NAT: Rename snat plugin to nat (VPP-955)

Change-Id: I30a7e3da7a4efc6038a91e27b48045d4b07e2764
Signed-off-by: Matus Fabian <matfabia@cisco.com>

21 files changed, 21142 insertions, 0 deletions

diff --git a/src/plugins/nat/in2out.c b/src/plugins/nat/in2out.c
new file mode 100644
index 00000000000..62a11170ef3
--- /dev/null
+++ b/src/plugins/nat/in2out.c
@@ -0,0 +1,3454 @@
+/*
+ * 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/pg/pg.h>
+#include <vnet/handoff.h>
+
+#include <vnet/ip/ip.h>
+#include <vnet/ethernet/ethernet.h>
+#include <vnet/fib/ip4_fib.h>
+#include <nat/nat.h>
+#include <nat/nat_ipfix_logging.h>
+#include <nat/nat_det.h>
+
+#include <vppinfra/hash.h>
+#include <vppinfra/error.h>
+#include <vppinfra/elog.h>
+
+typedef struct {
+  u32 sw_if_index;
+  u32 next_index;
+  u32 session_index;
+  u32 is_slow_path;
+} snat_in2out_trace_t;
+
+typedef struct {
+  u32 next_worker_index;
+  u8 do_handoff;
+} snat_in2out_worker_handoff_trace_t;
+
+/* packet trace format function */
+static u8 * format_snat_in2out_trace (u8 * s, va_list * args)
+{
+  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
+  snat_in2out_trace_t * t = va_arg (*args, snat_in2out_trace_t *);
+  char * tag;
+
+  tag = t->is_slow_path ? "NAT44_IN2OUT_SLOW_PATH" : "NAT44_IN2OUT_FAST_PATH";
+
+  s = format (s, "%s: sw_if_index %d, next index %d, session %d", tag,
+              t->sw_if_index, t->next_index, t->session_index);
+
+  return s;
+}
+
+static u8 * format_snat_in2out_fast_trace (u8 * s, va_list * args)
+{
+  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
+  snat_in2out_trace_t * t = va_arg (*args, snat_in2out_trace_t *);
+
+  s = format (s, "NAT44_IN2OUT_FAST: sw_if_index %d, next index %d",
+              t->sw_if_index, t->next_index);
+
+  return s;
+}
+
+static u8 * format_snat_in2out_worker_handoff_trace (u8 * s, va_list * args)
+{
+  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
+  snat_in2out_worker_handoff_trace_t * t =
+    va_arg (*args, snat_in2out_worker_handoff_trace_t *);
+  char * m;
+
+  m = t->do_handoff ? "next worker" : "same worker";
+  s = format (s, "NAT44_IN2OUT_WORKER_HANDOFF: %s %d", m, t->next_worker_index);
+
+  return s;
+}
+
+vlib_node_registration_t snat_in2out_node;
+vlib_node_registration_t snat_in2out_slowpath_node;
+vlib_node_registration_t snat_in2out_fast_node;
+vlib_node_registration_t snat_in2out_worker_handoff_node;
+vlib_node_registration_t snat_det_in2out_node;
+vlib_node_registration_t snat_in2out_output_node;
+vlib_node_registration_t snat_in2out_output_slowpath_node;
+vlib_node_registration_t snat_in2out_output_worker_handoff_node;
+vlib_node_registration_t snat_hairpin_dst_node;
+vlib_node_registration_t snat_hairpin_src_node;
+
+
+#define foreach_snat_in2out_error                       \
+_(UNSUPPORTED_PROTOCOL, "Unsupported protocol")         \
+_(IN2OUT_PACKETS, "Good in2out packets processed")      \
+_(OUT_OF_PORTS, "Out of ports")                         \
+_(BAD_OUTSIDE_FIB, "Outside VRF ID not found")          \
+_(BAD_ICMP_TYPE, "unsupported ICMP type")               \
+_(NO_TRANSLATION, "No translation")
+
+typedef enum {
+#define _(sym,str) SNAT_IN2OUT_ERROR_##sym,
+  foreach_snat_in2out_error
+#undef _
+  SNAT_IN2OUT_N_ERROR,
+} snat_in2out_error_t;
+
+static char * snat_in2out_error_strings[] = {
+#define _(sym,string) string,
+  foreach_snat_in2out_error
+#undef _
+};
+
+typedef enum {
+  SNAT_IN2OUT_NEXT_LOOKUP,
+  SNAT_IN2OUT_NEXT_DROP,
+  SNAT_IN2OUT_NEXT_ICMP_ERROR,
+  SNAT_IN2OUT_NEXT_SLOW_PATH,
+  SNAT_IN2OUT_N_NEXT,
+} snat_in2out_next_t;
+
+typedef enum {
+  SNAT_HAIRPIN_SRC_NEXT_DROP,
+  SNAT_HAIRPIN_SRC_NEXT_SNAT_IN2OUT,
+  SNAT_HAIRPIN_SRC_NEXT_SNAT_IN2OUT_WH,
+  SNAT_HAIRPIN_SRC_NEXT_INTERFACE_OUTPUT,
+  SNAT_HAIRPIN_SRC_N_NEXT,
+} snat_hairpin_next_t;
+
+/**
+ * @brief Check if packet should be translated
+ *
+ * Packets aimed at outside interface and external addresss with active session
+ * should be translated.
+ *
+ * @param sm            NAT main
+ * @param rt            NAT runtime data
+ * @param sw_if_index0  index of the inside interface
+ * @param ip0           IPv4 header
+ * @param proto0        NAT protocol
+ * @param rx_fib_index0 RX FIB index
+ *
+ * @returns 0 if packet should be translated otherwise 1
+ */
+static inline int
+snat_not_translate_fast (snat_main_t * sm, vlib_node_runtime_t *node,
+                         u32 sw_if_index0, ip4_header_t * ip0, u32 proto0,
+                         u32 rx_fib_index0)
+{
+  fib_node_index_t fei = FIB_NODE_INDEX_INVALID;
+  fib_prefix_t pfx = {
+    .fp_proto = FIB_PROTOCOL_IP4,
+    .fp_len = 32,
+    .fp_addr = {
+        .ip4.as_u32 = ip0->dst_address.as_u32,
+    },
+  };
+
+  /* Don't NAT packet aimed at the intfc address */
+  if (PREDICT_FALSE(is_interface_addr(sm, node, sw_if_index0,
+                                      ip0->dst_address.as_u32)))
+    return 1;
+
+  fei = fib_table_lookup (rx_fib_index0, &pfx);
+  if (FIB_NODE_INDEX_INVALID != fei)
+    {
+      u32 sw_if_index = fib_entry_get_resolving_interface (fei);
+      if (sw_if_index == ~0)
+        {
+          fei = fib_table_lookup (sm->outside_fib_index, &pfx);
+          if (FIB_NODE_INDEX_INVALID != fei)
+            sw_if_index = fib_entry_get_resolving_interface (fei);
+        }
+      snat_interface_t *i;
+      pool_foreach (i, sm->interfaces,
+      ({
+        /* NAT packet aimed at outside interface */
+        if ((i->is_inside == 0) && (sw_if_index == i->sw_if_index))
+          return 0;
+      }));
+    }
+
+  return 1;
+}
+
+static inline int
+snat_not_translate (snat_main_t * sm, vlib_node_runtime_t *node,
+                    u32 sw_if_index0, ip4_header_t * ip0, u32 proto0,
+                    u32 rx_fib_index0)
+{
+  udp_header_t * udp0 = ip4_next_header (ip0);
+  snat_session_key_t key0, sm0;
+  clib_bihash_kv_8_8_t kv0, value0;
+
+  key0.addr = ip0->dst_address;
+  key0.port = udp0->dst_port;
+  key0.protocol = proto0;
+  key0.fib_index = sm->outside_fib_index;
+  kv0.key = key0.as_u64;
+
+  /* NAT packet aimed at external address if */
+  /* has active sessions */
+  if (clib_bihash_search_8_8 (&sm->out2in, &kv0, &value0))
+    {
+      /* or is static mappings */
+      if (!snat_static_mapping_match(sm, key0, &sm0, 1, 0))
+        return 0;
+    }
+  else
+    return 0;
+
+  return snat_not_translate_fast(sm, node, sw_if_index0, ip0, proto0,
+                                 rx_fib_index0);
+}
+
+static u32 slow_path (snat_main_t *sm, vlib_buffer_t *b0,
+                      ip4_header_t * ip0,
+                      u32 rx_fib_index0,
+                      snat_session_key_t * key0,
+                      snat_session_t ** sessionp,
+                      vlib_node_runtime_t * node,
+                      u32 next0,
+                      u32 thread_index)
+{
+  snat_user_t *u;
+  snat_user_key_t user_key;
+  snat_session_t *s;
+  clib_bihash_kv_8_8_t kv0, value0;
+  u32 oldest_per_user_translation_list_index;
+  dlist_elt_t * oldest_per_user_translation_list_elt;
+  dlist_elt_t * per_user_translation_list_elt;
+  dlist_elt_t * per_user_list_head_elt;
+  u32 session_index;
+  snat_session_key_t key1;
+  u32 address_index = ~0;
+  u32 outside_fib_index;
+  uword * p;
+  snat_worker_key_t worker_by_out_key;
+
+  p = hash_get (sm->ip4_main->fib_index_by_table_id, sm->outside_vrf_id);
+  if (! p)
+    {
+      b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_OUTSIDE_FIB];
+      return SNAT_IN2OUT_NEXT_DROP;
+    }
+  outside_fib_index = p[0];
+
+  key1.protocol = key0->protocol;
+  user_key.addr = ip0->src_address;
+  user_key.fib_index = rx_fib_index0;
+  kv0.key = user_key.as_u64;
+
+  /* Ever heard of the "user" = src ip4 address before? */
+  if (clib_bihash_search_8_8 (&sm->user_hash, &kv0, &value0))
+    {
+      /* no, make a new one */
+      pool_get (sm->per_thread_data[thread_index].users, u);
+      memset (u, 0, sizeof (*u));
+      u->addr = ip0->src_address;
+      u->fib_index = rx_fib_index0;
+
+      pool_get (sm->per_thread_data[thread_index].list_pool, per_user_list_head_elt);
+
+      u->sessions_per_user_list_head_index = per_user_list_head_elt -
+        sm->per_thread_data[thread_index].list_pool;
+
+      clib_dlist_init (sm->per_thread_data[thread_index].list_pool,
+                       u->sessions_per_user_list_head_index);
+
+      kv0.value = u - sm->per_thread_data[thread_index].users;
+
+      /* add user */
+      clib_bihash_add_del_8_8 (&sm->user_hash, &kv0, 1 /* is_add */);
+    }
+  else
+    {
+      u = pool_elt_at_index (sm->per_thread_data[thread_index].users,
+                             value0.value);
+    }
+
+  /* Over quota? Recycle the least recently used dynamic translation */
+  if (u->nsessions >= sm->max_translations_per_user)
+    {
+      /* Remove the oldest dynamic translation */
+      do {
+          oldest_per_user_translation_list_index =
+            clib_dlist_remove_head (sm->per_thread_data[thread_index].list_pool,
+                                    u->sessions_per_user_list_head_index);
+
+          ASSERT (oldest_per_user_translation_list_index != ~0);
+
+          /* add it back to the end of the LRU list */
+          clib_dlist_addtail (sm->per_thread_data[thread_index].list_pool,
+                              u->sessions_per_user_list_head_index,
+                              oldest_per_user_translation_list_index);
+          /* Get the list element */
+          oldest_per_user_translation_list_elt =
+            pool_elt_at_index (sm->per_thread_data[thread_index].list_pool,
+                               oldest_per_user_translation_list_index);
+
+          /* Get the session index from the list element */
+          session_index = oldest_per_user_translation_list_elt->value;
+
+          /* Get the session */
+          s = pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
+                                 session_index);
+      } while (snat_is_session_static (s));
+
+      if (snat_is_unk_proto_session (s))
+        {
+          clib_bihash_kv_16_8_t up_kv;
+          snat_unk_proto_ses_key_t key;
+
+          /* Remove from lookup tables */
+          key.l_addr = s->in2out.addr;
+          key.r_addr = s->ext_host_addr;
+          key.fib_index = s->in2out.fib_index;
+          key.proto = s->in2out.port;
+          up_kv.key[0] = key.as_u64[0];
+          up_kv.key[1] = key.as_u64[1];
+          if (clib_bihash_add_del_16_8 (&sm->in2out_unk_proto, &up_kv, 0))
+            clib_warning ("in2out key del failed");
+
+          key.l_addr = s->out2in.addr;
+          key.fib_index = s->out2in.fib_index;
+          up_kv.key[0] = key.as_u64[0];
+          up_kv.key[1] = key.as_u64[1];
+          if (clib_bihash_add_del_16_8 (&sm->out2in_unk_proto, &up_kv, 0))
+            clib_warning ("out2in key del failed");
+        }
+      else
+        {
+          /* Remove in2out, out2in keys */
+          kv0.key = s->in2out.as_u64;
+          if (clib_bihash_add_del_8_8 (&sm->in2out, &kv0, 0 /* is_add */))
+              clib_warning ("in2out key delete failed");
+          kv0.key = s->out2in.as_u64;
+          if (clib_bihash_add_del_8_8 (&sm->out2in, &kv0, 0 /* is_add */))
+              clib_warning ("out2in key delete failed");
+
+          /* log NAT event */
+          snat_ipfix_logging_nat44_ses_delete(s->in2out.addr.as_u32,
+                                              s->out2in.addr.as_u32,
+                                              s->in2out.protocol,
+                                              s->in2out.port,
+                                              s->out2in.port,
+                                              s->in2out.fib_index);
+
+          snat_free_outside_address_and_port
+            (sm, &s->out2in, s->outside_address_index);
+        }
+      s->outside_address_index = ~0;
+
+      if (snat_alloc_outside_address_and_port (sm, rx_fib_index0, thread_index,
+                                               &key1, &address_index))
+        {
+          ASSERT(0);
+
+          b0->error = node->errors[SNAT_IN2OUT_ERROR_OUT_OF_PORTS];
+          return SNAT_IN2OUT_NEXT_DROP;
+        }
+      s->outside_address_index = address_index;
+    }
+  else
+    {
+      u8 static_mapping = 1;
+
+      /* First try to match static mapping by local address and port */
+      if (snat_static_mapping_match (sm, *key0, &key1, 0, 0))
+        {
+          static_mapping = 0;
+          /* Try to create dynamic translation */
+          if (snat_alloc_outside_address_and_port (sm, rx_fib_index0,
+                                                   thread_index, &key1,
+                                                   &address_index))
+            {
+              b0->error = node->errors[SNAT_IN2OUT_ERROR_OUT_OF_PORTS];
+              return SNAT_IN2OUT_NEXT_DROP;
+            }
+        }
+
+      /* Create a new session */
+      pool_get (sm->per_thread_data[thread_index].sessions, s);
+      memset (s, 0, sizeof (*s));
+
+      s->outside_address_index = address_index;
+
+      if (static_mapping)
+        {
+          u->nstaticsessions++;
+          s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
+        }
+      else
+        {
+          u->nsessions++;
+        }
+
+      /* Create list elts */
+      pool_get (sm->per_thread_data[thread_index].list_pool,
+                per_user_translation_list_elt);
+      clib_dlist_init (sm->per_thread_data[thread_index].list_pool,
+                       per_user_translation_list_elt -
+                       sm->per_thread_data[thread_index].list_pool);
+
+      per_user_translation_list_elt->value =
+        s - sm->per_thread_data[thread_index].sessions;
+      s->per_user_index = per_user_translation_list_elt -
+                          sm->per_thread_data[thread_index].list_pool;
+      s->per_user_list_head_index = u->sessions_per_user_list_head_index;
+
+      clib_dlist_addtail (sm->per_thread_data[thread_index].list_pool,
+                          s->per_user_list_head_index,
+                          per_user_translation_list_elt -
+                          sm->per_thread_data[thread_index].list_pool);
+   }
+
+  s->in2out = *key0;
+  s->out2in = key1;
+  s->out2in.protocol = key0->protocol;
+  s->out2in.fib_index = outside_fib_index;
+  s->ext_host_addr.as_u32 = ip0->dst_address.as_u32;
+  *sessionp = s;
+
+  /* Add to translation hashes */
+  kv0.key = s->in2out.as_u64;
+  kv0.value = s - sm->per_thread_data[thread_index].sessions;
+  if (clib_bihash_add_del_8_8 (&sm->in2out, &kv0, 1 /* is_add */))
+      clib_warning ("in2out key add failed");
+
+  kv0.key = s->out2in.as_u64;
+  kv0.value = s - sm->per_thread_data[thread_index].sessions;
+
+  if (clib_bihash_add_del_8_8 (&sm->out2in, &kv0, 1 /* is_add */))
+      clib_warning ("out2in key add failed");
+
+  /* Add to translated packets worker lookup */
+  worker_by_out_key.addr = s->out2in.addr;
+  worker_by_out_key.port = s->out2in.port;
+  worker_by_out_key.fib_index = s->out2in.fib_index;
+  kv0.key = worker_by_out_key.as_u64;
+  kv0.value = thread_index;
+  clib_bihash_add_del_8_8 (&sm->worker_by_out, &kv0, 1);
+
+  /* log NAT event */
+  snat_ipfix_logging_nat44_ses_create(s->in2out.addr.as_u32,
+                                      s->out2in.addr.as_u32,
+                                      s->in2out.protocol,
+                                      s->in2out.port,
+                                      s->out2in.port,
+                                      s->in2out.fib_index);
+  return next0;
+}
+
+static_always_inline
+snat_in2out_error_t icmp_get_key(ip4_header_t *ip0,
+                                 snat_session_key_t *p_key0)
+{
+  icmp46_header_t *icmp0;
+  snat_session_key_t key0;
+  icmp_echo_header_t *echo0, *inner_echo0 = 0;
+  ip4_header_t *inner_ip0 = 0;
+  void *l4_header = 0;
+  icmp46_header_t *inner_icmp0;
+
+  icmp0 = (icmp46_header_t *) ip4_next_header (ip0);
+  echo0 = (icmp_echo_header_t *)(icmp0+1);
+
+  if (!icmp_is_error_message (icmp0))
+    {
+      key0.protocol = SNAT_PROTOCOL_ICMP;
+      key0.addr = ip0->src_address;
+      key0.port = echo0->identifier;
+    }
+  else
+    {
+      inner_ip0 = (ip4_header_t *)(echo0+1);
+      l4_header = ip4_next_header (inner_ip0);
+      key0.protocol = ip_proto_to_snat_proto (inner_ip0->protocol);
+      key0.addr = inner_ip0->dst_address;
+      switch (key0.protocol)
+        {
+        case SNAT_PROTOCOL_ICMP:
+          inner_icmp0 = (icmp46_header_t*)l4_header;
+          inner_echo0 = (icmp_echo_header_t *)(inner_icmp0+1);
+          key0.port = inner_echo0->identifier;
+          break;
+        case SNAT_PROTOCOL_UDP:
+        case SNAT_PROTOCOL_TCP:
+          key0.port = ((tcp_udp_header_t*)l4_header)->dst_port;
+          break;
+        default:
+          return SNAT_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL;
+        }
+    }
+  *p_key0 = key0;
+  return -1; /* success */
+}
+
+/**
+ * Get address and port values to be used for ICMP packet translation
+ * and create session if needed
+ *
+ * @param[in,out] sm             NAT main
+ * @param[in,out] node           NAT node runtime
+ * @param[in] thread_index       thread index
+ * @param[in,out] b0             buffer containing packet to be translated
+ * @param[out] p_proto           protocol used for matching
+ * @param[out] p_value           address and port after NAT translation
+ * @param[out] p_dont_translate  if packet should not be translated
+ * @param d                      optional parameter
+ * @param e                      optional parameter
+ */
+u32 icmp_match_in2out_slow(snat_main_t *sm, vlib_node_runtime_t *node,
+                           u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
+                           snat_session_key_t *p_value,
+                           u8 *p_dont_translate, void *d, void *e)
+{
+  ip4_header_t *ip0;
+  icmp46_header_t *icmp0;
+  u32 sw_if_index0;
+  u32 rx_fib_index0;
+  snat_session_key_t key0;
+  snat_session_t *s0 = 0;
+  u8 dont_translate = 0;
+  clib_bihash_kv_8_8_t kv0, value0;
+  u32 next0 = ~0;
+  int err;
+  u32 iph_offset0 = 0;
+
+  if (PREDICT_FALSE(vnet_buffer(b0)->sw_if_index[VLIB_TX] != ~0))
+    {
+      iph_offset0 = vnet_buffer (b0)->ip.save_rewrite_length;
+    }
+  ip0 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b0) + iph_offset0);
+  icmp0 = (icmp46_header_t *) ip4_next_header (ip0);
+  sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
+  rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index (sw_if_index0);
+
+  err = icmp_get_key (ip0, &key0);
+  if (err != -1)
+    {
+      b0->error = node->errors[err];
+      next0 = SNAT_IN2OUT_NEXT_DROP;
+      goto out;
+    }
+  key0.fib_index = rx_fib_index0;
+
+  kv0.key = key0.as_u64;
+
+  if (clib_bihash_search_8_8 (&sm->in2out, &kv0, &value0))
+    {
+      if (PREDICT_FALSE(snat_not_translate(sm, node, sw_if_index0, ip0,
+          IP_PROTOCOL_ICMP, rx_fib_index0) &&
+          vnet_buffer(b0)->sw_if_index[VLIB_TX] == ~0))
+        {
+          dont_translate = 1;
+          goto out;
+        }
+
+      if (PREDICT_FALSE(icmp_is_error_message (icmp0)))
+        {
+          b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
+          next0 = SNAT_IN2OUT_NEXT_DROP;
+          goto out;
+        }
+
+      next0 = slow_path (sm, b0, ip0, rx_fib_index0, &key0,
+                         &s0, node, next0, thread_index);
+
+      if (PREDICT_FALSE (next0 == SNAT_IN2OUT_NEXT_DROP))
+        goto out;
+    }
+  else
+    {
+      if (PREDICT_FALSE(icmp0->type != ICMP4_echo_request &&
+                        icmp0->type != ICMP4_echo_reply &&
+                        !icmp_is_error_message (icmp0)))
+        {
+          b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
+          next0 = SNAT_IN2OUT_NEXT_DROP;
+          goto out;
+        }
+
+      s0 = pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
+                              value0.value);
+    }
+
+out:
+  *p_proto = key0.protocol;
+  if (s0)
+    *p_value = s0->out2in;
+  *p_dont_translate = dont_translate;
+  if (d)
+    *(snat_session_t**)d = s0;
+  return next0;
+}
+
+/**
+ * Get address and port values to be used for ICMP packet translation
+ *
+ * @param[in] sm                 NAT main
+ * @param[in,out] node           NAT node runtime
+ * @param[in] thread_index       thread index
+ * @param[in,out] b0             buffer containing packet to be translated
+ * @param[out] p_proto           protocol used for matching
+ * @param[out] p_value           address and port after NAT translation
+ * @param[out] p_dont_translate  if packet should not be translated
+ * @param d                      optional parameter
+ * @param e                      optional parameter
+ */
+u32 icmp_match_in2out_fast(snat_main_t *sm, vlib_node_runtime_t *node,
+                           u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
+                           snat_session_key_t *p_value,
+                           u8 *p_dont_translate, void *d, void *e)
+{
+  ip4_header_t *ip0;
+  icmp46_header_t *icmp0;
+  u32 sw_if_index0;
+  u32 rx_fib_index0;
+  snat_session_key_t key0;
+  snat_session_key_t sm0;
+  u8 dont_translate = 0;
+  u8 is_addr_only;
+  u32 next0 = ~0;
+  int err;
+
+  ip0 = vlib_buffer_get_current (b0);
+  icmp0 = (icmp46_header_t *) ip4_next_header (ip0);
+  sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
+  rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index (sw_if_index0);
+
+  err = icmp_get_key (ip0, &key0);
+  if (err != -1)
+    {
+      b0->error = node->errors[err];
+      next0 = SNAT_IN2OUT_NEXT_DROP;
+      goto out2;
+    }
+  key0.fib_index = rx_fib_index0;
+
+  if (snat_static_mapping_match(sm, key0, &sm0, 0, &is_addr_only))
+    {
+      if (PREDICT_FALSE(snat_not_translate_fast(sm, node, sw_if_index0, ip0,
+          IP_PROTOCOL_ICMP, rx_fib_index0)))
+        {
+          dont_translate = 1;
+          goto out;
+        }
+
+      if (icmp_is_error_message (icmp0))
+        {
+          next0 = SNAT_IN2OUT_NEXT_DROP;
+          goto out;
+        }
+
+      b0->error = node->errors[SNAT_IN2OUT_ERROR_NO_TRANSLATION];
+      next0 = SNAT_IN2OUT_NEXT_DROP;
+      goto out;
+    }
+
+  if (PREDICT_FALSE(icmp0->type != ICMP4_echo_request &&
+                    (icmp0->type != ICMP4_echo_reply || !is_addr_only) &&
+                    !icmp_is_error_message (icmp0)))
+    {
+      b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
+      next0 = SNAT_IN2OUT_NEXT_DROP;
+      goto out;
+    }
+
+out:
+  *p_value = sm0;
+out2:
+  *p_proto = key0.protocol;
+  *p_dont_translate = dont_translate;
+  return next0;
+}
+
+static inline u32 icmp_in2out (snat_main_t *sm,
+                               vlib_buffer_t * b0,
+                               ip4_header_t * ip0,
+                               icmp46_header_t * icmp0,
+                               u32 sw_if_index0,
+                               u32 rx_fib_index0,
+                               vlib_node_runtime_t * node,
+                               u32 next0,
+                               u32 thread_index,
+                               void *d,
+                               void *e)
+{
+  snat_session_key_t sm0;
+  u8 protocol;
+  icmp_echo_header_t *echo0, *inner_echo0 = 0;
+  ip4_header_t *inner_ip0;
+  void *l4_header = 0;
+  icmp46_header_t *inner_icmp0;
+  u8 dont_translate;
+  u32 new_addr0, old_addr0;
+  u16 old_id0, new_id0;
+  ip_csum_t sum0;
+  u16 checksum0;
+  u32 next0_tmp;
+
+  echo0 = (icmp_echo_header_t *)(icmp0+1);
+
+  next0_tmp = sm->icmp_match_in2out_cb(sm, node, thread_index, b0,
+                                       &protocol, &sm0, &dont_translate, d, e);
+  if (next0_tmp != ~0)
+    next0 = next0_tmp;
+  if (next0 == SNAT_IN2OUT_NEXT_DROP || dont_translate)
+    goto out;
+
+  sum0 = ip_incremental_checksum (0, icmp0,
+                                  ntohs(ip0->length) - ip4_header_bytes (ip0));
+  checksum0 = ~ip_csum_fold (sum0);
+  if (PREDICT_FALSE(checksum0 != 0 && checksum0 != 0xffff))
+    {
+      next0 = SNAT_IN2OUT_NEXT_DROP;
+      goto out;
+    }
+
+  old_addr0 = ip0->src_address.as_u32;
+  new_addr0 = ip0->src_address.as_u32 = sm0.addr.as_u32;
+  if (vnet_buffer(b0)->sw_if_index[VLIB_TX] == ~0)
+    vnet_buffer(b0)->sw_if_index[VLIB_TX] = sm0.fib_index;
+
+  sum0 = ip0->checksum;
+  sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
+                         src_address /* changed member */);
+  ip0->checksum = ip_csum_fold (sum0);
+
+  if (!icmp_is_error_message (icmp0))
+    {
+      new_id0 = sm0.port;
+      if (PREDICT_FALSE(new_id0 != echo0->identifier))
+        {
+          old_id0 = echo0->identifier;
+          new_id0 = sm0.port;
+          echo0->identifier = new_id0;
+
+          sum0 = icmp0->checksum;
+          sum0 = ip_csum_update (sum0, old_id0, new_id0, icmp_echo_header_t,
+                                 identifier);
+          icmp0->checksum = ip_csum_fold (sum0);
+        }
+    }
+  else
+    {
+      inner_ip0 = (ip4_header_t *)(echo0+1);
+      l4_header = ip4_next_header (inner_ip0);
+
+      if (!ip4_header_checksum_is_valid (inner_ip0))
+        {
+          next0 = SNAT_IN2OUT_NEXT_DROP;
+          goto out;
+        }
+
+      old_addr0 = inner_ip0->dst_address.as_u32;
+      inner_ip0->dst_address = sm0.addr;
+      new_addr0 = inner_ip0->dst_address.as_u32;
+
+      sum0 = icmp0->checksum;
+      sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
+                             dst_address /* changed member */);
+      icmp0->checksum = ip_csum_fold (sum0);
+
+      switch (protocol)
+        {
+          case SNAT_PROTOCOL_ICMP:
+            inner_icmp0 = (icmp46_header_t*)l4_header;
+            inner_echo0 = (icmp_echo_header_t *)(inner_icmp0+1);
+
+            old_id0 = inner_echo0->identifier;
+            new_id0 = sm0.port;
+            inner_echo0->identifier = new_id0;
+
+            sum0 = icmp0->checksum;
+            sum0 = ip_csum_update (sum0, old_id0, new_id0, icmp_echo_header_t,
+                                   identifier);
+            icmp0->checksum = ip_csum_fold (sum0);
+            break;
+          case SNAT_PROTOCOL_UDP:
+          case SNAT_PROTOCOL_TCP:
+            old_id0 = ((tcp_udp_header_t*)l4_header)->dst_port;
+            new_id0 = sm0.port;
+            ((tcp_udp_header_t*)l4_header)->dst_port = new_id0;
+
+            sum0 = icmp0->checksum;
+            sum0 = ip_csum_update (sum0, old_id0, new_id0, tcp_udp_header_t,
+                                   dst_port);
+            icmp0->checksum = ip_csum_fold (sum0);
+            break;
+          default:
+            ASSERT(0);
+        }
+    }
+
+out:
+  return next0;
+}
+
+/**
+ * @brief Hairpinning
+ *
+ * Hairpinning allows two endpoints on the internal side of the NAT to
+ * communicate even if they only use each other's external IP addresses
+ * and ports.
