO_PROTO_MPLS);
+    }
+    ASSERT(0);
+    return (0);
+}
+
+fib_protocol_t
+dpo_proto_to_fib (dpo_proto_t dpo_proto)
+{
+    switch (dpo_proto)
+    {
+    case DPO_PROTO_IP6:
+        return (FIB_PROTOCOL_IP6);
+    case DPO_PROTO_IP4:
+        return (FIB_PROTOCOL_IP4);
+    case DPO_PROTO_MPLS:
+        return (FIB_PROTOCOL_MPLS);
+    default:
+	break;
+    }
+    ASSERT(0);
+    return (0);
+}
+
+vnet_link_t
+fib_proto_to_link (fib_protocol_t proto)
+{
+    switch (proto)
+    {
+    case FIB_PROTOCOL_IP4:
+	return (VNET_LINK_IP4);
+    case FIB_PROTOCOL_IP6:
+	return (VNET_LINK_IP6);
+    case FIB_PROTOCOL_MPLS:
+	return (VNET_LINK_MPLS);
+    }
+    ASSERT(0);
+    return (0);
+}
+
+fib_forward_chain_type_t
+fib_forw_chain_type_from_dpo_proto (dpo_proto_t proto)
+{
+    switch (proto)
+    {
+    case DPO_PROTO_IP4:
+	return (FIB_FORW_CHAIN_TYPE_UNICAST_IP4);
+    case DPO_PROTO_IP6:
+	return (FIB_FORW_CHAIN_TYPE_UNICAST_IP6);
+    case DPO_PROTO_MPLS:
+	return (FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS);
+    case DPO_PROTO_ETHERNET:
+	return (FIB_FORW_CHAIN_TYPE_ETHERNET);
+    }
+    ASSERT(0);
+    return (FIB_FORW_CHAIN_TYPE_UNICAST_IP4);
+}
+
+vnet_link_t
+fib_forw_chain_type_to_link_type (fib_forward_chain_type_t fct)
+{
+    switch (fct)
+    {
+    case FIB_FORW_CHAIN_TYPE_UNICAST_IP4:
+	return (VNET_LINK_IP4);
+    case FIB_FORW_CHAIN_TYPE_UNICAST_IP6:
+	return (VNET_LINK_IP6);
+    case FIB_FORW_CHAIN_TYPE_ETHERNET:
+	return (VNET_LINK_ETHERNET);
+    case FIB_FORW_CHAIN_TYPE_MPLS_EOS:
+	/*
+	 * insufficient information to to convert
+	 */
+	ASSERT(0);
+	break;
+    case FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS:
+	return (VNET_LINK_MPLS);
+    }
+    return (VNET_LINK_IP4);
+}
+
+dpo_proto_t
+fib_forw_chain_type_to_dpo_proto (fib_forward_chain_type_t fct)
+{
+    switch (fct)
+    {
+    case FIB_FORW_CHAIN_TYPE_UNICAST_IP4:
+	return (DPO_PROTO_IP4);
+    case FIB_FORW_CHAIN_TYPE_UNICAST_IP6:
+	return (DPO_PROTO_IP6);
+    case FIB_FORW_CHAIN_TYPE_ETHERNET:
+	return (DPO_PROTO_ETHERNET);
+    case FIB_FORW_CHAIN_TYPE_MPLS_EOS:
+    case FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS:
+	return (DPO_PROTO_MPLS);
+    }
+    return (DPO_PROTO_IP4);
+}
diff --git a/src/vnet/fib/fib_types.h b/src/vnet/fib/fib_types.h
new file mode 100644
index 00000000000..0a15fef1b28
--- /dev/null
+++ b/src/vnet/fib/fib_types.h
@@ -0,0 +1,340 @@
+ /*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __FIB_TYPES_H__
+#define __FIB_TYPES_H__
+
+#include <vlib/vlib.h>
+#include <vnet/ip/ip6_packet.h>
+#include <vnet/mpls/packet.h>
+#include <vnet/dpo/dpo.h>
+
+/**
+ * A typedef of a node index.
+ * we make this typedef so the code becomes easier for a human to parse.
+ */
+typedef u32 fib_node_index_t;
+#define FIB_NODE_INDEX_INVALID ((fib_node_index_t)(~0))
+
+/**
+ * Protocol Type. packed so it consumes a u8 only
+ */
+typedef enum fib_protocol_t_ {
+    FIB_PROTOCOL_IP4 = 0,
+    FIB_PROTOCOL_IP6,
+    FIB_PROTOCOL_MPLS,
+}  __attribute__ ((packed)) fib_protocol_t;
+
+#define FIB_PROTOCOLS {			\
+    [FIB_PROTOCOL_IP4] = "ipv4",	\
+    [FIB_PROTOCOL_IP6] = "ipv6",        \
+    [FIB_PROTOCOL_MPLS] = "MPLS",       \
+}
+
+/**
+ * Definition outside of enum so it does not need to be included in non-defaulted
+ * switch statements
+ */
+#define FIB_PROTOCOL_MAX (FIB_PROTOCOL_MPLS + 1)
+
+/**
+ * Not part of the enum so it does not have to be handled in switch statements
+ */
+#define FIB_PROTOCOL_NONE (FIB_PROTOCOL_MAX+1)
+
+#define FOR_EACH_FIB_PROTOCOL(_item)    \
+    for (_item = FIB_PROTOCOL_IP4;      \
+	 _item <= FIB_PROTOCOL_MPLS;    \
+	 _item++)
+
+#define FOR_EACH_FIB_IP_PROTOCOL(_item)    \
+    for (_item = FIB_PROTOCOL_IP4;         \
+	 _item <= FIB_PROTOCOL_IP6;        \
+	 _item++)
+
+/**
+ * @brief Convert from a protocol to a link type
+ */
+vnet_link_t fib_proto_to_link (fib_protocol_t proto);
+
+/**
+ * FIB output chain type. When a child object requests a forwarding contribution
+ * from a parent, it does so for a particular scenario. This enumererates those
+ * sceanrios
+ */
+typedef enum fib_forward_chain_type_t_ {
+    /**
+     * Contribute an object that is to be used to forward IP4 packets
+     */
+    FIB_FORW_CHAIN_TYPE_UNICAST_IP4,
+    /**
+     * Contribute an object that is to be used to forward IP6 packets
+     */
+    FIB_FORW_CHAIN_TYPE_UNICAST_IP6,
+    /**
+     * Contribute an object that is to be used to forward non-end-of-stack
+     * MPLS packets
+     */
+    FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS,
+    /**
+     * Contribute an object that is to be used to forward end-of-stack
+     * MPLS packets. This is a convenient ID for clients. A real EOS chain
+     * must be pay-load protocol specific. This
+     * option is converted into one of the other three internally.
+     */
+    FIB_FORW_CHAIN_TYPE_MPLS_EOS,
+    /**
+     * Contribute an object that is to be used to forward Ethernet packets.
+     * This is last in the list since it is not valid for many FIB objects,
+     * and thus their array of per-chain-type DPOs can be sized smaller.
+     */
+    FIB_FORW_CHAIN_TYPE_ETHERNET,
+}  __attribute__ ((packed)) fib_forward_chain_type_t;
+
+#define FIB_FORW_CHAINS {					\
+    [FIB_FORW_CHAIN_TYPE_ETHERNET]      = "ethernet",     	\
+    [FIB_FORW_CHAIN_TYPE_UNICAST_IP4]   = "unicast-ip4",	\
+    [FIB_FORW_CHAIN_TYPE_UNICAST_IP6]   = "unicast-ip6",	\
+    [FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS]  = "mpls-neos",	        \
+    [FIB_FORW_CHAIN_TYPE_MPLS_EOS]      = "mpls-eos",	        \
+}
+
+#define FIB_FORW_CHAIN_NUM (FIB_FORW_CHAIN_TYPE_MPLS_ETHERNET+1)
+#define FIB_FORW_CHAIN_MPLS_NUM (FIB_FORW_CHAIN_TYPE_MPLS_EOS+1)
+
+#define FOR_EACH_FIB_FORW_CHAIN(_item)			  \
+    for (_item = FIB_FORW_CHAIN_TYPE_UNICAST_IP4;   	  \
+	 _item <= FIB_FORW_CHAIN_TYPE_ETHERNET;		  \
+	 _item++)
+
+#define FOR_EACH_FIB_FORW_MPLS_CHAIN(_item)		  \
+    for (_item = FIB_FORW_CHAIN_TYPE_UNICAST_IP4;   	  \
+	 _item <= FIB_FORW_CHAIN_TYPE_MPLS_EOS;		  \
+	 _item++)
+
+/**
+ * @brief Convert from a chain type to the adjacencies link type
+ */
+extern vnet_link_t fib_forw_chain_type_to_link_type(fib_forward_chain_type_t fct);
+
+/**
+ * @brief Convert from a payload-protocol to a chain type.
+ */
+extern fib_forward_chain_type_t fib_forw_chain_type_from_dpo_proto(dpo_proto_t proto);
+
+/**
+ * @brief Convert from a chain type to the DPO proto it will install
+ */
+extern dpo_proto_t fib_forw_chain_type_to_dpo_proto(fib_forward_chain_type_t fct);
+
+/**
+ * Aggregrate type for a prefix
+ */
+typedef struct fib_prefix_t_ {
+    /**
+     * The mask length
+     */
+    u16 fp_len;
+
+    /**
+     * protocol type
+     */
+    fib_protocol_t fp_proto;
+
+    /**
+     * Pad to keep the address 4 byte aligned
+     */
+    u8 ___fp___pad;
+
+    union {
+	/**
+	 * The address type is not deriveable from the fp_addr member.
+	 * If it's v4, then the first 3 u32s of the address will be 0.
+	 * v6 addresses (even v4 mapped ones) have at least 2 u32s assigned
+	 * to non-zero values. true. but when it's all zero, one cannot decide.
+	 */
+	ip46_address_t fp_addr;
+
+	struct {
+	    mpls_label_t fp_label;
+	    mpls_eos_bit_t fp_eos;
+	    /**
+	     * This protocol determines the payload protocol of packets
+	     * that will be forwarded by this entry once the label is popped.
+	     * For a non-eos entry it will be MPLS.
+	     */
+	    dpo_proto_t fp_payload_proto;
+	};
+    };
+} fib_prefix_t;
+
+STATIC_ASSERT(STRUCT_OFFSET_OF(fib_prefix_t, fp_addr) == 4,
+	      "FIB Prefix's address is 4 byte aligned.");
+
+/**
+ * \brief Compare two prefixes for equality
+ */
+extern int fib_prefix_cmp(const fib_prefix_t *p1,
+			  const fib_prefix_t *p2);
+
+/**
+ * \brief Compare two prefixes for covering relationship
+ *
+ * \return non-zero if the first prefix is a cover for the second
+ */
+extern int fib_prefix_is_cover(const fib_prefix_t *p1,
+			       const fib_prefix_t *p2);
+
+/**
+ * \brief Return true is the prefix is a host prefix
+ */
+extern int fib_prefix_is_host(const fib_prefix_t *p);
+
+
+/**
+ * \brief Host prefix from ip
+ */
+extern void fib_prefix_from_ip46_addr (const ip46_address_t *addr,
+			   fib_prefix_t *pfx);
+
+extern u8 * format_fib_prefix(u8 * s, va_list * args);
+extern u8 * format_fib_forw_chain_type(u8 * s, va_list * args);
+
+extern dpo_proto_t fib_proto_to_dpo(fib_protocol_t fib_proto);
+extern fib_protocol_t dpo_proto_to_fib(dpo_proto_t dpo_proto);
+
+/**
+ * Enurmeration of special path/entry types
+ */
+typedef enum fib_special_type_t_ {
+    /**
+     * Marker. Add new types after this one.
+     */
+    FIB_SPECIAL_TYPE_FIRST = 0,
+    /**
+     * Local/for-us paths
+     */
+    FIB_SPECIAL_TYPE_LOCAL = FIB_SPECIAL_TYPE_FIRST,
+    /**
+     * drop paths
+     */
+    FIB_SPECIAL_TYPE_DROP,
+    /**
+     * Marker. Add new types before this one, then update it.
+     */
+    FIB_SPECIAL_TYPE_LAST = FIB_SPECIAL_TYPE_DROP,
+} __attribute__ ((packed)) fib_special_type_t;
+
+/**
+ * The maximum number of types
+ */
+#define FIB_SPEICAL_TYPE_MAX (FIB_SPEICAL_TYPE_LAST + 1)
+
+#define FOR_EACH_FIB_SPEICAL_TYPE(_item)		\
+    for (_item = FIB_TYPE_SPEICAL_FIRST;		\
+	 _item <= FIB_SPEICAL_TYPE_LAST; _item++)
+
+extern u8 * format_fib_protocol(u8 * s, va_list ap);
+extern u8 * format_vnet_link(u8 *s, va_list ap);
+
+/**
+ * Path flags from the control plane
+ */
+typedef enum fib_route_path_flags_t_
+{
+    FIB_ROUTE_PATH_FLAG_NONE = 0,
+    /**
+     * Recursion constraint of via a host prefix
+     */
+    FIB_ROUTE_PATH_RESOLVE_VIA_HOST = (1 << 0),
+    /**
+     * Recursion constraint of via an attahced prefix
+     */
+    FIB_ROUTE_PATH_RESOLVE_VIA_ATTACHED = (1 << 1),
+} fib_route_path_flags_t;
+
+/**
+ * @brief 
+ * A representation of a path as described by a route producer.
+ * These paramenters will determine the path 'type', of which there are:
+ * 1) Attached-next-hop:
+ *   a single peer on a link.
+ *   It is 'attached' because it is in the same sub-net as the router, on a link
+ *   directly connected to the route.
+ *   It is 'next=hop' since the next-hop address of the peer is known.
+ * 2) Attached:
+ *  the next-hop is not known. but we can ARP for it.
+ * 3) Recursive.
+ *  The next-hop is known but the interface is not. So to find the adj to use
+ *  we must recursively resolve the next-hop.
+ * 3) deaggregate (deag)
+ *  A further lookup is required.
+ */
+typedef struct fib_route_path_t_ {
+    /**
+     * The protocol of the address below. We need this since the all
+     * zeros address is ambiguous.
+     */
+    fib_protocol_t frp_proto;
+
+    union {
+	/**
+	 * The next-hop address.
+	 * Will be NULL for attached paths.
+	 * Will be all zeros for attached-next-hop paths on a p2p interface
+	 * Will be all zeros for a deag path.
+	 */
+	ip46_address_t frp_addr;
+
+	/**
+	 * The MPLS local Label to reursively resolve through.
+	 * This is valid when the path type is MPLS.
+	 */
+	mpls_label_t frp_local_label;
+    };
+    /**
+     * The interface.
+     * Will be invalid for recursive paths.
+     */
+    u32 frp_sw_if_index;
+    /**
+     * The FIB index to lookup the nexthop
+     * Only valid for recursive paths.
+     */
+    u32 frp_fib_index;
+    /**
+     * [un]equal cost path weight
+     */
+    u32 frp_weight;
+    /**
+     * flags on the path
+     */
+    fib_route_path_flags_t frp_flags;
+    /**
+     * The outgoing MPLS label Stack. NULL implies no label.
+     */
+    mpls_label_t *frp_label_stack;
+} fib_route_path_t;
+
+/**
+ * @brief 
+ * A representation of a fib path for fib_path_encode to convey the information to the caller
+ */
+typedef struct fib_route_path_encode_t_ {
+    fib_route_path_t rpath;
+    dpo_id_t dpo;
+} fib_route_path_encode_t;
+
+#endif
diff --git a/src/vnet/fib/fib_urpf_list.c b/src/vnet/fib/fib_urpf_list.c
new file mode 100644
index 00000000000..263812ade40
--- /dev/null
+++ b/src/vnet/fib/fib_urpf_list.c
@@ -0,0 +1,260 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vnet/fib/fib_urpf_list.h>
+#include <vnet/adj/adj.h>
+
+/**
+ * @brief pool of all fib_urpf_list
+ */
+fib_urpf_list_t *fib_urpf_list_pool;
+
+u8 *
+format_fib_urpf_list (u8 *s, va_list args)
+{
+    fib_urpf_list_t *urpf;
+    index_t ui;
+    u32 *swi;
+
+    ui = va_arg(args, index_t);
+    urpf = fib_urpf_list_get(ui);
+
+    s = format(s, "uPRF-list:%d len:%d itfs:[",
+	       ui, vec_len(urpf->furpf_itfs));
+
+    vec_foreach(swi, urpf->furpf_itfs)
+    {
+	s = format(s, "%d, ", *swi);
+    }
+    s = format(s, "]");
+
+    return (s);
+}
+
+index_t
+fib_urpf_list_alloc_and_lock (void)
+{
+    fib_urpf_list_t *urpf;
+
+    pool_get(fib_urpf_list_pool, urpf);
+    memset(urpf, 0, sizeof(*urpf));
+
+    urpf->furpf_locks++;
+
+    return (urpf - fib_urpf_list_pool);
+}
+
+void
+fib_urpf_list_unlock (index_t ui)
+{
+    fib_urpf_list_t *urpf;
+
+    if (INDEX_INVALID == ui)
+	return;
+
+    urpf = fib_urpf_list_get(ui);
+
+    urpf->furpf_locks--;
+
+    if (0 == urpf->furpf_locks)
+    {
+	vec_free(urpf->furpf_itfs);
+	pool_put(fib_urpf_list_pool, urpf);
+    }
+}
+
+void
+fib_urpf_list_lock (index_t ui)
+{
+    fib_urpf_list_t *urpf;
+
+    urpf = fib_urpf_list_get(ui);
+
+    urpf->furpf_locks++;
+}
+
+/**
+ * @brief Append another interface to the list.
+ */
+void
+fib_urpf_list_append (index_t ui,
+		      u32 sw_if_index)
+{
+    fib_urpf_list_t *urpf;
+
+    urpf = fib_urpf_list_get(ui);
+
+    vec_add1(urpf->furpf_itfs, sw_if_index);
+}
+
+/**
+ * @brief Combine to interface lists
+ */
+void
+fib_urpf_list_combine (index_t ui1,
+		       index_t ui2)
+{
+    fib_urpf_list_t *urpf1, *urpf2;
+
+    urpf1 = fib_urpf_list_get(ui1);
+    urpf2 = fib_urpf_list_get(ui2);
+
+    vec_append(urpf1->furpf_itfs, urpf2->furpf_itfs);
+}
+
+/**
+ * @brief Sort the interface indicies.
+ * The sort is the first step in obtaining a unique list, so the order,
+ * w.r.t. next-hop, interface,etc is not important. So a sort based on the
+ * index is all we need.