+ *
+ * @param sm     NAT main.
+ * @param b0     Vlib buffer.
+ * @param ip0    IP header.
+ * @param udp0   UDP header.
+ * @param tcp0   TCP header.
+ * @param proto0 NAT protocol.
+ */
+static inline void
+snat_hairpinning (snat_main_t *sm,
+                  vlib_buffer_t * b0,
+                  ip4_header_t * ip0,
+                  udp_header_t * udp0,
+                  tcp_header_t * tcp0,
+                  u32 proto0)
+{
+  snat_session_key_t key0, sm0;
+  snat_worker_key_t k0;
+  snat_session_t * s0;
+  clib_bihash_kv_8_8_t kv0, value0;
+  ip_csum_t sum0;
+  u32 new_dst_addr0 = 0, old_dst_addr0, ti = 0, si;
+  u16 new_dst_port0, old_dst_port0;
+
+  key0.addr = ip0->dst_address;
+  key0.port = udp0->dst_port;
+  key0.protocol = proto0;
+  key0.fib_index = sm->outside_fib_index;
+  kv0.key = key0.as_u64;
+
+  /* Check if destination is in active sessions */
+  if (clib_bihash_search_8_8 (&sm->out2in, &kv0, &value0))
+    {
+      /* or static mappings */
+      if (!snat_static_mapping_match(sm, key0, &sm0, 1, 0))
+        {
+          new_dst_addr0 = sm0.addr.as_u32;
+          new_dst_port0 = sm0.port;
+          vnet_buffer(b0)->sw_if_index[VLIB_TX] = sm0.fib_index;
+        }
+    }
+  else
+    {
+      si = value0.value;
+      if (sm->num_workers > 1)
+        {
+          k0.addr = ip0->dst_address;
+          k0.port = udp0->dst_port;
+          k0.fib_index = sm->outside_fib_index;
+          kv0.key = k0.as_u64;
+          if (clib_bihash_search_8_8 (&sm->worker_by_out, &kv0, &value0))
+            ASSERT(0);
+          else
+            ti = value0.value;
+        }
+      else
+        ti = sm->num_workers;
+
+      s0 = pool_elt_at_index (sm->per_thread_data[ti].sessions, si);
+      new_dst_addr0 = s0->in2out.addr.as_u32;
+      new_dst_port0 = s0->in2out.port;
+      vnet_buffer(b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
+    }
+
+  /* Destination is behind the same NAT, use internal address and port */
+  if (new_dst_addr0)
+    {
+      old_dst_addr0 = ip0->dst_address.as_u32;
+      ip0->dst_address.as_u32 = new_dst_addr0;
+      sum0 = ip0->checksum;
+      sum0 = ip_csum_update (sum0, old_dst_addr0, new_dst_addr0,
+                             ip4_header_t, dst_address);
+      ip0->checksum = ip_csum_fold (sum0);
+
+      old_dst_port0 = tcp0->dst;
+      if (PREDICT_TRUE(new_dst_port0 != old_dst_port0))
+        {
+          if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
+            {
+              tcp0->dst = new_dst_port0;
+              sum0 = tcp0->checksum;
+              sum0 = ip_csum_update (sum0, old_dst_addr0, new_dst_addr0,
+                                     ip4_header_t, dst_address);
+              sum0 = ip_csum_update (sum0, old_dst_port0, new_dst_port0,
+                                     ip4_header_t /* cheat */, length);
+              tcp0->checksum = ip_csum_fold(sum0);
+            }
+          else
+            {
+              udp0->dst_port = new_dst_port0;
+              udp0->checksum = 0;
+            }
+        }
+      else
+        {
+          if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
+            {
+              sum0 = tcp0->checksum;
+              sum0 = ip_csum_update (sum0, old_dst_addr0, new_dst_addr0,
+                                     ip4_header_t, dst_address);
+              tcp0->checksum = ip_csum_fold(sum0);
+            }
+        }
+    }
+}
+
+static inline void
+snat_icmp_hairpinning (snat_main_t *sm,
+                       vlib_buffer_t * b0,
+                       ip4_header_t * ip0,
+                       icmp46_header_t * icmp0)
+{
+  snat_session_key_t key0, sm0;
+  clib_bihash_kv_8_8_t kv0, value0;
+  snat_worker_key_t k0;
+  u32 new_dst_addr0 = 0, old_dst_addr0, si, ti = 0;
+  ip_csum_t sum0;
+  snat_session_t *s0;
+
+  if (!icmp_is_error_message (icmp0))
+    {
+      icmp_echo_header_t *echo0 = (icmp_echo_header_t *)(icmp0+1);
+      u16 icmp_id0 = echo0->identifier;
+      key0.addr = ip0->dst_address;
+      key0.port = icmp_id0;
+      key0.protocol = SNAT_PROTOCOL_ICMP;
+      key0.fib_index = sm->outside_fib_index;
+      kv0.key = key0.as_u64;
+
+      /* Check if destination is in active sessions */
+      if (clib_bihash_search_8_8 (&sm->out2in, &kv0, &value0))
+        {
+          /* or static mappings */
+          if (!snat_static_mapping_match(sm, key0, &sm0, 1, 0))
+            {
+              new_dst_addr0 = sm0.addr.as_u32;
+              vnet_buffer(b0)->sw_if_index[VLIB_TX] = sm0.fib_index;
+            }
+        }
+      else
+        {
+          si = value0.value;
+          if (sm->num_workers > 1)
+            {
+              k0.addr = ip0->dst_address;
+              k0.port = icmp_id0;
+              k0.fib_index = sm->outside_fib_index;
+              kv0.key = k0.as_u64;
+              if (clib_bihash_search_8_8 (&sm->worker_by_out, &kv0, &value0))
+                ASSERT(0);
+              else
+                ti = value0.value;
+            }
+          else
+            ti = sm->num_workers;
+
+          s0 = pool_elt_at_index (sm->per_thread_data[ti].sessions, si);
+          new_dst_addr0 = s0->in2out.addr.as_u32;
+          vnet_buffer(b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
+          echo0->identifier = s0->in2out.port;
+          sum0 = icmp0->checksum;
+          sum0 = ip_csum_update (sum0, icmp_id0, s0->in2out.port,
+                                 icmp_echo_header_t, identifier);
+          icmp0->checksum = ip_csum_fold (sum0);
+        }
+
+      /* Destination is behind the same NAT, use internal address and port */
+      if (new_dst_addr0)
+        {
+          old_dst_addr0 = ip0->dst_address.as_u32;
+          ip0->dst_address.as_u32 = new_dst_addr0;
+          sum0 = ip0->checksum;
+          sum0 = ip_csum_update (sum0, old_dst_addr0, new_dst_addr0,
+                                 ip4_header_t, dst_address);
+          ip0->checksum = ip_csum_fold (sum0);
+        }
+    }
+
+}
+
+static inline u32 icmp_in2out_slow_path (snat_main_t *sm,
+                                         vlib_buffer_t * b0,
+                                         ip4_header_t * ip0,
+                                         icmp46_header_t * icmp0,
+                                         u32 sw_if_index0,
+                                         u32 rx_fib_index0,
+                                         vlib_node_runtime_t * node,
+                                         u32 next0,
+                                         f64 now,
+                                         u32 thread_index,
+                                         snat_session_t ** p_s0)
+{
+  next0 = icmp_in2out(sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
+                      next0, thread_index, p_s0, 0);
+  snat_session_t * s0 = *p_s0;
+  if (PREDICT_TRUE(next0 != SNAT_IN2OUT_NEXT_DROP && s0))
+    {
+      /* Hairpinning */
+      if (vnet_buffer(b0)->sw_if_index[VLIB_TX] == 0)
+        snat_icmp_hairpinning(sm, b0, ip0, icmp0);
+      /* Accounting */
+      s0->last_heard = now;
+      s0->total_pkts++;
+      s0->total_bytes += vlib_buffer_length_in_chain (sm->vlib_main, b0);
+      /* Per-user LRU list maintenance for dynamic translations */
+      if (!snat_is_session_static (s0))
+        {
+          clib_dlist_remove (sm->per_thread_data[thread_index].list_pool,
+                             s0->per_user_index);
+          clib_dlist_addtail (sm->per_thread_data[thread_index].list_pool,
+                              s0->per_user_list_head_index,
+                              s0->per_user_index);
+        }
+    }
+  return next0;
+}
+static inline void
+snat_hairpinning_unknown_proto (snat_main_t *sm,
+                                vlib_buffer_t * b,
+                                ip4_header_t * ip)
+{
+  u32 old_addr, new_addr = 0, ti = 0;
+  clib_bihash_kv_8_8_t kv, value;
+  clib_bihash_kv_16_8_t s_kv, s_value;
+  snat_unk_proto_ses_key_t key;
+  snat_session_key_t m_key;
+  snat_worker_key_t w_key;
+  snat_static_mapping_t *m;
+  ip_csum_t sum;
+  snat_session_t *s;
+
+  old_addr = ip->dst_address.as_u32;
+  key.l_addr.as_u32 = ip->dst_address.as_u32;
+  key.r_addr.as_u32 = ip->src_address.as_u32;
+  key.fib_index = sm->outside_fib_index;
+  key.proto = ip->protocol;
+  key.rsvd[0] = key.rsvd[1] = key.rsvd[2] = 0;
+  s_kv.key[0] = key.as_u64[0];
+  s_kv.key[1] = key.as_u64[1];
+  if (clib_bihash_search_16_8 (&sm->out2in_unk_proto, &s_kv, &s_value))
+    {
+      m_key.addr = ip->dst_address;
+      m_key.fib_index = sm->outside_fib_index;
+      m_key.port = 0;
+      m_key.protocol = 0;
+      kv.key = m_key.as_u64;
+      if (clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv, &value))
+        return;
+
+      m = pool_elt_at_index (sm->static_mappings, value.value);
+      if (vnet_buffer(b)->sw_if_index[VLIB_TX] == ~0)
+        vnet_buffer(b)->sw_if_index[VLIB_TX] = m->fib_index;
+      new_addr = ip->dst_address.as_u32 = m->local_addr.as_u32;
+    }
+  else
+    {
+      if (sm->num_workers > 1)
+        {
+          w_key.addr = ip->dst_address;
+          w_key.port = 0;
+          w_key.fib_index = sm->outside_fib_index;
+          kv.key = w_key.as_u64;
+          if (clib_bihash_search_8_8 (&sm->worker_by_out, &kv, &value))
+            return;
+          else
+            ti = value.value;
+        }
+      else
+        ti = sm->num_workers;
+
+      s = pool_elt_at_index (sm->per_thread_data[ti].sessions, s_value.value);
+      if (vnet_buffer(b)->sw_if_index[VLIB_TX] == ~0)
+        vnet_buffer(b)->sw_if_index[VLIB_TX] = s->in2out.fib_index;
+      new_addr = ip->dst_address.as_u32 = s->in2out.addr.as_u32;
+    }
+  sum = ip->checksum;
+  sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, dst_address);
+  ip->checksum = ip_csum_fold (sum);
+}
+
+static void
+snat_in2out_unknown_proto (snat_main_t *sm,
+                           vlib_buffer_t * b,
+                           ip4_header_t * ip,
+                           u32 rx_fib_index,
+                           u32 thread_index,
+                           f64 now,
+                           vlib_main_t * vm)
+{
+  clib_bihash_kv_8_8_t kv, value;
+  clib_bihash_kv_16_8_t s_kv, s_value;
+  snat_static_mapping_t *m;
+  snat_session_key_t m_key;
+  u32 old_addr, new_addr = 0;
+  ip_csum_t sum;
+  snat_user_key_t u_key;
+  snat_user_t *u;
+  dlist_elt_t *head, *elt, *oldest;
+  snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
+  u32 elt_index, head_index, ses_index, oldest_index;
+  snat_session_t * s;
+  snat_unk_proto_ses_key_t key;
+  u32 address_index = ~0;
+  int i;
+  u8 is_sm = 0;
+
+  old_addr = ip->src_address.as_u32;
+
+  key.l_addr = ip->src_address;
+  key.r_addr = ip->dst_address;
+  key.fib_index = rx_fib_index;
+  key.proto = ip->protocol;
+  key.rsvd[0] = key.rsvd[1] = key.rsvd[2] = 0;
+  s_kv.key[0] = key.as_u64[0];
+  s_kv.key[1] = key.as_u64[1];
+
+  if (!clib_bihash_search_16_8 (&sm->in2out_unk_proto, &s_kv, &s_value))
+    {
+      s = pool_elt_at_index (tsm->sessions, s_value.value);
+      new_addr = ip->src_address.as_u32 = s->out2in.addr.as_u32;
+    }
+  else
+    {
+      u_key.addr = ip->src_address;
+      u_key.fib_index = rx_fib_index;
+      kv.key = u_key.as_u64;
+
+      /* Ever heard of the "user" = src ip4 address before? */
+      if (clib_bihash_search_8_8 (&sm->user_hash, &kv, &value))
+        {
+          /* no, make a new one */
+          pool_get (tsm->users, u);
+          memset (u, 0, sizeof (*u));
+          u->addr = ip->src_address;
+          u->fib_index = rx_fib_index;
+
+          pool_get (tsm->list_pool, head);
+          u->sessions_per_user_list_head_index = head - tsm->list_pool;
+
+          clib_dlist_init (tsm->list_pool,
+                           u->sessions_per_user_list_head_index);
+
+          kv.value = u - tsm->users;
+
+          /* add user */
+          clib_bihash_add_del_8_8 (&sm->user_hash, &kv, 1);
+        }
+      else
+        {
+          u = pool_elt_at_index (tsm->users, value.value);
+        }
+
+      m_key.addr = ip->src_address;
+      m_key.port = 0;
+      m_key.protocol = 0;
+      m_key.fib_index = rx_fib_index;
+      kv.key = m_key.as_u64;
+
+      /* Try to find static mapping first */
+      if (!clib_bihash_search_8_8 (&sm->static_mapping_by_local, &kv, &value))
+        {
+          m = pool_elt_at_index (sm->static_mappings, value.value);
+          new_addr = ip->src_address.as_u32 = m->external_addr.as_u32;
+          is_sm = 1;
+          goto create_ses;
+        }
+      /* Fallback to 3-tuple key */
+      else
+        {
+          /* Choose same out address as for TCP/UDP session to same destination */
+          if (!clib_bihash_search_8_8 (&sm->user_hash, &kv, &value))
+            {
+              head_index = u->sessions_per_user_list_head_index;
+              head = pool_elt_at_index (tsm->list_pool, head_index);
+              elt_index = head->next;
+              elt = pool_elt_at_index (tsm->list_pool, elt_index);
+              ses_index = elt->value;
+              while (ses_index != ~0)
+                {
+                  s =  pool_elt_at_index (tsm->sessions, ses_index);
+                  elt_index = elt->next;
+                  elt = pool_elt_at_index (tsm->list_pool, elt_index);
+                  ses_index = elt->value;
+
+                  if (s->ext_host_addr.as_u32 == ip->dst_address.as_u32)
+                    {
+                      new_addr = ip->src_address.as_u32 = s->out2in.addr.as_u32;
+                      address_index = s->outside_address_index;
+
+                      key.fib_index = sm->outside_fib_index;
+                      key.l_addr.as_u32 = new_addr;
+                      s_kv.key[0] = key.as_u64[0];
+                      s_kv.key[1] = key.as_u64[1];
+                      if (clib_bihash_search_16_8 (&sm->out2in_unk_proto, &s_kv, &s_value))
+                        break;
+
+                      goto create_ses;
+                    }
+                }
+            }
+          key.fib_index = sm->outside_fib_index;
+          for (i = 0; i < vec_len (sm->addresses); i++)
+            {
+              key.l_addr.as_u32 = sm->addresses[i].addr.as_u32;
+              s_kv.key[0] = key.as_u64[0];
+              s_kv.key[1] = key.as_u64[1];
+              if (clib_bihash_search_16_8 (&sm->out2in_unk_proto, &s_kv, &s_value))
+                {
+                  new_addr = ip->src_address.as_u32 = key.l_addr.as_u32;
+                  address_index = i;
+                  goto create_ses;
+                }
+            }
+          return;
+        }
+
+create_ses:
+      /* Over quota? Recycle the least recently used dynamic translation */
+      if (u->nsessions >= sm->max_translations_per_user && !is_sm)
+        {
+          /* Remove the oldest dynamic translation */
+          do {
+              oldest_index = clib_dlist_remove_head (
+                tsm->list_pool, u->sessions_per_user_list_head_index);
+
+              ASSERT (oldest_index != ~0);
+
+              /* add it back to the end of the LRU list */
+              clib_dlist_addtail (tsm->list_pool,
+                                  u->sessions_per_user_list_head_index,
+                                  oldest_index);
+              /* Get the list element */
+              oldest = pool_elt_at_index (tsm->list_pool, oldest_index);
+
+              /* Get the session index from the list element */
+              ses_index = oldest->value;
+
+              /* Get the session */
+              s = pool_elt_at_index (tsm->sessions, ses_index);
+          } while (snat_is_session_static (s));
+
+          if (snat_is_unk_proto_session (s))
+            {
+              /* Remove from lookup tables */
+              key.l_addr = s->in2out.addr;
+              key.r_addr = s->ext_host_addr;
+              key.fib_index = s->in2out.fib_index;
+              key.proto = s->in2out.port;
+              s_kv.key[0] = key.as_u64[0];
+              s_kv.key[1] = key.as_u64[1];
+              if (clib_bihash_add_del_16_8 (&sm->in2out_unk_proto, &s_kv, 0))
+                clib_warning ("in2out key del failed");
+
+              key.l_addr = s->out2in.addr;
+              key.fib_index = s->out2in.fib_index;
+              s_kv.key[0] = key.as_u64[0];
+              s_kv.key[1] = key.as_u64[1];
+              if (clib_bihash_add_del_16_8 (&sm->out2in_unk_proto, &s_kv, 0))
+                clib_warning ("out2in key del failed");
+            }
+          else
+            {
+              /* log NAT event */
+              snat_ipfix_logging_nat44_ses_delete(s->in2out.addr.as_u32,
+                                                  s->out2in.addr.as_u32,
+                                                  s->in2out.protocol,
+                                                  s->in2out.port,
+                                                  s->out2in.port,
+                                                  s->in2out.fib_index);
+
+              snat_free_outside_address_and_port (sm, &s->out2in,
+                                                  s->outside_address_index);
+
+              /* Remove in2out, out2in keys */
+              kv.key = s->in2out.as_u64;
+              if (clib_bihash_add_del_8_8 (&sm->in2out, &kv, 0))
+                clib_warning ("in2out key del failed");
+              kv.key = s->out2in.as_u64;
+              if (clib_bihash_add_del_8_8 (&sm->out2in, &kv, 0))
+                clib_warning ("out2in key del failed");
+            }
+        }
+      else
+        {
+          /* Create a new session */
+          pool_get (tsm->sessions, s);
+          memset (s, 0, sizeof (*s));
+
+          /* Create list elts */
+          pool_get (tsm->list_pool, elt);
+          clib_dlist_init (tsm->list_pool, elt - tsm->list_pool);
+          elt->value = s - tsm->sessions;
+          s->per_user_index = elt - tsm->list_pool;
+          s->per_user_list_head_index = u->sessions_per_user_list_head_index;
+          clib_dlist_addtail (tsm->list_pool, s->per_user_list_head_index,
+                              s->per_user_index);
+        }
+
+      s->ext_host_addr.as_u32 = ip->dst_address.as_u32;
+      s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
+      s->outside_address_index = address_index;
+      s->out2in.addr.as_u32 = new_addr;
+      s->out2in.fib_index = sm->outside_fib_index;
+      s->in2out.addr.as_u32 = old_addr;
+      s->in2out.fib_index = rx_fib_index;
+      s->in2out.port = s->out2in.port = ip->protocol;
+      if (is_sm)
+        {
+          u->nstaticsessions++;
+          s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
+        }
+      else
+        {
+          u->nsessions++;
+        }
+
+      /* Add to lookup tables */
+      key.l_addr.as_u32 = old_addr;
+      key.r_addr = ip->dst_address;
+      key.proto = ip->protocol;
+      key.fib_index = rx_fib_index;
+      s_kv.key[0] = key.as_u64[0];
+      s_kv.key[1] = key.as_u64[1];
+      s_kv.value = s - tsm->sessions;
+      if (clib_bihash_add_del_16_8 (&sm->in2out_unk_proto, &s_kv, 1))
+        clib_warning ("in2out key add failed");
+
+      key.l_addr.as_u32 = new_addr;
+      key.fib_index = sm->outside_fib_index;
+      s_kv.key[0] = key.as_u64[0];
+      s_kv.key[1] = key.as_u64[1];
+      if (clib_bihash_add_del_16_8 (&sm->out2in_unk_proto, &s_kv, 1))
+        clib_warning ("out2in key add failed");
+  }
+
+  /* Update IP checksum */
+  sum = ip->checksum;
+  sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, src_address);
+  ip->checksum = ip_csum_fold (sum);
+
+  /* Accounting */
+  s->last_heard = now;
+  s->total_pkts++;
+  s->total_bytes += vlib_buffer_length_in_chain (vm, b);
+  /* Per-user LRU list maintenance */
+  clib_dlist_remove (tsm->list_pool, s->per_user_index);
+  clib_dlist_addtail (tsm->list_pool, s->per_user_list_head_index,
+                      s->per_user_index);
+
+  /* Hairpinning */
+  if (vnet_buffer(b)->sw_if_index[VLIB_TX] == ~0)
+    snat_hairpinning_unknown_proto(sm, b, ip);
+
+  if (vnet_buffer(b)->sw_if_index[VLIB_TX] == ~0)
+    vnet_buffer(b)->sw_if_index[VLIB_TX] = sm->outside_fib_index;
+}
+
+static inline uword
+snat_in2out_node_fn_inline (vlib_main_t * vm,
+                            vlib_node_runtime_t * node,
+                            vlib_frame_t * frame, int is_slow_path,
+                            int is_output_feature)
+{
+  u32 n_left_from, * from, * to_next;
+  snat_in2out_next_t next_index;
+  u32 pkts_processed = 0;
+  snat_main_t * sm = &snat_main;
+  f64 now = vlib_time_now (vm);
+  u32 stats_node_index;
+  u32 thread_index = vlib_get_thread_index ();
+
+  stats_node_index = is_slow_path ? snat_in2out_slowpath_node.index :
+    snat_in2out_node.index;
+
+  from = vlib_frame_vector_args (frame);
+  n_left_from = frame->n_vectors;
+  next_index = node->cached_next_index;
+
+  while (n_left_from > 0)
+    {
+      u32 n_left_to_next;
+
+      vlib_get_next_frame (vm, node, next_index,
+			   to_next, n_left_to_next);
+
+      while (n_left_from >= 4 && n_left_to_next >= 2)
+	{
+          u32 bi0, bi1;
+	  vlib_buffer_t * b0, * b1;
+          u32 next0, next1;
+          u32 sw_if_index0, sw_if_index1;
+          ip4_header_t * ip0, * ip1;
+          ip_csum_t sum0, sum1;
+          u32 new_addr0, old_addr0, new_addr1, old_addr1;
+          u16 old_port0, new_port0, old_port1, new_port1;
+          udp_header_t * udp0, * udp1;
+          tcp_header_t * tcp0, * tcp1;
+          icmp46_header_t * icmp0, * icmp1;
+          snat_session_key_t key0, key1;
+          u32 rx_fib_index0, rx_fib_index1;
+          u32 proto0, proto1;
+          snat_session_t * s0 = 0, * s1 = 0;
+          clib_bihash_kv_8_8_t kv0, value0, kv1, value1;
+          u32 iph_offset0 = 0, iph_offset1 = 0;
+
+	  /* Prefetch next iteration. */
+	  {
+	    vlib_buffer_t * p2, * p3;
+
+	    p2 = vlib_get_buffer (vm, from[2]);
+	    p3 = vlib_get_buffer (vm, from[3]);
+
+	    vlib_prefetch_buffer_header (p2, LOAD);
+	    vlib_prefetch_buffer_header (p3, LOAD);
+
+	    CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, STORE);
+	    CLIB_PREFETCH (p3->data, CLIB_CACHE_LINE_BYTES, STORE);
+	  }
+
+          /* speculatively enqueue b0 and b1 to the current next frame */
+	  to_next[0] = bi0 = from[0];
+	  to_next[1] = bi1 = from[1];
+	  from += 2;
+	  to_next += 2;
+	  n_left_from -= 2;
+	  n_left_to_next -= 2;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+	  b1 = vlib_get_buffer (vm, bi1);
+
+          if (is_output_feature)
+            iph_offset0 = vnet_buffer (b0)->ip.save_rewrite_length;
+
+          ip0 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b0) +
+                 iph_offset0);
+
+          udp0 = ip4_next_header (ip0);
+          tcp0 = (tcp_header_t *) udp0;
+          icmp0 = (icmp46_header_t *) udp0;
+
+          sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
+	  rx_fib_index0 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index,
+                                   sw_if_index0);
+
+          next0 = next1 = SNAT_IN2OUT_NEXT_LOOKUP;
+
+          if (PREDICT_FALSE(ip0->ttl == 1))
+            {
+              vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+              icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
+                                           ICMP4_time_exceeded_ttl_exceeded_in_transit,
+                                           0);
+              next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
+              goto trace00;
+            }
+
+          proto0 = ip_proto_to_snat_proto (ip0->protocol);
+
+          /* Next configured feature, probably ip4-lookup */
+          if (is_slow_path)
+            {
+              if (PREDICT_FALSE (proto0 == ~0))
+                {
+                  snat_in2out_unknown_proto (sm, b0, ip0, rx_fib_index0,
+                                             thread_index, now, vm);
+                  goto trace00;
+                }
+
+              if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
+                {
+                  next0 = icmp_in2out_slow_path
+                    (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0,
+                     node, next0, now, thread_index, &s0);
+                  goto trace00;
+                }
+            }
+          else
+            {
+              if (PREDICT_FALSE (proto0 == ~0 || proto0 == SNAT_PROTOCOL_ICMP))
+                {
+                  next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
+                  goto trace00;
+                }
+            }
+
+          key0.addr = ip0->src_address;
+          key0.port = udp0->src_port;
+          key0.protocol = proto0;
+          key0.fib_index = rx_fib_index0;
+
+          kv0.key = key0.as_u64;
+
+          if (PREDICT_FALSE (clib_bihash_search_8_8 (&sm->in2out, &kv0, &value0) != 0))
+            {
+              if (is_slow_path)
+                {
+                  if (PREDICT_FALSE(snat_not_translate(sm, node, sw_if_index0,
+                      ip0, proto0, rx_fib_index0)) && !is_output_feature)
+                    goto trace00;
+
+                  next0 = slow_path (sm, b0, ip0, rx_fib_index0, &key0,
+                                     &s0, node, next0, thread_index);
+                  if (PREDICT_FALSE (next0 == SNAT_IN2OUT_NEXT_DROP))
+                    goto trace00;
+                }
+              else
+                {
+                  next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
+                  goto trace00;
+                }
+            }
+          else
+            s0 = pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
+                                    value0.value);
+
+          old_addr0 = ip0->src_address.as_u32;
+          ip0->src_address = s0->out2in.addr;
+          new_addr0 = ip0->src_address.as_u32;
+          if (!is_output_feature)
+            vnet_buffer(b0)->sw_if_index[VLIB_TX] = s0->out2in.fib_index;
+
+          sum0 = ip0->checksum;
+          sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
+                                 ip4_header_t,
+                                 src_address /* changed member */);
+          ip0->checksum = ip_csum_fold (sum0);
+
+          if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
+            {
+              old_port0 = tcp0->src_port;
+              tcp0->src_port = s0->out2in.port;
+              new_port0 = tcp0->src_port;
+
+              sum0 = tcp0->checksum;
+              sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
+                                     ip4_header_t,
+                                     dst_address /* changed member */);
+              sum0 = ip_csum_update (sum0, old_port0, new_port0,
+                                     ip4_header_t /* cheat */,
+                                     length /* changed member */);
+              tcp0->checksum = ip_csum_fold(sum0);
+            }
+          else
+            {
+              old_port0 = udp0->src_port;
+              udp0->src_port = s0->out2in.port;
+              udp0->checksum = 0;
+            }
+
+          /* Hairpinning */
+          if (!is_output_feature)
+            snat_hairpinning (sm, b0, ip0, udp0, tcp0, proto0);
+
+          /* Accounting */
+          s0->last_heard = now;
+          s0->total_pkts++;
+          s0->total_bytes += vlib_buffer_length_in_chain (vm, b0);
+          /* Per-user LRU list maintenance for dynamic translation */
+          if (!snat_is_session_static (s0))
+            {
+              clib_dlist_remove (sm->per_thread_data[thread_index].list_pool,
+                                 s0->per_user_index);
+              clib_dlist_addtail (sm->per_thread_data[thread_index].list_pool,
+                                  s0->per_user_list_head_index,
+                                  s0->per_user_index);
+            }
+        trace00:
+
+          if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
+                            && (b0->flags & VLIB_BUFFER_IS_TRACED)))
+            {
+              snat_in2out_trace_t *t =
+                 vlib_add_trace (vm, node, b0, sizeof (*t));
+              t->is_slow_path = is_slow_path;
+              t->sw_if_index = sw_if_index0;
+              t->next_index = next0;
+                  t->session_index = ~0;
+              if (s0)
+                t->session_index = s0 - sm->per_thread_data[thread_index].sessions;
+            }
+
+          pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;
+
+          if (is_output_feature)
+            iph_offset1 = vnet_buffer (b1)->ip.save_rewrite_length;
+
+          ip1 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b1) +
+                 iph_offset1);
+
+          udp1 = ip4_next_header (ip1);
+          tcp1 = (tcp_header_t *) udp1;
+          icmp1 = (icmp46_header_t *) udp1;
+
+          sw_if_index1 = vnet_buffer(b1)->sw_if_index[VLIB_RX];
+	  rx_fib_index1 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index,
+                                   sw_if_index1);
+
+          if (PREDICT_FALSE(ip1->ttl == 1))
+            {
+              vnet_buffer (b1)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+              icmp4_error_set_vnet_buffer (b1, ICMP4_time_exceeded,
+                                           ICMP4_time_exceeded_ttl_exceeded_in_transit,
+                                           0);
+              next1 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
+              goto trace01;
+            }
+
+          proto1 = ip_proto_to_snat_proto (ip1->protocol);
+
+          /* Next configured feature, probably ip4-lookup */
+          if (is_slow_path)
+            {
+              if (PREDICT_FALSE (proto1 == ~0))
+                {
+                  snat_in2out_unknown_proto (sm, b1, ip1, rx_fib_index1,
+                                             thread_index, now, vm);
+                  goto trace01;
+                }
+
+              if (PREDICT_FALSE (proto1 == SNAT_PROTOCOL_ICMP))
+                {
+                  next1 = icmp_in2out_slow_path
+                    (sm, b1, ip1, icmp1, sw_if_index1, rx_fib_index1, node,
+                     next1, now, thread_index, &s1);
+                  goto trace01;
+                }
+            }
+          else
+            {
+              if (PREDICT_FALSE (proto1 == ~0 || proto1 == SNAT_PROTOCOL_ICMP))
+                {
+                  next1 = SNAT_IN2OUT_NEXT_SLOW_PATH;
+                  goto trace01;
+                }
+            }
+
+          key1.addr = ip1->src_address;
+          key1.port = udp1->src_port;
+          key1.protocol = proto1;
+          key1.fib_index = rx_fib_index1;
+
+          kv1.key = key1.as_u64;
+
+            if (PREDICT_FALSE(clib_bihash_search_8_8 (&sm->in2out, &kv1, &value1) != 0))
+            {
+              if (is_slow_path)
+                {
+                  if (PREDICT_FALSE(snat_not_translate(sm, node, sw_if_index1,
+                      ip1, proto1, rx_fib_index1)) && !is_output_feature)
+                    goto trace01;
+
+                  next1 = slow_path (sm, b1, ip1, rx_fib_index1, &key1,
+                                     &s1, node, next1, thread_index);
+                  if (PREDICT_FALSE (next1 == SNAT_IN2OUT_NEXT_DROP))
+                    goto trace01;
+                }
+              else
+                {
+                  next1 = SNAT_IN2OUT_NEXT_SLOW_PATH;
+                  goto trace01;
+                }
+            }
+          else
+            s1 = pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
+                                    value1.value);
+
+          old_addr1 = ip1->src_address.as_u32;
+          ip1->src_address = s1->out2in.addr;
+          new_addr1 = ip1->src_address.as_u32;
+          if (!is_output_feature)
+            vnet_buffer(b1)->sw_if_index[VLIB_TX] = s1->out2in.fib_index;
+
+          sum1 = ip1->checksum;
+          sum1 = ip_csum_update (sum1, old_addr1, new_addr1,
+                                 ip4_header_t,
+                                 src_address /* changed member */);
+          ip1->checksum = ip_csum_fold (sum1);
+
+          if (PREDICT_TRUE(proto1 == SNAT_PROTOCOL_TCP))
+            {
+              old_port1 = tcp1->src_port;
+              tcp1->src_port = s1->out2in.port;
+              new_port1 = tcp1->src_port;
+
+              sum1 = tcp1->checksum;
+              sum1 = ip_csum_update (sum1, old_addr1, new_addr1,
+                                     ip4_header_t,
+                                     dst_address /* changed member */);
+              sum1 = ip_csum_update (sum1, old_port1, new_port1,
+                                     ip4_header_t /* cheat */,
+                                     length /* changed member */);
+              tcp1->checksum = ip_csum_fold(sum1);
+            }
+          else
+            {
+              old_port1 = udp1->src_port;
+              udp1->src_port = s1->out2in.port;
+              udp1->checksum = 0;
+            }
+
+          /* Hairpinning */
+          if (!is_output_feature)
+            snat_hairpinning (sm, b1, ip1, udp1, tcp1, proto1);
+
+          /* Accounting */
+          s1->last_heard = now;
+          s1->total_pkts++;
+          s1->total_bytes += vlib_buffer_length_in_chain (vm, b1);
+          /* Per-user LRU list maintenance for dynamic translation */
+          if (!snat_is_session_static (s1))
+            {
+              clib_dlist_remove (sm->per_thread_data[thread_index].list_pool,
+                                 s1->per_user_index);
+              clib_dlist_addtail (sm->per_thread_data[thread_index].list_pool,
+                                  s1->per_user_list_head_index,
+                                  s1->per_user_index);
+            }
+        trace01:
+
+          if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
+                            && (b1->flags & VLIB_BUFFER_IS_TRACED)))
+            {
+              snat_in2out_trace_t *t =
+                 vlib_add_trace (vm, node, b1, sizeof (*t));
+              t->sw_if_index = sw_if_index1;
+              t->next_index = next1;
+              t->session_index = ~0;
+              if (s1)
+                t->session_index = s1 - sm->per_thread_data[thread_index].sessions;
+            }
+
+          pkts_processed += next1 != SNAT_IN2OUT_NEXT_DROP;
+
+          /* verify speculative enqueues, maybe switch current next frame */
+          vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
+                                           to_next, n_left_to_next,
+                                           bi0, bi1, next0, next1);
+        }
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+          u32 bi0;
+	  vlib_buffer_t * b0;
+          u32 next0;
+          u32 sw_if_index0;
+          ip4_header_t * ip0;
+          ip_csum_t sum0;
+          u32 new_addr0, old_addr0;
+          u16 old_port0, new_port0;
+          udp_header_t * udp0;
+          tcp_header_t * tcp0;
+          icmp46_header_t * icmp0;
+          snat_session_key_t key0;
+          u32 rx_fib_index0;
+          u32 proto0;
+          snat_session_t * s0 = 0;
+          clib_bihash_kv_8_8_t kv0, value0;
+          u32 iph_offset0 = 0;
+
+          /* speculatively enqueue b0 to the current next frame */
+	  bi0 = from[0];
+	  to_next[0] = bi0;
+	  from += 1;
+	  to_next += 1;
+	  n_left_from -= 1;
+	  n_left_to_next -= 1;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+          next0 = SNAT_IN2OUT_NEXT_LOOKUP;
+
+          if (is_output_feature)
+            iph_offset0 = vnet_buffer (b0)->ip.save_rewrite_length;
+
+          ip0 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b0) +
+                 iph_offset0);
+
+          udp0 = ip4_next_header (ip0);
+          tcp0 = (tcp_header_t *) udp0;
+          icmp0 = (icmp46_header_t *) udp0;
+
+          sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
+	  rx_fib_index0 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index,
+                                   sw_if_index0);
+
+          if (PREDICT_FALSE(ip0->ttl == 1))
+            {
+              vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+              icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
+                                           ICMP4_time_exceeded_ttl_exceeded_in_transit,
+                                           0);
+              next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
+              goto trace0;
+            }
+
+          proto0 = ip_proto_to_snat_proto (ip0->protocol);
+
+          /* Next configured feature, probably ip4-lookup */
+          if (is_slow_path)
+            {
+              if (PREDICT_FALSE (proto0 == ~0))
+                {
+                  snat_in2out_unknown_proto (sm, b0, ip0, rx_fib_index0,
+                                             thread_index, now, vm);
+                  goto trace0;
+                }
+
+              if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
+                {
+                  next0 = icmp_in2out_slow_path
+                    (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
+                     next0, now, thread_index, &s0);
+                  goto trace0;
+                }
+            }
+          else
+            {
+              if (PREDICT_FALSE (proto0 == ~0 || proto0 == SNAT_PROTOCOL_ICMP))
+                {
+                  next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
+                  goto trace0;
+                }
+            }
+
+          key0.addr = ip0->src_address;
+          key0.port = udp0->src_port;
+          key0.protocol = proto0;
+          key0.fib_index = rx_fib_index0;
+
+          kv0.key = key0.as_u64;
+
+          if (clib_bihash_search_8_8 (&sm->in2out, &kv0, &value0))
+            {
+              if (is_slow_path)
+                {
+                  if (PREDICT_FALSE(snat_not_translate(sm, node, sw_if_index0,
+                      ip0, proto0, rx_fib_index0)) && !is_output_feature)
+                    goto trace0;
+
+                  next0 = slow_path (sm, b0, ip0, rx_fib_index0, &key0,
+                                     &s0, node, next0, thread_index);
+
+                  if (PREDICT_FALSE (next0 == SNAT_IN2OUT_NEXT_DROP))
+                    goto trace0;
+                }
+              else
+                {
+                  next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
+                  goto trace0;
+                }
+            }
+          else
+            s0 = pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
+                                    value0.value);
+
+          old_addr0 = ip0->src_address.as_u32;
+          ip0->src_address = s0->out2in.addr;
+          new_addr0 = ip0->src_address.as_u32;
+          if (!is_output_feature)
+            vnet_buffer(b0)->sw_if_index[VLIB_TX] = s0->out2in.fib_index;
+
+          sum0 = ip0->checksum;
+          sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
+                                 ip4_header_t,
+                                 src_address /* changed member */);
+          ip0->checksum = ip_csum_fold (sum0);
+
+          if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
+            {
+              old_port0 = tcp0->src_port;
+              tcp0->src_port = s0->out2in.port;
+              new_port0 = tcp0->src_port;
+
+              sum0 = tcp0->checksum;
+              sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
+                                     ip4_header_t,
+                                     dst_address /* changed member */);
+              sum0 = ip_csum_update (sum0, old_port0, new_port0,
+                                     ip4_header_t /* cheat */,
+                                     length /* changed member */);
+              tcp0->checksum = ip_csum_fold(sum0);
+            }
+          else
+            {
+              old_port0 = udp0->src_port;
+              udp0->src_port = s0->out2in.port;
+              udp0->checksum = 0;
+            }
+
+          /* Hairpinning */
+          if (!is_output_feature)
+            snat_hairpinning (sm, b0, ip0, udp0, tcp0, proto0);
+
+          /* Accounting */
+          s0->last_heard = now;
+          s0->total_pkts++;
+          s0->total_bytes += vlib_buffer_length_in_chain (vm, b0);
+          /* Per-user LRU list maintenance for dynamic translation */
+          if (!snat_is_session_static (s0))
+            {
+              clib_dlist_remove (sm->per_thread_data[thread_index].list_pool,
+                                 s0->per_user_index);
+              clib_dlist_addtail (sm->per_thread_data[thread_index].list_pool,
+                                  s0->per_user_list_head_index,
+                                  s0->per_user_index);
+            }
+
+        trace0:
+          if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
+                            && (b0->flags & VLIB_BUFFER_IS_TRACED)))
+            {
+              snat_in2out_trace_t *t =
+                 vlib_add_trace (vm, node, b0, sizeof (*t));
+              t->is_slow_path = is_slow_path;
+              t->sw_if_index = sw_if_index0;
+              t->next_index = next0;
+                  t->session_index = ~0;
+              if (s0)
+                t->session_index = s0 - sm->per_thread_data[thread_index].sessions;
+            }
+
+          pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;
+
+          /* verify speculative enqueue, maybe switch current next frame */
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
+					   to_next, n_left_to_next,
+					   bi0, next0);
+	}
+
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+
+  vlib_node_increment_counter (vm, stats_node_index,
+                               SNAT_IN2OUT_ERROR_IN2OUT_PACKETS,
+                               pkts_processed);
+  return frame->n_vectors;
+}
+
+static uword
+snat_in2out_fast_path_fn (vlib_main_t * vm,
+                          vlib_node_runtime_t * node,
+                          vlib_frame_t * frame)
+{
+  return snat_in2out_node_fn_inline (vm, node, frame, 0 /* is_slow_path */, 0);
+}
+
+VLIB_REGISTER_NODE (snat_in2out_node) = {
+  .function = snat_in2out_fast_path_fn,
+  .name = "nat44-in2out",
+  .vector_size = sizeof (u32),
+  .format_trace = format_snat_in2out_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+
+  .n_errors = ARRAY_LEN(snat_in2out_error_strings),
+  .error_strings = snat_in2out_error_strings,
+
+  .runtime_data_bytes = sizeof (snat_runtime_t),
+
+  .n_next_nodes = SNAT_IN2OUT_N_NEXT,
+
+  /* edit / add dispositions here */
+  .next_nodes = {
+    [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
+    [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
+    [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-slowpath",
+    [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
+  },
+};
+
+VLIB_NODE_FUNCTION_MULTIARCH (snat_in2out_node, snat_in2out_fast_path_fn);
+
+static uword
+snat_in2out_output_fast_path_fn (vlib_main_t * vm,
+                                 vlib_node_runtime_t * node,
+                                 vlib_frame_t * frame)
+{
+  return snat_in2out_node_fn_inline (vm, node, frame, 0 /* is_slow_path */, 1);
+}
+
+VLIB_REGISTER_NODE (snat_in2out_output_node) = {
+  .function = snat_in2out_output_fast_path_fn,
+  .name = "nat44-in2out-output",
+  .vector_size = sizeof (u32),
+  .format_trace = format_snat_in2out_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+
+  .n_errors = ARRAY_LEN(snat_in2out_error_strings),
+  .error_strings = snat_in2out_error_strings,
+
+  .runtime_data_bytes = sizeof (snat_runtime_t),
+
+  .n_next_nodes = SNAT_IN2OUT_N_NEXT,
+
+  /* edit / add dispositions here */
+  .next_nodes = {
+    [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
+    [SNAT_IN2OUT_NEXT_LOOKUP] = "interface-output",
+    [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-output-slowpath",
+    [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
+  },
+};
+
+VLIB_NODE_FUNCTION_MULTIARCH (snat_in2out_output_node,
+                              snat_in2out_output_fast_path_fn);
+
+static uword
+snat_in2out_slow_path_fn (vlib_main_t * vm,
+                          vlib_node_runtime_t * node,
+                          vlib_frame_t * frame)
+{
+  return snat_in2out_node_fn_inline (vm, node, frame, 1 /* is_slow_path */, 0);
+}
+
+VLIB_REGISTER_NODE (snat_in2out_slowpath_node) = {
+  .function = snat_in2out_slow_path_fn,
+  .name = "nat44-in2out-slowpath",
+  .vector_size = sizeof (u32),
+  .format_trace = format_snat_in2out_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+
+  .n_errors = ARRAY_LEN(snat_in2out_error_strings),
+  .error_strings = snat_in2out_error_strings,
+
+  .runtime_data_bytes = sizeof (snat_runtime_t),
+
+  .n_next_nodes = SNAT_IN2OUT_N_NEXT,
+
+  /* edit / add dispositions here */
+  .next_nodes = {
+    [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
+    [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
+    [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-slowpath",
+    [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
+  },
+};
+
+VLIB_NODE_FUNCTION_MULTIARCH (snat_in2out_slowpath_node,
+                              snat_in2out_slow_path_fn);
+
+static uword
+snat_in2out_output_slow_path_fn (vlib_main_t * vm,
+                                 vlib_node_runtime_t * node,
+                                 vlib_frame_t * frame)
+{
+  return snat_in2out_node_fn_inline (vm, node, frame, 1 /* is_slow_path */, 1);
+}
+
+VLIB_REGISTER_NODE (snat_in2out_output_slowpath_node) = {
+  .function = snat_in2out_output_slow_path_fn,
+  .name = "nat44-in2out-output-slowpath",
+  .vector_size = sizeof (u32),
+  .format_trace = format_snat_in2out_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+
+  .n_errors = ARRAY_LEN(snat_in2out_error_strings),
+  .error_strings = snat_in2out_error_strings,
+
+  .runtime_data_bytes = sizeof (snat_runtime_t),
+
+  .n_next_nodes = SNAT_IN2OUT_N_NEXT,
+
+  /* edit / add dispositions here */
+  .next_nodes = {
+    [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
+    [SNAT_IN2OUT_NEXT_LOOKUP] = "interface-output",
+    [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-output-slowpath",
+    [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
+  },
+};
+
+VLIB_NODE_FUNCTION_MULTIARCH (snat_in2out_output_slowpath_node,
+                              snat_in2out_output_slow_path_fn);
+
+/**************************/
+/*** deterministic mode ***/
+/**************************/
+static uword
+snat_det_in2out_node_fn (vlib_main_t * vm,
+                         vlib_node_runtime_t * node,
+                         vlib_frame_t * frame)
+{
+  u32 n_left_from, * from, * to_next;
+  snat_in2out_next_t next_index;
+  u32 pkts_processed = 0;
+  snat_main_t * sm = &snat_main;
+  u32 now = (u32) vlib_time_now (vm);
+  u32 thread_index = vlib_get_thread_index ();
+
+  from = vlib_frame_vector_args (frame);
+  n_left_from = frame->n_vectors;
+  next_index = node->cached_next_index;
+
+  while (n_left_from > 0)
+    {
+      u32 n_left_to_next;
+
+      vlib_get_next_frame (vm, node, next_index,
+			   to_next, n_left_to_next);
+
+      while (n_left_from >= 4 && n_left_to_next >= 2)
+        {
+          u32 bi0, bi1;
+	  vlib_buffer_t * b0, * b1;
+          u32 next0, next1;
+          u32 sw_if_index0, sw_if_index1;
+          ip4_header_t * ip0, * ip1;
+          ip_csum_t sum0, sum1;
+          ip4_address_t new_addr0, old_addr0, new_addr1, old_addr1;
+          u16 old_port0, new_port0, lo_port0, i0;
+          u16 old_port1, new_port1, lo_port1, i1;
+          udp_header_t * udp0, * udp1;
+          tcp_header_t * tcp0, * tcp1;
+          u32 proto0, proto1;
+          snat_det_out_key_t key0, key1;
+          snat_det_map_t * dm0, * dm1;
+          snat_det_session_t * ses0 = 0, * ses1 = 0;
+          u32 rx_fib_index0, rx_fib_index1;
+          icmp46_header_t * icmp0, * icmp1;
+
+	  /* Prefetch next iteration. */
+	  {
+	    vlib_buffer_t * p2, * p3;
+
+	    p2 = vlib_get_buffer (vm, from[2]);
+	    p3 = vlib_get_buffer (vm, from[3]);
+
+	    vlib_prefetch_buffer_header (p2, LOAD);
+	    vlib_prefetch_buffer_header (p3, LOAD);
+
+	    CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, STORE);
+	    CLIB_PREFETCH (p3->data, CLIB_CACHE_LINE_BYTES, STORE);
+	  }
+
+          /* speculatively enqueue b0 and b1 to the current next frame */
+	  to_next[0] = bi0 = from[0];
+	  to_next[1] = bi1 = from[1];
+	  from += 2;
+	  to_next += 2;
+	  n_left_from -= 2;
+	  n_left_to_next -= 2;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+	  b1 = vlib_get_buffer (vm, bi1);
+
+          next0 = SNAT_IN2OUT_NEXT_LOOKUP;
+          next1 = SNAT_IN2OUT_NEXT_LOOKUP;
+
+          ip0 = vlib_buffer_get_current (b0);
+          udp0 = ip4_next_header (ip0);
+          tcp0 = (tcp_header_t *) udp0;
+
+          sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
+
+          if (PREDICT_FALSE(ip0->ttl == 1))
+            {
+              vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+              icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
+                                           ICMP4_time_exceeded_ttl_exceeded_in_transit,
+                                           0);
+              next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
+              goto trace0;
+            }
+
+          proto0 = ip_proto_to_snat_proto (ip0->protocol);
+
+          if (PREDICT_FALSE(proto0 == SNAT_PROTOCOL_ICMP))
+            {
+              rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index(sw_if_index0);
+              icmp0 = (icmp46_header_t *) udp0;
+
+              next0 = icmp_in2out(sm, b0, ip0, icmp0, sw_if_index0,
+                                  rx_fib_index0, node, next0, thread_index,
+                                  &ses0, &dm0);
+              goto trace0;
+            }
+
+          dm0 = snat_det_map_by_user(sm, &ip0->src_address);
+          if (PREDICT_FALSE(!dm0))
+            {
+              clib_warning("no match for internal host %U",
+                           format_ip4_address, &ip0->src_address);
+              next0 = SNAT_IN2OUT_NEXT_DROP;
+              b0->error = node->errors[SNAT_IN2OUT_ERROR_NO_TRANSLATION];
+              goto trace0;
+            }
+
+          snat_det_forward(dm0, &ip0->src_address, &new_addr0, &lo_port0);
+
+          key0.ext_host_addr = ip0->dst_address;
+          key0.ext_host_port = tcp0->dst;
+
+          ses0 = snat_det_find_ses_by_in(dm0, &ip0->src_address, tcp0->src, key0);
+          if (PREDICT_FALSE(!ses0))
+            {
+              for (i0 = 0; i0 < dm0->ports_per_host; i0++)
+                {
+                  key0.out_port = clib_host_to_net_u16 (lo_port0 +
+                    ((i0 + clib_net_to_host_u16 (tcp0->src)) % dm0->ports_per_host));
+
+                  if (snat_det_get_ses_by_out (dm0, &ip0->src_address, key0.as_u64))
+                    continue;
+
+                  ses0 = snat_det_ses_create(dm0, &ip0->src_address, tcp0->src, &key0);
+                  break;
+                }
+              if (PREDICT_FALSE(!ses0))
+                {
+                  /* too many sessions for user, send ICMP error packet */
+
+                  vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+                  icmp4_error_set_vnet_buffer (b0, ICMP4_destination_unreachable,
+                                               ICMP4_destination_unreachable_destination_unreachable_host,
+                                               0);
+                  next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
+                  goto trace0;
+                }
+            }
+
+          new_port0 = ses0->out.out_port;
+
+          old_addr0.as_u32 = ip0->src_address.as_u32;
+          ip0->src_address.as_u32 = new_addr0.as_u32;
+          vnet_buffer(b0)->sw_if_index[VLIB_TX] = sm->outside_fib_index;
+
+          sum0 = ip0->checksum;
+          sum0 = ip_csum_update (sum0, old_addr0.as_u32, new_addr0.as_u32,
+                                 ip4_header_t,
+                                 src_address /* changed member */);
+          ip0->checksum = ip_csum_fold (sum0);
+
+          if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
+            {
+              if (tcp0->flags & TCP_FLAG_SYN)
+                ses0->state = SNAT_SESSION_TCP_SYN_SENT;
+              else if (tcp0->flags & TCP_FLAG_ACK && ses0->state == SNAT_SESSION_TCP_SYN_SENT)
+                ses0->state = SNAT_SESSION_TCP_ESTABLISHED;
+              else if (tcp0->flags & TCP_FLAG_FIN && ses0->state == SNAT_SESSION_TCP_ESTABLISHED)
+                ses0->state = SNAT_SESSION_TCP_FIN_WAIT;
+              else if (tcp0->flags & TCP_FLAG_ACK && ses0->state == SNAT_SESSION_TCP_FIN_WAIT)
+                snat_det_ses_close(dm0, ses0);
+              else if (tcp0->flags & TCP_FLAG_FIN && ses0->state == SNAT_SESSION_TCP_CLOSE_WAIT)
+                ses0->state = SNAT_SESSION_TCP_LAST_ACK;
+              else if (tcp0->flags == 0 && ses0->state == SNAT_SESSION_UNKNOWN)
+                ses0->state = SNAT_SESSION_TCP_ESTABLISHED;
+
+              old_port0 = tcp0->src;
+              tcp0->src = new_port0;
+