+ */
+static int
+fib_urpf_itf_cmp_for_sort (void * v1,
+			   void * v2)
+{
+    fib_node_index_t *i1 = v1, *i2 = v2;
+
+    return (*i2 < *i1);
+}
+
+/**
+ * @brief Convert the uRPF list from the itf set obtained during the walk
+ * to a unique list.
+ */
+void
+fib_urpf_list_bake (index_t ui)
+{
+    fib_urpf_list_t *urpf;
+
+    urpf = fib_urpf_list_get(ui);
+
+    ASSERT(!(urpf->furpf_flags & FIB_URPF_LIST_BAKED));
+
+    if (vec_len(urpf->furpf_itfs) > 1)
+    {
+	u32 i,j;
+
+	/*
+	 * cat list | sort | uniq > rpf_list
+	 */
+	vec_sort_with_function(urpf->furpf_itfs, fib_urpf_itf_cmp_for_sort);
+
+	i = 0, j = 1;
+	while (j < vec_len(urpf->furpf_itfs))
+	{
+	    if (urpf->furpf_itfs[i] == urpf->furpf_itfs[j])
+	    {
+		/*
+		 * the itfacenct entries are the same.
+		 * search forward for a unique one
+		 */
+		while (urpf->furpf_itfs[i] == urpf->furpf_itfs[j] &&
+		       j < vec_len(urpf->furpf_itfs))
+		{
+		    j++;
+		}
+		if (j == vec_len(urpf->furpf_itfs))
+		{
+		    /*
+		     * ran off the end without finding a unique index.
+		     * we are done.
+		     */
+		    break;
+		}
+		else
+		{
+		    urpf->furpf_itfs[i+1] = urpf->furpf_itfs[j];
+		}
+	    }
+	    i++, j++;
+	}
+
+	/*
+	 * set the length of the vector to the number of unique itfs
+	 */
+	_vec_len(urpf->furpf_itfs) = i+1;
+    }
+
+    urpf->furpf_flags |= FIB_URPF_LIST_BAKED;
+}
+
+void
+fib_urpf_list_show_mem (void)
+{
+    fib_show_memory_usage("uRPF-list",
+			  pool_elts(fib_urpf_list_pool),
+			  pool_len(fib_urpf_list_pool),
+			  sizeof(fib_urpf_list_t));
+}
+
+static clib_error_t *
+show_fib_urpf_list_command (vlib_main_t * vm,
+			    unformat_input_t * input,
+			    vlib_cli_command_t * cmd)
+{
+    index_t ui;
+
+    if (unformat (input, "%d", &ui))
+    {
+	/*
+	 * show one in detail
+	 */
+	if (!pool_is_free_index(fib_urpf_list_pool, ui))
+	{
+	    vlib_cli_output (vm, "%d@%U",
+			     ui,
+			     format_fib_urpf_list, ui);
+	}
+	else
+	{
+	    vlib_cli_output (vm, "uRPF %d invalid", ui);
+	}
+    }
+    else
+    {
+	/*
+	 * show all
+	 */
+	vlib_cli_output (vm, "FIB uRPF Entries:");
+	pool_foreach_index(ui, fib_urpf_list_pool,
+        ({
+	    vlib_cli_output (vm, "%d@%U",
+			     ui,
+			     format_fib_urpf_list, ui);
+	}));
+    }
+
+    return (NULL);
+}
+
+/* *INDENT-OFF* */
+/*?
+ * The '<em>sh fib uRPF [index] </em>' command displays the uRPF lists
+ *
+ * @cliexpar
+ * @cliexstart{show fib uRPF}
+ * FIB uRPF Entries:
+ *  0@uPRF-list:0 len:0 itfs:[]
+ *  1@uPRF-list:1 len:2 itfs:[1, 2, ]
+ *  2@uPRF-list:2 len:1 itfs:[3, ]
+ *  3@uPRF-list:3 len:1 itfs:[9, ]
+ * @cliexend
+?*/
+VLIB_CLI_COMMAND (show_fib_urpf_list, static) = {
+  .path = "show fib uRPF",
+  .function = show_fib_urpf_list_command,
+  .short_help = "show fib uRPF",
+};
+/* *INDENT-OFF* */
diff --git a/src/vnet/fib/fib_urpf_list.h b/src/vnet/fib/fib_urpf_list.h
new file mode 100644
index 00000000000..09f475747cf
--- /dev/null
+++ b/src/vnet/fib/fib_urpf_list.h
@@ -0,0 +1,146 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/**
+ * @brief A unicast RPF list.
+ * The uRPF list is the set of interfaces that a prefix can be reached through.
+ * There are 3 levels of RPF check:
+ *   - do we have any route to the source (i.e. it's not drop)
+ *   - did the packet arrive on an interface that the source is reachable through
+ *   - did the packet arrive from a peer that the source is reachable through
+ * we don't support the last. But it could be done by storing adjs in the uPRF
+ * list rather than interface indices.
+ *
+ * these conditions are checked against the list by:
+ *   - the list is not empty
+ *   - there is an interface in the list that is on the input interface.
+ *   - there is an adj in the list whose MAC address matches the packet's
+ *     source MAC and input interface.
+ *
+ * To speed the last two checks the interface list only needs to have the unique
+ * interfaces present. If the uRPF check was instead implemented by forward
+ * walking the DPO chain, then that walk would encounter a great deal of
+ * non-adjacency objects (i.e. load-balances, mpls-labels, etc) and potentially
+ * the same adjacency many times (esp. when UCMP is used).
+ * To that end the uRPF list is a collapsed, unique interface only list.
+ */
+
+#ifndef __FIB_URPF_LIST_H__
+#define __FIB_URPF_LIST_H__
+
+#include <vnet/fib/fib_types.h>
+#include <vnet/adj/adj.h>
+
+/**
+ * @brief flags
+ */
+typedef enum fib_urpf_list_flag_t_
+{
+    /**
+     * @brief Set to indicated that the uRPF list has already been baked.
+     * This is protection against it being baked more than once. These
+     * are not chunky fries - once is enough.
+     */
+    FIB_URPF_LIST_BAKED = (1 << 0),
+} fib_urpf_list_flag_t;
+
+typedef struct fib_urpf_list_t_
+{
+    /**
+     * The list of interfaces that comprise the allowed accepting interfaces
+     */
+    adj_index_t *furpf_itfs;
+
+    /**
+     * flags
+     */
+    fib_urpf_list_flag_t furpf_flags;
+
+    /**
+     * uRPF lists are shared amongst many entries so we require a locking
+     * mechanism.
+     */
+    u32 furpf_locks;
+} fib_urpf_list_t;
+
+extern index_t fib_urpf_list_alloc_and_lock(void);
+extern void fib_urpf_list_unlock(index_t urpf);
+extern void fib_urpf_list_lock(index_t urpf);
+
+extern void fib_urpf_list_append(index_t urpf, adj_index_t adj);
+extern void fib_urpf_list_combine(index_t urpf1, index_t urpf2);
+
+extern void fib_urpf_list_bake(index_t urpf);
+
+extern u8 *format_fib_urpf_list(u8 *s, va_list ap);
+
+extern void fib_urpf_list_show_mem(void);
+
+/**
+ * @brief pool of all fib_urpf_list
+ */
+extern fib_urpf_list_t *fib_urpf_list_pool;
+
+static inline fib_urpf_list_t *
+fib_urpf_list_get (index_t index)
+{
+    return (pool_elt_at_index(fib_urpf_list_pool, index));
+}
+
+/**
+ * @brief Data-Plane function to check an input interface against an uRPF list
+ *
+ * @param ui The uRPF list index to check against. Get this from the load-balance
+ *             object that is the result of the FIB lookup
+ * @param sw_if_index The SW interface index to validate
+ *
+ * @return 1 if the interface is found, 0 otherwise
+ */
+always_inline int
+fib_urpf_check (index_t ui, u32 sw_if_index)
+{
+    fib_urpf_list_t *urpf;
+    u32 *swi;
+
+    urpf = fib_urpf_list_get(ui);
+
+    vec_foreach(swi, urpf->furpf_itfs)
+    {
+	if (*swi == sw_if_index)
+	    return (1);
+    }
+
+    return (0);
+}
+
+/**
+ * @brief Data-Plane function to check the size of an uRPF list, (i.e. the number
+ *        of interfaces in the list).
+ *
+ * @param ui The uRPF list index to check against. Get this from the load-balance
+ *             object that is the result of the FIB lookup
+ *
+ * @return the number of interfaces in the list
+ */
+always_inline int
+fib_urpf_check_size (index_t ui)
+{
+    fib_urpf_list_t *urpf;
+
+    urpf = fib_urpf_list_get(ui);
+
+    return (vec_len(urpf->furpf_itfs));
+}
+
+#endif
diff --git a/src/vnet/fib/fib_walk.c b/src/vnet/fib/fib_walk.c
new file mode 100644
index 00000000000..938f7b8c1c6
--- /dev/null
+++ b/src/vnet/fib/fib_walk.c
@@ -0,0 +1,1108 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vnet/fib/fib_walk.h>
+#include <vnet/fib/fib_node_list.h>
+
+/**
+ * The flags on a walk
+ */
+typedef enum fib_walk_flags_t_
+{
+    /**
+     * A synchronous walk.
+     * This walk will run to completion, i.e. visit ALL the children.
+     * It is a depth first traversal of the graph.
+     */
+    FIB_WALK_FLAG_SYNC = (1 << 0),
+    /**
+     * An asynchronous walk.
+     * This walk will be scheduled to run in the background. It will thus visits
+     * the children at a later point in time.
+     * It is a depth first traversal of the graph.
+     */
+    FIB_WALK_FLAG_ASYNC = (1 << 1),
+    /**
+     * An indication that the walk is currently executing.
+     */
+    FIB_WALK_FLAG_EXECUTING = (1 << 2),
+} fib_walk_flags_t;
+
+/**
+ * A representation of a graph walk from a parent object to its children
+ */
+typedef struct fib_walk_t_
+{
+    /**
+     * FIB node linkage. This object is not in the FIB object graph,
+     * but it is present in other node's dependency lists, so it needs to
+     * be pointerable to.
+     */
+    fib_node_t fw_node;
+
+    /**
+     * the walk's flags
+     */
+    fib_walk_flags_t fw_flags;
+
+    /**
+     * Sibling index in the dependency list
+     */
+    u32 fw_dep_sibling;
+
+    /**
+     * Sibling index in the list of all walks
+     */
+    u32 fw_prio_sibling;
+
+    /**
+     * Pointer to the node whose dependants this walk is walking
+     */
+    fib_node_ptr_t fw_parent;
+
+    /**
+     * Number of nodes visited by this walk. saved for debugging purposes.
+     */
+    u32 fw_n_visits;
+
+    /**
+     * Time the walk started
+     */
+    f64 fw_start_time;
+
+    /**
+     * The reasons this walk is occuring.
+     * This is a vector ordered in time. The reasons and the front were started
+     * first, and so should be acted first when a node is visisted.
+     */
+    fib_node_back_walk_ctx_t *fw_ctx;
+} fib_walk_t;
+
+/**
+ * @brief The pool of all walk objects
+ */
+static fib_walk_t *fib_walk_pool;
+
+/**
+ * @brief There's only one event type sent to the walk process
+ */
+#define FIB_WALK_EVENT 0
+
+/**
+ * Statistics maintained per-walk queue
+ */
+typedef enum fib_walk_queue_stats_t_
+{
+    FIB_WALK_SCHEDULED,
+    FIB_WALK_COMPLETED,
+} fib_walk_queue_stats_t;
+#define FIB_WALK_QUEUE_STATS_NUM ((fib_walk_queue_stats_t)(FIB_WALK_COMPLETED+1))
+
+#define FIB_WALK_QUEUE_STATS {           \
+    [FIB_WALK_SCHEDULED] = "scheduled",  \
+    [FIB_WALK_COMPLETED] = "completed",  \
+}
+
+#define FOR_EACH_FIB_WALK_QUEUE_STATS(_wqs)   \
+    for ((_wqs) = FIB_WALK_SCHEDULED;         \
+	 (_wqs) < FIB_WALK_QUEUE_STATS_NUM;   \
+	 (_wqs)++)
+
+/**
+ * The names of the walk stats
+ */
+static const char * const fib_walk_queue_stats_names[] = FIB_WALK_QUEUE_STATS;
+/**
+ * The names of the walk reasons
+ */
+static const char * const fib_node_bw_reason_names[] = FIB_NODE_BW_REASONS;
+
+/**
+ * A represenation of one queue of walk
+ */
+typedef struct fib_walk_queue_t_
+{
+    /**
+     * Qeuee stats
+     */
+    u64 fwq_stats[FIB_WALK_QUEUE_STATS_NUM];
+
+    /**
+     * The node list which acts as the queue
+     */
+    fib_node_list_t fwq_queue;
+} fib_walk_queue_t;
+
+/**
+ * A set of priority queues for outstanding walks
+ */
+typedef struct fib_walk_queues_t_
+{
+    fib_walk_queue_t fwqs_queues[FIB_WALK_PRIORITY_NUM];
+} fib_walk_queues_t;
+
+/**
+ * The global queues of outstanding walks
+ */
+static fib_walk_queues_t fib_walk_queues;
+
+/**
+ * The names of the walk priorities
+ */
+static const char * const fib_walk_priority_names[] = FIB_WALK_PRIORITIES;
+
+/**
+ * @brief Histogram stats on the lenths of each walk in elemenets visisted.
+ * Store upto 1<<23 elements in increments of 1<<10
+ */
+#define HISTOGRAM_VISITS_PER_WALK_MAX (1<<23)
+#define HISTOGRAM_VISITS_PER_WALK_INCR (1<<10)
+#define HISTOGRAM_VISITS_PER_WALK_N_BUCKETS \
+    (HISTOGRAM_VISITS_PER_WALK_MAX/HISTOGRAM_VISITS_PER_WALK_INCR)
+static u64 fib_walk_hist_vists_per_walk[HISTOGRAM_VISITS_PER_WALK_N_BUCKETS];
+
+/**
+ * @brief History of state for the last 128 walks
+ */
+#define HISTORY_N_WALKS 128
+#define MAX_HISTORY_REASONS 16
+static u32 history_last_walk_pos;
+typedef struct fib_walk_history_t_ {
+    u32 fwh_n_visits;
+    f64 fwh_duration;
+    f64 fwh_completed;
+    fib_node_ptr_t fwh_parent;
+    fib_walk_flags_t fwh_flags;
+    fib_node_bw_reason_flag_t fwh_reason[MAX_HISTORY_REASONS];
+} fib_walk_history_t;
+static fib_walk_history_t fib_walk_history[HISTORY_N_WALKS];
+
+u8*
+format_fib_walk_priority (u8 *s, va_list ap)
+{
+    fib_walk_priority_t prio = va_arg(ap, fib_walk_priority_t);
+
+    ASSERT(prio < FIB_WALK_PRIORITY_NUM);
+
+    return (format(s, "%s", fib_walk_priority_names[prio]));
+}
+static u8*
+format_fib_walk_queue_stats (u8 *s, va_list ap)
+{
+    fib_walk_queue_stats_t wqs = va_arg(ap, fib_walk_queue_stats_t);
+
+    ASSERT(wqs < FIB_WALK_QUEUE_STATS_NUM);
+
+    return (format(s, "%s", fib_walk_queue_stats_names[wqs]));
+}
+
+static index_t
+fib_walk_get_index (fib_walk_t *fwalk)
+{
+    return (fwalk - fib_walk_pool);
+}
+
+static fib_walk_t *
+fib_walk_get (index_t fwi)
+{
+    return (pool_elt_at_index(fib_walk_pool, fwi));
+}
+
+/*
+ * not static so it can be used in the unit tests
+ */
+u32
+fib_walk_queue_get_size (fib_walk_priority_t prio)
+{
+    return (fib_node_list_get_size(fib_walk_queues.fwqs_queues[prio].fwq_queue));
+}
+
+static fib_node_index_t
+fib_walk_queue_get_front (fib_walk_priority_t prio)
+{
+    fib_node_ptr_t wp;
+
+    fib_node_list_get_front(fib_walk_queues.fwqs_queues[prio].fwq_queue, &wp);
+
+    return (wp.fnp_index);
+}
+
+static void
+fib_walk_destroy (fib_walk_t *fwalk)
+{
+    u32 bucket, ii;
+
+    if (FIB_NODE_INDEX_INVALID != fwalk->fw_prio_sibling)
+    {
+	fib_node_list_elt_remove(fwalk->fw_prio_sibling);
+    }
+    fib_node_child_remove(fwalk->fw_parent.fnp_type,
+			  fwalk->fw_parent.fnp_index,
+			  fwalk->fw_dep_sibling);
+
+    /*
+     * add the stats to the continuous histogram collection.
+     */
+    bucket = (fwalk->fw_n_visits / HISTOGRAM_VISITS_PER_WALK_INCR);
+    bucket = (bucket >= HISTOGRAM_VISITS_PER_WALK_N_BUCKETS ?
+	      HISTOGRAM_VISITS_PER_WALK_N_BUCKETS - 1 :
+	      bucket);
+    fib_walk_hist_vists_per_walk[bucket]++;
+
+    /*
+     * save stats to the recent history
+     */
+
+    fib_walk_history[history_last_walk_pos].fwh_n_visits =
+	fwalk->fw_n_visits;
+    fib_walk_history[history_last_walk_pos].fwh_completed =
+	vlib_time_now(vlib_get_main());
+    fib_walk_history[history_last_walk_pos].fwh_duration =
+	fib_walk_history[history_last_walk_pos].fwh_completed -
+        fwalk->fw_start_time;
+    fib_walk_history[history_last_walk_pos].fwh_parent =
+	fwalk->fw_parent;
+    fib_walk_history[history_last_walk_pos].fwh_flags =
+	fwalk->fw_flags;
+
+    vec_foreach_index(ii, fwalk->fw_ctx)
+    {
+        if (ii < MAX_HISTORY_REASONS)
+        {
+            fib_walk_history[history_last_walk_pos].fwh_reason[ii] =
+                fwalk->fw_ctx[ii].fnbw_reason;
+        }
+    }
+
+    history_last_walk_pos = (history_last_walk_pos + 1) % HISTORY_N_WALKS;
+
+    fib_node_deinit(&fwalk->fw_node);
+    vec_free(fwalk->fw_ctx);
+    pool_put(fib_walk_pool, fwalk);
+}
+
+/**
+ * return code when advancing a walk
+ */
+typedef enum fib_walk_advance_rc_t_
+{
+    /**
+     * The walk is complete
+     */
+    FIB_WALK_ADVANCE_DONE,
+    /**
+     * the walk has more work
+     */
+    FIB_WALK_ADVANCE_MORE,
+    /**
+     * The walk merged with the one in front
+     */
+    FIB_WALK_ADVANCE_MERGE,
+} fib_walk_advance_rc_t;
+
+/**
+ * @brief Advance the walk one element in its work list
+ */
+static fib_walk_advance_rc_t
+fib_walk_advance (fib_node_index_t fwi)
+{
+    fib_node_back_walk_ctx_t *ctx, *old;
+    fib_node_back_walk_rc_t wrc;
+    fib_node_ptr_t sibling;
+    fib_walk_t *fwalk;
+    int more_elts;
+
+    /*
+     * this walk function is re-entrant - walks acan spawn walks.