+              sum0 = tcp0->checksum;
+              sum0 = ip_csum_update (sum0, old_addr0.as_u32, new_addr0.as_u32,
+                                     ip4_header_t,
+                                     dst_address /* changed member */);
+              sum0 = ip_csum_update (sum0, old_port0, new_port0,
+                                     ip4_header_t /* cheat */,
+                                     length /* changed member */);
+              tcp0->checksum = ip_csum_fold(sum0);
+            }
+          else
+            {
+              ses0->state = SNAT_SESSION_UDP_ACTIVE;
+              old_port0 = udp0->src_port;
+              udp0->src_port = new_port0;
+              udp0->checksum = 0;
+            }
+
+          switch(ses0->state)
+            {
+            case SNAT_SESSION_UDP_ACTIVE:
+                ses0->expire = now + sm->udp_timeout;
+                break;
+            case SNAT_SESSION_TCP_SYN_SENT:
+            case SNAT_SESSION_TCP_FIN_WAIT:
+            case SNAT_SESSION_TCP_CLOSE_WAIT:
+            case SNAT_SESSION_TCP_LAST_ACK:
+                ses0->expire = now + sm->tcp_transitory_timeout;
+                break;
+            case SNAT_SESSION_TCP_ESTABLISHED:
+                ses0->expire = now + sm->tcp_established_timeout;
+                break;
+            }
+
+        trace0:
+          if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
+                            && (b0->flags & VLIB_BUFFER_IS_TRACED)))
+            {
+              snat_in2out_trace_t *t =
+                 vlib_add_trace (vm, node, b0, sizeof (*t));
+              t->is_slow_path = 0;
+              t->sw_if_index = sw_if_index0;
+              t->next_index = next0;
+              t->session_index = ~0;
+              if (ses0)
+                t->session_index = ses0 - dm0->sessions;
+            }
+
+          pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;
+
+          ip1 = vlib_buffer_get_current (b1);
+          udp1 = ip4_next_header (ip1);
+          tcp1 = (tcp_header_t *) udp1;
+
+          sw_if_index1 = vnet_buffer(b1)->sw_if_index[VLIB_RX];
+
+          if (PREDICT_FALSE(ip1->ttl == 1))
+            {
+              vnet_buffer (b1)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+              icmp4_error_set_vnet_buffer (b1, ICMP4_time_exceeded,
+                                           ICMP4_time_exceeded_ttl_exceeded_in_transit,
+                                           0);
+              next1 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
+              goto trace1;
+            }
+
+          proto1 = ip_proto_to_snat_proto (ip1->protocol);
+
+          if (PREDICT_FALSE(proto1 == SNAT_PROTOCOL_ICMP))
+            {
+              rx_fib_index1 = ip4_fib_table_get_index_for_sw_if_index(sw_if_index1);
+              icmp1 = (icmp46_header_t *) udp1;
+
+              next1 = icmp_in2out(sm, b1, ip1, icmp1, sw_if_index1,
+                                  rx_fib_index1, node, next1, thread_index,
+                                  &ses1, &dm1);
+              goto trace1;
+            }
+
+          dm1 = snat_det_map_by_user(sm, &ip1->src_address);
+          if (PREDICT_FALSE(!dm1))
+            {
+              clib_warning("no match for internal host %U",
+                           format_ip4_address, &ip0->src_address);
+              next1 = SNAT_IN2OUT_NEXT_DROP;
+              b1->error = node->errors[SNAT_IN2OUT_ERROR_NO_TRANSLATION];
+              goto trace1;
+            }
+
+          snat_det_forward(dm1, &ip1->src_address, &new_addr1, &lo_port1);
+
+          key1.ext_host_addr = ip1->dst_address;
+          key1.ext_host_port = tcp1->dst;
+
+          ses1 = snat_det_find_ses_by_in(dm1, &ip1->src_address, tcp1->src, key1);
+          if (PREDICT_FALSE(!ses1))
+            {
+              for (i1 = 0; i1 < dm1->ports_per_host; i1++)
+                {
+                  key1.out_port = clib_host_to_net_u16 (lo_port1 +
+                    ((i1 + clib_net_to_host_u16 (tcp1->src)) % dm1->ports_per_host));
+
+                  if (snat_det_get_ses_by_out (dm1, &ip1->src_address, key1.as_u64))
+                    continue;
+
+                  ses1 = snat_det_ses_create(dm1, &ip1->src_address, tcp1->src, &key1);
+                  break;
+                }
+              if (PREDICT_FALSE(!ses1))
+                {
+                  /* too many sessions for user, send ICMP error packet */
+
+                  vnet_buffer (b1)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+                  icmp4_error_set_vnet_buffer (b1, ICMP4_destination_unreachable,
+                                               ICMP4_destination_unreachable_destination_unreachable_host,
+                                               0);
+                  next1 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
+                  goto trace1;
+                }
+            }
+
+          new_port1 = ses1->out.out_port;
+
+          old_addr1.as_u32 = ip1->src_address.as_u32;
+          ip1->src_address.as_u32 = new_addr1.as_u32;
+          vnet_buffer(b1)->sw_if_index[VLIB_TX] = sm->outside_fib_index;
+
+          sum1 = ip1->checksum;
+          sum1 = ip_csum_update (sum1, old_addr1.as_u32, new_addr1.as_u32,
+                                 ip4_header_t,
+                                 src_address /* changed member */);
+          ip1->checksum = ip_csum_fold (sum1);
+
+          if (PREDICT_TRUE(proto1 == SNAT_PROTOCOL_TCP))
+            {
+              if (tcp1->flags & TCP_FLAG_SYN)
+                ses1->state = SNAT_SESSION_TCP_SYN_SENT;
+              else if (tcp1->flags & TCP_FLAG_ACK && ses1->state == SNAT_SESSION_TCP_SYN_SENT)
+                ses1->state = SNAT_SESSION_TCP_ESTABLISHED;
+              else if (tcp1->flags & TCP_FLAG_FIN && ses1->state == SNAT_SESSION_TCP_ESTABLISHED)
+                ses1->state = SNAT_SESSION_TCP_FIN_WAIT;
+              else if (tcp1->flags & TCP_FLAG_ACK && ses1->state == SNAT_SESSION_TCP_FIN_WAIT)
+                snat_det_ses_close(dm1, ses1);
+              else if (tcp1->flags & TCP_FLAG_FIN && ses1->state == SNAT_SESSION_TCP_CLOSE_WAIT)
+                ses1->state = SNAT_SESSION_TCP_LAST_ACK;
+              else if (tcp1->flags == 0 && ses1->state == SNAT_SESSION_UNKNOWN)
+                ses1->state = SNAT_SESSION_TCP_ESTABLISHED;
+
+              old_port1 = tcp1->src;
+              tcp1->src = new_port1;
+
+              sum1 = tcp1->checksum;
+              sum1 = ip_csum_update (sum1, old_addr1.as_u32, new_addr1.as_u32,
+                                     ip4_header_t,
+                                     dst_address /* changed member */);
+              sum1 = ip_csum_update (sum1, old_port1, new_port1,
+                                     ip4_header_t /* cheat */,
+                                     length /* changed member */);
+              tcp1->checksum = ip_csum_fold(sum1);
+            }
+          else
+            {
+              ses1->state = SNAT_SESSION_UDP_ACTIVE;
+              old_port1 = udp1->src_port;
+              udp1->src_port = new_port1;
+              udp1->checksum = 0;
+            }
+
+          switch(ses1->state)
+            {
+            case SNAT_SESSION_UDP_ACTIVE:
+                ses1->expire = now + sm->udp_timeout;
+                break;
+            case SNAT_SESSION_TCP_SYN_SENT:
+            case SNAT_SESSION_TCP_FIN_WAIT:
+            case SNAT_SESSION_TCP_CLOSE_WAIT:
+            case SNAT_SESSION_TCP_LAST_ACK:
+                ses1->expire = now + sm->tcp_transitory_timeout;
+                break;
+            case SNAT_SESSION_TCP_ESTABLISHED:
+                ses1->expire = now + sm->tcp_established_timeout;
+                break;
+            }
+
+        trace1:
+          if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
+                            && (b1->flags & VLIB_BUFFER_IS_TRACED)))
+            {
+              snat_in2out_trace_t *t =
+                 vlib_add_trace (vm, node, b1, sizeof (*t));
+              t->is_slow_path = 0;
+              t->sw_if_index = sw_if_index1;
+              t->next_index = next1;
+              t->session_index = ~0;
+              if (ses1)
+                t->session_index = ses1 - dm1->sessions;
+            }
+
+          pkts_processed += next1 != SNAT_IN2OUT_NEXT_DROP;
+
+          /* verify speculative enqueues, maybe switch current next frame */
+          vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
+                                           to_next, n_left_to_next,
+                                           bi0, bi1, next0, next1);
+         }
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+          u32 bi0;
+	  vlib_buffer_t * b0;
+          u32 next0;
+          u32 sw_if_index0;
+          ip4_header_t * ip0;
+          ip_csum_t sum0;
+          ip4_address_t new_addr0, old_addr0;
+          u16 old_port0, new_port0, lo_port0, i0;
+          udp_header_t * udp0;
+          tcp_header_t * tcp0;
+          u32 proto0;
+          snat_det_out_key_t key0;
+          snat_det_map_t * dm0;
+          snat_det_session_t * ses0 = 0;
+          u32 rx_fib_index0;
+          icmp46_header_t * icmp0;
+
+          /* speculatively enqueue b0 to the current next frame */
+	  bi0 = from[0];
+	  to_next[0] = bi0;
+	  from += 1;
+	  to_next += 1;
+	  n_left_from -= 1;
+	  n_left_to_next -= 1;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+          next0 = SNAT_IN2OUT_NEXT_LOOKUP;
+
+          ip0 = vlib_buffer_get_current (b0);
+          udp0 = ip4_next_header (ip0);
+          tcp0 = (tcp_header_t *) udp0;
+
+          sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
+
+          if (PREDICT_FALSE(ip0->ttl == 1))
+            {
+              vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+              icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
+                                           ICMP4_time_exceeded_ttl_exceeded_in_transit,
+                                           0);
+              next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
+              goto trace00;
+            }
+
+          proto0 = ip_proto_to_snat_proto (ip0->protocol);
+
+          if (PREDICT_FALSE(proto0 == SNAT_PROTOCOL_ICMP))
+            {
+              rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index(sw_if_index0);
+              icmp0 = (icmp46_header_t *) udp0;
+
+              next0 = icmp_in2out(sm, b0, ip0, icmp0, sw_if_index0,
+                                  rx_fib_index0, node, next0, thread_index,
+                                  &ses0, &dm0);
+              goto trace00;
+            }
+
+          dm0 = snat_det_map_by_user(sm, &ip0->src_address);
+          if (PREDICT_FALSE(!dm0))
+            {
+              clib_warning("no match for internal host %U",
+                           format_ip4_address, &ip0->src_address);
+              next0 = SNAT_IN2OUT_NEXT_DROP;
+              b0->error = node->errors[SNAT_IN2OUT_ERROR_NO_TRANSLATION];
+              goto trace00;
+            }
+
+          snat_det_forward(dm0, &ip0->src_address, &new_addr0, &lo_port0);
+
+          key0.ext_host_addr = ip0->dst_address;
+          key0.ext_host_port = tcp0->dst;
+
+          ses0 = snat_det_find_ses_by_in(dm0, &ip0->src_address, tcp0->src, key0);
+          if (PREDICT_FALSE(!ses0))
+            {
+              for (i0 = 0; i0 < dm0->ports_per_host; i0++)
+                {
+                  key0.out_port = clib_host_to_net_u16 (lo_port0 +
+                    ((i0 + clib_net_to_host_u16 (tcp0->src)) % dm0->ports_per_host));
+
+                  if (snat_det_get_ses_by_out (dm0, &ip0->src_address, key0.as_u64))
+                    continue;
+
+                  ses0 = snat_det_ses_create(dm0, &ip0->src_address, tcp0->src, &key0);
+                  break;
+                }
+              if (PREDICT_FALSE(!ses0))
+                {
+                  /* too many sessions for user, send ICMP error packet */
+
+                  vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+                  icmp4_error_set_vnet_buffer (b0, ICMP4_destination_unreachable,
+                                               ICMP4_destination_unreachable_destination_unreachable_host,
+                                               0);
+                  next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
+                  goto trace00;
+                }
+            }
+
+          new_port0 = ses0->out.out_port;
+
+          old_addr0.as_u32 = ip0->src_address.as_u32;
+          ip0->src_address.as_u32 = new_addr0.as_u32;
+          vnet_buffer(b0)->sw_if_index[VLIB_TX] = sm->outside_fib_index;
+
+          sum0 = ip0->checksum;
+          sum0 = ip_csum_update (sum0, old_addr0.as_u32, new_addr0.as_u32,
+                                 ip4_header_t,
+                                 src_address /* changed member */);
+          ip0->checksum = ip_csum_fold (sum0);
+
+          if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
+            {
+              if (tcp0->flags & TCP_FLAG_SYN)
+                ses0->state = SNAT_SESSION_TCP_SYN_SENT;
+              else if (tcp0->flags & TCP_FLAG_ACK && ses0->state == SNAT_SESSION_TCP_SYN_SENT)
+                ses0->state = SNAT_SESSION_TCP_ESTABLISHED;
+              else if (tcp0->flags & TCP_FLAG_FIN && ses0->state == SNAT_SESSION_TCP_ESTABLISHED)
+                ses0->state = SNAT_SESSION_TCP_FIN_WAIT;
+              else if (tcp0->flags & TCP_FLAG_ACK && ses0->state == SNAT_SESSION_TCP_FIN_WAIT)
+                snat_det_ses_close(dm0, ses0);
+              else if (tcp0->flags & TCP_FLAG_FIN && ses0->state == SNAT_SESSION_TCP_CLOSE_WAIT)
+                ses0->state = SNAT_SESSION_TCP_LAST_ACK;
+              else if (tcp0->flags == 0 && ses0->state == SNAT_SESSION_UNKNOWN)
+                ses0->state = SNAT_SESSION_TCP_ESTABLISHED;
+
+              old_port0 = tcp0->src;
+              tcp0->src = new_port0;
+
+              sum0 = tcp0->checksum;
+              sum0 = ip_csum_update (sum0, old_addr0.as_u32, new_addr0.as_u32,
+                                     ip4_header_t,
+                                     dst_address /* changed member */);
+              sum0 = ip_csum_update (sum0, old_port0, new_port0,
+                                     ip4_header_t /* cheat */,
+                                     length /* changed member */);
+              tcp0->checksum = ip_csum_fold(sum0);
+            }
+          else
+            {
+              ses0->state = SNAT_SESSION_UDP_ACTIVE;
+              old_port0 = udp0->src_port;
+              udp0->src_port = new_port0;
+              udp0->checksum = 0;
+            }
+
+          switch(ses0->state)
+            {
+            case SNAT_SESSION_UDP_ACTIVE:
+                ses0->expire = now + sm->udp_timeout;
+                break;
+            case SNAT_SESSION_TCP_SYN_SENT:
+            case SNAT_SESSION_TCP_FIN_WAIT:
+            case SNAT_SESSION_TCP_CLOSE_WAIT:
+            case SNAT_SESSION_TCP_LAST_ACK:
+                ses0->expire = now + sm->tcp_transitory_timeout;
+                break;
+            case SNAT_SESSION_TCP_ESTABLISHED:
+                ses0->expire = now + sm->tcp_established_timeout;
+                break;
+            }
+
+        trace00:
+          if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
+                            && (b0->flags & VLIB_BUFFER_IS_TRACED)))
+            {
+              snat_in2out_trace_t *t =
+                 vlib_add_trace (vm, node, b0, sizeof (*t));
+              t->is_slow_path = 0;
+              t->sw_if_index = sw_if_index0;
+              t->next_index = next0;
+              t->session_index = ~0;
+              if (ses0)
+                t->session_index = ses0 - dm0->sessions;
+            }
+
+          pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;
+
+          /* verify speculative enqueue, maybe switch current next frame */
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
+					   to_next, n_left_to_next,
+					   bi0, next0);
+	}
+
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+
+  vlib_node_increment_counter (vm, snat_det_in2out_node.index,
+                               SNAT_IN2OUT_ERROR_IN2OUT_PACKETS,
+                               pkts_processed);
+  return frame->n_vectors;
+}
+
+VLIB_REGISTER_NODE (snat_det_in2out_node) = {
+  .function = snat_det_in2out_node_fn,
+  .name = "nat44-det-in2out",
+  .vector_size = sizeof (u32),
+  .format_trace = format_snat_in2out_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+
+  .n_errors = ARRAY_LEN(snat_in2out_error_strings),
+  .error_strings = snat_in2out_error_strings,
+
+  .runtime_data_bytes = sizeof (snat_runtime_t),
+
+  .n_next_nodes = 3,
+
+  /* edit / add dispositions here */
+  .next_nodes = {
+    [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
+    [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
+    [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
+  },
+};
+
+VLIB_NODE_FUNCTION_MULTIARCH (snat_det_in2out_node, snat_det_in2out_node_fn);
+
+/**
+ * Get address and port values to be used for ICMP packet translation
+ * and create session if needed
+ *
+ * @param[in,out] sm             NAT main
+ * @param[in,out] node           NAT node runtime
+ * @param[in] thread_index       thread index
+ * @param[in,out] b0             buffer containing packet to be translated
+ * @param[out] p_proto           protocol used for matching
+ * @param[out] p_value           address and port after NAT translation
+ * @param[out] p_dont_translate  if packet should not be translated
+ * @param d                      optional parameter
+ * @param e                      optional parameter
+ */
+u32 icmp_match_in2out_det(snat_main_t *sm, vlib_node_runtime_t *node,
+                          u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
+                          snat_session_key_t *p_value,
+                          u8 *p_dont_translate, void *d, void *e)
+{
+  ip4_header_t *ip0;
+  icmp46_header_t *icmp0;
+  u32 sw_if_index0;
+  u32 rx_fib_index0;
+  u8 protocol;
+  snat_det_out_key_t key0;
+  u8 dont_translate = 0;
+  u32 next0 = ~0;
+  icmp_echo_header_t *echo0, *inner_echo0 = 0;
+  ip4_header_t *inner_ip0;
+  void *l4_header = 0;
+  icmp46_header_t *inner_icmp0;
+  snat_det_map_t * dm0 = 0;
+  ip4_address_t new_addr0;
+  u16 lo_port0, i0;
+  snat_det_session_t * ses0 = 0;
+  ip4_address_t in_addr;
+  u16 in_port;
+
+  ip0 = vlib_buffer_get_current (b0);
+  icmp0 = (icmp46_header_t *) ip4_next_header (ip0);
+  echo0 = (icmp_echo_header_t *)(icmp0+1);
+  sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
+  rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index (sw_if_index0);
+
+  if (!icmp_is_error_message (icmp0))
+    {
+      protocol = SNAT_PROTOCOL_ICMP;
+      in_addr = ip0->src_address;
+      in_port = echo0->identifier;
+    }
+  else
+    {
+      inner_ip0 = (ip4_header_t *)(echo0+1);
+      l4_header = ip4_next_header (inner_ip0);
+      protocol = ip_proto_to_snat_proto (inner_ip0->protocol);
+      in_addr = inner_ip0->dst_address;
+      switch (protocol)
+        {
+        case SNAT_PROTOCOL_ICMP:
+          inner_icmp0 = (icmp46_header_t*)l4_header;
+          inner_echo0 = (icmp_echo_header_t *)(inner_icmp0+1);
+          in_port = inner_echo0->identifier;
+          break;
+        case SNAT_PROTOCOL_UDP:
+        case SNAT_PROTOCOL_TCP:
+          in_port = ((tcp_udp_header_t*)l4_header)->dst_port;
+          break;
+        default:
+          b0->error = node->errors[SNAT_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL];
+          next0 = SNAT_IN2OUT_NEXT_DROP;
+          goto out;
+        }
+    }
+
+  dm0 = snat_det_map_by_user(sm, &in_addr);
+  if (PREDICT_FALSE(!dm0))
+    {
+      clib_warning("no match for internal host %U",
+                   format_ip4_address, &in_addr);
+      if (PREDICT_FALSE(snat_not_translate_fast(sm, node, sw_if_index0, ip0,
+          IP_PROTOCOL_ICMP, rx_fib_index0)))
+        {
+          dont_translate = 1;
+          goto out;
+        }
+      next0 = SNAT_IN2OUT_NEXT_DROP;
+      b0->error = node->errors[SNAT_IN2OUT_ERROR_NO_TRANSLATION];
+      goto out;
+    }
+
+  snat_det_forward(dm0, &in_addr, &new_addr0, &lo_port0);
+
+  key0.ext_host_addr = ip0->dst_address;
+  key0.ext_host_port = 0;
+
+  ses0 = snat_det_find_ses_by_in(dm0, &in_addr, in_port, key0);
+  if (PREDICT_FALSE(!ses0))
+    {
+      if (PREDICT_FALSE(snat_not_translate_fast(sm, node, sw_if_index0, ip0,
+          IP_PROTOCOL_ICMP, rx_fib_index0)))
+        {
+          dont_translate = 1;
+          goto out;
+        }
+      if (icmp0->type != ICMP4_echo_request)
+        {
+          b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
+          next0 = SNAT_IN2OUT_NEXT_DROP;
+          goto out;
+        }
+      for (i0 = 0; i0 < dm0->ports_per_host; i0++)
+        {
+          key0.out_port = clib_host_to_net_u16 (lo_port0 +
+            ((i0 + clib_net_to_host_u16 (echo0->identifier)) % dm0->ports_per_host));
+
+          if (snat_det_get_ses_by_out (dm0, &in_addr, key0.as_u64))
+            continue;
+
+          ses0 = snat_det_ses_create(dm0, &in_addr, echo0->identifier, &key0);
+          break;
+        }
+      if (PREDICT_FALSE(!ses0))
+        {
+          next0 = SNAT_IN2OUT_NEXT_DROP;
+          b0->error = node->errors[SNAT_IN2OUT_ERROR_OUT_OF_PORTS];
+          goto out;
+        }
+    }
+
+  if (PREDICT_FALSE(icmp0->type != ICMP4_echo_request &&
+                    !icmp_is_error_message (icmp0)))
+    {
+      b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
+      next0 = SNAT_IN2OUT_NEXT_DROP;
+      goto out;
+    }
+
+  u32 now = (u32) vlib_time_now (sm->vlib_main);
+
+  ses0->state = SNAT_SESSION_ICMP_ACTIVE;
+  ses0->expire = now + sm->icmp_timeout;
+
+out:
+  *p_proto = protocol;
+  if (ses0)
+    {
+      p_value->addr = new_addr0;
+      p_value->fib_index = sm->outside_fib_index;
+      p_value->port = ses0->out.out_port;
+    }
+  *p_dont_translate = dont_translate;
+  if (d)
+    *(snat_det_session_t**)d = ses0;
+  if (e)
+    *(snat_det_map_t**)e = dm0;
+  return next0;
+}
+
+/**********************/
+/*** worker handoff ***/
+/**********************/
+static inline uword
+snat_in2out_worker_handoff_fn_inline (vlib_main_t * vm,
+                                      vlib_node_runtime_t * node,
+                                      vlib_frame_t * frame,
+                                      u8 is_output)
+{
+  snat_main_t *sm = &snat_main;
+  vlib_thread_main_t *tm = vlib_get_thread_main ();
+  u32 n_left_from, *from, *to_next = 0;
+  static __thread vlib_frame_queue_elt_t **handoff_queue_elt_by_worker_index;
+  static __thread vlib_frame_queue_t **congested_handoff_queue_by_worker_index
+    = 0;
+  vlib_frame_queue_elt_t *hf = 0;
+  vlib_frame_t *f = 0;
+  int i;
+  u32 n_left_to_next_worker = 0, *to_next_worker = 0;
+  u32 next_worker_index = 0;
+  u32 current_worker_index = ~0;
+  u32 thread_index = vlib_get_thread_index ();
+  u32 fq_index;
+  u32 to_node_index;
+
+  ASSERT (vec_len (sm->workers));
+
+  if (is_output)
+    {
+      fq_index = sm->fq_in2out_output_index;
+      to_node_index = sm->in2out_output_node_index;
+    }
+  else
+    {
+      fq_index = sm->fq_in2out_index;
+      to_node_index = sm->in2out_node_index;
+    }
+
+  if (PREDICT_FALSE (handoff_queue_elt_by_worker_index == 0))
+    {
+      vec_validate (handoff_queue_elt_by_worker_index, tm->n_vlib_mains - 1);
+
+      vec_validate_init_empty (congested_handoff_queue_by_worker_index,
+			       sm->first_worker_index + sm->num_workers - 1,
+			       (vlib_frame_queue_t *) (~0));
+    }
+
+  from = vlib_frame_vector_args (frame);
+  n_left_from = frame->n_vectors;
+
+  while (n_left_from > 0)
+    {
+      u32 bi0;
+      vlib_buffer_t *b0;
+      u32 sw_if_index0;
+      u32 rx_fib_index0;
+      ip4_header_t * ip0;
+      u8 do_handoff;
+
+      bi0 = from[0];
+      from += 1;
+      n_left_from -= 1;
+
+      b0 = vlib_get_buffer (vm, bi0);
+
+      sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
+      rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index(sw_if_index0);
+
+      ip0 = vlib_buffer_get_current (b0);
+
+      next_worker_index = sm->worker_in2out_cb(ip0, rx_fib_index0);
+
+      if (PREDICT_FALSE (next_worker_index != thread_index))
+        {
+          do_handoff = 1;
+
+          if (next_worker_index != current_worker_index)
+            {
+              if (hf)
+                hf->n_vectors = VLIB_FRAME_SIZE - n_left_to_next_worker;
+
+              hf = vlib_get_worker_handoff_queue_elt (fq_index,
+                                                      next_worker_index,
+                                                      handoff_queue_elt_by_worker_index);
+
+              n_left_to_next_worker = VLIB_FRAME_SIZE - hf->n_vectors;
+              to_next_worker = &hf->buffer_index[hf->n_vectors];
+              current_worker_index = next_worker_index;
+            }
+
+          /* enqueue to correct worker thread */
+          to_next_worker[0] = bi0;
+          to_next_worker++;
+          n_left_to_next_worker--;
+
+          if (n_left_to_next_worker == 0)
+            {
+              hf->n_vectors = VLIB_FRAME_SIZE;
+              vlib_put_frame_queue_elt (hf);
+              current_worker_index = ~0;
+              handoff_queue_elt_by_worker_index[next_worker_index] = 0;
+              hf = 0;
+            }
+        }
+      else
+        {
+          do_handoff = 0;
+          /* if this is 1st frame */
+          if (!f)
+            {
+              f = vlib_get_frame_to_node (vm, to_node_index);
+              to_next = vlib_frame_vector_args (f);
+            }
+
+          to_next[0] = bi0;
+          to_next += 1;
+          f->n_vectors++;
+        }
+
+      if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
+			 && (b0->flags & VLIB_BUFFER_IS_TRACED)))
+	{
+          snat_in2out_worker_handoff_trace_t *t =
+            vlib_add_trace (vm, node, b0, sizeof (*t));
+          t->next_worker_index = next_worker_index;
+          t->do_handoff = do_handoff;
+        }
+    }
+
+  if (f)
+    vlib_put_frame_to_node (vm, to_node_index, f);
+
+  if (hf)
+    hf->n_vectors = VLIB_FRAME_SIZE - n_left_to_next_worker;
+
+  /* Ship frames to the worker nodes */
+  for (i = 0; i < vec_len (handoff_queue_elt_by_worker_index); i++)
+    {
+      if (handoff_queue_elt_by_worker_index[i])
+	{
+	  hf = handoff_queue_elt_by_worker_index[i];
+	  /*
+	   * It works better to let the handoff node
+	   * rate-adapt, always ship the handoff queue element.