+     * fib_walk_t objects come from a pool, so they can realloc. we need
+     * to retch from said pool at the appropriate times.
+     */
+    fwalk = fib_walk_get(fwi);
+
+    more_elts = fib_node_list_elt_get_next(fwalk->fw_dep_sibling, &sibling);
+
+    if (more_elts)
+    {
+        old = fwalk->fw_ctx;
+
+	vec_foreach(ctx, fwalk->fw_ctx)
+	{
+	    wrc = fib_node_back_walk_one(&sibling, ctx);
+
+	    fwalk = fib_walk_get(fwi);
+	    fwalk->fw_n_visits++;
+
+	    if (FIB_NODE_BACK_WALK_MERGE == wrc)
+	    {
+		/*
+		 * this walk has merged with the one further along the node's
+		 * dependecy list.
+		 */
+		return (FIB_WALK_ADVANCE_MERGE);
+	    }
+            if (old != fwalk->fw_ctx)
+            {
+                /*
+                 * nasty re-entrant addition of a walk has realloc'd the vector
+                 * break out
+                 */
+		return (FIB_WALK_ADVANCE_MERGE);
+	    }
+	}
+	/*
+	 * move foward to the next node to visit
+	 */
+	more_elts = fib_node_list_advance(fwalk->fw_dep_sibling);
+    }
+
+    if (more_elts)
+    {
+	return (FIB_WALK_ADVANCE_MORE);
+    }
+
+    return (FIB_WALK_ADVANCE_DONE);
+}
+
+/**
+ * @breif Enurmerate the times of sleep between walks
+ */
+typedef enum fib_walk_sleep_type_t_
+{
+    FIB_WALK_SHORT_SLEEP,
+    FIB_WALK_LONG_SLEEP,
+} fib_walk_sleep_type_t;
+
+#define FIB_WALK_N_SLEEP (FIB_WALK_LONG_SLEEP+1)
+
+/**
+ * @brief Durations for the sleep types
+ */
+static f64 fib_walk_sleep_duration[] = {
+    [FIB_WALK_LONG_SLEEP] = 1e-3,
+    [FIB_WALK_SHORT_SLEEP] = 1e-8,
+};
+
+/**
+ * @brief The time quota for a walk. When more than this amount of time is
+ * spent, the walk process will yield.
+ */
+static f64 quota = 1e-4;
+
+/**
+ * Histogram on the amount of work done (in msecs) in each walk
+ */
+#define N_TIME_BUCKETS 128
+#define TIME_INCREMENTS (N_TIME_BUCKETS/2)
+static u64 fib_walk_work_time_taken[N_TIME_BUCKETS];
+
+/**
+ * Histogram on the number of nodes visted in each quota
+ */
+#define N_ELTS_BUCKETS 128
+static u32 fib_walk_work_nodes_visisted_incr = 2;
+static u64 fib_walk_work_nodes_visited[N_ELTS_BUCKETS];
+
+/**
+ * Histogram of the sleep lengths
+ */
+static u64 fib_walk_sleep_lengths[2];
+
+/**
+ * @brief Service the queues
+ * This is not declared static so that it can be unit tested - i know i know...
+ */
+f64
+fib_walk_process_queues (vlib_main_t * vm,
+			 const f64 quota)
+{
+    f64 start_time, consumed_time;
+    fib_walk_sleep_type_t sleep;
+    fib_walk_priority_t prio;
+    fib_walk_advance_rc_t rc;
+    fib_node_index_t fwi;
+    fib_walk_t *fwalk;
+    u32 n_elts;
+    i32 bucket;
+
+    consumed_time = 0;
+    start_time = vlib_time_now(vm);
+    n_elts = 0;
+
+    FOR_EACH_FIB_WALK_PRIORITY(prio)
+    {
+	while (0 != fib_walk_queue_get_size(prio))
+	{
+	    fwi = fib_walk_queue_get_front(prio);
+
+	    /*
+	     * set this walk as executing
+	     */
+	    fwalk = fib_walk_get(fwi);
+	    fwalk->fw_flags |= FIB_WALK_FLAG_EXECUTING;
+
+	    do
+	    {
+		rc = fib_walk_advance(fwi);
+		n_elts++;
+		consumed_time = (vlib_time_now(vm) - start_time);
+	    } while ((consumed_time < quota) &&
+		     (FIB_WALK_ADVANCE_MORE == rc));
+
+	    /*
+	     * if this walk has no more work then pop it from the queue
+	     * and move on to the next.
+	     */
+	    if (FIB_WALK_ADVANCE_MORE != rc)
+	    {
+		fwalk = fib_walk_get(fwi);
+		fib_walk_destroy(fwalk);
+		fib_walk_queues.fwqs_queues[prio].fwq_stats[FIB_WALK_COMPLETED]++;
+	    }
+	    else
+	    {
+		/*
+		 * passed our work quota. sleep time.
+		 */
+		fwalk = fib_walk_get(fwi);
+		fwalk->fw_flags &= ~FIB_WALK_FLAG_EXECUTING;
+		sleep = FIB_WALK_SHORT_SLEEP;
+		goto that_will_do_for_now;
+	    }
+	}
+    }
+    /*
+     * got to the end of all the work
+     */
+    sleep = FIB_WALK_LONG_SLEEP;
+
+that_will_do_for_now:
+
+    /*
+     * collect the stats:
+     *  - for the number of nodes visisted we store 128 increments
+     *  - for the time consumed we store quota/TIME_INCREMENTS increments.
+     */
+    bucket = ((n_elts/fib_walk_work_nodes_visisted_incr) > N_ELTS_BUCKETS ?
+	      N_ELTS_BUCKETS-1 :
+	      n_elts/fib_walk_work_nodes_visisted_incr);
+    ++fib_walk_work_nodes_visited[bucket];
+
+    bucket = (consumed_time - quota) / (quota / TIME_INCREMENTS);
+    bucket += N_TIME_BUCKETS/2;
+    bucket = (bucket < 0 ? 0 : bucket);
+    bucket = (bucket > N_TIME_BUCKETS-1 ? N_TIME_BUCKETS-1 : bucket);
+    ++fib_walk_work_time_taken[bucket];
+
+    ++fib_walk_sleep_lengths[sleep];
+
+    return (fib_walk_sleep_duration[sleep]);
+}
+
+/**
+ * @brief The 'fib-walk' process's main loop.
+ */
+static uword
+fib_walk_process (vlib_main_t * vm,
+		  vlib_node_runtime_t * node,
+		  vlib_frame_t * f)
+{
+    f64 sleep_time;
+
+    sleep_time = fib_walk_sleep_duration[FIB_WALK_SHORT_SLEEP];
+
+    while (1)
+    {
+	vlib_process_wait_for_event_or_clock(vm, sleep_time);
+
+	/*
+	 * there may be lots of event queued between the processes,
+	 * but the walks we want to schedule are in the priority queues,
+	 * so we ignore the process events.
+	 */
+	vlib_process_get_events(vm, NULL);
+
+	sleep_time = fib_walk_process_queues(vm, quota);
+    }
+
+    /*
+     * Unreached
+     */
+    ASSERT(!"WTF");
+    return 0;
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (fib_walk_process_node,static) = {
+    .function = fib_walk_process,
+    .type = VLIB_NODE_TYPE_PROCESS,
+    .name = "fib-walk",
+};
+/* *INDENT-ON* */
+
+/**
+ * @brief Allocate a new walk object
+ */
+static fib_walk_t *
+fib_walk_alloc (fib_node_type_t parent_type,
+		fib_node_index_t parent_index,
+		fib_walk_flags_t flags,
+		fib_node_back_walk_ctx_t *ctx)
+{
+    fib_walk_t *fwalk;
+
+    pool_get(fib_walk_pool, fwalk);
+
+    fib_node_init(&fwalk->fw_node, FIB_NODE_TYPE_WALK);
+
+    fwalk->fw_flags = flags;
+    fwalk->fw_dep_sibling  = FIB_NODE_INDEX_INVALID;
+    fwalk->fw_prio_sibling = FIB_NODE_INDEX_INVALID;
+    fwalk->fw_parent.fnp_index = parent_index;
+    fwalk->fw_parent.fnp_type = parent_type;
+    fwalk->fw_ctx = NULL;
+    fwalk->fw_start_time = vlib_time_now(vlib_get_main());
+    fwalk->fw_n_visits = 0;
+
+    /*
+     * make a copy of the backwalk context so the depth count remains
+     * the same for each sibling visitsed. This is important in the case
+     * where a parent has a loop via one child, but all the others are not.
+     * if the looped child were visited first, the depth count would exceed, the
+     * max and the walk would terminate before it reached the other siblings.
+     */
+    vec_add1(fwalk->fw_ctx, *ctx);
+
+    return (fwalk);
+}
+
+/**
+ * @brief Enqueue a walk onto the appropriate priority queue. Then signal
+ * the background process there is work to do.
+ */
+static index_t
+fib_walk_prio_queue_enquue (fib_walk_priority_t prio,
+			    fib_walk_t *fwalk)
+{
+    index_t sibling;
+
+    sibling = fib_node_list_push_front(fib_walk_queues.fwqs_queues[prio].fwq_queue,
+				       0,
+				       FIB_NODE_TYPE_WALK,
+				       fib_walk_get_index(fwalk));
+    fib_walk_queues.fwqs_queues[prio].fwq_stats[FIB_WALK_SCHEDULED]++;
+
+    /*
+     * poke the fib-walk process to perform the async walk.
+     * we are not passing it specific data, hence the last two args,
+     * the process will drain the queues
+     */
+    vlib_process_signal_event(vlib_get_main(),
+			      fib_walk_process_node.index,
+			      FIB_WALK_EVENT,
+			      FIB_WALK_EVENT);
+
+    return (sibling);
+}
+
+void
+fib_walk_async (fib_node_type_t parent_type,
+		fib_node_index_t parent_index,
+		fib_walk_priority_t prio,
+		fib_node_back_walk_ctx_t *ctx)
+{
+    fib_walk_t *fwalk;
+
+    if (FIB_NODE_GRAPH_MAX_DEPTH < ++ctx->fnbw_depth)
+    {
+	/*
+	 * The walk has reached the maximum depth. there is a loop in the graph.
+	 * bail.
+	 */
+	return;
+    }
+    if (0 == fib_node_get_n_children(parent_type,
+                                     parent_index))
+    {
+        /*
+         * no children to walk - quit now
+         */
+        return;
+    }
+    if (ctx->fnbw_flags & FIB_NODE_BW_FLAG_FORCE_SYNC)
+    {
+        /*
+         * the originator of the walk wanted it to be synchronous, but the
+         * parent object chose async - denied.
+         */
+        return (fib_walk_sync(parent_type, parent_index, ctx));
+    }
+
+
+    fwalk = fib_walk_alloc(parent_type,
+			   parent_index,
+			   FIB_WALK_FLAG_ASYNC,
+			   ctx);
+
+    fwalk->fw_dep_sibling = fib_node_child_add(parent_type,
+					       parent_index,
+					       FIB_NODE_TYPE_WALK,
+					       fib_walk_get_index(fwalk));
+
+    fwalk->fw_prio_sibling = fib_walk_prio_queue_enquue(prio, fwalk);
+}
+
+/**
+ * @brief Back walk all the children of a FIB node.
+ *
+ * note this is a synchronous depth first walk. Children visited may propagate
+ * the walk to thier children. Other children node types may not propagate,
+ * synchronously but instead queue the walk for later async completion.
+ */
+void
+fib_walk_sync (fib_node_type_t parent_type,
+	       fib_node_index_t parent_index,
+	       fib_node_back_walk_ctx_t *ctx)
+{
+    fib_walk_advance_rc_t rc;
+    fib_node_index_t fwi;
+    fib_walk_t *fwalk;
+
+    if (FIB_NODE_GRAPH_MAX_DEPTH < ++ctx->fnbw_depth)
+    {
+	/*
+	 * The walk has reached the maximum depth. there is a loop in the graph.
+	 * bail.
+	 */
+	return;
+    }
+    if (0 == fib_node_get_n_children(parent_type,
+                                     parent_index))
+    {
+        /*
+         * no children to walk - quit now
+         */
+        return;
+    }
+
+    fwalk = fib_walk_alloc(parent_type,
+			   parent_index,
+			   FIB_WALK_FLAG_SYNC,
+			   ctx);
+
+    fwalk->fw_dep_sibling = fib_node_child_add(parent_type,
+					       parent_index,
+					       FIB_NODE_TYPE_WALK,
+					       fib_walk_get_index(fwalk));
+    fwi = fib_walk_get_index(fwalk);
+
+    while (1)
+    {
+	/*
+	 * set this walk as executing
+	 */
+	fwalk->fw_flags |= FIB_WALK_FLAG_EXECUTING;
+
+	do
+	{
+	    rc = fib_walk_advance(fwi);
+	} while (FIB_WALK_ADVANCE_MORE == rc);
+
+
+	/*
+	 * this walk function is re-entrant - walks can spawn walks.
+	 * fib_walk_t objects come from a pool, so they can realloc. we need
+	 * to re-fetch from said pool at the appropriate times.
+	 */
+	fwalk = fib_walk_get(fwi);
+
+	if (FIB_WALK_ADVANCE_MERGE == rc)
+	{
+	    /*
+	     * this sync walk merged with an walk in front.
+	     * by reqeusting a sync walk the client wanted all children walked,
+	     * so we ditch the walk object in hand and continue with the one
+	     * we merged into
+	     */
+	    fib_node_ptr_t merged_walk;
+
+	    fib_node_list_elt_get_next(fwalk->fw_dep_sibling, &merged_walk);
+
+	    ASSERT(FIB_NODE_INDEX_INVALID != merged_walk.fnp_index);
+	    ASSERT(FIB_NODE_TYPE_WALK == merged_walk.fnp_type);
+
+	    fib_walk_destroy(fwalk);
+
+	    fwi = merged_walk.fnp_index;
+	    fwalk = fib_walk_get(fwi);
+
+	    if (FIB_WALK_FLAG_EXECUTING & fwalk->fw_flags)
+	    {
+		/*
+		 * we are executing a sync walk, and we have met with another
+		 * walk that is also executing. since only one walk executs at once
+		 * (there is no multi-threading) this implies we have met ourselves
+		 * and hence the is a loop in the graph.
+		 * This function is re-entrant, so the walk object we met is being
+		 * acted on in a stack frame below this one. We must therefore not
+		 * continue with it now, but let the stack unwind and along the
+		 * appropriate frame to read the depth count and bail.
+		 */
+		fwalk = NULL;
+		break;
+	    }
+	}
+	else
+	{
+	    /*
+	     * the walk reached the end of the depdency list.
+	     */
+	    break;
+	}
+    }
+
+    if (NULL != fwalk)
+    {
+	fib_walk_destroy(fwalk);
+    }
+}
+
+static fib_node_t *
+fib_walk_get_node (fib_node_index_t index)
+{
+    fib_walk_t *fwalk;
+
+    fwalk = fib_walk_get(index);
+
+    return (&(fwalk->fw_node));
+}
+
+/**
+ * Walk objects are not parents, nor are they locked.
+ * are no-ops
+ */
+static void
+fib_walk_last_lock_gone (fib_node_t *node)
+{
+    ASSERT(0);
+}
+
+static fib_walk_t*
+fib_walk_get_from_node (fib_node_t *node)
+{
+    return ((fib_walk_t*)(((char*)node) -
+			  STRUCT_OFFSET_OF(fib_walk_t, fw_node)));
+}
+
+/**
+ * @brief Another back walk has reach this walk.
+ * Megre them so there is only one left. It is this node being
+ * visited that will remain, so copy or merge the context onto it.
+ */
+static fib_node_back_walk_rc_t
+fib_walk_back_walk_notify (fib_node_t *node,
+			   fib_node_back_walk_ctx_t *ctx)
+{
+    fib_node_back_walk_ctx_t *last;
+    fib_walk_t *fwalk;
+
+    fwalk = fib_walk_get_from_node(node);
+
+    /*
+     * check whether the walk context can be merged with the most recent.
+     * the most recent was the one last added and is thus at the back of the vector.
+     * we can merge walks if the reason for the walk is the same.
+     */
+    last = vec_end(fwalk->fw_ctx) - 1;
+
+    if (last->fnbw_reason == ctx->fnbw_reason)
+    {
+        /*
+         * copy the largest of the depth values. in the presence of a loop,
+         * the same walk will merge with itself. if we take the smaller depth
+         * then it will never end.
+         */
+        last->fnbw_depth = ((last->fnbw_depth >= ctx->fnbw_depth) ?
+                            last->fnbw_depth :
+                            ctx->fnbw_depth);
+    }
+    else
+    {
+        /*
+         * walks could not be merged, this means that the walk infront needs to
+         * perform different action to this one that has caught up. the one in
+         * front was scheduled first so append the new walk context to the back
+         * of the list.
+         */
+        vec_add1(fwalk->fw_ctx, *ctx);
+    }
+
+    return (FIB_NODE_BACK_WALK_MERGE);
+}
+
+/**
+ * The FIB walk's graph node virtual function table
+ */
+static const fib_node_vft_t fib_walk_vft = {
+    .fnv_get = fib_walk_get_node,
+    .fnv_last_lock = fib_walk_last_lock_gone,
+    .fnv_back_walk = fib_walk_back_walk_notify,
+};
+
+void
+fib_walk_module_init (void)
+{
+    fib_walk_priority_t prio;
+
+    FOR_EACH_FIB_WALK_PRIORITY(prio)
+    {
+	fib_walk_queues.fwqs_queues[prio].fwq_queue = fib_node_list_create();
+    }
+
+    fib_node_register_type(FIB_NODE_TYPE_WALK, &fib_walk_vft);
+}
+
+static u8*
+format_fib_walk (u8* s, va_list ap)
+{
+    fib_node_index_t fwi = va_arg(ap, fib_node_index_t);
+    fib_walk_t *fwalk;
+
+    fwalk = fib_walk_get(fwi);
+
+    return (format(s, "  parent:{%s:%d} visits:%d flags:%d",
+		   fib_node_type_get_name(fwalk->fw_parent.fnp_type),
+		   fwalk->fw_parent.fnp_index,
+		   fwalk->fw_n_visits,
+		   fwalk->fw_flags));
+}
+
+static clib_error_t *
+fib_walk_show (vlib_main_t * vm,
+	       unformat_input_t * input,
+	       vlib_cli_command_t * cmd)
+{
+    fib_walk_queue_stats_t wqs;
+    fib_walk_priority_t prio;
+    fib_node_ptr_t sibling;
+    fib_node_index_t fwi;
+    fib_walk_t *fwalk;
+    int more_elts, ii;
+    u8 *s = NULL;
+
+#define USEC 1000000
+    vlib_cli_output(vm, "FIB Walk Quota = %.2fusec:", quota * USEC);
+    vlib_cli_output(vm, "FIB Walk queues:");
+
+    FOR_EACH_FIB_WALK_PRIORITY(prio)
+    {
+	vlib_cli_output(vm, " %U priority queue:",
+			format_fib_walk_priority, prio);
+	vlib_cli_output(vm, "  Stats: ");
+
+	FOR_EACH_FIB_WALK_QUEUE_STATS(wqs)
+	{
+	    vlib_cli_output(vm, "    %U:%d",
+			    format_fib_walk_queue_stats, wqs,
+			    fib_walk_queues.fwqs_queues[prio].fwq_stats[wqs]);
+	}
+	vlib_cli_output(vm, "  Occupancy:%d",
+			fib_node_list_get_size(
+			    fib_walk_queues.fwqs_queues[prio].fwq_queue));
+
+	more_elts = fib_node_list_get_front(
+			fib_walk_queues.fwqs_queues[prio].fwq_queue,
+			&sibling);
+
+	while (more_elts)
+	{
+	    ASSERT(FIB_NODE_INDEX_INVALID != sibling.fnp_index);
+	    ASSERT(FIB_NODE_TYPE_WALK == sibling.fnp_type);
+
+	    fwi = sibling.fnp_index;
+	    fwalk = fib_walk_get(fwi);
+
+	    vlib_cli_output(vm, "  %U", format_fib_walk, fwi);
+
+	    more_elts = fib_node_list_elt_get_next(fwalk->fw_prio_sibling,
+						   &sibling);
+	}
+    }
+
+    vlib_cli_output(vm, "Histogram Statistics:");
+    vlib_cli_output(vm, " Number of Elements visit per-quota:");
+    for (ii = 0; ii < N_ELTS_BUCKETS; ii++)
+    {
+	if (0 != fib_walk_work_nodes_visited[ii])
+	    s = format(s, "%d:%d ",
+		       (ii * fib_walk_work_nodes_visisted_incr),
+		       fib_walk_work_nodes_visited[ii]);
+    }
+    vlib_cli_output(vm, "  %v", s);
+    vec_free(s);
+
+    vlib_cli_output(vm, " Time consumed per-quota (Quota=%f usec):", quota*USEC);
+    s = format(s, "0:%d ", fib_walk_work_time_taken[0]);
+    for (ii = 1; ii < N_TIME_BUCKETS; ii++)
+    {
+	if (0 != fib_walk_work_time_taken[ii])
+	    s = format(s, "%d:%d ", (u32)((((ii - N_TIME_BUCKETS/2) *
+					   (quota / TIME_INCREMENTS)) + quota) *
+					 USEC),
+		       fib_walk_work_time_taken[ii]);
+    }
+    vlib_cli_output(vm, "  %v", s);
+    vec_free(s);
+
+    vlib_cli_output(vm, " Sleep Types:");
+    vlib_cli_output(vm, "  Short  Long:");
+    vlib_cli_output(vm, "  %d %d:",
+		    fib_walk_sleep_lengths[FIB_WALK_SHORT_SLEEP],
+		    fib_walk_sleep_lengths[FIB_WALK_LONG_SLEEP]);
+
+    vlib_cli_output(vm, " Number of Elements visited per-walk:");
+    for (ii = 0; ii < HISTOGRAM_VISITS_PER_WALK_N_BUCKETS; ii++)
+    {
+	if (0 != fib_walk_hist_vists_per_walk[ii])
+	    s = format(s, "%d:%d ",
+		       ii*HISTOGRAM_VISITS_PER_WALK_INCR,
+		       fib_walk_hist_vists_per_walk[ii]);
+    }
+    vlib_cli_output(vm, "  %v", s);
+    vec_free(s);
+
+
+    vlib_cli_output(vm, "Brief History (last %d walks):", HISTORY_N_WALKS);
+    ii = history_last_walk_pos - 1;
+    if (ii < 0)
+        ii = HISTORY_N_WALKS - 1;
+
+    while (ii != history_last_walk_pos)
+    {
+	if (0 != fib_walk_history[ii].fwh_reason[0])
+	{
+            fib_node_back_walk_reason_t reason;
+            u8 *s = NULL;
+            u32 jj;
+
+	    s = format(s, "[@%d]: %s:%d visits:%d duration:%.2f completed:%.2f ",
+                       ii, fib_node_type_get_name(fib_walk_history[ii].fwh_parent.fnp_type),
+                       fib_walk_history[ii].fwh_parent.fnp_index,
+                       fib_walk_history[ii].fwh_n_visits,
+                       fib_walk_history[ii].fwh_duration,
+                       fib_walk_history[ii].fwh_completed);
+            if (FIB_WALK_FLAG_SYNC & fib_walk_history[ii].fwh_flags)
+                s = format(s, "sync, ");
+            if (FIB_WALK_FLAG_ASYNC & fib_walk_history[ii].fwh_flags)
+                s = format(s, "async, ");
+
+            s = format(s, "reason:");
+            jj = 0;
+            while (0 != fib_walk_history[ii].fwh_reason[jj])
+            {
+                FOR_EACH_FIB_NODE_BW_REASON(reason) {
+                    if ((1<<reason) & fib_walk_history[ii].fwh_reason[jj]) {
+                        s = format (s, "%s,", fib_node_bw_reason_names[reason]);
+                    }
+                }
+                jj++;
+            }
+            vlib_cli_output(vm, "%v", s);
+	}
+
+        ii--;
+        if (ii < 0)
+            ii = HISTORY_N_WALKS - 1;
+    }
+
+    return (NULL);
+}
+
+VLIB_CLI_COMMAND (fib_walk_show_command, static) = {
+    .path = "show fib walk",
+    .short_help = "show fib walk",
+    .function = fib_walk_show,
+};
+
+static clib_error_t *
+fib_walk_set_quota (vlib_main_t * vm,
+		    unformat_input_t * input,
+		    vlib_cli_command_t * cmd)
+{
+    clib_error_t * error = NULL;
+    f64 new_quota;
+
+    if (unformat (input, "%f", &new_quota))
+    {
+	quota = new_quota;
+    }
+    else
+    {
+	error = clib_error_return(0 , "Pass a float value");
+    }
+
+    return (error);
+}
+
+VLIB_CLI_COMMAND (fib_walk_set_quota_command, static) = {
+    .path = "set fib walk quota",
+    .short_help = "set fib walk quota",
+    .function = fib_walk_set_quota,
+};
+
+static clib_error_t *
+fib_walk_set_histogram_elements_size (vlib_main_t * vm,
+				      unformat_input_t * input,
+				      vlib_cli_command_t * cmd)
+{
+    clib_error_t * error = NULL;
+    u32 new;
+
+    if (unformat (input, "%d", &new))
+    {
+	fib_walk_work_nodes_visisted_incr = new;
+    }
+    else
+    {
+	error = clib_error_return(0 , "Pass an int value");
+    }
+
+    return (error);
+}
+
+VLIB_CLI_COMMAND (fib_walk_set_histogram_elements_size_command, static) = {
+    .path = "set fib walk histogram elements size",
+    .short_help = "set fib walk histogram elements size",
+    .function = fib_walk_set_histogram_elements_size,
+};
+
+static clib_error_t *
+fib_walk_clear (vlib_main_t * vm,
+		unformat_input_t * input,
+		vlib_cli_command_t * cmd)
+{
+    memset(fib_walk_hist_vists_per_walk, 0, sizeof(fib_walk_hist_vists_per_walk));
+    memset(fib_walk_history, 0, sizeof(fib_walk_history));
+    memset(fib_walk_work_time_taken, 0, sizeof(fib_walk_work_time_taken));
+    memset(fib_walk_work_nodes_visited, 0, sizeof(fib_walk_work_nodes_visited));
+    memset(fib_walk_sleep_lengths, 0, sizeof(fib_walk_sleep_lengths));
+
+    return (NULL);
+}
+
+VLIB_CLI_COMMAND (fib_walk_clear_command, static) = {
+    .path = "clear fib walk",
+    .short_help = "clear fib walk",
+    .function = fib_walk_clear,
+};
diff --git a/src/vnet/fib/fib_walk.h b/src/vnet/fib/fib_walk.h
new file mode 100644
index 00000000000..7413d8a2c78
--- /dev/null
+++ b/src/vnet/fib/fib_walk.h
@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __FIB_WALK_H__
+#define __FIB_WALK_H__
+
+#include <vnet/fib/fib_node.h>
+
+/**
+ * @brief Walk priorities.
+ * Strict priorities. All walks a priority n are completed before n+1 is started.
+ * Increasing numerical value implies decreasing priority.
+ */
+typedef enum fib_walk_priority_t_
+{
+    FIB_WALK_PRIORITY_HIGH = 0,
+    FIB_WALK_PRIORITY_LOW  = 1,
+} fib_walk_priority_t;
+
+#define FIB_WALK_PRIORITY_NUM ((fib_walk_priority_t)(FIB_WALK_PRIORITY_LOW+1))
+
+#define FIB_WALK_PRIORITIES {           \
+    [FIB_WALK_PRIORITY_HIGH] = "high",  \
+    [FIB_WALK_PRIORITY_LOW]  = "low",   \
+}
+
+#define FOR_EACH_FIB_WALK_PRIORITY(_prio)         \
+    for ((_prio) = FIB_WALK_PRIORITY_HIGH;        \
+         (_prio) < FIB_WALK_PRIORITY_NUM;         \
+         (_prio)++)
+
+extern void fib_walk_module_init(void);
+
+extern void fib_walk_async(fib_node_type_t parent_type,
+                           fib_node_index_t parent_index,
+                           fib_walk_priority_t prio,
+                           fib_node_back_walk_ctx_t *ctx);
+
+extern void fib_walk_sync(fib_node_type_t parent_type,
+                          fib_node_index_t parent_index,
+                          fib_node_back_walk_ctx_t *ctx);
+
+extern u8* format_fib_walk_priority(u8 *s, va_list ap);
+
+#endif
+
diff --git a/src/vnet/fib/ip4_fib.c b/src/vnet/fib/ip4_fib.c
new file mode 100644
index 00000000000..f6ebce00837
--- /dev/null
+++ b/src/vnet/fib/ip4_fib.c
@@ -0,0 +1,664 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vnet/fib/fib_table.h>
+#include <vnet/fib/fib_entry.h>
+#include <vnet/fib/ip4_fib.h>
+
+/*
+ * A table of pefixes to be added to tables and the sources for them
+ */
+typedef struct ip4_fib_table_special_prefix_t_ {
+    fib_prefix_t ift_prefix;
+    fib_source_t ift_source;
+    fib_entry_flag_t ift_flag;
+} ip4_fib_table_special_prefix_t;
+
+static const ip4_fib_table_special_prefix_t ip4_specials[] = {
+    {
+	/* 0.0.0.0/0*/
+	.ift_prefix = {
+	    .fp_addr = {
+		.ip4.data_u32 = 0,
+	    },
+	    .fp_len  = 0,
+	    .fp_proto = FIB_PROTOCOL_IP4,
+	},
+	.ift_source = FIB_SOURCE_DEFAULT_ROUTE,
+	.ift_flag   = FIB_ENTRY_FLAG_DROP,
+    },
+    {
+	/* 0.0.0.0/32*/
+	.ift_prefix = {
+	    .fp_addr = {
+		.ip4.data_u32 = 0,
+	    },
+	    .fp_len  = 32,
+	    .fp_proto = FIB_PROTOCOL_IP4,
+	},
+	.ift_source = FIB_SOURCE_DEFAULT_ROUTE,
+	.ift_flag   = FIB_ENTRY_FLAG_DROP,
+    },
+    {
+	/*
+	 * 240.0.0.0/4
+	 * drop class E
+	 */
+	.ift_prefix = {
+	    .fp_addr = {
+		.ip4.data_u32 = 0xf0000000,
+	    },
+	    .fp_len   = 4,
+	    .fp_proto = FIB_PROTOCOL_IP4,
+	},
+	.ift_source = FIB_SOURCE_SPECIAL,
+	.ift_flag   = FIB_ENTRY_FLAG_DROP,
+
+    },
+    {
+	/*
+	 * 224.0.0.0/4
+	 * drop all mcast
+	 */
+	.ift_prefix = {
+	    .fp_addr = {
+		.ip4.data_u32 = 0xe0000000,
+	    },
+	    .fp_len   = 4,
+	    .fp_proto = FIB_PROTOCOL_IP4,
+	},
+	.ift_source = FIB_SOURCE_SPECIAL,
+	.ift_flag    = FIB_ENTRY_FLAG_DROP,
+    },
+    {
+	/*
+	 * 255.255.255.255/32
+	 * drop, but we'll allow it to be usurped by the likes of DHCP
+	 */
+	.ift_prefix = {
+	    .fp_addr = {
+		.ip4.data_u32 = 0xffffffff,
+	    },
+	    .fp_len   = 32,
+	    .fp_proto = FIB_PROTOCOL_IP4,
+	},
+	.ift_source = FIB_SOURCE_DEFAULT_ROUTE,
+	.ift_flag   = FIB_ENTRY_FLAG_DROP,
+    }
+};
+
+
+static u32
+ip4_create_fib_with_table_id (u32 table_id)
+{
+    fib_table_t *fib_table;
+
+    pool_get_aligned(ip4_main.fibs, fib_table, CLIB_CACHE_LINE_BYTES);
+    memset(fib_table, 0, sizeof(*fib_table));
+
+    fib_table->ft_proto = FIB_PROTOCOL_IP4;
+    fib_table->ft_index =
+	fib_table->v4.index =
+	    (fib_table - ip4_main.fibs);
+
+    hash_set (ip4_main.fib_index_by_table_id, table_id, fib_table->ft_index);
+
+    fib_table->ft_table_id =
+	fib_table->v4.table_id =
+	    table_id;
+    fib_table->ft_flow_hash_config = 
+	fib_table->v4.flow_hash_config =
+	    IP_FLOW_HASH_DEFAULT;
+    fib_table->v4.fwd_classify_table_index = ~0;
+    fib_table->v4.rev_classify_table_index = ~0;
+    
+    fib_table_lock(fib_table->ft_index, FIB_PROTOCOL_IP4);
+
+    ip4_mtrie_init(&fib_table->v4.mtrie);
+
+    /*
+     * add the special entries into the new FIB
+     */
+    int ii;
+
+    for (ii = 0; ii < ARRAY_LEN(ip4_specials); ii++)
+    {
+	fib_prefix_t prefix = ip4_specials[ii].ift_prefix;
+
+	prefix.fp_addr.ip4.data_u32 =
+	    clib_host_to_net_u32(prefix.fp_addr.ip4.data_u32);
+
+	fib_table_entry_special_add(fib_table->ft_index,
+				    &prefix,
+				    ip4_specials[ii].ift_source,
+				    ip4_specials[ii].ift_flag,
+				    ADJ_INDEX_INVALID);
+    }
+
+    return (fib_table->ft_index);
+}
+
+void
+ip4_fib_table_destroy (ip4_fib_t *fib)
+{
+    fib_table_t *fib_table = (fib_table_t*)fib;
+    int ii;
+
+    /*
+     * remove all the specials we added when the table was created.
+     */
+    for (ii = 0; ii < ARRAY_LEN(ip4_specials); ii++)
+    {
+	fib_prefix_t prefix = ip4_specials[ii].ift_prefix;
+
+	prefix.fp_addr.ip4.data_u32 =
+	    clib_host_to_net_u32(prefix.fp_addr.ip4.data_u32);
+
+	fib_table_entry_special_remove(fib_table->ft_index,
+				       &prefix,
+				       ip4_specials[ii].ift_source);
+    }
+
+    /*
+     * validate no more routes.