+	   */
+	  if (1 || hf->n_vectors == hf->last_n_vectors)
+	    {
+	      vlib_put_frame_queue_elt (hf);
+	      handoff_queue_elt_by_worker_index[i] = 0;
+	    }
+	  else
+	    hf->last_n_vectors = hf->n_vectors;
+	}
+      congested_handoff_queue_by_worker_index[i] =
+	(vlib_frame_queue_t *) (~0);
+    }
+  hf = 0;
+  current_worker_index = ~0;
+  return frame->n_vectors;
+}
+
+static uword
+snat_in2out_worker_handoff_fn (vlib_main_t * vm,
+                               vlib_node_runtime_t * node,
+                               vlib_frame_t * frame)
+{
+  return snat_in2out_worker_handoff_fn_inline (vm, node, frame, 0);
+}
+
+VLIB_REGISTER_NODE (snat_in2out_worker_handoff_node) = {
+  .function = snat_in2out_worker_handoff_fn,
+  .name = "nat44-in2out-worker-handoff",
+  .vector_size = sizeof (u32),
+  .format_trace = format_snat_in2out_worker_handoff_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+
+  .n_next_nodes = 1,
+
+  .next_nodes = {
+    [0] = "error-drop",
+  },
+};
+
+VLIB_NODE_FUNCTION_MULTIARCH (snat_in2out_worker_handoff_node,
+                              snat_in2out_worker_handoff_fn);
+
+static uword
+snat_in2out_output_worker_handoff_fn (vlib_main_t * vm,
+                                      vlib_node_runtime_t * node,
+                                      vlib_frame_t * frame)
+{
+  return snat_in2out_worker_handoff_fn_inline (vm, node, frame, 1);
+}
+
+VLIB_REGISTER_NODE (snat_in2out_output_worker_handoff_node) = {
+  .function = snat_in2out_output_worker_handoff_fn,
+  .name = "nat44-in2out-output-worker-handoff",
+  .vector_size = sizeof (u32),
+  .format_trace = format_snat_in2out_worker_handoff_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+
+  .n_next_nodes = 1,
+
+  .next_nodes = {
+    [0] = "error-drop",
+  },
+};
+
+VLIB_NODE_FUNCTION_MULTIARCH (snat_in2out_output_worker_handoff_node,
+                              snat_in2out_output_worker_handoff_fn);
+
+static_always_inline int
+is_hairpinning (snat_main_t *sm, ip4_address_t * dst_addr)
+{
+  snat_address_t * ap;
+  clib_bihash_kv_8_8_t kv, value;
+  snat_session_key_t m_key;
+
+  vec_foreach (ap, sm->addresses)
+    {
+      if (ap->addr.as_u32 == dst_addr->as_u32)
+        return 1;
+    }
+
+  m_key.addr.as_u32 = dst_addr->as_u32;
+  m_key.fib_index = sm->outside_fib_index;
+  m_key.port = 0;
+  m_key.protocol = 0;
+  kv.key = m_key.as_u64;
+  if (!clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv, &value))
+    return 1;
+
+  return 0;
+}
+
+static uword
+snat_hairpin_dst_fn (vlib_main_t * vm,
+                     vlib_node_runtime_t * node,
+                     vlib_frame_t * frame)
+{
+  u32 n_left_from, * from, * to_next;
+  snat_in2out_next_t next_index;
+  u32 pkts_processed = 0;
+  snat_main_t * sm = &snat_main;
+
+  from = vlib_frame_vector_args (frame);
+  n_left_from = frame->n_vectors;
+  next_index = node->cached_next_index;
+
+  while (n_left_from > 0)
+    {
+      u32 n_left_to_next;
+
+      vlib_get_next_frame (vm, node, next_index,
+			   to_next, n_left_to_next);
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+          u32 bi0;
+	  vlib_buffer_t * b0;
+          u32 next0;
+          ip4_header_t * ip0;
+          u32 proto0;
+
+          /* speculatively enqueue b0 to the current next frame */
+	  bi0 = from[0];
+	  to_next[0] = bi0;
+	  from += 1;
+	  to_next += 1;
+	  n_left_from -= 1;
+	  n_left_to_next -= 1;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+          next0 = SNAT_IN2OUT_NEXT_LOOKUP;
+          ip0 = vlib_buffer_get_current (b0);
+
+          proto0 = ip_proto_to_snat_proto (ip0->protocol);
+
+          vnet_buffer (b0)->snat.flags = 0;
+          if (PREDICT_FALSE (is_hairpinning (sm, &ip0->dst_address)))
+            {
+              if (proto0 == SNAT_PROTOCOL_TCP || proto0 == SNAT_PROTOCOL_UDP)
+                {
+                  udp_header_t * udp0 = ip4_next_header (ip0);
+                  tcp_header_t * tcp0 = (tcp_header_t *) udp0;
+
+                  snat_hairpinning (sm, b0, ip0, udp0, tcp0, proto0);
+                }
+              else if (proto0 == SNAT_PROTOCOL_ICMP)
+                {
+                  icmp46_header_t * icmp0 = ip4_next_header (ip0);
+
+                  snat_icmp_hairpinning (sm, b0, ip0, icmp0);
+                }
+              else
+                {
+                  snat_hairpinning_unknown_proto (sm, b0, ip0);
+                }
+
+              vnet_buffer (b0)->snat.flags = SNAT_FLAG_HAIRPINNING;
+              clib_warning("is hairpinning");
+            }
+
+          pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;
+
+          /* verify speculative enqueue, maybe switch current next frame */
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
+					   to_next, n_left_to_next,
+					   bi0, next0);
+         }
+
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+
+  vlib_node_increment_counter (vm, snat_hairpin_dst_node.index,
+                               SNAT_IN2OUT_ERROR_IN2OUT_PACKETS,
+                               pkts_processed);
+  return frame->n_vectors;
+}
+
+VLIB_REGISTER_NODE (snat_hairpin_dst_node) = {
+  .function = snat_hairpin_dst_fn,
+  .name = "nat44-hairpin-dst",
+  .vector_size = sizeof (u32),
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN(snat_in2out_error_strings),
+  .error_strings = snat_in2out_error_strings,
+  .n_next_nodes = 2,
+  .next_nodes = {
+    [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
+    [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
+  },
+};
+
+VLIB_NODE_FUNCTION_MULTIARCH (snat_hairpin_dst_node,
+                              snat_hairpin_dst_fn);
+
+static uword
+snat_hairpin_src_fn (vlib_main_t * vm,
+                     vlib_node_runtime_t * node,
+                     vlib_frame_t * frame)
+{
+  u32 n_left_from, * from, * to_next;
+  snat_in2out_next_t next_index;
+  u32 pkts_processed = 0;
+  snat_main_t *sm = &snat_main;
+
+  from = vlib_frame_vector_args (frame);
+  n_left_from = frame->n_vectors;
+  next_index = node->cached_next_index;
+
+  while (n_left_from > 0)
+    {
+      u32 n_left_to_next;
+
+      vlib_get_next_frame (vm, node, next_index,
+			   to_next, n_left_to_next);
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+          u32 bi0;
+	  vlib_buffer_t * b0;
+          u32 next0;
+
+          /* speculatively enqueue b0 to the current next frame */
+	  bi0 = from[0];
+	  to_next[0] = bi0;
+	  from += 1;
+	  to_next += 1;
+	  n_left_from -= 1;
+	  n_left_to_next -= 1;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+          next0 = SNAT_HAIRPIN_SRC_NEXT_INTERFACE_OUTPUT;
+
+          if (PREDICT_FALSE ((vnet_buffer (b0)->snat.flags) & SNAT_FLAG_HAIRPINNING))
+            {
+              if (PREDICT_TRUE (sm->num_workers > 1))
+                next0 = SNAT_HAIRPIN_SRC_NEXT_SNAT_IN2OUT_WH;
+              else
+                next0 = SNAT_HAIRPIN_SRC_NEXT_SNAT_IN2OUT;
+            }
+
+          pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;
+
+          /* verify speculative enqueue, maybe switch current next frame */
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
+					   to_next, n_left_to_next,
+					   bi0, next0);
+         }
+
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+
+  vlib_node_increment_counter (vm, snat_hairpin_src_node.index,
+                               SNAT_IN2OUT_ERROR_IN2OUT_PACKETS,
+                               pkts_processed);
+  return frame->n_vectors;
+}
+
+VLIB_REGISTER_NODE (snat_hairpin_src_node) = {
+  .function = snat_hairpin_src_fn,
+  .name = "nat44-hairpin-src",
+  .vector_size = sizeof (u32),
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN(snat_in2out_error_strings),
+  .error_strings = snat_in2out_error_strings,
+  .n_next_nodes = SNAT_HAIRPIN_SRC_N_NEXT,
+  .next_nodes = {
+     [SNAT_HAIRPIN_SRC_NEXT_DROP] = "error-drop",
+     [SNAT_HAIRPIN_SRC_NEXT_SNAT_IN2OUT] = "nat44-in2out-output",
+     [SNAT_HAIRPIN_SRC_NEXT_INTERFACE_OUTPUT] = "interface-output",
+     [SNAT_HAIRPIN_SRC_NEXT_SNAT_IN2OUT_WH] = "nat44-in2out-output-worker-handoff",
+  },
+};
+
+VLIB_NODE_FUNCTION_MULTIARCH (snat_hairpin_src_node,
+                              snat_hairpin_src_fn);
+
+static uword
+snat_in2out_fast_static_map_fn (vlib_main_t * vm,
+                                vlib_node_runtime_t * node,
+                                vlib_frame_t * frame)
+{
+  u32 n_left_from, * from, * to_next;
+  snat_in2out_next_t next_index;
+  u32 pkts_processed = 0;
+  snat_main_t * sm = &snat_main;
+  u32 stats_node_index;
+
+  stats_node_index = snat_in2out_fast_node.index;
+
+  from = vlib_frame_vector_args (frame);
+  n_left_from = frame->n_vectors;
+  next_index = node->cached_next_index;
+
+  while (n_left_from > 0)
+    {
+      u32 n_left_to_next;
+
+      vlib_get_next_frame (vm, node, next_index,
+			   to_next, n_left_to_next);
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+          u32 bi0;
+	  vlib_buffer_t * b0;
+          u32 next0;
+          u32 sw_if_index0;
+          ip4_header_t * ip0;
+          ip_csum_t sum0;
+          u32 new_addr0, old_addr0;
+          u16 old_port0, new_port0;
+          udp_header_t * udp0;
+          tcp_header_t * tcp0;
+          icmp46_header_t * icmp0;
+          snat_session_key_t key0, sm0;
+          u32 proto0;
+          u32 rx_fib_index0;
+
+          /* speculatively enqueue b0 to the current next frame */
+	  bi0 = from[0];
+	  to_next[0] = bi0;
+	  from += 1;
+	  to_next += 1;
+	  n_left_from -= 1;
+	  n_left_to_next -= 1;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+          next0 = SNAT_IN2OUT_NEXT_LOOKUP;
+
+          ip0 = vlib_buffer_get_current (b0);
+          udp0 = ip4_next_header (ip0);
+          tcp0 = (tcp_header_t *) udp0;
+          icmp0 = (icmp46_header_t *) udp0;
+
+          sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
+	  rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index(sw_if_index0);
+
+          if (PREDICT_FALSE(ip0->ttl == 1))
+            {
+              vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+              icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
+                                           ICMP4_time_exceeded_ttl_exceeded_in_transit,
+                                           0);
+              next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
+              goto trace0;
+            }
+
+          proto0 = ip_proto_to_snat_proto (ip0->protocol);
+
+          if (PREDICT_FALSE (proto0 == ~0))
+              goto trace0;
+
+          if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
+            {
+              next0 = icmp_in2out(sm, b0, ip0, icmp0, sw_if_index0,
+                                  rx_fib_index0, node, next0, ~0, 0, 0);
+              goto trace0;
+            }
+
+          key0.addr = ip0->src_address;
+          key0.port = udp0->src_port;
+          key0.fib_index = rx_fib_index0;
+
+          if (snat_static_mapping_match(sm, key0, &sm0, 0, 0))
+            {
+              b0->error = node->errors[SNAT_IN2OUT_ERROR_NO_TRANSLATION];
+              next0= SNAT_IN2OUT_NEXT_DROP;
+              goto trace0;
+            }
+
+          new_addr0 = sm0.addr.as_u32;
+          new_port0 = sm0.port;
+          vnet_buffer(b0)->sw_if_index[VLIB_TX] = sm0.fib_index;
+          old_addr0 = ip0->src_address.as_u32;
+          ip0->src_address.as_u32 = new_addr0;
+
+          sum0 = ip0->checksum;
+          sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
+                                 ip4_header_t,
+                                 src_address /* changed member */);
+          ip0->checksum = ip_csum_fold (sum0);
+
+          if (PREDICT_FALSE(new_port0 != udp0->dst_port))
+            {
+              if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
+                {
+                  old_port0 = tcp0->src_port;
+                  tcp0->src_port = new_port0;
+
+                  sum0 = tcp0->checksum;
+                  sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
+                                         ip4_header_t,
+                                         dst_address /* changed member */);
+                  sum0 = ip_csum_update (sum0, old_port0, new_port0,
+                                         ip4_header_t /* cheat */,
+                                         length /* changed member */);
+                  tcp0->checksum = ip_csum_fold(sum0);
+                }
+              else
+                {
+                  old_port0 = udp0->src_port;
+                  udp0->src_port = new_port0;
+                  udp0->checksum = 0;
+                }
+            }
+          else
+            {
+              if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
+                {
+                  sum0 = tcp0->checksum;
+                  sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
+                                         ip4_header_t,
+                                         dst_address /* changed member */);
+                  tcp0->checksum = ip_csum_fold(sum0);
+                }
+            }
+
+          /* Hairpinning */
+          snat_hairpinning (sm, b0, ip0, udp0, tcp0, proto0);
+
+        trace0:
+          if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
+                            && (b0->flags & VLIB_BUFFER_IS_TRACED)))
+            {
+              snat_in2out_trace_t *t =
+                 vlib_add_trace (vm, node, b0, sizeof (*t));
+              t->sw_if_index = sw_if_index0;
+              t->next_index = next0;
+            }
+
+          pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;
+
+          /* verify speculative enqueue, maybe switch current next frame */
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
+					   to_next, n_left_to_next,
+					   bi0, next0);
+	}
+
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+
+  vlib_node_increment_counter (vm, stats_node_index,
+                               SNAT_IN2OUT_ERROR_IN2OUT_PACKETS,
+                               pkts_processed);
+  return frame->n_vectors;
+}
+
+
+VLIB_REGISTER_NODE (snat_in2out_fast_node) = {
+  .function = snat_in2out_fast_static_map_fn,
+  .name = "nat44-in2out-fast",
+  .vector_size = sizeof (u32),
+  .format_trace = format_snat_in2out_fast_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+
+  .n_errors = ARRAY_LEN(snat_in2out_error_strings),
+  .error_strings = snat_in2out_error_strings,
+
+  .runtime_data_bytes = sizeof (snat_runtime_t),
+
+  .n_next_nodes = SNAT_IN2OUT_N_NEXT,
+
+  /* edit / add dispositions here */
+  .next_nodes = {
+    [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
+    [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
+    [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-slowpath",
+    [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
+  },
+};
+
+VLIB_NODE_FUNCTION_MULTIARCH (snat_in2out_fast_node, snat_in2out_fast_static_map_fn);
diff --git a/src/plugins/nat/nat.api b/src/plugins/nat/nat.api
new file mode 100644
index 00000000000..7245cb078b9
--- /dev/null
+++ b/src/plugins/nat/nat.api
@@ -0,0 +1,1513 @@
+/*
+ * 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.
+ */
+/**
+ * @file nat.api
+ * @brief VPP control-plane API messages.
+ *
+ * This file defines VPP control-plane API messages which are generally
+ * called through a shared memory interface.