+     */
+    ASSERT(0 == fib_table->ft_total_route_counts);
+    FOR_EACH_FIB_SOURCE(ii)
+    {
+	ASSERT(0 == fib_table->ft_src_route_counts[ii]);
+    }
+
+    if (~0 != fib_table->ft_table_id)
+    {
+	hash_unset (ip4_main.fib_index_by_table_id, fib_table->ft_table_id);
+    }
+    pool_put(ip4_main.fibs, fib_table);
+}
+
+
+u32
+ip4_fib_table_find_or_create_and_lock (u32 table_id)
+{
+    u32 index;
+
+    index = ip4_fib_index_from_table_id(table_id);
+    if (~0 == index)
+	return ip4_create_fib_with_table_id(table_id);
+
+    fib_table_lock(index, FIB_PROTOCOL_IP4);
+
+    return (index);
+}
+
+u32
+ip4_fib_table_create_and_lock (void)
+{
+    return (ip4_create_fib_with_table_id(~0));
+}
+
+u32
+ip4_fib_table_get_index_for_sw_if_index (u32 sw_if_index)
+{
+    if (sw_if_index >= vec_len(ip4_main.fib_index_by_sw_if_index))
+    {
+	/*
+	 * This is the case for interfaces that are not yet mapped to
+	 * a IP table
+	 */
+	return (~0);
+    }
+    return (ip4_main.fib_index_by_sw_if_index[sw_if_index]);
+}
+
+flow_hash_config_t
+ip4_fib_table_get_flow_hash_config (u32 fib_index)
+{
+    return (ip4_fib_get(fib_index)->flow_hash_config);
+}
+
+/*
+ * ip4_fib_table_lookup_exact_match
+ *
+ * Exact match prefix lookup
+ */
+fib_node_index_t
+ip4_fib_table_lookup_exact_match (const ip4_fib_t *fib,
+				  const ip4_address_t *addr,
+				  u32 len)
+{
+    uword * hash, * result;
+    u32 key;
+
+    hash = fib->fib_entry_by_dst_address[len];
+    key  = (addr->data_u32 & ip4_main.fib_masks[len]);
+
+    result = hash_get(hash, key);
+
+    if (NULL != result) {
+	return (result[0]);
+    }
+    return (FIB_NODE_INDEX_INVALID);
+}
+
+/*
+ * ip4_fib_table_lookup_adj
+ *
+ * Longest prefix match
+ */
+index_t
+ip4_fib_table_lookup_lb (ip4_fib_t *fib,
+			 const ip4_address_t *addr)
+{
+    fib_node_index_t fei;
+
+    fei = ip4_fib_table_lookup(fib, addr, 32);
+
+    if (FIB_NODE_INDEX_INVALID != fei)
+    {
+	const dpo_id_t *dpo;
+
+	dpo = fib_entry_contribute_ip_forwarding(fei);
+
+	return (dpo->dpoi_index);
+    }
+    return (INDEX_INVALID);
+}
+
+/*
+ * ip4_fib_table_lookup
+ *
+ * Longest prefix match
+ */
+fib_node_index_t
+ip4_fib_table_lookup (const ip4_fib_t *fib,
+		      const ip4_address_t *addr,
+		      u32 len)
+{
+    uword * hash, * result;
+    i32 mask_len;
+    u32 key;
+
+    for (mask_len = len; mask_len >= 0; mask_len--)
+    {
+	hash = fib->fib_entry_by_dst_address[mask_len];
+	key = (addr->data_u32 & ip4_main.fib_masks[mask_len]);
+
+	result = hash_get (hash, key);
+
+	if (NULL != result) {
+	    return (result[0]);
+	}
+    }
+    return (FIB_NODE_INDEX_INVALID);
+}
+
+void
+ip4_fib_table_entry_insert (ip4_fib_t *fib,
+			    const ip4_address_t *addr,
+			    u32 len,
+			    fib_node_index_t fib_entry_index)
+{
+    uword * hash, * result;
+    u32 key;
+
+    key = (addr->data_u32 & ip4_main.fib_masks[len]);
+    hash = fib->fib_entry_by_dst_address[len];
+    result = hash_get (hash, key);
+
+    if (NULL == result) {
+	/*
+	 * adding a new entry
+	 */
+	if (NULL == hash) {
+	    hash = hash_create (32 /* elts */, sizeof (uword));
+	    hash_set_flags (hash, HASH_FLAG_NO_AUTO_SHRINK);
+	}
+	hash = hash_set(hash, key, fib_entry_index);
+	fib->fib_entry_by_dst_address[len] = hash;
+    }
+    else
+    {
+	ASSERT(0);
+    }
+}
+
+void
+ip4_fib_table_entry_remove (ip4_fib_t *fib,
+			    const ip4_address_t *addr,
+			    u32 len)
+{
+    uword * hash, * result;
+    u32 key;
+
+    key = (addr->data_u32 & ip4_main.fib_masks[len]);
+    hash = fib->fib_entry_by_dst_address[len];
+    result = hash_get (hash, key);
+
+    if (NULL == result)
+    {
+	/*
+	 * removing a non-existant entry. i'll allow it.
+	 */
+    }
+    else 
+    {
+	hash_unset(hash, key);
+    }
+
+    fib->fib_entry_by_dst_address[len] = hash;
+}
+
+void
+ip4_fib_table_fwding_dpo_update (ip4_fib_t *fib,
+				 const ip4_address_t *addr,
+				 u32 len,
+				 const dpo_id_t *dpo)
+{
+    ip4_fib_mtrie_add_del_route(fib, *addr, len, dpo->dpoi_index, 0); // ADD
+}
+
+void
+ip4_fib_table_fwding_dpo_remove (ip4_fib_t *fib,
+				 const ip4_address_t *addr,
+				 u32 len,
+				 const dpo_id_t *dpo)
+{
+    ip4_fib_mtrie_add_del_route(fib, *addr, len, dpo->dpoi_index, 1); // DELETE
+}
+
+static void
+ip4_fib_table_show_all (ip4_fib_t *fib,
+			vlib_main_t * vm)
+{
+    fib_node_index_t *fib_entry_indicies;
+    fib_node_index_t *fib_entry_index;
+    int i;
+
+    fib_entry_indicies = NULL;
+
+    for (i = 0; i < ARRAY_LEN (fib->fib_entry_by_dst_address); i++)
+    {
+	uword * hash = fib->fib_entry_by_dst_address[i];
+
+	if (NULL != hash)
+	{
+	    hash_pair_t * p;
+
+	    hash_foreach_pair (p, hash,
+	    ({
+		vec_add1(fib_entry_indicies, p->value[0]);
+	    }));
+	}
+    }
+
+    vec_sort_with_function(fib_entry_indicies, fib_entry_cmp_for_sort);
+
+    vec_foreach(fib_entry_index, fib_entry_indicies)
+    {
+	vlib_cli_output(vm, "%U",
+                        format_fib_entry,
+                        *fib_entry_index,
+                        FIB_ENTRY_FORMAT_BRIEF);
+    }
+
+    vec_free(fib_entry_indicies);
+}
+
+static void
+ip4_fib_table_show_one (ip4_fib_t *fib,
+			vlib_main_t * vm,
+			ip4_address_t *address,
+			u32 mask_len)
+{    
+    vlib_cli_output(vm, "%U",
+                    format_fib_entry,
+                    ip4_fib_table_lookup(fib, address, mask_len),
+                    FIB_ENTRY_FORMAT_DETAIL);
+}
+
+static clib_error_t *
+ip4_show_fib (vlib_main_t * vm,
+	      unformat_input_t * input,
+	      vlib_cli_command_t * cmd)
+{
+    ip4_main_t * im4 = &ip4_main;
+    fib_table_t * fib_table;
+    int verbose, matching, mtrie;
+    ip4_address_t matching_address;
+    u32 matching_mask = 32;
+    int i, table_id = -1, fib_index = ~0;
+
+    verbose = 1;
+    matching = 0;
+    mtrie = 0;
+    while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+    {
+	if (unformat (input, "brief") || unformat (input, "summary")
+	    || unformat (input, "sum"))
+	    verbose = 0;
+
+	else if (unformat (input, "mtrie"))
+	    mtrie = 1;
+
+	else if (unformat (input, "%U/%d",
+			   unformat_ip4_address, &matching_address, &matching_mask))
+	    matching = 1;
+
+	else if (unformat (input, "%U", unformat_ip4_address, &matching_address))
+	    matching = 1;
+
+	else if (unformat (input, "table %d", &table_id))
+	    ;
+	else if (unformat (input, "index %d", &fib_index))
+	    ;
+	else
+	    break;
+    }
+
+    pool_foreach (fib_table, im4->fibs,
+    ({
+	ip4_fib_t *fib = &fib_table->v4;
+
+	if (table_id >= 0 && table_id != (int)fib->table_id)
+	    continue;
+	if (fib_index != ~0 && fib_index != (int)fib->index)
+	    continue;
+
+	vlib_cli_output (vm, "%U, fib_index %d, flow hash: %U", 
+			 format_fib_table_name, fib->index, FIB_PROTOCOL_IP4,
+			 fib->index,
+			 format_ip_flow_hash_config, fib->flow_hash_config);
+
+	/* Show summary? */
+	if (! verbose)
+	{
+	    vlib_cli_output (vm, "%=20s%=16s", "Prefix length", "Count");
+	    for (i = 0; i < ARRAY_LEN (fib->fib_entry_by_dst_address); i++)
+	    {
+		uword * hash = fib->fib_entry_by_dst_address[i];
+		uword n_elts = hash_elts (hash);
+		if (n_elts > 0)
+		    vlib_cli_output (vm, "%20d%16d", i, n_elts);
+	    }
+	    continue;
+	}
+
+	if (!matching)
+	{
+	    ip4_fib_table_show_all(fib, vm);
+	}
+	else
+	{
+	    ip4_fib_table_show_one(fib, vm, &matching_address, matching_mask);
+	}
+
+	if (mtrie)
+	    vlib_cli_output (vm, "%U", format_ip4_fib_mtrie, &fib->mtrie);
+    }));
+
+    return 0;
+}
+
+/*?
+ * This command displays the IPv4 FIB Tables (VRF Tables) and the route
+ * entries for each table.
+ *
+ * @note This command will run for a long time when the FIB tables are
+ * comprised of millions of entries. For those senarios, consider displaying
+ * a single table or summary mode.
+ *
+ * @cliexpar
+ * Example of how to display all the IPv4 FIB tables:
+ * @cliexstart{show ip fib}
+ * ipv4-VRF:0, fib_index 0, flow hash: src dst sport dport proto
+ * 0.0.0.0/0
+ *   unicast-ip4-chain
+ *   [@0]: dpo-load-balance: [index:0 buckets:1 uRPF:0 to:[0:0]]
+ *     [0] [@0]: dpo-drop ip6
+ * 0.0.0.0/32
+ *   unicast-ip4-chain
+ *   [@0]: dpo-load-balance: [index:1 buckets:1 uRPF:1 to:[0:0]]
+ *     [0] [@0]: dpo-drop ip6
+ * 6.0.1.2/32
+ *   unicast-ip4-chain
+ *   [@0]: dpo-load-balance: [index:30 buckets:1 uRPF:29 to:[0:0]]
+ *     [0] [@3]: arp-ipv4: via 6.0.0.1 af_packet0
+ * 7.0.0.1/32
+ *   unicast-ip4-chain
+ *   [@0]: dpo-load-balance: [index:31 buckets:4 uRPF:30 to:[0:0]]
+ *     [0] [@3]: arp-ipv4: via 6.0.0.2 af_packet0
+ *     [1] [@3]: arp-ipv4: via 6.0.0.2 af_packet0
+ *     [2] [@3]: arp-ipv4: via 6.0.0.2 af_packet0
+ *     [3] [@3]: arp-ipv4: via 6.0.0.1 af_packet0
+ * 224.0.0.0/8
+ *   unicast-ip4-chain
+ *   [@0]: dpo-load-balance: [index:3 buckets:1 uRPF:3 to:[0:0]]
+ *     [0] [@0]: dpo-drop ip6
+ * 240.0.0.0/8
+ *   unicast-ip4-chain
+ *   [@0]: dpo-load-balance: [index:2 buckets:1 uRPF:2 to:[0:0]]
+ *     [0] [@0]: dpo-drop ip6
+ * 255.255.255.255/32
+ *   unicast-ip4-chain
+ *   [@0]: dpo-load-balance: [index:4 buckets:1 uRPF:4 to:[0:0]]
+ *     [0] [@0]: dpo-drop ip6
+ * ipv4-VRF:7, fib_index 1, flow hash: src dst sport dport proto
+ * 0.0.0.0/0
+ *   unicast-ip4-chain
+ *   [@0]: dpo-load-balance: [index:12 buckets:1 uRPF:11 to:[0:0]]
+ *     [0] [@0]: dpo-drop ip6
+ * 0.0.0.0/32
+ *   unicast-ip4-chain
+ *   [@0]: dpo-load-balance: [index:13 buckets:1 uRPF:12 to:[0:0]]
+ *     [0] [@0]: dpo-drop ip6
+ * 172.16.1.0/24
+ *   unicast-ip4-chain
+ *   [@0]: dpo-load-balance: [index:17 buckets:1 uRPF:16 to:[0:0]]
+ *     [0] [@4]: ipv4-glean: af_packet0
+ * 172.16.1.1/32
+ *   unicast-ip4-chain
+ *   [@0]: dpo-load-balance: [index:18 buckets:1 uRPF:17 to:[1:84]]
+ *     [0] [@2]: dpo-receive: 172.16.1.1 on af_packet0
+ * 172.16.1.2/32
+ *   unicast-ip4-chain
+ *   [@0]: dpo-load-balance: [index:21 buckets:1 uRPF:20 to:[0:0]]
+ *     [0] [@5]: ipv4 via 172.16.1.2 af_packet0: IP4: 02:fe:9e:70:7a:2b -> 26:a5:f6:9c:3a:36
+ * 172.16.2.0/24
+ *   unicast-ip4-chain
+ *   [@0]: dpo-load-balance: [index:19 buckets:1 uRPF:18 to:[0:0]]
+ *     [0] [@4]: ipv4-glean: af_packet1
+ * 172.16.2.1/32
+ *   unicast-ip4-chain
+ *   [@0]: dpo-load-balance: [index:20 buckets:1 uRPF:19 to:[0:0]]
+ *     [0] [@2]: dpo-receive: 172.16.2.1 on af_packet1
+ * 224.0.0.0/8
+ *   unicast-ip4-chain
+ *   [@0]: dpo-load-balance: [index:15 buckets:1 uRPF:14 to:[0:0]]
+ *     [0] [@0]: dpo-drop ip6
+ * 240.0.0.0/8
+ *   unicast-ip4-chain
+ *   [@0]: dpo-load-balance: [index:14 buckets:1 uRPF:13 to:[0:0]]
+ *     [0] [@0]: dpo-drop ip6
+ * 255.255.255.255/32
+ *   unicast-ip4-chain
+ *   [@0]: dpo-load-balance: [index:16 buckets:1 uRPF:15 to:[0:0]]
+ *     [0] [@0]: dpo-drop ip6
+ * @cliexend
+ * Example of how to display a single IPv4 FIB table:
+ * @cliexstart{show ip fib table 7}
+ * ipv4-VRF:7, fib_index 1, flow hash: src dst sport dport proto
+ * 0.0.0.0/0
+ *   unicast-ip4-chain
+ *   [@0]: dpo-load-balance: [index:12 buckets:1 uRPF:11 to:[0:0]]
+ *     [0] [@0]: dpo-drop ip6
+ * 0.0.0.0/32
+ *   unicast-ip4-chain
+ *   [@0]: dpo-load-balance: [index:13 buckets:1 uRPF:12 to:[0:0]]
+ *     [0] [@0]: dpo-drop ip6
+ * 172.16.1.0/24
+ *   unicast-ip4-chain
+ *   [@0]: dpo-load-balance: [index:17 buckets:1 uRPF:16 to:[0:0]]
+ *     [0] [@4]: ipv4-glean: af_packet0
+ * 172.16.1.1/32
+ *   unicast-ip4-chain
+ *   [@0]: dpo-load-balance: [index:18 buckets:1 uRPF:17 to:[1:84]]
+ *     [0] [@2]: dpo-receive: 172.16.1.1 on af_packet0
+ * 172.16.1.2/32
+ *   unicast-ip4-chain
+ *   [@0]: dpo-load-balance: [index:21 buckets:1 uRPF:20 to:[0:0]]
+ *     [0] [@5]: ipv4 via 172.16.1.2 af_packet0: IP4: 02:fe:9e:70:7a:2b -> 26:a5:f6:9c:3a:36
+ * 172.16.2.0/24
+ *   unicast-ip4-chain
+ *   [@0]: dpo-load-balance: [index:19 buckets:1 uRPF:18 to:[0:0]]
+ *     [0] [@4]: ipv4-glean: af_packet1
+ * 172.16.2.1/32
+ *   unicast-ip4-chain
+ *   [@0]: dpo-load-balance: [index:20 buckets:1 uRPF:19 to:[0:0]]
+ *     [0] [@2]: dpo-receive: 172.16.2.1 on af_packet1
+ * 224.0.0.0/8
+ *   unicast-ip4-chain
+ *   [@0]: dpo-load-balance: [index:15 buckets:1 uRPF:14 to:[0:0]]
+ *     [0] [@0]: dpo-drop ip6
+ * 240.0.0.0/8
+ *   unicast-ip4-chain
+ *   [@0]: dpo-load-balance: [index:14 buckets:1 uRPF:13 to:[0:0]]
+ *     [0] [@0]: dpo-drop ip6
+ * 255.255.255.255/32
+ *   unicast-ip4-chain
+ *   [@0]: dpo-load-balance: [index:16 buckets:1 uRPF:15 to:[0:0]]
+ *     [0] [@0]: dpo-drop ip6
+ * @cliexend
+ * Example of how to display a summary of all IPv4 FIB tables:
+ * @cliexstart{show ip fib summary}
+ * ipv4-VRF:0, fib_index 0, flow hash: src dst sport dport proto
+ *     Prefix length         Count
+ *                    0               1
+ *                    8               2
+ *                   32               4
+ * ipv4-VRF:7, fib_index 1, flow hash: src dst sport dport proto
+ *     Prefix length         Count
+ *                    0               1
+ *                    8               2
+ *                   24               2
+ *                   32               4
+ * @cliexend
+ ?*/
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (ip4_show_fib_command, static) = {
+    .path = "show ip fib",
+    .short_help = "show ip fib [summary] [table <table-id>] [index <fib-id>] [<ip4-addr>[/<mask>]] [mtrie]",
+    .function = ip4_show_fib,
+};
+/* *INDENT-ON* */
diff --git a/src/vnet/fib/ip4_fib.h b/src/vnet/fib/ip4_fib.h
new file mode 100644
index 00000000000..cf312cdc629
--- /dev/null
+++ b/src/vnet/fib/ip4_fib.h
@@ -0,0 +1,141 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/**
+ * @brief The IPv4 FIB
+ *
+ * FIBs are composed of two prefix data-bases (akak tables). The non-forwarding
+ * table contains all the routes that the control plane has programmed, the
+ * forwarding table contains the sub-set of those routes that can be used to
+ * forward packets.
+ * In the IPv4 FIB the non-forwarding table is an array of hash tables indexed
+ * by mask length, the forwarding table is an mtrie
+ *
+ * This IPv4 FIB is used by the protocol independent FIB. So directly using
+ * this APIs in client code is not encouraged. However, this IPv4 FIB can be
+ * used if all the client wants is an IPv4 prefix data-base
+ */
+
+#ifndef __IP4_FIB_H__
+#define __IP4_FIB_H__
+
+#include <vlib/vlib.h>
+#include <vnet/ip/ip.h>
+#include <vnet/fib/fib_entry.h>
+#include <vnet/fib/fib_table.h>
+
+extern fib_node_index_t ip4_fib_table_lookup(const ip4_fib_t *fib,
+					     const ip4_address_t *addr,
+					     u32 len);
+extern fib_node_index_t ip4_fib_table_lookup_exact_match(const ip4_fib_t *fib,
+							 const ip4_address_t *addr,
+							 u32 len);
+
+extern void ip4_fib_table_entry_remove(ip4_fib_t *fib,
+				       const ip4_address_t *addr,
+				       u32 len);
+
+extern void ip4_fib_table_entry_insert(ip4_fib_t *fib,
+				       const ip4_address_t *addr,
+				       u32 len,
+				       fib_node_index_t fib_entry_index);
+extern void ip4_fib_table_destroy(ip4_fib_t *fib);
+
+extern void ip4_fib_table_fwding_dpo_update(ip4_fib_t *fib,
+					    const ip4_address_t *addr,
+					    u32 len,
+					    const dpo_id_t *dpo);
+
+extern void ip4_fib_table_fwding_dpo_remove(ip4_fib_t *fib,
+					    const ip4_address_t *addr,
+					    u32 len,
+					    const dpo_id_t *dpo);
+extern u32 ip4_fib_table_lookup_lb (ip4_fib_t *fib,
+				    const ip4_address_t * dst);
+
+/**
+ * @brief Get the FIB at the given index
+ */
+static inline ip4_fib_t *
+ip4_fib_get (u32 index)
+{
+    return (&(pool_elt_at_index(ip4_main.fibs, index)->v4));
+}
+
+always_inline u32
+ip4_fib_lookup (ip4_main_t * im, u32 sw_if_index, ip4_address_t * dst)
+{
+    return (ip4_fib_table_lookup_lb(
+		ip4_fib_get(vec_elt (im->fib_index_by_sw_if_index, sw_if_index)),
+		dst));
+}
+
+/**
+ * @brief Get or create an IPv4 fib.
+ *
+ * Get or create an IPv4 fib with the provided table ID.
+ *
+ * @param table_id
+ *      When set to \c ~0, an arbitrary and unused fib ID is picked
+ *      and can be retrieved with \c ret->table_id.
+ *      Otherwise, the fib ID to be used to retrieve or create the desired fib.
+ * @returns A pointer to the retrieved or created fib.
+ *
+ */
+extern u32 ip4_fib_table_find_or_create_and_lock(u32 table_id);
+extern u32 ip4_fib_table_create_and_lock(void);
+
+
+static inline 
+u32 ip4_fib_index_from_table_id (u32 table_id)
+{
+  ip4_main_t * im = &ip4_main;
+  uword * p;
+
+  p = hash_get (im->fib_index_by_table_id, table_id);
+  if (!p)
+    return ~0;
+
+  return p[0];
+}
+
+extern u32 ip4_fib_table_get_index_for_sw_if_index(u32 sw_if_index);
+
+extern flow_hash_config_t ip4_fib_table_get_flow_hash_config(u32 fib_index);
+
+
+always_inline index_t
+ip4_fib_forwarding_lookup (u32 fib_index,
+                           const ip4_address_t * addr)
+{
+    ip4_fib_mtrie_leaf_t leaf;
+    ip4_fib_mtrie_t * mtrie;
+
+    mtrie = &ip4_fib_get(fib_index)->mtrie;
+
+    leaf = IP4_FIB_MTRIE_LEAF_ROOT;
+    leaf = ip4_fib_mtrie_lookup_step (mtrie, leaf, addr, 0);
+    leaf = ip4_fib_mtrie_lookup_step (mtrie, leaf, addr, 1);
+    leaf = ip4_fib_mtrie_lookup_step (mtrie, leaf, addr, 2);
+    leaf = ip4_fib_mtrie_lookup_step (mtrie, leaf, addr, 3);
+
+    /* Handle default route. */
+    leaf = (leaf == IP4_FIB_MTRIE_LEAF_EMPTY ? mtrie->default_leaf : leaf);
+    
+    return (ip4_fib_mtrie_leaf_get_adj_index(leaf));
+}
+
+
+#endif
+
diff --git a/src/vnet/fib/ip6_fib.c b/src/vnet/fib/ip6_fib.c
new file mode 100644
index 00000000000..d5b9bdcbd52
--- /dev/null
+++ b/src/vnet/fib/ip6_fib.c
@@ -0,0 +1,784 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vnet/fib/ip6_fib.h>
+#include <vnet/fib/fib_table.h>
+
+static void
+vnet_ip6_fib_init (u32 fib_index)
+{
+    fib_prefix_t pfx = {
+	.fp_proto = FIB_PROTOCOL_IP6,
+	.fp_len = 0,
+	.fp_addr = {
+	    .ip6 = {
+		{ 0, 0, },
+	    },
+	}
+    };
+
+    /*
+     * Add the default route.
+     */
+    fib_table_entry_special_add(fib_index,
+				&pfx,
+				FIB_SOURCE_DEFAULT_ROUTE,
+				FIB_ENTRY_FLAG_DROP,
+				ADJ_INDEX_INVALID);
+
+    /*
+     * Add ff02::1:ff00:0/104 via local route for all tables.
+     *  This is required for neighbor discovery to work.
+     */
+    ip6_set_solicited_node_multicast_address(&pfx.fp_addr.ip6, 0);
+    pfx.fp_len = 104;
+    fib_table_entry_special_add(fib_index,
+				&pfx,
+				FIB_SOURCE_SPECIAL,
+				FIB_ENTRY_FLAG_LOCAL,
+				ADJ_INDEX_INVALID);
+
+    /*
+     * Add all-routers multicast address via local route for all tables
+     */
+    ip6_set_reserved_multicast_address (&pfx.fp_addr.ip6,
+					IP6_MULTICAST_SCOPE_link_local,
+					IP6_MULTICAST_GROUP_ID_all_routers);
+    pfx.fp_len = 128;
+    fib_table_entry_special_add(fib_index,
+				&pfx,
+				FIB_SOURCE_SPECIAL,
+				FIB_ENTRY_FLAG_LOCAL,
+				ADJ_INDEX_INVALID);
+
+    /*
+     * Add all-nodes multicast address via local route for all tables
+     */
+    ip6_set_reserved_multicast_address (&pfx.fp_addr.ip6,
+					IP6_MULTICAST_SCOPE_link_local,
+					IP6_MULTICAST_GROUP_ID_all_hosts);
+    pfx.fp_len = 128;
+    fib_table_entry_special_add(fib_index,
+				&pfx,
+				FIB_SOURCE_SPECIAL,
+				FIB_ENTRY_FLAG_LOCAL,
+				ADJ_INDEX_INVALID);
+
+    /*
+     *  Add all-mldv2  multicast address via local route for all tables
+     */
+    ip6_set_reserved_multicast_address (&pfx.fp_addr.ip6,
+					IP6_MULTICAST_SCOPE_link_local,
+					IP6_MULTICAST_GROUP_ID_mldv2_routers);
+    pfx.fp_len = 128;
+    fib_table_entry_special_add(fib_index,
+				&pfx,
+				FIB_SOURCE_SPECIAL,
+				FIB_ENTRY_FLAG_LOCAL,
+				ADJ_INDEX_INVALID);
+
+    /*
+     * all link local for us
+     */
+    pfx.fp_addr.ip6.as_u64[0] = clib_host_to_net_u64 (0xFE80000000000000ULL);
+    pfx.fp_addr.ip6.as_u64[1] = 0;
+    pfx.fp_len = 10;
+    fib_table_entry_special_add(fib_index,
+				&pfx,
+				FIB_SOURCE_SPECIAL,
+				FIB_ENTRY_FLAG_LOCAL,
+				ADJ_INDEX_INVALID);
+}
+
+static u32
+create_fib_with_table_id (u32 table_id)
+{
+    fib_table_t *fib_table;
+
+    pool_get_aligned(ip6_main.fibs, fib_table, CLIB_CACHE_LINE_BYTES);
+    memset(fib_table, 0, sizeof(*fib_table));
+
+    fib_table->ft_proto = FIB_PROTOCOL_IP6;
+    fib_table->ft_index =
+	fib_table->v6.index =
+	    (fib_table - ip6_main.fibs);
+
+    hash_set(ip6_main.fib_index_by_table_id, table_id, fib_table->ft_index);
+
+    fib_table->ft_table_id =
+	fib_table->v6.table_id =
+	    table_id;
+    fib_table->ft_flow_hash_config = 
+	fib_table->v6.flow_hash_config =
+	    IP_FLOW_HASH_DEFAULT;
+
+    vnet_ip6_fib_init(fib_table->ft_index);
+    fib_table_lock(fib_table->ft_index, FIB_PROTOCOL_IP6);
+
+    return (fib_table->ft_index);
+}
+
+u32
+ip6_fib_table_find_or_create_and_lock (u32 table_id)
+{
+    uword * p;
+
+    p = hash_get (ip6_main.fib_index_by_table_id, table_id);
+    if (NULL == p)
+	return create_fib_with_table_id(table_id);
+    
+    fib_table_lock(p[0], FIB_PROTOCOL_IP6);
+
+    return (p[0]);
+}
+
+u32
+ip6_fib_table_create_and_lock (void)
+{
+    return (create_fib_with_table_id(~0));
+}
+
+void
+ip6_fib_table_destroy (u32 fib_index)
+{
+    fib_prefix_t pfx = {
+	.fp_proto = FIB_PROTOCOL_IP6,
+	.fp_len = 0,
+	.fp_addr = {
+	    .ip6 = {
+		{ 0, 0, },
+	    },
+	}
+    };
+
+    /*
+     * the default route.
+     */
+    fib_table_entry_special_remove(fib_index,
+				   &pfx,
+				   FIB_SOURCE_DEFAULT_ROUTE);
+
+
+    /*
+     * ff02::1:ff00:0/104
+     */
+    ip6_set_solicited_node_multicast_address(&pfx.fp_addr.ip6, 0);
+    pfx.fp_len = 104;
+    fib_table_entry_special_remove(fib_index,
+				   &pfx,
+				   FIB_SOURCE_SPECIAL);
+
+    /*
+     * all-routers multicast address
+     */
+    ip6_set_reserved_multicast_address (&pfx.fp_addr.ip6,
+					IP6_MULTICAST_SCOPE_link_local,
+					IP6_MULTICAST_GROUP_ID_all_routers);
+    pfx.fp_len = 128;
+    fib_table_entry_special_remove(fib_index,
+				   &pfx,
+				   FIB_SOURCE_SPECIAL);
+
+    /*
+     * all-nodes multicast address
+     */
+    ip6_set_reserved_multicast_address (&pfx.fp_addr.ip6,
+					IP6_MULTICAST_SCOPE_link_local,
+					IP6_MULTICAST_GROUP_ID_all_hosts);
+    pfx.fp_len = 128;
+    fib_table_entry_special_remove(fib_index,
+				   &pfx,
+				   FIB_SOURCE_SPECIAL);
+
+    /*
+     * all-mldv2 multicast address
+     */
+    ip6_set_reserved_multicast_address (&pfx.fp_addr.ip6,
+					IP6_MULTICAST_SCOPE_link_local,
+					IP6_MULTICAST_GROUP_ID_mldv2_routers);
+    pfx.fp_len = 128;
+    fib_table_entry_special_remove(fib_index,
+				   &pfx,
+				   FIB_SOURCE_SPECIAL);
+
+    /*
+     * all link local 
+     */
+    pfx.fp_addr.ip6.as_u64[0] = clib_host_to_net_u64 (0xFE80000000000000ULL);
+    pfx.fp_addr.ip6.as_u64[1] = 0;
+    pfx.fp_len = 10;
+    fib_table_entry_special_remove(fib_index,
+				   &pfx,
+				   FIB_SOURCE_SPECIAL);
+
+    fib_table_t *fib_table = fib_table_get(fib_index, FIB_PROTOCOL_IP6);
+    fib_source_t source;
+    
+     /*
+     * validate no more routes.
+     */
+    ASSERT(0 == fib_table->ft_total_route_counts);
+    FOR_EACH_FIB_SOURCE(source)
+    {
+	ASSERT(0 == fib_table->ft_src_route_counts[source]);
+    }
+
+    if (~0 != fib_table->ft_table_id)
+    {
+	hash_unset (ip6_main.fib_index_by_table_id, fib_table->ft_table_id);
+    }
+    pool_put(ip6_main.fibs, fib_table);
+}
+
+fib_node_index_t
+ip6_fib_table_lookup (u32 fib_index,
+		      const ip6_address_t *addr,
+		      u32 len)
+{
+    const ip6_fib_table_instance_t *table;
+    BVT(clib_bihash_kv) kv, value;
+    int i, n_p, rv;
+    u64 fib;
+
+    table = &ip6_main.ip6_table[IP6_FIB_TABLE_NON_FWDING];
+    n_p = vec_len (table->prefix_lengths_in_search_order);
+
+    kv.key[0] = addr->as_u64[0];
+    kv.key[1] = addr->as_u64[1];
+    fib = ((u64)((fib_index))<<32);
+
+    /*
+     * start search from a mask length same length or shorter.
+     * we don't want matches longer than the mask passed
+     */
+    i = 0;
+    while (i < n_p && table->prefix_lengths_in_search_order[i] > len)
+    {
+        i++;
+    }
+
+    for (; i < n_p; i++)
+    {
+	int dst_address_length = table->prefix_lengths_in_search_order[i];
+	ip6_address_t * mask = &ip6_main.fib_masks[dst_address_length];
+      
+	ASSERT(dst_address_length >= 0 && dst_address_length <= 128);
+	//As lengths are decreasing, masks are increasingly specific.
+	kv.key[0] &= mask->as_u64[0];
+	kv.key[1] &= mask->as_u64[1];
+	kv.key[2] = fib | dst_address_length;
+      
+	rv = BV(clib_bihash_search_inline_2)(&table->ip6_hash, &kv, &value);
+	if (rv == 0)
+	    return value.value;
+    }
+
+    return (FIB_NODE_INDEX_INVALID);
+}
+
+fib_node_index_t
+ip6_fib_table_lookup_exact_match (u32 fib_index,
+				  const ip6_address_t *addr,
+				  u32 len)
+{
+    const ip6_fib_table_instance_t *table;
+    BVT(clib_bihash_kv) kv, value;
+    ip6_address_t *mask;
+    u64 fib;
+    int rv;
+
+    table = &ip6_main.ip6_table[IP6_FIB_TABLE_NON_FWDING];
+    mask = &ip6_main.fib_masks[len];
+    fib = ((u64)((fib_index))<<32);
+
+    kv.key[0] = addr->as_u64[0] & mask->as_u64[0];
+    kv.key[1] = addr->as_u64[1] & mask->as_u64[1];
+    kv.key[2] = fib | len;
+      
+    rv = BV(clib_bihash_search_inline_2)(&table->ip6_hash, &kv, &value);
+    if (rv == 0)
+	return value.value;
+
+    return (FIB_NODE_INDEX_INVALID);
+}
+
+static void
+compute_prefix_lengths_in_search_order (ip6_fib_table_instance_t *table)
+{
+    int i;
+    vec_reset_length (table->prefix_lengths_in_search_order);
+    /* Note: bitmap reversed so this is in fact a longest prefix match */
+    clib_bitmap_foreach (i, table->non_empty_dst_address_length_bitmap,
+    ({
+	int dst_address_length = 128 - i;
+	vec_add1(table->prefix_lengths_in_search_order, dst_address_length);
+    }));
+}
+
+void
+ip6_fib_table_entry_remove (u32 fib_index,
+			    const ip6_address_t *addr,
+			    u32 len)
+{
+    ip6_fib_table_instance_t *table;
+    BVT(clib_bihash_kv) kv;
+    ip6_address_t *mask;
+    u64 fib;
+
+    table = &ip6_main.ip6_table[IP6_FIB_TABLE_NON_FWDING];
+    mask = &ip6_main.fib_masks[len];
+    fib = ((u64)((fib_index))<<32);
+
+    kv.key[0] = addr->as_u64[0] & mask->as_u64[0];
+    kv.key[1] = addr->as_u64[1] & mask->as_u64[1];
+    kv.key[2] = fib | len;
+
+    BV(clib_bihash_add_del)(&table->ip6_hash, &kv, 0);
+
+    /* refcount accounting */
+    ASSERT (table->dst_address_length_refcounts[len] > 0);
+    if (--table->dst_address_length_refcounts[len] == 0)
+    {
+	table->non_empty_dst_address_length_bitmap =
+            clib_bitmap_set (table->non_empty_dst_address_length_bitmap, 
+                             128 - len, 0);
+	compute_prefix_lengths_in_search_order (table);
+    }
+}
+
+void
+ip6_fib_table_entry_insert (u32 fib_index,
+			    const ip6_address_t *addr,
+			    u32 len,
+			    fib_node_index_t fib_entry_index)
+{
+    ip6_fib_table_instance_t *table;
+    BVT(clib_bihash_kv) kv;
+    ip6_address_t *mask;
+    u64 fib;
+
+    table = &ip6_main.ip6_table[IP6_FIB_TABLE_NON_FWDING];
+    mask = &ip6_main.fib_masks[len];
+    fib = ((u64)((fib_index))<<32);
+
+    kv.key[0] = addr->as_u64[0] & mask->as_u64[0];
+    kv.key[1] = addr->as_u64[1] & mask->as_u64[1];
+    kv.key[2] = fib | len;
+    kv.value = fib_entry_index;
+
+    BV(clib_bihash_add_del)(&table->ip6_hash, &kv, 1);
+
+    table->dst_address_length_refcounts[len]++;
+
+    table->non_empty_dst_address_length_bitmap =
+        clib_bitmap_set (table->non_empty_dst_address_length_bitmap, 
+			 128 - len, 1);
+    compute_prefix_lengths_in_search_order (table);
+}
+
+u32 
+ip6_fib_table_fwding_lookup (ip6_main_t * im,
+                             u32 fib_index,
+                             const ip6_address_t * dst)
+{
+    const ip6_fib_table_instance_t *table;
+    int i, len;
+    int rv;
+    BVT(clib_bihash_kv) kv, value;
+    u64 fib;
+
+    table = &ip6_main.ip6_table[IP6_FIB_TABLE_FWDING];
+    len = vec_len (table->prefix_lengths_in_search_order);
+
+    kv.key[0] = dst->as_u64[0];
+    kv.key[1] = dst->as_u64[1];
+    fib = ((u64)((fib_index))<<32);
+
+    for (i = 0; i < len; i++)
+    {
+	int dst_address_length = table->prefix_lengths_in_search_order[i];
+	ip6_address_t * mask = &ip6_main.fib_masks[dst_address_length];
+      
+	ASSERT(dst_address_length >= 0 && dst_address_length <= 128);
+	//As lengths are decreasing, masks are increasingly specific.