+ */
+
+/*
+ * Old "snat" APIs, will be deprecated after 17.10
+ */
+
+/** \brief Add/del NAT44 address range
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param is_ip4 - 1 if address type is IPv4
+    @param first_ip_address - first IP address
+    @param last_ip_address - last IP address
+    @param vrf_id - VRF id of tenant, ~0 means independent of VRF
+    @param is_add - 1 if add, 0 if delete
+*/
+autoreply define snat_add_address_range {
+  u32 client_index;
+  u32 context;
+  u8 is_ip4;
+  u8 first_ip_address[16];
+  u8 last_ip_address[16];
+  u32 vrf_id;
+  u8 is_add;
+};
+
+/** \brief Dump NAT44 addresses
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+*/
+define snat_address_dump {
+  u32 client_index;
+  u32 context;
+};
+
+/** \brief NAT44 address details response
+    @param context - sender context, to match reply w/ request
+    @param is_ip4 - 1 if address type is IPv4
+    @param ip_address - IP address
+    @param vrf_id - VRF id of tenant, ~0 means independent of VRF
+*/
+define snat_address_details {
+  u32 context;
+  u8 is_ip4;
+  u8 ip_address[16];
+  u32 vrf_id;
+};
+
+/** \brief Enable/disable NAT44 feature on the interface
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param is_add - 1 if add, 0 if delete
+    @param is_inside - 1 if inside, 0 if outside
+    @param sw_if_index - software index of the interface
+*/
+autoreply define snat_interface_add_del_feature {
+  u32 client_index;
+  u32 context;
+  u8 is_add;
+  u8 is_inside;
+  u32 sw_if_index;
+};
+
+/** \brief Dump interfaces with NAT44 feature
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+*/
+define snat_interface_dump {
+  u32 client_index;
+  u32 context;
+};
+
+/** \brief NAT44 interface details response
+    @param context - sender context, to match reply w/ request
+    @param is_inside - 1 if inside, 0 if outside
+    @param sw_if_index - software index of the interface
+*/
+define snat_interface_details {
+  u32 context;
+  u8 is_inside;
+  u32 sw_if_index;
+};
+
+/** \brief Enable/disbale NAT44 as an interface output feature (postrouting
+           in2out translation)
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param is_add - 1 if add, 0 if delete
+    @param is_inside - 1 if inside, 0 if outside
+    @param sw_if_index - software index of the interface
+*/
+autoreply define snat_interface_add_del_output_feature {
+  u32 client_index;
+  u32 context;
+  u8 is_add;
+  u8 is_inside;
+  u32 sw_if_index;
+};
+
+/** \brief Dump interfaces with NAT44 output feature
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+*/
+define snat_interface_output_feature_dump {
+  u32 client_index;
+  u32 context;
+};
+
+/** \brief NAT44 interface with output feature details response
+    @param context - sender context, to match reply w/ request
+    @param is_inside - 1 if inside, 0 if outside
+    @param sw_if_index - software index of the interface
+*/
+define snat_interface_output_feature_details {
+  u32 context;
+  u8 is_inside;
+  u32 sw_if_index;
+};
+
+/** \brief Add/delete NAT44 static mapping
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param is_add - 1 if add, 0 if delete
+    @param is_ip4 - 1 if address type is IPv4
+    @param addr_only - 1 if address only mapping
+    @param local_ip_address - local IP address
+    @param external_ip_address - external IP address
+    @param protocol - IP protocol
+    @param local_port - local port number
+    @param external_port - external port number
+    @param external_sw_if_index - external interface (if set
+                                  external_ip_address is ignored, ~0 means not
+                                  used)
+    @param vfr_id - VRF ID
+*/
+autoreply define snat_add_static_mapping {
+  u32 client_index;
+  u32 context;
+  u8 is_add;
+  u8 is_ip4;
+  u8 addr_only;
+  u8 local_ip_address[16];
+  u8 external_ip_address[16];
+  u8 protocol;
+  u16 local_port;
+  u16 external_port;
+  u32 external_sw_if_index;
+  u32 vrf_id;
+};
+
+/** \brief Dump NAT44 static mappings
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+*/
+define snat_static_mapping_dump {
+  u32 client_index;
+  u32 context;
+};
+
+/** \brief NAT44 static mapping details response
+    @param context - sender context, to match reply w/ request
+    @param is_ip4 - 1 if address type is IPv4
+    @param addr_only - 1 if address only mapping
+    @param local_ip_address - local IP address
+    @param external_ip_address - external IP address
+    @param protocol - IP protocol
+    @param local_port - local port number
+    @param external_port - external port number
+    @param external_sw_if_index - external interface
+    @param vfr_id - VRF ID
+*/
+define snat_static_mapping_details {
+  u32 context;
+  u8 is_ip4;
+  u8 addr_only;
+  u8 local_ip_address[16];
+  u8 external_ip_address[16];
+  u8 protocol;
+  u16 local_port;
+  u16 external_port;
+  u32 external_sw_if_index;
+  u32 vrf_id;
+};
+
+/** \brief Control ping from client to api server request
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+*/
+define snat_control_ping
+{
+  u32 client_index;
+  u32 context;
+};
+
+/** \brief Control ping from the client to the server response
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param retval - return code for the request
+    @param vpe_pid - the pid of the vpe, returned by the server
+*/
+define snat_control_ping_reply
+{
+  u32 context;
+  i32 retval;
+  u32 client_index;
+  u32 vpe_pid;
+};
+
+/** \brief Show NAT plugin startup config
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+*/
+define snat_show_config
+{
+  u32 client_index;
+  u32 context;
+};
+
+/** \brief Show NAT plugin startup config reply
+    @param context - sender context, to match reply w/ request
+    @param retval - return code for the request
+    @param static_mapping_only - if 1 dynamic translations disabled
+    @param static_mapping_connection_tracking - if 1 create session data
+    @param deterministic - if 1 deterministic mapping
+    @param translation_buckets - number of translation hash buckets
+    @param translation_memory_size - translation hash memory size
+    @param user_buckets - number of user hash buckets
+    @param user_memory_size - user hash memory size
+    @param max_translations_per_user - maximum number of translations per user
+    @param outside_vrf_id - outside VRF id
+    @param inside_vrf_id - default inside VRF id
+*/
+define snat_show_config_reply
+{
+  u32 context;
+  i32 retval;
+  u8 static_mapping_only;
+  u8 static_mapping_connection_tracking;
+  u8 deterministic;
+  u32 translation_buckets;
+  u32 translation_memory_size;
+  u32 user_buckets;
+  u32 user_memory_size;
+  u32 max_translations_per_user;
+  u32 outside_vrf_id;
+  u32 inside_vrf_id;
+};
+
+/** \brief Set NAT workers
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param worker_mask - NAT workers mask
+*/
+autoreply define snat_set_workers {
+  u32 client_index;
+  u32 context;
+  u64 worker_mask;
+};
+
+/** \brief Dump NAT workers
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+*/
+define snat_worker_dump {
+  u32 client_index;
+  u32 context;
+};
+
+/** \brief NAT workers details response
+    @param context - sender context, to match reply w/ request
+    @param worker_index - worker index
+    @param lcore_id - lcore ID
+    @param name - worker name
+*/
+define snat_worker_details {
+  u32 context;
+  u32 worker_index;
+  u32 lcore_id;
+  u8 name[64];
+};
+
+/** \brief Add/delete NAT44 pool address from specific interfce
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param is_add - 1 if add, 0 if delete
+    @param sw_if_index - software index of the interface
+*/
+autoreply define snat_add_del_interface_addr {
+  u32 client_index;
+  u32 context;
+  u8 is_add;
+  u8 is_inside;
+  u32 sw_if_index;
+};
+
+/** \brief Dump NAT44 pool addresses interfaces
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+*/
+define snat_interface_addr_dump {
+  u32 client_index;
+  u32 context;
+};
+
+/** \brief NAT44 pool addresses interfaces details response
+    @param context - sender context, to match reply w/ request
+    @param sw_if_index - software index of the interface
+*/
+define snat_interface_addr_details {
+  u32 context;
+  u32 sw_if_index;
+};
+
+/** \brief Enable/disable NAT IPFIX logging
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param domain_id - observation domain ID
+    @param src_port - source port number
+    @param enable - 1 if enable, 0 if disable
+*/
+autoreply define snat_ipfix_enable_disable {
+  u32 client_index;
+  u32 context;
+  u32 domain_id;
+  u16 src_port;
+  u8 enable;
+};
+
+/** \brief Dump NAT44 users
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+*/
+define snat_user_dump {
+  u32 client_index;
+  u32 context;
+};
+
+/** \brief NAT44 users response
+    @param context - sender context, to match reply w/ request
+    @vrf_id - VRF ID
+    @param is_ip4 - 1 if address type is IPv4
+    @param ip_adress - IP address
+    @param nsessions - number of dynamic sessions
+    @param nstaticsessions - number of static sessions
+*/
+define snat_user_details {
+  u32 context;
+  u32 vrf_id;
+  u8 is_ip4;
+  u8 ip_address[16];
+  u32 nsessions;
+  u32 nstaticsessions;
+};
+
+/** \brief NAT44 user's sessions
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param is_ip4 - 1 if address type is IPv4
+    @param user_ip - IP address of the user to dump
+    @param vrf_id - VRF_ID
+*/
+define snat_user_session_dump {
+  u32 client_index;
+  u32 context;
+  u8 is_ip4;
+  u8 ip_address[16];
+  u32 vrf_id;
+};
+
+/** \brief NAT44 user's sessions response
+    @param context - sender context, to match reply w/ request
+    @param is_ip4 - 1 if address type is IPv4
+    @param outside_ip_address - outside IP address
+    @param outside_port - outside port
+    @param inside_ip_address - inside IP address
+    @param inside_port - inside port
+    @param protocol - protocol
+    @param is_static - 1 if session is static
+    @param last_heard - last heard timer
+    @param total_bytes - count of bytes sent through session
+    @param total_pkts - count of pakets sent through session
+*/
+define snat_user_session_details {
+  u32 context;
+  u8 is_ip4;
+  u8 outside_ip_address[16];
+  u16 outside_port;
+  u8 inside_ip_address[16];
+  u16 inside_port;
+  u16 protocol;
+  u8 is_static;
+  u64 last_heard;
+  u64 total_bytes;
+  u32 total_pkts;
+};
+
+/** \brief Add/delete NAT deterministic mapping
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param is_add - 1 if add, 0 if delete
+    @param is_ip4 - 1 if address type is IPv4
+    @param in_addr - inside IP address
+    @param in_plen - inside IP address prefix length
+    @param out_addr - outside IP address
+    @param out_addr - outside IP address prefix length
+*/
+autoreply define snat_add_det_map {
+  u32 client_index;
+  u32 context;
+  u8 is_add;
+  u8 is_ip4;
+  u8 addr_only;
+  u8 in_addr[16];
+  u8 in_plen;
+  u8 out_addr[16];
+  u8 out_plen;
+};
+
+/** \brief Get outside address and port range from inside address
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param is_ip4 - 1 if address type is IPv4
+    @param in_addr - inside IP address
+*/
+define snat_det_forward {
+  u32 client_index;
+  u32 context;
+  u8 is_ip4;
+  u8 in_addr[16];
+};
+
+/** \brief Get outside address and port range from inside address
+    @param context - sender context, to match reply w/ request
+    @param retval - return code
+    @param out_port_lo - outside port range start
+    @param out_port_hi - outside port range end
+    @param is_ip4 - 1 if address type is IPv4
+    @param out_addr - outside IP address
+*/
+define snat_det_forward_reply {
+  u32 context;
+  i32 retval;
+  u16 out_port_lo;
+  u16 out_port_hi;
+  u8 is_ip4;
+  u8 out_addr[16];
+};
+
+/** \brief Get inside address from outside address and port
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param out_port - outside port
+    @param is_ip4 - 1 if address type is IPv4
+    @param out_addr - outside IP address
+*/
+define snat_det_reverse {
+  u32 client_index;
+  u32 context;
+  u16 out_port;
+  u8 is_ip4;
+  u8 out_addr[16];
+};
+
+/** \brief Get inside address from outside address and port reply
+    @param context - sender context, to match reply w/ request
+    @param retval - return code
+    @param is_ip4 - 1 if address type is IPv4
+    @param in_addr - inside IP address
+*/
+define snat_det_reverse_reply {
+  u32 context;
+  i32 retval;
+  u8 is_ip4;
+  u8 in_addr[16];
+};
+
+/** \brief Dump NAT deterministic mappings
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+*/
+define snat_det_map_dump {
+  u32 client_index;
+  u32 context;
+};
+
+/** \brief NAT users response
+    @param context - sender context, to match reply w/ request
+    @param is_ip4 - 1 if address type is IPv4
+    @param in_addr - inside IP address
+    @param in_plen - inside IP address prefix length
+    @param out_addr - outside IP address
+    @param out_plen - outside IP address prefix length
+    @param sharing_ratio - outside to inside address sharing ratio
+    @param ports_per_host - number of ports available to a host
+    @param ses_num - number of sessions belonging to this mapping
+*/
+define snat_det_map_details {
+  u32 context;
+  u8 is_ip4;
+  u8 in_addr[16];
+  u8 in_plen;
+  u8 out_addr[16];
+  u8 out_plen;
+  u32 sharing_ratio;
+  u16 ports_per_host;
+  u32 ses_num;
+};
+
+/** \brief Set values of timeouts for deterministic NAT (seconds, 0 = default)
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param udp - UDP timeout (default 300sec)
+    @param tcp_established - TCP established timeout (default 7440sec)
+    @param tcp_transitory - TCP transitory timeout (default 240sec)
+    @param icmp - ICMP timeout (default 60sec)
+*/
+autoreply define snat_det_set_timeouts {
+  u32 client_index;
+  u32 context;
+  u32 udp;
+  u32 tcp_established;
+  u32 tcp_transitory;
+  u32 icmp;
+};
+
+/** \brief Get values of timeouts for deterministic NAT (seconds)
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+*/
+define snat_det_get_timeouts {
+  u32 client_index;
+  u32 context;
+};
+
+/** \brief Get values of timeouts for deterministic NAT reply
+    @param context - sender context, to match reply w/ request
+    @param retval - return code
+    @param udp - UDP timeout (default 300sec)
+    @param tcp_established - TCP established timeout (default 7440sec)
+    @param tcp_transitory - TCP transitory timeout (default 240sec)
+    @param icmp - ICMP timeout (default 60sec)
+*/
+define snat_det_get_timeouts_reply {
+  u32 context;
+  i32 retval;
+  u32 udp;
+  u32 tcp_established;
+  u32 tcp_transitory;
+  u32 icmp;
+};
+
+/** \brief Close deterministic NAT session by outside address and port
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param is_ip4 - 1 if address type is IPv4
+    @param out_addr - outside IP address
+    @param out_port - outside port
+    @param ext_addr - external host address
+    @param ext_port - external host port
+*/
+autoreply define snat_det_close_session_out {
+  u32 client_index;
+  u32 context;
+  u8 is_ip4;
+  u8 out_addr[16];
+  u16 out_port;
+  u8 ext_addr[16];
+  u16 ext_port;
+};
+
+/** \brief Close deterministic NAT session by inside address and port
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param is_ip4 - 1 if address type is IPv4
+    @param in_addr - inside IP address
+    @param in_port - inside port
+    @param ext_addr - external host address
+    @param ext_port - external host port
+*/
+autoreply define snat_det_close_session_in {
+  u32 client_index;
+  u32 context;
+  u8 is_ip4;
+  u8 in_addr[16];
+  u16 in_port;
+  u8 ext_addr[16];
+  u16 ext_port;
+};
+
+/** \brief Dump determinstic NAT sessions
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param is_ip4 - 1 if address type is IPv4
+    @param user_addr - address of an inside user whose sessions to dump
+*/
+define snat_det_session_dump {
+  u32 client_index;
+  u32 context;
+  u8 is_ip4;
+  u8 user_addr[16];
+};
+
+/** \brief Deterministic NAT sessions reply
+    @param context - sender context, to match reply w/ request
+    @param is_ip4 - 1 if address type is IPv4
+    @param in_port - inside port
+    @param ext_addr - external host address
+    @param ext_port - external host port
+    @param out_port - outside NAT port
+    @param state - session state
+    @param expire - session expiration timestamp
+*/
+define snat_det_session_details {
+  u32 client_index;
+  u32 context;
+  u8 is_ip4;
+  u16 in_port;
+  u8 ext_addr[16];
+  u16 ext_port;
+  u16 out_port;
+  u8 state;
+  u32 expire;
+};
+
+/*
+ * Common NAT plugin APIs
+ */
+
+/** \brief Control ping from client to api server request
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+*/
+define nat_control_ping
+{
+  u32 client_index;
+  u32 context;
+};
+
+/** \brief Control ping from the client to the server response
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param retval - return code for the request
+    @param vpe_pid - the pid of the vpe, returned by the server
+*/
+define nat_control_ping_reply
+{
+  u32 context;
+  i32 retval;
+  u32 client_index;
+  u32 vpe_pid;
+};
+
+/** \brief Show NAT plugin startup config
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+*/
+define nat_show_config
+{
+  u32 client_index;
+  u32 context;
+};
+
+/** \brief Show NAT plugin startup config reply
+    @param context - sender context, to match reply w/ request
+    @param retval - return code for the request
+    @param static_mapping_only - if 1 dynamic translations disabled
+    @param static_mapping_connection_tracking - if 1 create session data
+    @param deterministic - if 1 deterministic mapping
+    @param translation_buckets - number of translation hash buckets
+    @param translation_memory_size - translation hash memory size
+    @param user_buckets - number of user hash buckets
+    @param user_memory_size - user hash memory size
+    @param max_translations_per_user - maximum number of translations per user
+    @param outside_vrf_id - outside VRF id
+    @param inside_vrf_id - default inside VRF id
+*/
+define nat_show_config_reply
+{
+  u32 context;
+  i32 retval;
+  u8 static_mapping_only;
+  u8 static_mapping_connection_tracking;
+  u8 deterministic;
+  u32 translation_buckets;
+  u32 translation_memory_size;
+  u32 user_buckets;
+  u32 user_memory_size;
+  u32 max_translations_per_user;
+  u32 outside_vrf_id;
+  u32 inside_vrf_id;
+};
+
+/** \brief Set NAT workers
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param worker_mask - NAT workers mask
+*/
+autoreply define nat_set_workers {
+  u32 client_index;
+  u32 context;
+  u64 worker_mask;
+};
+
+/** \brief Dump NAT workers
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+*/
+define nat_worker_dump {
+  u32 client_index;
+  u32 context;
+};
+
+/** \brief NAT workers details response
+    @param context - sender context, to match reply w/ request
+    @param worker_index - worker index
+    @param lcore_id - lcore ID
+    @param name - worker name
+*/
+define nat_worker_details {
+  u32 context;
+  u32 worker_index;
+  u32 lcore_id;
+  u8 name[64];
+};
+
+/** \brief Enable/disable NAT IPFIX logging
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param domain_id - observation domain ID
+    @param src_port - source port number
+    @param enable - 1 if enable, 0 if disable
+*/
+autoreply define nat_ipfix_enable_disable {
+  u32 client_index;
+  u32 context;
+  u32 domain_id;
+  u16 src_port;
+  u8 enable;
+};
+
+/*
+ * NAT44 APIs
+ */
+
+/** \brief Add/del NAT44 address range
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param first_ip_address - first IPv4 address
+    @param last_ip_address - last IPv4 address
+    @param vrf_id - VRF id of tenant, ~0 means independent of VRF
+    @param is_add - 1 if add, 0 if delete
+*/
+autoreply define nat44_add_del_address_range {
+  u32 client_index;
+  u32 context;
+  u8 first_ip_address[4];
+  u8 last_ip_address[4];
+  u32 vrf_id;
+  u8 is_add;
+};
+
+/** \brief Dump NAT44 addresses
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+*/
+define nat44_address_dump {
+  u32 client_index;
+  u32 context;
+};
+
+/** \brief NAT44 address details response
+    @param context - sender context, to match reply w/ request
+    @param ip_address - IPv4 address
+    @param vrf_id - VRF id of tenant, ~0 means independent of VRF
+*/
+define nat44_address_details {
+  u32 context;
+  u8 ip_address[4];
+  u32 vrf_id;
+};
+
+/** \brief Enable/disable NAT44 feature on the interface
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param is_add - 1 if add, 0 if delete
+    @param is_inside - 1 if inside, 0 if outside
+    @param sw_if_index - software index of the interface
+*/
+autoreply define nat44_interface_add_del_feature {
+  u32 client_index;
+  u32 context;
+  u8 is_add;
+  u8 is_inside;
+  u32 sw_if_index;
+};
+
+/** \brief Dump interfaces with NAT44 feature
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+*/
+define nat44_interface_dump {
+  u32 client_index;
+  u32 context;
+};
+
+/** \brief NAT44 interface details response
+    @param context - sender context, to match reply w/ request
+    @param is_inside - 1 if inside, 0 if outside
+    @param sw_if_index - software index of the interface
+*/
+define nat44_interface_details {
+  u32 context;
+  u8 is_inside;
+  u32 sw_if_index;
+};
+
+/** \brief Enable/disbale NAT44 as an interface output feature (postrouting
+           in2out translation)
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param is_add - 1 if add, 0 if delete
+    @param is_inside - 1 if inside, 0 if outside
+    @param sw_if_index - software index of the interface
+*/
+autoreply define nat44_interface_add_del_output_feature {
+  u32 client_index;
+  u32 context;
+  u8 is_add;
+  u8 is_inside;
+  u32 sw_if_index;
+};
+
+/** \brief Dump interfaces with NAT44 output feature
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+*/
+define nat44_interface_output_feature_dump {
+  u32 client_index;
+  u32 context;
+};
+
+/** \brief NAT44 interface with output feature details response
+    @param context - sender context, to match reply w/ request
+    @param is_inside - 1 if inside, 0 if outside
+    @param sw_if_index - software index of the interface
+*/
+define nat44_interface_output_feature_details {
+  u32 context;
+  u8 is_inside;
+  u32 sw_if_index;
+};
+
+/** \brief Add/delete NAT44 static mapping
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param is_add - 1 if add, 0 if delete
+    @param addr_only - 1 if address only mapping
+    @param local_ip_address - local IPv4 address
+    @param external_ip_address - external IPv4 address
+    @param protocol - IP protocol
+    @param local_port - local port number
+    @param external_port - external port number
+    @param external_sw_if_index - external interface (if set
+                                  external_ip_address is ignored, ~0 means not
+                                  used)
+    @param vfr_id - VRF ID
+*/
+autoreply define nat44_add_del_static_mapping {
+  u32 client_index;
+  u32 context;
+  u8 is_add;
+  u8 addr_only;
+  u8 local_ip_address[4];
+  u8 external_ip_address[4];
+  u8 protocol;
+  u16 local_port;
+  u16 external_port;
+  u32 external_sw_if_index;
+  u32 vrf_id;
+};
+
+/** \brief Dump NAT44 static mappings
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+*/
+define nat44_static_mapping_dump {
+  u32 client_index;
+  u32 context;
+};
+
+/** \brief NAT44 static mapping details response