+	kv.key[0] &= mask->as_u64[0];
+	kv.key[1] &= mask->as_u64[1];
+	kv.key[2] = fib | dst_address_length;
+      
+	rv = BV(clib_bihash_search_inline_2)(&table->ip6_hash, &kv, &value);
+	if (rv == 0)
+	    return value.value;
+    }
+
+    /* default route is always present */
+    ASSERT(0);
+    return 0;
+}
+
+u32 ip6_fib_table_fwding_lookup_with_if_index (ip6_main_t * im,
+					       u32 sw_if_index,
+					       const ip6_address_t * dst)
+{
+    u32 fib_index = vec_elt (im->fib_index_by_sw_if_index, sw_if_index);
+    return ip6_fib_table_fwding_lookup(im, fib_index, dst);
+}
+
+flow_hash_config_t
+ip6_fib_table_get_flow_hash_config (u32 fib_index)
+{
+    return (ip6_fib_get(fib_index)->flow_hash_config);
+}
+
+u32
+ip6_fib_table_get_index_for_sw_if_index (u32 sw_if_index)
+{
+    if (sw_if_index >= vec_len(ip6_main.fib_index_by_sw_if_index))
+    {
+	/*
+	 * This is the case for interfaces that are not yet mapped to
+	 * a IP table
+	 */
+	return (~0);
+    }
+    return (ip6_main.fib_index_by_sw_if_index[sw_if_index]);
+}
+
+void
+ip6_fib_table_fwding_dpo_update (u32 fib_index,
+				 const ip6_address_t *addr,
+				 u32 len,
+				 const dpo_id_t *dpo)
+{
+    ip6_fib_table_instance_t *table;
+    BVT(clib_bihash_kv) kv;
+    ip6_address_t *mask;
+    u64 fib;
+
+    table = &ip6_main.ip6_table[IP6_FIB_TABLE_FWDING];
+    mask = &ip6_main.fib_masks[len];
+    fib = ((u64)((fib_index))<<32);
+
+    kv.key[0] = addr->as_u64[0] & mask->as_u64[0];
+    kv.key[1] = addr->as_u64[1] & mask->as_u64[1];
+    kv.key[2] = fib | len;
+    kv.value = dpo->dpoi_index;
+
+    BV(clib_bihash_add_del)(&table->ip6_hash, &kv, 1);
+
+    table->dst_address_length_refcounts[len]++;
+
+    table->non_empty_dst_address_length_bitmap =
+        clib_bitmap_set (table->non_empty_dst_address_length_bitmap, 
+			 128 - len, 1);
+    compute_prefix_lengths_in_search_order (table);
+}
+
+void
+ip6_fib_table_fwding_dpo_remove (u32 fib_index,
+				 const ip6_address_t *addr,
+				 u32 len,
+				 const dpo_id_t *dpo)
+{
+    ip6_fib_table_instance_t *table;
+    BVT(clib_bihash_kv) kv;
+    ip6_address_t *mask;
+    u64 fib;
+
+    table = &ip6_main.ip6_table[IP6_FIB_TABLE_FWDING];
+    mask = &ip6_main.fib_masks[len];
+    fib = ((u64)((fib_index))<<32);
+
+    kv.key[0] = addr->as_u64[0] & mask->as_u64[0];
+    kv.key[1] = addr->as_u64[1] & mask->as_u64[1];
+    kv.key[2] = fib | len;
+    kv.value = dpo->dpoi_index;
+
+    BV(clib_bihash_add_del)(&table->ip6_hash, &kv, 0);
+
+    /* refcount accounting */
+    ASSERT (table->dst_address_length_refcounts[len] > 0);
+    if (--table->dst_address_length_refcounts[len] == 0)
+    {
+	table->non_empty_dst_address_length_bitmap =
+            clib_bitmap_set (table->non_empty_dst_address_length_bitmap, 
+                             128 - len, 0);
+	compute_prefix_lengths_in_search_order (table);
+    }
+}
+
+typedef struct ip6_fib_show_ctx_t_ {
+    u32 fib_index;
+    fib_node_index_t *entries;
+} ip6_fib_show_ctx_t;
+
+static void
+ip6_fib_table_collect_entries (clib_bihash_kv_24_8_t * kvp,
+			       void *arg)
+{
+    ip6_fib_show_ctx_t *ctx = arg;
+
+    if ((kvp->key[2] >> 32) == ctx->fib_index)
+    {
+	vec_add1(ctx->entries, kvp->value);
+    }
+}
+
+static void
+ip6_fib_table_show_all (ip6_fib_t *fib,
+			vlib_main_t * vm)
+{
+    fib_node_index_t *fib_entry_index;
+    ip6_fib_show_ctx_t ctx = {
+	.fib_index = fib->index,
+	.entries = NULL,
+    };
+    ip6_main_t *im = &ip6_main;
+
+    BV(clib_bihash_foreach_key_value_pair)(&im->ip6_table[IP6_FIB_TABLE_NON_FWDING].ip6_hash,
+					   ip6_fib_table_collect_entries,
+					   &ctx);
+
+    vec_sort_with_function(ctx.entries, fib_entry_cmp_for_sort);
+
+    vec_foreach(fib_entry_index, ctx.entries)
+    {
+	vlib_cli_output(vm, "%U",
+                        format_fib_entry,
+                        *fib_entry_index,
+                        FIB_ENTRY_FORMAT_BRIEF);
+    }
+
+    vec_free(ctx.entries);
+}
+
+static void
+ip6_fib_table_show_one (ip6_fib_t *fib,
+			vlib_main_t * vm,
+			ip6_address_t *address,
+			u32 mask_len)
+{
+    vlib_cli_output(vm, "%U",
+                    format_fib_entry,
+                    ip6_fib_table_lookup(fib->index, address, mask_len),
+                    FIB_ENTRY_FORMAT_DETAIL);
+}
+
+typedef struct {
+  u32 fib_index;
+  u64 count_by_prefix_length[129];
+} count_routes_in_fib_at_prefix_length_arg_t;
+
+static void count_routes_in_fib_at_prefix_length 
+(BVT(clib_bihash_kv) * kvp, void *arg)
+{
+  count_routes_in_fib_at_prefix_length_arg_t * ap = arg;
+  int mask_width;
+
+  if ((kvp->key[2]>>32) != ap->fib_index)
+    return;
+
+  mask_width = kvp->key[2] & 0xFF;
+
+  ap->count_by_prefix_length[mask_width]++;
+}
+
+static clib_error_t *
+ip6_show_fib (vlib_main_t * vm,
+	      unformat_input_t * input,
+	      vlib_cli_command_t * cmd)
+{
+    count_routes_in_fib_at_prefix_length_arg_t _ca, *ca = &_ca;
+    ip6_main_t * im6 = &ip6_main;
+    fib_table_t *fib_table;
+    ip6_fib_t * fib;
+    int verbose, matching;
+    ip6_address_t matching_address;
+    u32 mask_len  = 128;
+    int table_id = -1, fib_index = ~0;
+
+    verbose = 1;
+    matching = 0;
+
+    while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+    {
+	if (unformat (input, "brief")   ||
+	    unformat (input, "summary") ||
+	    unformat (input, "sum"))
+	    verbose = 0;
+
+	else if (unformat (input, "%U/%d",
+			   unformat_ip6_address, &matching_address, &mask_len))
+	    matching = 1;
+
+	else if (unformat (input, "%U", unformat_ip6_address, &matching_address))
+	    matching = 1;
+
+	else if (unformat (input, "table %d", &table_id))
+	    ;
+	else if (unformat (input, "index %d", &fib_index))
+	    ;
+	else
+	    break;
+    }
+
+    pool_foreach (fib_table, im6->fibs,
+    ({
+	fib = &(fib_table->v6);
+	if (table_id >= 0 && table_id != (int)fib->table_id)
+	    continue;
+	if (fib_index != ~0 && fib_index != (int)fib->index)
+	    continue;
+
+	vlib_cli_output (vm, "%s, fib_index %d, flow hash: %U", 
+			 fib_table->ft_desc, fib->index,
+			 format_ip_flow_hash_config, fib->flow_hash_config);
+
+	/* Show summary? */
+	if (! verbose)
+	{
+	    BVT(clib_bihash) * h = &im6->ip6_table[IP6_FIB_TABLE_NON_FWDING].ip6_hash;
+	    int len;
+
+	    vlib_cli_output (vm, "%=20s%=16s", "Prefix length", "Count");
+
+	    memset (ca, 0, sizeof(*ca));
+	    ca->fib_index = fib->index;
+
+	    BV(clib_bihash_foreach_key_value_pair)
+		(h, count_routes_in_fib_at_prefix_length, ca);
+
+	    for (len = 128; len >= 0; len--)
+            {
+		if (ca->count_by_prefix_length[len])
+		    vlib_cli_output (vm, "%=20d%=16lld", 
+				     len, ca->count_by_prefix_length[len]);
+            }
+	    continue;
+	}
+
+	if (!matching)
+	{
+	    ip6_fib_table_show_all(fib, vm);
+	}
+	else
+	{
+	    ip6_fib_table_show_one(fib, vm, &matching_address, mask_len);
+	}
+    }));
+
+    return 0;
+}
+
+/*?
+ * This command displays the IPv6 FIB Tables (VRF Tables) and the route
+ * entries for each table.
+ *
+ * @note This command will run for a long time when the FIB tables are
+ * comprised of millions of entries. For those senarios, consider displaying
+ * in summary mode.
+ *
+ * @cliexpar
+ * @parblock
+ * Example of how to display all the IPv6 FIB tables:
+ * @cliexstart{show ip6 fib}
+ * ipv6-VRF:0, fib_index 0, flow hash: src dst sport dport proto
+ * @::/0
+ *   unicast-ip6-chain
+ *   [@0]: dpo-load-balance: [index:5 buckets:1 uRPF:5 to:[0:0]]
+ *     [0] [@0]: dpo-drop ip6
+ * fe80::/10
+ *   unicast-ip6-chain
+ *   [@0]: dpo-load-balance: [index:10 buckets:1 uRPF:10 to:[0:0]]
+ *     [0] [@2]: dpo-receive
+ * ff02::1/128
+ *   unicast-ip6-chain
+ *   [@0]: dpo-load-balance: [index:8 buckets:1 uRPF:8 to:[0:0]]
+ *     [0] [@2]: dpo-receive
+ * ff02::2/128
+ *   unicast-ip6-chain
+ *   [@0]: dpo-load-balance: [index:7 buckets:1 uRPF:7 to:[0:0]]
+ *     [0] [@2]: dpo-receive
+ * ff02::16/128
+ *   unicast-ip6-chain
+ *   [@0]: dpo-load-balance: [index:9 buckets:1 uRPF:9 to:[0:0]]
+ *     [0] [@2]: dpo-receive
+ * ff02::1:ff00:0/104
+ *   unicast-ip6-chain
+ *   [@0]: dpo-load-balance: [index:6 buckets:1 uRPF:6 to:[0:0]]
+ *     [0] [@2]: dpo-receive
+ * ipv6-VRF:8, fib_index 1, flow hash: src dst sport dport proto
+ * @::/0
+ *   unicast-ip6-chain
+ *   [@0]: dpo-load-balance: [index:21 buckets:1 uRPF:20 to:[0:0]]
+ *     [0] [@0]: dpo-drop ip6
+ * @::a:1:1:0:4/126
+ *   unicast-ip6-chain
+ *   [@0]: dpo-load-balance: [index:27 buckets:1 uRPF:26 to:[0:0]]
+ *     [0] [@4]: ipv6-glean: af_packet0
+ * @::a:1:1:0:7/128
+ *   unicast-ip6-chain
+ *   [@0]: dpo-load-balance: [index:28 buckets:1 uRPF:27 to:[0:0]]
+ *     [0] [@2]: dpo-receive: @::a:1:1:0:7 on af_packet0
+ * fe80::/10
+ *   unicast-ip6-chain
+ *   [@0]: dpo-load-balance: [index:26 buckets:1 uRPF:25 to:[0:0]]
+ *     [0] [@2]: dpo-receive
+ * fe80::fe:3eff:fe3e:9222/128
+ *   unicast-ip6-chain
+ *   [@0]: dpo-load-balance: [index:29 buckets:1 uRPF:28 to:[0:0]]
+ *     [0] [@2]: dpo-receive: fe80::fe:3eff:fe3e:9222 on af_packet0
+ * ff02::1/128
+ *   unicast-ip6-chain
+ *   [@0]: dpo-load-balance: [index:24 buckets:1 uRPF:23 to:[0:0]]
+ *     [0] [@2]: dpo-receive
+ * ff02::2/128
+ *   unicast-ip6-chain
+ *   [@0]: dpo-load-balance: [index:23 buckets:1 uRPF:22 to:[0:0]]
+ *     [0] [@2]: dpo-receive
+ * ff02::16/128
+ *   unicast-ip6-chain
+ *   [@0]: dpo-load-balance: [index:25 buckets:1 uRPF:24 to:[0:0]]
+ *     [0] [@2]: dpo-receive
+ * ff02::1:ff00:0/104
+ *   unicast-ip6-chain
+ *   [@0]: dpo-load-balance: [index:22 buckets:1 uRPF:21 to:[0:0]]
+ *     [0] [@2]: dpo-receive
+ * @cliexend
+ *
+ * Example of how to display a summary of all IPv6 FIB tables:
+ * @cliexstart{show ip6 fib summary}
+ * ipv6-VRF:0, fib_index 0, flow hash: src dst sport dport proto
+ *     Prefix length         Count
+ *          128                3
+ *          104                1
+ *          10                 1
+ *           0                 1
+ * ipv6-VRF:8, fib_index 1, flow hash: src dst sport dport proto
+ *     Prefix length         Count
+ *          128                5
+ *          126                1
+ *          104                1
+ *          10                 1
+ *           0                 1
+ * @cliexend
+ * @endparblock
+ ?*/
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (ip6_show_fib_command, static) = {
+    .path = "show ip6 fib",
+    .short_help = "show ip6 fib [summary] [table <table-id>] [index <fib-id>] [<ip6-addr>[/<width>]]",
+    .function = ip6_show_fib,
+};
+/* *INDENT-ON* */
diff --git a/src/vnet/fib/ip6_fib.h b/src/vnet/fib/ip6_fib.h
new file mode 100644
index 00000000000..f6af993a3c2
--- /dev/null
+++ b/src/vnet/fib/ip6_fib.h
@@ -0,0 +1,130 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __IP6_FIB_H__
+#define __IP6_FIB_H__
+
+#include <vlib/vlib.h>
+#include <vnet/ip/format.h>
+#include <vnet/fib/fib_entry.h>
+#include <vnet/fib/fib_table.h>
+#include <vnet/ip/lookup.h>
+#include <vnet/dpo/load_balance.h>
+
+extern fib_node_index_t ip6_fib_table_lookup(u32 fib_index,
+					     const ip6_address_t *addr,
+					     u32 len);
+extern fib_node_index_t ip6_fib_table_lookup_exact_match(u32 fib_index,
+							 const ip6_address_t *addr,
+							 u32 len);
+
+extern void ip6_fib_table_entry_remove(u32 fib_index,
+				       const ip6_address_t *addr,
+				       u32 len);
+
+extern void ip6_fib_table_entry_insert(u32 fib_index,
+				       const ip6_address_t *addr,
+				       u32 len,
+				       fib_node_index_t fib_entry_index);
+extern void ip6_fib_table_destroy(u32 fib_index);
+
+extern void ip6_fib_table_fwding_dpo_update(u32 fib_index,
+					    const ip6_address_t *addr,
+					    u32 len,
+					    const dpo_id_t *dpo);
+
+extern void ip6_fib_table_fwding_dpo_remove(u32 fib_index,
+					    const ip6_address_t *addr,
+					    u32 len,
+					    const dpo_id_t *dpo);
+
+u32 ip6_fib_table_fwding_lookup_with_if_index(ip6_main_t * im,
+					      u32 sw_if_index,
+					      const ip6_address_t * dst);
+u32 ip6_fib_table_fwding_lookup(ip6_main_t * im,
+				u32 fib_index, 
+				const ip6_address_t * dst);
+
+/**
+ * @biref return the DPO that the LB stacks on.
+ */
+always_inline u32
+ip6_src_lookup_for_packet (ip6_main_t * im,
+                           vlib_buffer_t * b,
+                           ip6_header_t * i)
+{
+    if (vnet_buffer (b)->ip.adj_index[VLIB_RX] == ~0)
+    {
+        const dpo_id_t *dpo;
+        index_t lbi;
+
+        lbi = ip6_fib_table_fwding_lookup_with_if_index(
+                  im,
+                  vnet_buffer (b)->sw_if_index[VLIB_RX],
+                  &i->src_address);
+
+        dpo = load_balance_get_bucket_i(load_balance_get(lbi), 0);
+
+        if (dpo_is_adj(dpo))
+        {
+            vnet_buffer (b)->ip.adj_index[VLIB_RX] = dpo->dpoi_index;
+        }
+    }
+    return vnet_buffer (b)->ip.adj_index[VLIB_RX];
+}
+
+/**
+ * \brief Get or create an IPv6 fib.
+ *
+ * Get or create an IPv4 fib with the provided table ID.
+ *
+ * \param im
+ *      ip4_main pointer.
+ * \param table_id
+ *      When set to \c ~0, an arbitrary and unused fib ID is picked
+ *      and can be retrieved with \c ret->table_id.
+ *      Otherwise, the fib ID to be used to retrieve or create the desired fib.
+ * \returns A pointer to the retrieved or created fib.
+ *
+ */
+extern u32 ip6_fib_table_find_or_create_and_lock(u32 table_id);
+extern u32 ip6_fib_table_create_and_lock(void);
+
+static inline ip6_fib_t *
+ip6_fib_get (fib_node_index_t index)
+{
+    ASSERT(!pool_is_free_index(ip6_main.fibs, index));
+    return (&pool_elt_at_index (ip6_main.fibs, index)->v6);
+}
+
+static inline 
+u32 ip6_fib_index_from_table_id (u32 table_id)
+{
+  ip6_main_t * im = &ip6_main;
+  uword * p;
+
+  p = hash_get (im->fib_index_by_table_id, table_id);
+  if (!p)
+    return ~0;
+
+  return p[0];
+}
+
+extern u32 ip6_fib_table_get_index_for_sw_if_index(u32 sw_if_index);
+
+extern flow_hash_config_t ip6_fib_table_get_flow_hash_config(u32 fib_index);
+
+#endif
+
diff --git a/src/vnet/fib/mpls_fib.c b/src/vnet/fib/mpls_fib.c
new file mode 100644
index 00000000000..6a9b1ac2989
--- /dev/null
+++ b/src/vnet/fib/mpls_fib.c
@@ -0,0 +1,439 @@
+/*
+ * mpls_fib.h: The Label/MPLS FIB
+ *
+ * Copyright (c) 2012 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/**
+ * An MPLS_FIB table;
+ *
+ * The entries in the table are programmed wtih one or more MOIs. These MOIs
+ * may result in different forwarding actions for end-of-stack (EOS) and non-EOS
+ * packets. Whether the two actions are the same more often than they are
+ * different, or vice versa, is a function of the deployment in which the router
+ * is used and thus not predictable.