+    @param context - sender context, to match reply w/ request
+    @param addr_only - 1 if address only mapping
+    @param local_ip_address - local IPv4 address
+    @param external_ip_address - external IPv4 address
+    @param protocol - IP protocol
+    @param local_port - local port number
+    @param external_port - external port number
+    @param external_sw_if_index - external interface
+    @param vfr_id - VRF ID
+*/
+define nat44_static_mapping_details {
+  u32 context;
+  u8 addr_only;
+  u8 local_ip_address[4];
+  u8 external_ip_address[4];
+  u8 protocol;
+  u16 local_port;
+  u16 external_port;
+  u32 external_sw_if_index;
+  u32 vrf_id;
+};
+
+/** \brief Add/delete NAT44 pool address from specific interfce
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param is_add - 1 if add, 0 if delete
+    @param sw_if_index - software index of the interface
+*/
+autoreply define nat44_add_del_interface_addr {
+  u32 client_index;
+  u32 context;
+  u8 is_add;
+  u8 is_inside;
+  u32 sw_if_index;
+};
+
+/** \brief Dump NAT44 pool addresses interfaces
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+*/
+define nat44_interface_addr_dump {
+  u32 client_index;
+  u32 context;
+};
+
+/** \brief NAT44 pool addresses interfaces details response
+    @param context - sender context, to match reply w/ request
+    @param sw_if_index - software index of the interface
+*/
+define nat44_interface_addr_details {
+  u32 context;
+  u32 sw_if_index;
+};
+
+/** \brief Dump NAT44 users
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+*/
+define nat44_user_dump {
+  u32 client_index;
+  u32 context;
+};
+
+/** \brief NAT44 users response
+    @param context - sender context, to match reply w/ request
+    @vrf_id - VRF ID
+    @param ip_adress - IPv4 address
+    @param nsessions - number of dynamic sessions
+    @param nstaticsessions - number of static sessions
+*/
+define nat44_user_details {
+  u32 context;
+  u32 vrf_id;
+  u8 ip_address[4];
+  u32 nsessions;
+  u32 nstaticsessions;
+};
+
+/** \brief NAT44 user's sessions
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param is_ip4 - 1 if address type is IPv4
+    @param user_ip - IP address of the user to dump
+    @param vrf_id - VRF_ID
+*/
+define nat44_user_session_dump {
+  u32 client_index;
+  u32 context;
+  u8 ip_address[4];
+  u32 vrf_id;
+};
+
+/** \brief NAT44 user's sessions response
+    @param context - sender context, to match reply w/ request
+    @param outside_ip_address - outside IPv4 address
+    @param outside_port - outside port
+    @param inside_ip_address - inside IPv4 address
+    @param inside_port - inside port
+    @param protocol - protocol
+    @param is_static - 1 if session is static
+    @param last_heard - last heard timer
+    @param total_bytes - count of bytes sent through session
+    @param total_pkts - count of pakets sent through session
+*/
+define nat44_user_session_details {
+  u32 context;
+  u8 outside_ip_address[4];
+  u16 outside_port;
+  u8 inside_ip_address[4];
+  u16 inside_port;
+  u16 protocol;
+  u8 is_static;
+  u64 last_heard;
+  u64 total_bytes;
+  u32 total_pkts;
+};
+
+/*
+ * Deterministic NAT (CGN) APIs
+ */
+
+/** \brief Add/delete NAT deterministic mapping
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param is_add - 1 if add, 0 if delete
+    @param is_nat44 - 1 if NAT44
+    @param in_addr - inside IP address
+    @param in_plen - inside IP address prefix length
+    @param out_addr - outside IPv4 address
+    @param out_addr - outside IPv4 address prefix length
+*/
+autoreply define nat_det_add_del_map {
+  u32 client_index;
+  u32 context;
+  u8 is_add;
+  u8 is_nat44;
+  u8 addr_only;
+  u8 in_addr[16];
+  u8 in_plen;
+  u8 out_addr[4];
+  u8 out_plen;
+};
+
+/** \brief Get outside address and port range from inside address
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param is_nat44 - 1 if NAT44
+    @param in_addr - inside IP address
+*/
+define nat_det_forward {
+  u32 client_index;
+  u32 context;
+  u8 is_nat44;
+  u8 in_addr[16];
+};
+
+/** \brief Get outside address and port range from inside address
+    @param context - sender context, to match reply w/ request
+    @param retval - return code
+    @param out_port_lo - outside port range start
+    @param out_port_hi - outside port range end
+    @param out_addr - outside IPv4 address
+*/
+define nat_det_forward_reply {
+  u32 context;
+  i32 retval;
+  u16 out_port_lo;
+  u16 out_port_hi;
+  u8 out_addr[4];
+};
+
+/** \brief Get inside address from outside address and port
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param out_port - outside port
+    @param out_addr - outside IPv4 address
+*/
+define nat_det_reverse {
+  u32 client_index;
+  u32 context;
+  u16 out_port;
+  u8 out_addr[4];
+};
+
+/** \brief Get inside address from outside address and port reply
+    @param context - sender context, to match reply w/ request
+    @param retval - return code
+    @param is_nat44 - 1 if NAT44
+    @param in_addr - inside IP address
+*/
+define nat_det_reverse_reply {
+  u32 context;
+  i32 retval;
+  u8 is_nat44;
+  u8 in_addr[16];
+};
+
+/** \brief Dump NAT deterministic mappings
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+*/
+define nat_det_map_dump {
+  u32 client_index;
+  u32 context;
+};
+
+/** \brief NAT users response
+    @param context - sender context, to match reply w/ request
+    @param is_nat44 - 1 if NAT44
+    @param in_addr - inside IP address
+    @param in_plen - inside IP address prefix length
+    @param out_addr - outside IPv4 address
+    @param out_plen - outside IPv4 address prefix length
+    @param sharing_ratio - outside to inside address sharing ratio
+    @param ports_per_host - number of ports available to a host
+    @param ses_num - number of sessions belonging to this mapping
+*/
+define nat_det_map_details {
+  u32 context;
+  u8 is_nat44;
+  u8 in_addr[16];
+  u8 in_plen;
+  u8 out_addr[4];
+  u8 out_plen;
+  u32 sharing_ratio;
+  u16 ports_per_host;
+  u32 ses_num;
+};
+
+/** \brief Set values of timeouts for deterministic NAT (seconds, 0 = default)
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param udp - UDP timeout (default 300sec)
+    @param tcp_established - TCP established timeout (default 7440sec)
+    @param tcp_transitory - TCP transitory timeout (default 240sec)
+    @param icmp - ICMP timeout (default 60sec)
+*/
+autoreply define nat_det_set_timeouts {
+  u32 client_index;
+  u32 context;
+  u32 udp;
+  u32 tcp_established;
+  u32 tcp_transitory;
+  u32 icmp;
+};
+
+/** \brief Get values of timeouts for deterministic NAT (seconds)
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+*/
+define nat_det_get_timeouts {
+  u32 client_index;
+  u32 context;
+};
+
+/** \brief Get values of timeouts for deterministic NAT reply
+    @param context - sender context, to match reply w/ request
+    @param retval - return code
+    @param udp - UDP timeout (default 300sec)
+    @param tcp_established - TCP established timeout (default 7440sec)
+    @param tcp_transitory - TCP transitory timeout (default 240sec)
+    @param icmp - ICMP timeout (default 60sec)
+*/
+define nat_det_get_timeouts_reply {
+  u32 context;
+  i32 retval;
+  u32 udp;
+  u32 tcp_established;
+  u32 tcp_transitory;
+  u32 icmp;
+};
+
+/** \brief Close deterministic NAT session by outside address and port
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param out_addr - outside IPv4 address
+    @param out_port - outside port
+    @param ext_addr - external host IPv4 address
+    @param ext_port - external host port
+*/
+autoreply define nat_det_close_session_out {
+  u32 client_index;
+  u32 context;
+  u8 out_addr[4];
+  u16 out_port;
+  u8 ext_addr[4];
+  u16 ext_port;
+};
+
+/** \brief Close deterministic NAT session by inside address and port
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param is_nat44 - 1 if NAT44
+    @param in_addr - inside IP address
+    @param in_port - inside port
+    @param ext_addr - external host IP address
+    @param ext_port - external host port
+*/
+autoreply define nat_det_close_session_in {
+  u32 client_index;
+  u32 context;
+  u8 is_nat44;
+  u8 in_addr[16];
+  u16 in_port;
+  u8 ext_addr[16];
+  u16 ext_port;
+};
+
+/** \brief Dump determinstic NAT sessions
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param is_nat44 - 1 if NAT44
+    @param user_addr - address of an inside user whose sessions to dump
+*/
+define nat_det_session_dump {
+  u32 client_index;
+  u32 context;
+  u8 is_nat44;
+  u8 user_addr[16];
+};
+
+/** \brief Deterministic NAT sessions reply
+    @param context - sender context, to match reply w/ request
+    @param in_port - inside port
+    @param ext_addr - external host address
+    @param ext_port - external host port
+    @param out_port - outside NAT port
+    @param state - session state
+    @param expire - session expiration timestamp
+*/
+define nat_det_session_details {
+  u32 client_index;
+  u32 context;
+  u16 in_port;
+  u8 ext_addr[4];
+  u16 ext_port;
+  u16 out_port;
+  u8 state;
+  u32 expire;
+};
+
+/*
+ * NAT64 APIs
+ */
+
+/** \brief Add/delete address range to NAT64 pool
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param start_addr - start address of the range
+    @param end_addr - end address of the range
+    @param vrf_id - VRF id of tenant, ~0 means independent of VRF
+    @param is_add - 1 if add, 0 if delete
+*/
+autoreply define nat64_add_del_pool_addr_range {
+  u32 client_index;
+  u32 context;
+  u8 start_addr[4];
+  u8 end_addr[4];
+  u32 vrf_id;
+  u8 is_add;
+};
+
+/** \brief Dump NAT64 pool addresses
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+*/
+define nat64_pool_addr_dump {
+  u32 client_index;
+  u32 context;
+};
+
+/** \brief NAT64 pool address details response
+    @param context - sender context, to match reply w/ request
+    @param address - IPv4 address
+    @param vfr_id - VRF id of tenant, ~0 means independent of VRF
+*/
+define nat64_pool_addr_details {
+  u32 context;
+  u8 address[4];
+  u32 vrf_id;
+};
+
+/** \brief Enable/disable NAT64 feature on the interface
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param sw_if_index - index of the interface
+    @param is_inside - 1 if inside, 0 if outside
+    @param is_add - 1 if add, 0 if delete
+*/
+autoreply define nat64_add_del_interface {
+  u32 client_index;
+  u32 context;
+  u32 sw_if_index;
+  u8 is_inside;
+  u8 is_add;
+};
+
+/** \brief Dump interfaces with NAT64 feature
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+*/
+define nat64_interface_dump {
+  u32 client_index;
+  u32 context;
+};
+
+/** \brief NAT64 interface details response
+    @param context - sender context, to match reply w/ request
+    @param is_inside - 1 if inside, 0 if outside
+    @param sw_if_index - index of the interface
+*/
+define nat64_interface_details {
+  u32 context;
+  u8 is_inside;
+  u32 sw_if_index;
+};
+
+/** \brief Add/delete NAT64 static BIB entry
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param i_addr - inside IPv6 address
+    @param o_addr - outside IPv4 address
+    @param i_port - inside port number
+    @param o_port - outside port number
+    @param vrf_id - VRF id of tenant
+    @param proto - protocol number
+    @param is_add - 1 if add, 0 if delete
+*/
+ autoreply define nat64_add_del_static_bib {
+  u32 client_index;
+  u32 context;
+  u8 i_addr[16];
+  u8 o_addr[4];
+  u16 i_port;
+  u16 o_port;
+  u32 vrf_id;
+  u8 proto;
+  u8 is_add;
+};
+
+/** \brief Dump NAT64 BIB
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param proto - protocol of the BIB: 255 - all BIBs
+                                        6 - TCP BIB
+                                        17 - UDP BIB
+                                        1/58 - ICMP BIB
+                                        otherwise - "unknown" protocol BIB
+*/
+define nat64_bib_dump {
+  u32 client_index;
+  u32 context;
+  u8 proto;
+};
+
+/** \brief NAT64 BIB details response
+    @param context - sender context, to match reply w/ request
+    @param i_addr - inside IPv6 address
+    @param o_addr - outside IPv4 address
+    @param i_port - inside port number
+    @param o_port - outside port number
+    @param vrf_id - VRF id of tenant
+    @param proto - protocol number
+    @param is_static - 1 if static BIB entry, 0 if dynamic
+    @param ses_num - number of sessions associated with the BIB entry
+*/
+define nat64_bib_details {
+  u32 context;
+  u8 i_addr[16];
+  u8 o_addr[4];
+  u16 i_port;
+  u16 o_port;
+  u32 vrf_id;
+  u8 proto;
+  u8 is_static;
+  u32 ses_num;
+};
+
+/** \brief Set values of timeouts for NAT64 (seconds, 0 = default)
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param udp - UDP timeout (default 300sec)
+    @param icmp - ICMP timeout (default 60sec)
+    @param tcp_trans - TCP transitory timeout (default 240sec)
+    @param tcp_est - TCP established timeout (default 7440sec)
+    @param tcp_incoming_syn - TCP incoming SYN timeout (default 6sec)
+*/
+autoreply define nat64_set_timeouts {
+  u32 client_index;
+  u32 context;
+  u32 udp;
+  u32 icmp;
+  u32 tcp_trans;
+  u32 tcp_est;
+  u32 tcp_incoming_syn;
+};
+
+/** \brief Get values of timeouts for NAT64 (seconds)
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+*/
+define nat64_get_timeouts {
+  u32 client_index;
+  u32 context;
+};
+
+/** \brief Get values of timeouts for NAT64 reply
+    @param context - sender context, to match reply w/ request
+    @param retval - return code
+    @param udp - UDP timeout
+    @param icmp - ICMP timeout
+    @param tcp_trans - TCP transitory timeout
+    @param tcp_est - TCP established timeout
+    @param tcp_incoming_syn - TCP incoming SYN timeout
+*/
+define nat64_get_timeouts_reply {
+  u32 context;
+  i32 retval;
+  u32 udp;
+  u32 icmp;
+  u32 tcp_trans;
+  u32 tcp_est;
+  u32 tcp_incoming_syn;
+};
+
+/** \brief Dump NAT64 session table
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param proto - protocol of the session table: 255 - all STs
+                                                  6 - TCP ST
+                                                  17 - UDP ST
+                                                  1/58 - ICMP ST
+                                                  otherwise - "unknown" proto ST
+*/
+define nat64_st_dump {
+  u32 client_index;
+  u32 context;
+  u8 proto;
+};
+
+/** \brief NAT64 session table details response
+    @param context - sender context, to match reply w/ request
+    @param il_addr - inside IPv6 address of the local host
+    @param ol_addr - outside IPv4 address of the local host
+    @param il_port - inside port number id of the local host/inside ICMP id
+    @param ol_port - outside port number of the local host/outside ICMP id
+    @param il_addr - inside IPv6 address of the remote host
+    @param ol_addr - outside IPv4 address of the remote host
+    @param l_port - port number of the remote host (not used for ICMP)
+    @param vrf_id - VRF id of tenant
+    @param proto - protocol number
+*/
+define nat64_st_details {
+  u32 context;
+  u8 il_addr[16];
+  u8 ol_addr[4];
+  u16 il_port;
+  u16 ol_port;
+  u8 ir_addr[16];
+  u8 or_addr[4];
+  u16 r_port;
+  u32 vrf_id;
+  u8 proto;
+};
+
+/** \brief Add/del NAT64 prefix
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param prefix - NAT64 prefix
+    @param prefix - NAT64 prefix length
+    @param vrf_id - VRF id of tenant
+    @param is_add - 1 if add, 0 if delete
+*/
+autoreply define nat64_add_del_prefix {
+  u32 client_index;
+  u32 context;
+  u8 prefix[16];
+  u8 prefix_len;
+  u32 vrf_id;
+  u8 is_add;
+};
+
+/** \brief Dump NAT64 prefix
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+*/
+define nat64_prefix_dump {
+  u32 client_index;
+  u32 context;
+};
+
+/** \brief Dump NAT64 prefix details response
+    @param context - sender context, to match reply w/ request
+    @param prefix - NAT64 prefix
+    @param prefix - NAT64 prefix length
+    @param vrf_id - VRF id of tenant
+*/
+define nat64_prefix_details {
+  u32 context;
+  u8 prefix[16];
+  u8 prefix_len;
+  u32 vrf_id;
+};
diff --git a/src/plugins/nat/nat.c b/src/plugins/nat/nat.c
new file mode 100644
index 00000000000..ac39be956a8
--- /dev/null
+++ b/src/plugins/nat/nat.c
@@ -0,0 +1,2842 @@
+/*
+ * snat.c - simple nat plugin
+ *
+ * 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/vnet.h>
+#include <vnet/ip/ip.h>
+#include <vnet/ip/ip4.h>
+#include <vnet/plugin/plugin.h>
+#include <nat/nat.h>
+#include <nat/nat_ipfix_logging.h>
+#include <nat/nat_det.h>
+#include <nat/nat64.h>
+#include <vnet/fib/fib_table.h>
+#include <vnet/fib/ip4_fib.h>
+
+#include <vpp/app/version.h>
+
+snat_main_t snat_main;
+
+
+/* Hook up input features */
+VNET_FEATURE_INIT (ip4_snat_in2out, static) = {
+  .arc_name = "ip4-unicast",
+  .node_name = "nat44-in2out",
+  .runs_before = VNET_FEATURES ("nat44-out2in"),
+};
+VNET_FEATURE_INIT (ip4_snat_out2in, static) = {
+  .arc_name = "ip4-unicast",
+  .node_name = "nat44-out2in",
+  .runs_before = VNET_FEATURES ("ip4-lookup"),
+};
+VNET_FEATURE_INIT (ip4_snat_det_in2out, static) = {
+  .arc_name = "ip4-unicast",
+  .node_name = "nat44-det-in2out",
+  .runs_before = VNET_FEATURES ("nat44-det-out2in"),
+};
+VNET_FEATURE_INIT (ip4_snat_det_out2in, static) = {
+  .arc_name = "ip4-unicast",
+  .node_name = "nat44-det-out2in",
+  .runs_before = VNET_FEATURES ("ip4-lookup"),
+};
+VNET_FEATURE_INIT (ip4_snat_in2out_worker_handoff, static) = {
+  .arc_name = "ip4-unicast",
+  .node_name = "nat44-in2out-worker-handoff",
+  .runs_before = VNET_FEATURES ("nat44-out2in-worker-handoff"),
+};
+VNET_FEATURE_INIT (ip4_snat_out2in_worker_handoff, static) = {
+  .arc_name = "ip4-unicast",
+  .node_name = "nat44-out2in-worker-handoff",
+  .runs_before = VNET_FEATURES ("ip4-lookup"),
+};
+VNET_FEATURE_INIT (ip4_snat_in2out_fast, static) = {
+  .arc_name = "ip4-unicast",
+  .node_name = "nat44-in2out-fast",
+  .runs_before = VNET_FEATURES ("nat44-out2in-fast"),
+};
+VNET_FEATURE_INIT (ip4_snat_out2in_fast, static) = {
+  .arc_name = "ip4-unicast",
+  .node_name = "nat44-out2in-fast",
+  .runs_before = VNET_FEATURES ("ip4-lookup"),
+};
+VNET_FEATURE_INIT (ip4_snat_hairpin_dst, static) = {
+  .arc_name = "ip4-unicast",
+  .node_name = "nat44-hairpin-dst",
+  .runs_before = VNET_FEATURES ("ip4-lookup"),
+};
+
+/* Hook up output features */
+VNET_FEATURE_INIT (ip4_snat_in2out_output, static) = {
+  .arc_name = "ip4-output",
+  .node_name = "nat44-in2out-output",
+  .runs_before = VNET_FEATURES ("interface-output"),
+};
+VNET_FEATURE_INIT (ip4_snat_in2out_output_worker_handoff, static) = {
+  .arc_name = "ip4-output",
+  .node_name = "nat44-in2out-output-worker-handoff",
+  .runs_before = VNET_FEATURES ("interface-output"),
+};
+VNET_FEATURE_INIT (ip4_snat_hairpin_src, static) = {
+  .arc_name = "ip4-output",
+  .node_name = "nat44-hairpin-src",
+  .runs_before = VNET_FEATURES ("interface-output"),
+};
+
+
+/* *INDENT-OFF* */
+VLIB_PLUGIN_REGISTER () = {
+    .version = VPP_BUILD_VER,
+    .description = "Network Address Translation",
+};
+/* *INDENT-ON* */
+
+/**
+ * @brief Add/del NAT address to FIB.
+ *
+ * Add the external NAT address to the FIB as receive entries. This ensures
+ * that VPP will reply to ARP for this address and we don't need to enable
+ * proxy ARP on the outside interface.
+ *
+ * @param addr IPv4 address.
+ * @param plen address prefix length
+ * @param sw_if_index Interface.
+ * @param is_add If 0 delete, otherwise add.
+ */
+void
+snat_add_del_addr_to_fib (ip4_address_t * addr, u8 p_len, u32 sw_if_index,
+                          int is_add)
+{
+  fib_prefix_t prefix = {
+    .fp_len = p_len,
+    .fp_proto = FIB_PROTOCOL_IP4,
+    .fp_addr = {
+        .ip4.as_u32 = addr->as_u32,
+    },
+  };
+  u32 fib_index = ip4_fib_table_get_index_for_sw_if_index(sw_if_index);
+
+  if (is_add)
+    fib_table_entry_update_one_path(fib_index,
+                                    &prefix,
+                                    FIB_SOURCE_PLUGIN_HI,
+                                    (FIB_ENTRY_FLAG_CONNECTED |
+                                     FIB_ENTRY_FLAG_LOCAL |
+                                     FIB_ENTRY_FLAG_EXCLUSIVE),
+                                    DPO_PROTO_IP4,
+                                    NULL,
+                                    sw_if_index,
+                                    ~0,
+                                    1,
+                                    NULL,
+                                    FIB_ROUTE_PATH_FLAG_NONE);
+  else
+    fib_table_entry_delete(fib_index,
+                           &prefix,
+                           FIB_SOURCE_PLUGIN_HI);
+}
+
+void snat_add_address (snat_main_t *sm, ip4_address_t *addr, u32 vrf_id)
+{
+  snat_address_t * ap;
+  snat_interface_t *i;
+
+  if (vrf_id != ~0)
+    sm->vrf_mode = 1;
+
+  /* Check if address already exists */
+  vec_foreach (ap, sm->addresses)
+    {
+      if (ap->addr.as_u32 == addr->as_u32)
+        return;
+    }
+
+  vec_add2 (sm->addresses, ap, 1);
+  ap->addr = *addr;
+  if (vrf_id != ~0)
+    ap->fib_index =
+      fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4, vrf_id);
+  else
+    ap->fib_index = ~0;
+#define _(N, i, n, s) \
+  clib_bitmap_alloc (ap->busy_##n##_port_bitmap, 65535);
+  foreach_snat_protocol
+#undef _
+
+  /* Add external address to FIB */
+  pool_foreach (i, sm->interfaces,
+  ({
+    if (i->is_inside)
+      continue;
+
+    snat_add_del_addr_to_fib(addr, 32, i->sw_if_index, 1);
+    break;
+  }));
+  pool_foreach (i, sm->output_feature_interfaces,
+  ({
+    if (i->is_inside)
+      continue;
+
+    snat_add_del_addr_to_fib(addr, 32, i->sw_if_index, 1);
+    break;
+  }));
+}
+
+static int is_snat_address_used_in_static_mapping (snat_main_t *sm,
+                                                   ip4_address_t addr)
+{
+  snat_static_mapping_t *m;
+  pool_foreach (m, sm->static_mappings,
+  ({
+      if (m->external_addr.as_u32 == addr.as_u32)
+        return 1;
+  }));
+
+  return 0;
+}
+
+void increment_v4_address (ip4_address_t * a)
+{
+  u32 v;
+
+  v = clib_net_to_host_u32(a->as_u32) + 1;
+  a->as_u32 = clib_host_to_net_u32(v);
+}
+
+static void
+snat_add_static_mapping_when_resolved (snat_main_t * sm,
+                                       ip4_address_t l_addr,
+                                       u16 l_port,
+                                       u32 sw_if_index,
+                                       u16 e_port,
+                                       u32 vrf_id,
+                                       snat_protocol_t proto,
+                                       int addr_only,
+                                       int is_add)
+{
+  snat_static_map_resolve_t *rp;
+
+  vec_add2 (sm->to_resolve, rp, 1);
+  rp->l_addr.as_u32 = l_addr.as_u32;
+  rp->l_port = l_port;
+  rp->sw_if_index = sw_if_index;
+  rp->e_port = e_port;
+  rp->vrf_id = vrf_id;
+  rp->proto = proto;
+  rp->addr_only = addr_only;
+  rp->is_add = is_add;
+}
+
+/**
+ * @brief Add static mapping.
+ *
+ * Create static mapping between local addr+port and external addr+port.
+ *
+ * @param l_addr Local IPv4 address.
+ * @param e_addr External IPv4 address.
+ * @param l_port Local port number.
+ * @param e_port External port number.
+ * @param vrf_id VRF ID.
+ * @param addr_only If 0 address port and pair mapping, otherwise address only.
+ * @param sw_if_index External port instead of specific IP address.
+ * @param is_add If 0 delete static mapping, otherwise add.