+ * The desgin choice to make with an MPLS_FIB table is:
+ *  1 - 20 bit key: label only.
+ *      When the EOS and non-EOS actions differ the result is a 'EOS-choice' object.
+ *  2 - 21 bit key: label and EOS-bit.
+ *      The result is then the specific action based on EOS-bit.
+ *
+ * 20 bit key:
+ *   Advantages:
+ *    - lower memory overhead, since there are few DB entries.
+ *   Disadvantages:
+ *    - slower DP performance in the case the chains differ, as more objects are
+ *      encounterd in the switch path
+ *
+ * 21 bit key:
+ *   Advantages:
+ *    - faster DP performance
+ *   Disadvantages
+ *    - increased memory footprint.
+ *
+ * Switching between schemes based on observed/measured action similarity is not
+ * considered on the grounds of complexity and flip-flopping.
+ *
+ * VPP mantra - favour performance over memory. We choose a 21 bit key.  
+ */
+
+#include <vnet/fib/fib_table.h>
+#include <vnet/dpo/load_balance.h>
+#include <vnet/dpo/drop_dpo.h>
+#include <vnet/dpo/punt_dpo.h>
+#include <vnet/dpo/lookup_dpo.h>
+#include <vnet/mpls/mpls.h>
+
+/**
+ * All lookups in an MPLS_FIB table must result in a DPO of type load-balance.
+ * This is the default result which links to drop
+ */
+static index_t mpls_fib_drop_dpo_index = INDEX_INVALID;
+
+/**
+ * FIXME
+ */
+#define MPLS_FLOW_HASH_DEFAULT 0
+
+static inline u32
+mpls_fib_entry_mk_key (mpls_label_t label,
+		       mpls_eos_bit_t eos)
+{
+    ASSERT(eos <= 1);
+    return (label << 1 | eos);
+}
+
+u32
+mpls_fib_index_from_table_id (u32 table_id)
+{
+    mpls_main_t *mm = &mpls_main;
+    uword * p;
+
+    p = hash_get (mm->fib_index_by_table_id, table_id);
+    if (!p)
+	return FIB_NODE_INDEX_INVALID;
+
+    return p[0];
+}
+
+static u32
+mpls_fib_create_with_table_id (u32 table_id)
+{
+    dpo_id_t dpo = DPO_INVALID;
+    fib_table_t *fib_table;
+    mpls_eos_bit_t eos;
+    mpls_fib_t *mf;
+    int i;
+
+    pool_get_aligned(mpls_main.fibs, fib_table, CLIB_CACHE_LINE_BYTES);
+    memset(fib_table, 0, sizeof(*fib_table));
+
+    fib_table->ft_proto = FIB_PROTOCOL_MPLS;
+    fib_table->ft_index =
+	(fib_table - mpls_main.fibs);
+
+    hash_set (mpls_main.fib_index_by_table_id, table_id, fib_table->ft_index);
+
+    fib_table->ft_table_id =
+	table_id;
+    fib_table->ft_flow_hash_config = 
+	MPLS_FLOW_HASH_DEFAULT;
+    fib_table->v4.fwd_classify_table_index = ~0;
+    fib_table->v4.rev_classify_table_index = ~0;
+    
+    fib_table_lock(fib_table->ft_index, FIB_PROTOCOL_MPLS);
+
+    if (INDEX_INVALID == mpls_fib_drop_dpo_index)
+    {
+	mpls_fib_drop_dpo_index = load_balance_create(1, DPO_PROTO_MPLS, 0);
+	load_balance_set_bucket(mpls_fib_drop_dpo_index,
+				0,
+                                drop_dpo_get(DPO_PROTO_MPLS));
+    }
+
+    mf = &fib_table->mpls;
+    mf->mf_entries = hash_create(0, sizeof(fib_node_index_t));
+    for (i = 0; i < MPLS_FIB_DB_SIZE; i++)
+    {
+	/*
+	 * initialise each DPO in the data-path lookup table
+	 * to be the special MPLS drop
+	 */
+	mf->mf_lbs[i] = mpls_fib_drop_dpo_index;
+    }
+
+    /*
+     * non-default forwarding for the special labels.
+     */
+    fib_prefix_t prefix = {
+	.fp_proto = FIB_PROTOCOL_MPLS,
+	.fp_payload_proto = DPO_PROTO_MPLS,
+    };
+
+    /*
+     * PUNT the router alert, both EOS and non-eos
+     */
+    prefix.fp_label = MPLS_IETF_ROUTER_ALERT_LABEL;
+    FOR_EACH_MPLS_EOS_BIT(eos)
+    {
+	prefix.fp_eos = eos;
+        fib_table_entry_special_dpo_add(fib_table->ft_index,
+					&prefix,
+					FIB_SOURCE_SPECIAL,
+					FIB_ENTRY_FLAG_EXCLUSIVE,
+					punt_dpo_get(DPO_PROTO_MPLS));
+    }
+
+    /*
+     * IPv4 explicit NULL EOS lookup in the interface's IPv4 table
+     */
+    prefix.fp_label = MPLS_IETF_IPV4_EXPLICIT_NULL_LABEL;
+    prefix.fp_payload_proto = DPO_PROTO_IP4;
+    prefix.fp_eos = MPLS_EOS;
+
+    lookup_dpo_add_or_lock_w_fib_index(0, // unused
+                                       DPO_PROTO_IP4,
+                                       LOOKUP_INPUT_DST_ADDR,
+                                       LOOKUP_TABLE_FROM_INPUT_INTERFACE,
+                                       &dpo);
+    fib_table_entry_special_dpo_add(fib_table->ft_index,
+				    &prefix,
+				    FIB_SOURCE_SPECIAL,
+				    FIB_ENTRY_FLAG_EXCLUSIVE,
+                                    &dpo);
+
+    prefix.fp_payload_proto = DPO_PROTO_MPLS;
+    prefix.fp_eos = MPLS_NON_EOS;
+
+    lookup_dpo_add_or_lock_w_fib_index(0, //unsued
+                                       DPO_PROTO_MPLS,
+                                       LOOKUP_INPUT_DST_ADDR,
+                                       LOOKUP_TABLE_FROM_INPUT_INTERFACE,
+                                       &dpo);
+    fib_table_entry_special_dpo_add(fib_table->ft_index,
+				    &prefix,
+				    FIB_SOURCE_SPECIAL,
+				    FIB_ENTRY_FLAG_EXCLUSIVE,
+                                    &dpo);
+
+    /*
+     * IPv6 explicit NULL EOS lookup in the interface's IPv6 table
+     */
+    prefix.fp_label = MPLS_IETF_IPV6_EXPLICIT_NULL_LABEL;
+    prefix.fp_payload_proto = DPO_PROTO_IP6;
+    prefix.fp_eos = MPLS_EOS;
+
+    lookup_dpo_add_or_lock_w_fib_index(0, //unused
+                                       DPO_PROTO_IP6,
+                                       LOOKUP_INPUT_DST_ADDR,
+                                       LOOKUP_TABLE_FROM_INPUT_INTERFACE,
+                                       &dpo);
+    fib_table_entry_special_dpo_add(fib_table->ft_index,
+				    &prefix,
+				    FIB_SOURCE_SPECIAL,
+				    FIB_ENTRY_FLAG_EXCLUSIVE,
+                                    &dpo);
+
+    prefix.fp_payload_proto = DPO_PROTO_MPLS;
+    prefix.fp_eos = MPLS_NON_EOS;
+    lookup_dpo_add_or_lock_w_fib_index(0, // unsued
+                                       DPO_PROTO_MPLS,
+                                       LOOKUP_INPUT_DST_ADDR,
+                                       LOOKUP_TABLE_FROM_INPUT_INTERFACE,
+                                       &dpo);
+    fib_table_entry_special_dpo_add(fib_table->ft_index,
+				    &prefix,
+				    FIB_SOURCE_SPECIAL,
+				    FIB_ENTRY_FLAG_EXCLUSIVE,
+                                    &dpo);
+
+    return (fib_table->ft_index);
+}
+
+u32
+mpls_fib_table_find_or_create_and_lock (u32 table_id)
+{
+    u32 index;
+
+    index = mpls_fib_index_from_table_id(table_id);
+    if (~0 == index)
+	return mpls_fib_create_with_table_id(table_id);
+
+    fib_table_lock(index, FIB_PROTOCOL_MPLS);
+
+    return (index);
+}
+u32
+mpls_fib_table_create_and_lock (void)
+{
+    return (mpls_fib_create_with_table_id(~0));
+}
+
+void
+mpls_fib_table_destroy (mpls_fib_t *mf)
+{
+    fib_table_t *fib_table = (fib_table_t*)mf;
+    fib_prefix_t prefix = {
+	.fp_proto = FIB_PROTOCOL_MPLS,
+    };
+    mpls_label_t special_labels[] = {
+	MPLS_IETF_ROUTER_ALERT_LABEL,
+	MPLS_IETF_IPV6_EXPLICIT_NULL_LABEL,
+	MPLS_IETF_IPV4_EXPLICIT_NULL_LABEL,
+    };
+    mpls_eos_bit_t eos;
+    u32 ii;
+
+    for (ii = 0; ii < ARRAY_LEN(special_labels); ii++)
+    {
+	FOR_EACH_MPLS_EOS_BIT(eos)
+	{
+	    prefix.fp_label = special_labels[ii];
+	    prefix.fp_eos   = eos;
+
+	    fib_table_entry_delete(fib_table->ft_index,
+				   &prefix,
+				   FIB_SOURCE_SPECIAL);
+	}
+    }
+    if (~0 != fib_table->ft_table_id)
+    {
+	hash_unset(mpls_main.fib_index_by_table_id,
+		   fib_table->ft_table_id);
+    }
+    hash_delete(mf->mf_entries);
+
+    pool_put(mpls_main.fibs, fib_table);
+}
+
+fib_node_index_t
+mpls_fib_table_lookup (const mpls_fib_t *mf,
+		       mpls_label_t label,
+		       mpls_eos_bit_t eos)
+{
+    uword *p;
+
+    p = hash_get(mf->mf_entries, mpls_fib_entry_mk_key(label, eos));
+
+    if (NULL == p)
+	return FIB_NODE_INDEX_INVALID;
+
+    return p[0];
+}
+
+void
+mpls_fib_table_entry_insert (mpls_fib_t *mf,
+			     mpls_label_t label,
+			     mpls_eos_bit_t eos,
+			     fib_node_index_t lfei)
+{
+    hash_set(mf->mf_entries, mpls_fib_entry_mk_key(label, eos), lfei);
+}
+
+void
+mpls_fib_table_entry_remove (mpls_fib_t *mf,
+			     mpls_label_t label,
+			     mpls_eos_bit_t eos)
+{
+    hash_unset(mf->mf_entries, mpls_fib_entry_mk_key(label, eos));
+}
+
+void
+mpls_fib_forwarding_table_update (mpls_fib_t *mf,
+				  mpls_label_t label,
+				  mpls_eos_bit_t eos,
+				  const dpo_id_t *dpo)
+{
+    mpls_label_t key;
+
+    ASSERT(DPO_LOAD_BALANCE == dpo->dpoi_type);
+
+    key = mpls_fib_entry_mk_key(label, eos);
+
+    mf->mf_lbs[key] = dpo->dpoi_index;
+}
+
+void
+mpls_fib_forwarding_table_reset (mpls_fib_t *mf,
+				 mpls_label_t label,
+				 mpls_eos_bit_t eos)
+{
+    mpls_label_t key;
+
+    key = mpls_fib_entry_mk_key(label, eos);
+
+    mf->mf_lbs[key] = mpls_fib_drop_dpo_index;
+}
+
+flow_hash_config_t
+mpls_fib_table_get_flow_hash_config (u32 fib_index)
+{
+    // FIXME.
+    return (0);
+}
+
+static void
+mpls_fib_table_show_all (const mpls_fib_t *mpls_fib,
+			 vlib_main_t * vm)
+{
+    fib_node_index_t lfei, *lfeip, *lfeis = NULL;
+    mpls_label_t key;
+
+    hash_foreach(key, lfei, mpls_fib->mf_entries,
+    ({
+	vec_add1(lfeis, lfei);
+    }));
+
+    vec_sort_with_function(lfeis, fib_entry_cmp_for_sort);
+
+    vec_foreach(lfeip, lfeis)
+    {
+	vlib_cli_output (vm, "%U",
+			 format_fib_entry, *lfeip,
+			 FIB_ENTRY_FORMAT_DETAIL);
+    }
+    vec_free(lfeis);
+}
+
+static void
+mpls_fib_table_show_one (const mpls_fib_t *mpls_fib,
+			 mpls_label_t label,
+			 vlib_main_t * vm)
+{    
+    fib_node_index_t lfei;
+    mpls_eos_bit_t eos;
+
+    FOR_EACH_MPLS_EOS_BIT(eos)
+    {    
+	lfei = mpls_fib_table_lookup(mpls_fib, label, eos);
+
+	if (FIB_NODE_INDEX_INVALID != lfei)
+	{
+	    vlib_cli_output (vm, "%U", 
+			     format_fib_entry, lfei, FIB_ENTRY_FORMAT_DETAIL);
+	}
+    }
+}
+
+static clib_error_t *
+mpls_fib_show (vlib_main_t * vm,
+	       unformat_input_t * input,
+	       vlib_cli_command_t * cmd)
+{
+    fib_table_t * fib_table;
+    mpls_label_t label;
+    int table_id;
+
+    table_id = -1;
+    label = MPLS_LABEL_INVALID;
+
+    while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+    {
+	/* if (unformat (input, "brief") || unformat (input, "summary") */
+	/*     || unformat (input, "sum")) */
+	/*     verbose = 0; */
+
+	if (unformat (input, "%d", &label))
+	    continue;
+	else if (unformat (input, "table %d", &table_id))
+	    ;
+	else
+	    break;
+    }
+
+    pool_foreach (fib_table, mpls_main.fibs,
+    ({
+	if (table_id >= 0 && table_id != fib_table->ft_table_id)
+	    continue;
+
+	vlib_cli_output (vm, "%v, fib_index %d",
+			 fib_table->ft_desc, mpls_main.fibs - fib_table);
+
+	if (MPLS_LABEL_INVALID == label)
+	{
+	    mpls_fib_table_show_all(&(fib_table->mpls), vm);
+	}
+	else
+	{
+	    mpls_fib_table_show_one(&(fib_table->mpls), label, vm);
+	}
+    }));
+
+    return 0;
+}
+
+VLIB_CLI_COMMAND (mpls_fib_show_command, static) = {
+    .path = "show mpls fib",
+    .short_help = "show mpls fib [summary] [table <n>]",
+    .function = mpls_fib_show,
+};
diff --git a/src/vnet/fib/mpls_fib.h b/src/vnet/fib/mpls_fib.h
new file mode 100644
index 00000000000..93ae4623016
--- /dev/null
+++ b/src/vnet/fib/mpls_fib.h
@@ -0,0 +1,106 @@
+/*
+ * mpls_fib.h: The Label/MPLS FIB
+ *
+ * Copyright (c) 2012 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __MPLS_FIB_TABLE_H__
+#define __MPLS_FIB_TABLE_H__
+
+#include <vnet/vnet.h>
+#include <vnet/mpls/mpls.h>
+#include <vnet/fib/fib_types.h>
+#include <vnet/dpo/dpo.h>
+#include <vnet/mpls/mpls.h>
+#include <vnet/fib/fib_table.h>
+
+static inline mpls_fib_t*
+mpls_fib_get (fib_node_index_t index)
+{
+    if (!pool_is_free_index(mpls_main.fibs, index))
+	return (&(pool_elt_at_index(mpls_main.fibs, index)->mpls));
+    return (NULL);
+}
+
+extern u32 mpls_fib_table_find_or_create_and_lock(u32 table_id);
+extern u32 mpls_fib_table_create_and_lock(void);
+// extern mpls_fib_t * mpls_fib_find(u32 table_id);
+extern u32 mpls_fib_index_from_table_id(u32 table_id);
+
+extern u8 *format_mpls_fib_table_name(u8 * s, va_list * args);
+
+extern fib_node_index_t mpls_fib_table_entry_add_from_ip_fib_entry (
+    u32 table_id,
+    mpls_label_t label,
+    mpls_eos_bit_t eos,
+    fib_node_index_t fib_entry_index);
+
+
+extern fib_node_index_t mpls_fib_table_lookup(const mpls_fib_t *mf,
+					      mpls_label_t label,
+					      mpls_eos_bit_t eos);
+
+extern void mpls_fib_table_entry_remove(mpls_fib_t *mf,
+					mpls_label_t label,
+					mpls_eos_bit_t eos);
+extern void mpls_fib_table_entry_insert(mpls_fib_t *mf,
+					mpls_label_t label,
+					mpls_eos_bit_t eos,
+					fib_node_index_t fei);
+extern void mpls_fib_table_destroy(mpls_fib_t *mf);
+
+
+
+extern void mpls_fib_forwarding_table_update(mpls_fib_t *mf,
+					     mpls_label_t label,
+					     mpls_eos_bit_t eos,
+					     const dpo_id_t *dpo);
+extern void mpls_fib_forwarding_table_reset(mpls_fib_t *mf,
+					    mpls_label_t label,
+					    mpls_eos_bit_t eos);
+
+/**
+ * @brief
+ *  Lookup a label and EOS bit in the MPLS_FIB table to retrieve the
+ *  load-balance index to be used for packet forwarding.
+ */
+static inline index_t
+mpls_fib_table_forwarding_lookup (u32 mpls_fib_index,
+				  const mpls_unicast_header_t *hdr)
+{
+    mpls_label_t label;
+    mpls_fib_t *mf;
+    u32 key;
+
+    label = clib_net_to_host_u32(hdr->label_exp_s_ttl);
+    key = (vnet_mpls_uc_get_label(label) << 1) | vnet_mpls_uc_get_s(label);
+
+    mf = mpls_fib_get(mpls_fib_index);
+
+    return (mf->mf_lbs[key]);
+}
+
+static inline u32
+mpls_fib_table_get_index_for_sw_if_index (u32 sw_if_index)
+{
+    mpls_main_t *mm = &mpls_main;
+
+    ASSERT(vec_len(mm->fib_index_by_sw_if_index) > sw_if_index);
+
+    return (mm->fib_index_by_sw_if_index[sw_if_index]);
+}
+
+extern flow_hash_config_t mpls_fib_table_get_flow_hash_config(u32 fib_index);
+
+#endif