+ *
+ * @returns
+ */
+int snat_add_static_mapping(ip4_address_t l_addr, ip4_address_t e_addr,
+                            u16 l_port, u16 e_port, u32 vrf_id, int addr_only,
+                            u32 sw_if_index, snat_protocol_t proto, int is_add)
+{
+  snat_main_t * sm = &snat_main;
+  snat_static_mapping_t *m;
+  snat_session_key_t m_key;
+  clib_bihash_kv_8_8_t kv, value;
+  snat_address_t *a = 0;
+  u32 fib_index = ~0;
+  uword * p;
+  snat_interface_t *interface;
+  int i;
+
+  /* If the external address is a specific interface address */
+  if (sw_if_index != ~0)
+    {
+      ip4_address_t * first_int_addr;
+
+      /* Might be already set... */
+      first_int_addr = ip4_interface_first_address
+        (sm->ip4_main, sw_if_index, 0 /* just want the address*/);
+
+      /* DHCP resolution required? */
+      if (first_int_addr == 0)
+        {
+          snat_add_static_mapping_when_resolved
+            (sm, l_addr, l_port, sw_if_index, e_port, vrf_id, proto,
+             addr_only,  is_add);
+          return 0;
+        }
+        else
+          e_addr.as_u32 = first_int_addr->as_u32;
+    }
+
+  m_key.addr = e_addr;
+  m_key.port = addr_only ? 0 : e_port;
+  m_key.protocol = addr_only ? 0 : proto;
+  m_key.fib_index = sm->outside_fib_index;
+  kv.key = m_key.as_u64;
+  if (clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv, &value))
+    m = 0;
+  else
+    m = pool_elt_at_index (sm->static_mappings, value.value);
+
+  if (is_add)
+    {
+      if (m)
+        return VNET_API_ERROR_VALUE_EXIST;
+
+      /* Convert VRF id to FIB index */
+      if (vrf_id != ~0)
+        {
+          p = hash_get (sm->ip4_main->fib_index_by_table_id, vrf_id);
+          if (!p)
+            return VNET_API_ERROR_NO_SUCH_FIB;
+          fib_index = p[0];
+        }
+      /* If not specified use inside VRF id from SNAT plugin startup config */
+      else
+        {
+          fib_index = sm->inside_fib_index;
+          vrf_id = sm->inside_vrf_id;
+        }
+
+      /* Find external address in allocated addresses and reserve port for
+         address and port pair mapping when dynamic translations enabled */
+      if (!addr_only && !(sm->static_mapping_only))
+        {
+          for (i = 0; i < vec_len (sm->addresses); i++)
+            {
+              if (sm->addresses[i].addr.as_u32 == e_addr.as_u32)
+                {
+                  a = sm->addresses + i;
+                  /* External port must be unused */
+                  switch (proto)
+                    {
+#define _(N, j, n, s) \
+                    case SNAT_PROTOCOL_##N: \
+                      if (clib_bitmap_get_no_check (a->busy_##n##_port_bitmap, e_port)) \
+                        return VNET_API_ERROR_INVALID_VALUE; \
+                      clib_bitmap_set_no_check (a->busy_##n##_port_bitmap, e_port, 1); \
+                      if (e_port > 1024) \
+                        a->busy_##n##_ports++; \
+                      break;
+                      foreach_snat_protocol
+#undef _
+                    default:
+                      clib_warning("unknown_protocol");
+                      return VNET_API_ERROR_INVALID_VALUE_2;
+                    }
+                  break;
+                }
+            }
+          /* External address must be allocated */
+          if (!a)
+            return VNET_API_ERROR_NO_SUCH_ENTRY;
+        }
+
+      pool_get (sm->static_mappings, m);
+      memset (m, 0, sizeof (*m));
+      m->local_addr = l_addr;
+      m->external_addr = e_addr;
+      m->addr_only = addr_only;
+      m->vrf_id = vrf_id;
+      m->fib_index = fib_index;
+      if (!addr_only)
+        {
+          m->local_port = l_port;
+          m->external_port = e_port;
+          m->proto = proto;
+        }
+
+      m_key.addr = m->local_addr;
+      m_key.port = m->local_port;
+      m_key.protocol = m->proto;
+      m_key.fib_index = m->fib_index;
+      kv.key = m_key.as_u64;
+      kv.value = m - sm->static_mappings;
+      clib_bihash_add_del_8_8(&sm->static_mapping_by_local, &kv, 1);
+
+      m_key.addr = m->external_addr;
+      m_key.port = m->external_port;
+      m_key.fib_index = sm->outside_fib_index;
+      kv.key = m_key.as_u64;
+      kv.value = m - sm->static_mappings;
+      clib_bihash_add_del_8_8(&sm->static_mapping_by_external, &kv, 1);
+
+      /* Assign worker */
+      if (sm->workers)
+        {
+          snat_user_key_t w_key0;
+          snat_worker_key_t w_key1;
+
+          w_key0.addr = m->local_addr;
+          w_key0.fib_index = m->fib_index;
+          kv.key = w_key0.as_u64;
+
+          if (clib_bihash_search_8_8 (&sm->worker_by_in, &kv, &value))
+            {
+              kv.value = sm->first_worker_index +
+                sm->workers[sm->next_worker++ % vec_len (sm->workers)];
+
+              clib_bihash_add_del_8_8 (&sm->worker_by_in, &kv, 1);
+            }
+          else
+            {
+              kv.value = value.value;
+            }
+
+          w_key1.addr = m->external_addr;
+          w_key1.port = clib_host_to_net_u16 (m->external_port);
+          w_key1.fib_index = sm->outside_fib_index;
+          kv.key = w_key1.as_u64;
+          clib_bihash_add_del_8_8 (&sm->worker_by_out, &kv, 1);
+        }
+    }
+  else
+    {
+      if (!m)
+        return VNET_API_ERROR_NO_SUCH_ENTRY;
+
+      /* Free external address port */
+      if (!addr_only && !(sm->static_mapping_only))
+        {
+          for (i = 0; i < vec_len (sm->addresses); i++)
+            {
+              if (sm->addresses[i].addr.as_u32 == e_addr.as_u32)
+                {
+                  a = sm->addresses + i;
+                  switch (proto)
+                    {
+#define _(N, j, n, s) \
+                    case SNAT_PROTOCOL_##N: \
+                      clib_bitmap_set_no_check (a->busy_##n##_port_bitmap, e_port, 0); \
+                      if (e_port > 1024) \
+                        a->busy_##n##_ports--; \
+                      break;
+                      foreach_snat_protocol
+#undef _
+                    default:
+                      clib_warning("unknown_protocol");
+                      return VNET_API_ERROR_INVALID_VALUE_2;
+                    }
+                  break;
+                }
+            }
+        }
+
+      m_key.addr = m->local_addr;
+      m_key.port = m->local_port;
+      m_key.protocol = m->proto;
+      m_key.fib_index = m->fib_index;
+      kv.key = m_key.as_u64;
+      clib_bihash_add_del_8_8(&sm->static_mapping_by_local, &kv, 0);
+
+      m_key.addr = m->external_addr;
+      m_key.port = m->external_port;
+      m_key.fib_index = sm->outside_fib_index;
+      kv.key = m_key.as_u64;
+      clib_bihash_add_del_8_8(&sm->static_mapping_by_external, &kv, 0);
+
+      /* Delete session(s) for static mapping if exist */
+      if (!(sm->static_mapping_only) ||
+          (sm->static_mapping_only && sm->static_mapping_connection_tracking))
+        {
+          snat_user_key_t u_key;
+          snat_user_t *u;
+          dlist_elt_t * head, * elt;
+          u32 elt_index, head_index, del_elt_index;
+          u32 ses_index;
+          u64 user_index;
+          snat_session_t * s;
+          snat_main_per_thread_data_t *tsm;
+
+          u_key.addr = m->local_addr;
+          u_key.fib_index = m->fib_index;
+          kv.key = u_key.as_u64;
+          if (!clib_bihash_search_8_8 (&sm->user_hash, &kv, &value))
+            {
+              user_index = value.value;
+              if (!clib_bihash_search_8_8 (&sm->worker_by_in, &kv, &value))
+                tsm = vec_elt_at_index (sm->per_thread_data, value.value);
+              else
+                tsm = vec_elt_at_index (sm->per_thread_data, sm->num_workers);
+              u = pool_elt_at_index (tsm->users, user_index);
+              if (u->nstaticsessions)
+                {
+                  head_index = u->sessions_per_user_list_head_index;
+                  head = pool_elt_at_index (tsm->list_pool, head_index);
+                  elt_index = head->next;
+                  elt = pool_elt_at_index (tsm->list_pool, elt_index);
+                  ses_index = elt->value;
+                  while (ses_index != ~0)
+                    {
+                      s =  pool_elt_at_index (tsm->sessions, ses_index);
+                      del_elt_index = elt_index;
+                      elt_index = elt->next;
+                      elt = pool_elt_at_index (tsm->list_pool, elt_index);
+                      ses_index = elt->value;
+
+                      if (!addr_only)
+                        {
+                          if ((s->out2in.addr.as_u32 != e_addr.as_u32) &&
+                              (clib_net_to_host_u16 (s->out2in.port) != e_port))
+                            continue;
+                        }
+
+                      if (snat_is_unk_proto_session (s))
+                        {
+                          clib_bihash_kv_16_8_t up_kv;
+                          snat_unk_proto_ses_key_t up_key;
+                          up_key.l_addr = s->in2out.addr;
+                          up_key.r_addr = s->ext_host_addr;
+                          up_key.fib_index = s->in2out.fib_index;
+                          up_key.proto = s->in2out.port;
+                          up_key.rsvd[0] = up_key.rsvd[1] = up_key.rsvd[2] = 0;
+                          up_kv.key[0] = up_key.as_u64[0];
+                          up_kv.key[1] = up_key.as_u64[1];
+                          if (clib_bihash_add_del_16_8 (&sm->in2out_unk_proto,
+                                                        &up_kv, 0))
+                            clib_warning ("in2out key del failed");
+
+                          up_key.l_addr = s->out2in.addr;
+                          up_key.fib_index = s->out2in.fib_index;
+                          up_kv.key[0] = up_key.as_u64[0];
+                          up_kv.key[1] = up_key.as_u64[1];
+                          if (clib_bihash_add_del_16_8 (&sm->out2in_unk_proto,
+                                                        &up_kv, 0))
+                            clib_warning ("out2in key del failed");
+
+                          goto delete;
+                        }
+                      /* log NAT event */
+                      snat_ipfix_logging_nat44_ses_delete(s->in2out.addr.as_u32,
+                                                          s->out2in.addr.as_u32,
+                                                          s->in2out.protocol,
+                                                          s->in2out.port,
+                                                          s->out2in.port,
+                                                          s->in2out.fib_index);
+
+                      value.key = s->in2out.as_u64;
+                      if (clib_bihash_add_del_8_8 (&sm->in2out, &value, 0))
+                        clib_warning ("in2out key del failed");
+                      value.key = s->out2in.as_u64;
+                      if (clib_bihash_add_del_8_8 (&sm->out2in, &value, 0))
+                        clib_warning ("out2in key del failed");
+delete:
+                      pool_put (tsm->sessions, s);
+
+                      clib_dlist_remove (tsm->list_pool, del_elt_index);
+                      pool_put_index (tsm->list_pool, del_elt_index);
+                      u->nstaticsessions--;
+
+                      if (!addr_only)
+                        break;
+                    }
+                  if (addr_only)
+                    {
+                      pool_put (tsm->users, u);
+                      clib_bihash_add_del_8_8 (&sm->user_hash, &kv, 0);
+                    }
+                }
+            }
+        }
+
+      /* Delete static mapping from pool */
+      pool_put (sm->static_mappings, m);
+    }
+
+  if (!addr_only)
+    return 0;
+
+  /* Add/delete external address to FIB */
+  pool_foreach (interface, sm->interfaces,
+  ({
+    if (interface->is_inside)
+      continue;
+
+    snat_add_del_addr_to_fib(&e_addr, 32, interface->sw_if_index, is_add);
+    break;
+  }));
+  pool_foreach (interface, sm->output_feature_interfaces,
+  ({
+    if (interface->is_inside)
+      continue;
+
+    snat_add_del_addr_to_fib(&e_addr, 32, interface->sw_if_index, is_add);
+    break;
+  }));
+
+  return 0;
+}
+
+int snat_del_address (snat_main_t *sm, ip4_address_t addr, u8 delete_sm)
+{
+  snat_address_t *a = 0;
+  snat_session_t *ses;
+  u32 *ses_to_be_removed = 0, *ses_index;
+  clib_bihash_kv_8_8_t kv, value;
+  snat_user_key_t user_key;
+  snat_user_t *u;
+  snat_main_per_thread_data_t *tsm;
+  snat_static_mapping_t *m;
+  snat_interface_t *interface;
+  int i;
+
+  /* Find SNAT address */
+  for (i=0; i < vec_len (sm->addresses); i++)
+    {
+      if (sm->addresses[i].addr.as_u32 == addr.as_u32)
+        {
+          a = sm->addresses + i;
+          break;
+        }
+    }
+  if (!a)
+    return VNET_API_ERROR_NO_SUCH_ENTRY;
+
+  if (delete_sm)
+    {
+      pool_foreach (m, sm->static_mappings,
+      ({
+          if (m->external_addr.as_u32 == addr.as_u32)
+            (void) snat_add_static_mapping (m->local_addr, m->external_addr,
+                                            m->local_port, m->external_port,
+                                            m->vrf_id, m->addr_only, ~0,
+                                            m->proto, 0);
+      }));
+    }
+  else
+    {
+      /* Check if address is used in some static mapping */
+      if (is_snat_address_used_in_static_mapping(sm, addr))
+        {
+          clib_warning ("address used in static mapping");
+          return VNET_API_ERROR_UNSPECIFIED;
+        }
+    }
+
+  if (a->fib_index != ~0)
+    fib_table_unlock(a->fib_index, FIB_PROTOCOL_IP4);
+
+  /* Delete sessions using address */
+  if (a->busy_tcp_ports || a->busy_udp_ports || a->busy_icmp_ports)
+    {
+      vec_foreach (tsm, sm->per_thread_data)
+        {
+          pool_foreach (ses, tsm->sessions, ({
+            if (ses->out2in.addr.as_u32 == addr.as_u32)
+              {
+                if (snat_is_unk_proto_session (ses))
+                  {
+                    clib_bihash_kv_16_8_t up_kv;
+                    snat_unk_proto_ses_key_t up_key;
+                    up_key.l_addr = ses->in2out.addr;
+                    up_key.r_addr = ses->ext_host_addr;
+                    up_key.fib_index = ses->in2out.fib_index;
+                    up_key.proto = ses->in2out.port;
+                    up_key.rsvd[0] = up_key.rsvd[1] = up_key.rsvd[2] = 0;
+                    up_kv.key[0] = up_key.as_u64[0];
+                    up_kv.key[1] = up_key.as_u64[1];
+                    if (clib_bihash_add_del_16_8 (&sm->in2out_unk_proto,
+                                                  &up_kv, 0))
+                      clib_warning ("in2out key del failed");
+
+                    up_key.l_addr = ses->out2in.addr;
+                    up_key.fib_index = ses->out2in.fib_index;
+                    up_kv.key[0] = up_key.as_u64[0];
+                    up_kv.key[1] = up_key.as_u64[1];
+                    if (clib_bihash_add_del_16_8 (&sm->out2in_unk_proto,
+                                                  &up_kv, 0))
+                      clib_warning ("out2in key del failed");
+                  }
+                else
+                  {
+                    /* log NAT event */
+                    snat_ipfix_logging_nat44_ses_delete(ses->in2out.addr.as_u32,
+                                                        ses->out2in.addr.as_u32,
+                                                        ses->in2out.protocol,
+                                                        ses->in2out.port,
+                                                        ses->out2in.port,
+                                                        ses->in2out.fib_index);
+                    kv.key = ses->in2out.as_u64;
+                    clib_bihash_add_del_8_8 (&sm->in2out, &kv, 0);
+                    kv.key = ses->out2in.as_u64;
+                    clib_bihash_add_del_8_8 (&sm->out2in, &kv, 0);
+                  }
+                vec_add1 (ses_to_be_removed, ses - tsm->sessions);
+                clib_dlist_remove (tsm->list_pool, ses->per_user_index);
+                user_key.addr = ses->in2out.addr;
+                user_key.fib_index = ses->in2out.fib_index;
+                kv.key = user_key.as_u64;
+                if (!clib_bihash_search_8_8 (&sm->user_hash, &kv, &value))
+                  {
+                    u = pool_elt_at_index (tsm->users, value.value);
+                    u->nsessions--;
+                  }
+              }
+          }));
+
+          vec_foreach (ses_index, ses_to_be_removed)
+            pool_put_index (tsm->sessions, ses_index[0]);
+
+          vec_free (ses_to_be_removed);
+       }
+    }
+
+  vec_del1 (sm->addresses, i);
+
+  /* Delete external address from FIB */
+  pool_foreach (interface, sm->interfaces,
+  ({
+    if (interface->is_inside)
+      continue;
+
+    snat_add_del_addr_to_fib(&addr, 32, interface->sw_if_index, 0);
+    break;
+  }));
+  pool_foreach (interface, sm->output_feature_interfaces,
+  ({
+    if (interface->is_inside)
+      continue;
+
+    snat_add_del_addr_to_fib(&addr, 32, interface->sw_if_index, 0);
+    break;
+  }));
+
+  return 0;
+}
+
+int snat_interface_add_del (u32 sw_if_index, u8 is_inside, int is_del)
+{
+  snat_main_t *sm = &snat_main;
+  snat_interface_t *i;
+  const char * feature_name;
+  snat_address_t * ap;
+  snat_static_mapping_t * m;
+  snat_det_map_t * dm;
+
+  if (sm->static_mapping_only && !(sm->static_mapping_connection_tracking))
+    feature_name = is_inside ?  "nat44-in2out-fast" : "nat44-out2in-fast";
+  else
+    {
+      if (sm->num_workers > 1 && !sm->deterministic)
+        feature_name = is_inside ?  "nat44-in2out-worker-handoff" : "nat44-out2in-worker-handoff";
+      else if (sm->deterministic)
+        feature_name = is_inside ?  "nat44-det-in2out" : "nat44-det-out2in";
+      else
+        feature_name = is_inside ?  "nat44-in2out" : "nat44-out2in";
+    }
+
+  vnet_feature_enable_disable ("ip4-unicast", feature_name, sw_if_index,
+			       !is_del, 0, 0);
+
+  if (sm->fq_in2out_index == ~0 && !sm->deterministic && sm->num_workers > 1)
+    sm->fq_in2out_index = vlib_frame_queue_main_init (sm->in2out_node_index, 0);
+
+  if (sm->fq_out2in_index == ~0 && !sm->deterministic && sm->num_workers > 1)
+    sm->fq_out2in_index = vlib_frame_queue_main_init (sm->out2in_node_index, 0);
+
+  pool_foreach (i, sm->interfaces,
+  ({
+    if (i->sw_if_index == sw_if_index)
+      {
+        if (is_del)
+          pool_put (sm->interfaces, i);
+        else
+          return VNET_API_ERROR_VALUE_EXIST;
+
+        goto fib;
+      }
+  }));
+
+  if (is_del)
+    return VNET_API_ERROR_NO_SUCH_ENTRY;
+
+  pool_get (sm->interfaces, i);
+  i->sw_if_index = sw_if_index;
+  i->is_inside = is_inside;
+
+  /* Add/delete external addresses to FIB */
+fib:
+  if (is_inside)
+    return 0;
+
+  vec_foreach (ap, sm->addresses)
+    snat_add_del_addr_to_fib(&ap->addr, 32, sw_if_index, !is_del);
+
+  pool_foreach (m, sm->static_mappings,
+  ({
+    if (!(m->addr_only))
+      continue;
+
+    snat_add_del_addr_to_fib(&m->external_addr, 32, sw_if_index, !is_del);
+  }));
+
+  pool_foreach (dm, sm->det_maps,
+  ({
+    snat_add_del_addr_to_fib(&dm->out_addr, dm->out_plen, sw_if_index, !is_del);
+  }));
+
+  return 0;
+}
+
+int snat_interface_add_del_output_feature (u32 sw_if_index,
+                                           u8 is_inside,
+                                           int is_del)
+{
+  snat_main_t *sm = &snat_main;
+  snat_interface_t *i;
+  snat_address_t * ap;
+  snat_static_mapping_t * m;
+
+  if (sm->deterministic ||
+      (sm->static_mapping_only && !(sm->static_mapping_connection_tracking)))
+    return VNET_API_ERROR_UNSUPPORTED;
+
+  if (is_inside)
+    {
+      vnet_feature_enable_disable ("ip4-unicast", "nat44-hairpin-dst",
+                                   sw_if_index, !is_del, 0, 0);
+      vnet_feature_enable_disable ("ip4-output", "nat44-hairpin-src",
+                                   sw_if_index, !is_del, 0, 0);
+      goto fq;
+    }
+
+  if (sm->num_workers > 1)
+    {
+      vnet_feature_enable_disable ("ip4-unicast", "nat44-out2in-worker-handoff",
+                                   sw_if_index, !is_del, 0, 0);
+      vnet_feature_enable_disable ("ip4-output",
+                                   "nat44-in2out-output-worker-handoff",
+                                   sw_if_index, !is_del, 0, 0);
+    }
+  else
+    {
+      vnet_feature_enable_disable ("ip4-unicast", "nat44-out2in", sw_if_index,
+                                   !is_del, 0, 0);
+      vnet_feature_enable_disable ("ip4-output", "nat44-in2out-output",
+                                   sw_if_index, !is_del, 0, 0);
+    }
+
+fq:
+  if (sm->fq_in2out_output_index == ~0 && sm->num_workers > 1)
+    sm->fq_in2out_output_index =
+      vlib_frame_queue_main_init (sm->in2out_output_node_index, 0);
+
+  if (sm->fq_out2in_index == ~0 && sm->num_workers > 1)
+    sm->fq_out2in_index = vlib_frame_queue_main_init (sm->out2in_node_index, 0);
+
+  pool_foreach (i, sm->output_feature_interfaces,
+  ({
+    if (i->sw_if_index == sw_if_index)
+      {
+        if (is_del)
+          pool_put (sm->output_feature_interfaces, i);
+        else
+          return VNET_API_ERROR_VALUE_EXIST;
+
+        goto fib;
+      }
+  }));
+
+  if (is_del)
+    return VNET_API_ERROR_NO_SUCH_ENTRY;
+
+  pool_get (sm->output_feature_interfaces, i);
+  i->sw_if_index = sw_if_index;
+  i->is_inside = is_inside;
+
+  /* Add/delete external addresses to FIB */
+fib:
+  if (is_inside)
+    return 0;
+
+  vec_foreach (ap, sm->addresses)
+    snat_add_del_addr_to_fib(&ap->addr, 32, sw_if_index, !is_del);
+
+  pool_foreach (m, sm->static_mappings,
+  ({
+    if (!(m->addr_only))
+      continue;
+
+    snat_add_del_addr_to_fib(&m->external_addr, 32, sw_if_index, !is_del);
+  }));
+
+  return 0;
+}
+
+int snat_set_workers (uword * bitmap)
+{
+  snat_main_t *sm = &snat_main;
+  int i, j = 0;
+
+  if (sm->num_workers < 2)
+    return VNET_API_ERROR_FEATURE_DISABLED;
+
+  if (clib_bitmap_last_set (bitmap) >= sm->num_workers)
+    return VNET_API_ERROR_INVALID_WORKER;
+
+  vec_free (sm->workers);
+  clib_bitmap_foreach (i, bitmap,
+    ({
+      vec_add1(sm->workers, i);
+      sm->per_thread_data[i].snat_thread_index = j;
+      j++;
+    }));
+
+  sm->port_per_thread = (0xffff - 1024) / _vec_len (sm->workers);
+  sm->num_snat_thread = _vec_len (sm->workers);
+
+  return 0;
+}
+
+
+static void
+snat_ip4_add_del_interface_address_cb (ip4_main_t * im,
+                                       uword opaque,
+                                       u32 sw_if_index,
+                                       ip4_address_t * address,
+                                       u32 address_length,
+                                       u32 if_address_index,
+                                       u32 is_delete);
+
+static clib_error_t * snat_init (vlib_main_t * vm)
+{
+  snat_main_t * sm = &snat_main;
+  clib_error_t * error = 0;
+  ip4_main_t * im = &ip4_main;
+  ip_lookup_main_t * lm = &im->lookup_main;
+  uword *p;
+  vlib_thread_registration_t *tr;
+  vlib_thread_main_t *tm = vlib_get_thread_main ();
+  uword *bitmap = 0;
+  u32 i;
+  ip4_add_del_interface_address_callback_t cb4;
+
+  sm->vlib_main = vm;
+  sm->vnet_main = vnet_get_main();
+  sm->ip4_main = im;
+  sm->ip4_lookup_main = lm;
+  sm->api_main = &api_main;
+  sm->first_worker_index = 0;
+  sm->next_worker = 0;
+  sm->num_workers = 0;
+  sm->num_snat_thread = 1;
+  sm->workers = 0;
+  sm->port_per_thread = 0xffff - 1024;
+  sm->fq_in2out_index = ~0;
+  sm->fq_out2in_index = ~0;
+  sm->udp_timeout = SNAT_UDP_TIMEOUT;
+  sm->tcp_established_timeout = SNAT_TCP_ESTABLISHED_TIMEOUT;
+  sm->tcp_transitory_timeout = SNAT_TCP_TRANSITORY_TIMEOUT;
+  sm->icmp_timeout = SNAT_ICMP_TIMEOUT;
+
+  p = hash_get_mem (tm->thread_registrations_by_name, "workers");
+  if (p)
+    {
+      tr = (vlib_thread_registration_t *) p[0];
+      if (tr)
+        {
+          sm->num_workers = tr->count;
+          sm->first_worker_index = tr->first_index;
+        }
+    }
+
+  vec_validate (sm->per_thread_data, tm->n_vlib_mains - 1);
+
+  /* Use all available workers by default */
+  if (sm->num_workers > 1)
+    {
+      for (i=0; i < sm->num_workers; i++)
+        bitmap = clib_bitmap_set (bitmap, i, 1);
+      snat_set_workers(bitmap);
+      clib_bitmap_free (bitmap);
+    }
+  else
+    {
+      sm->per_thread_data[0].snat_thread_index = 0;
+    }
+
+  error = snat_api_init(vm, sm);
+  if (error)
+    return error;
+
+  /* Set up the interface address add/del callback */
+  cb4.function = snat_ip4_add_del_interface_address_cb;
+  cb4.function_opaque = 0;
+
+  vec_add1 (im->add_del_interface_address_callbacks, cb4);
+
+  /* Init IPFIX logging */
+  snat_ipfix_logging_init(vm);
+
+  error = nat64_init(vm);
+
+  return error;
+}
+
+VLIB_INIT_FUNCTION (snat_init);
+
+void snat_free_outside_address_and_port (snat_main_t * sm,
+                                         snat_session_key_t * k,
+                                         u32 address_index)
+{
+  snat_address_t *a;
+  u16 port_host_byte_order = clib_net_to_host_u16 (k->port);
+
+  ASSERT (address_index < vec_len (sm->addresses));
+
+  a = sm->addresses + address_index;
+
+  switch (k->protocol)
+    {
+#define _(N, i, n, s) \
+    case SNAT_PROTOCOL_##N: \
+      ASSERT (clib_bitmap_get_no_check (a->busy_##n##_port_bitmap, \
+        port_host_byte_order) == 1); \
+      clib_bitmap_set_no_check (a->busy_##n##_port_bitmap, \
+        port_host_byte_order, 0); \
+      a->busy_##n##_ports--; \
+      break;
+      foreach_snat_protocol
+#undef _
+    default:
+      clib_warning("unknown_protocol");
+      return;
+    }
+}
+
+/**
+ * @brief Match NAT44 static mapping.
+ *
+ * @param sm          NAT main.
+ * @param match       Address and port to match.
+ * @param mapping     External or local address and port of the matched mapping.
+ * @param by_external If 0 match by local address otherwise match by external
+ *                    address.
+ * @param is_addr_only If matched mapping is address only
+ *
+ * @returns 0 if match found otherwise 1.
+ */
+int snat_static_mapping_match (snat_main_t * sm,
+                               snat_session_key_t match,
+                               snat_session_key_t * mapping,
+                               u8 by_external,
+                               u8 *is_addr_only)
+{
+  clib_bihash_kv_8_8_t kv, value;
+  snat_static_mapping_t *m;
+  snat_session_key_t m_key;
+  clib_bihash_8_8_t *mapping_hash = &sm->static_mapping_by_local;
+
+  if (by_external)
+    mapping_hash = &sm->static_mapping_by_external;
+
+  m_key.addr = match.addr;
+  m_key.port = clib_net_to_host_u16 (match.port);
+  m_key.protocol = match.protocol;
+  m_key.fib_index = match.fib_index;
+
+  kv.key = m_key.as_u64;
+
+  if (clib_bihash_search_8_8 (mapping_hash, &kv, &value))
+    {
+      /* Try address only mapping */
+      m_key.port = 0;
+      m_key.protocol = 0;
+      kv.key = m_key.as_u64;
+      if (clib_bihash_search_8_8 (mapping_hash, &kv, &value))
+        return 1;
+    }
+
+  m = pool_elt_at_index (sm->static_mappings, value.value);
+
+  if (by_external)
+    {
+      mapping->addr = m->local_addr;
+      /* Address only mapping doesn't change port */
+      mapping->port = m->addr_only ? match.port
+        : clib_host_to_net_u16 (m->local_port);
+      mapping->fib_index = m->fib_index;
+    }
+  else
+    {
+      mapping->addr = m->external_addr;
+      /* Address only mapping doesn't change port */
+      mapping->port = m->addr_only ? match.port
+        : clib_host_to_net_u16 (m->external_port);
+      mapping->fib_index = sm->outside_fib_index;
+    }
+
+  if (PREDICT_FALSE(is_addr_only != 0))
+    *is_addr_only = m->addr_only;
+
+  return 0;
+}
+
+static_always_inline u16
+snat_random_port (snat_main_t * sm, u16 min, u16 max)
+{
+  return min + random_u32 (&sm->random_seed) /
+    (random_u32_max() / (max - min + 1) + 1);
+}
+
+int snat_alloc_outside_address_and_port (snat_main_t * sm,
+                                         u32 fib_index,
+                                         u32 thread_index,
+                                         snat_session_key_t * k,
+                                         u32 * address_indexp)
+{
+  int i;
+  snat_address_t *a;
+  u32 portnum;
+
+  for (i = 0; i < vec_len (sm->addresses); i++)
+    {
+      a = sm->addresses + i;
+      if (sm->vrf_mode && a->fib_index != ~0 && a->fib_index != fib_index)
+        continue;
+      switch (k->protocol)
+        {
+#define _(N, j, n, s) \
+        case SNAT_PROTOCOL_##N: \
+          if (a->busy_##n##_ports < (sm->port_per_thread * sm->num_snat_thread)) \
+            { \
+              while (1) \
+                { \
+                  portnum = (sm->port_per_thread * \
+                    sm->per_thread_data[thread_index].snat_thread_index) + \
+                    snat_random_port(sm, 0, sm->port_per_thread) + 1024; \
+                  if (clib_bitmap_get_no_check (a->busy_##n##_port_bitmap, portnum)) \
+                    continue; \
+                  clib_bitmap_set_no_check (a->busy_##n##_port_bitmap, portnum, 1); \
+                  a->busy_##n##_ports++; \
+                  k->addr = a->addr; \
+                  k->port = clib_host_to_net_u16(portnum); \
+                  *address_indexp = i; \
+                  return 0; \
+                } \
+            } \
+          break;
+          foreach_snat_protocol
+#undef _
+        default:
+          clib_warning("unknown protocol");
+          return 1;
+        }
+
+    }
+  /* Totally out of translations to use... */
+  snat_ipfix_logging_addresses_exhausted(0);
+  return 1;
+}
+
+
+static clib_error_t *
+add_address_command_fn (vlib_main_t * vm,
+                        unformat_input_t * input,
+                        vlib_cli_command_t * cmd)
+{
+  unformat_input_t _line_input, *line_input = &_line_input;
+  snat_main_t * sm = &snat_main;
+  ip4_address_t start_addr, end_addr, this_addr;
+  u32 start_host_order, end_host_order;
+  u32 vrf_id = ~0;
+  int i, count;
+  int is_add = 1;
+  int rv = 0;
+  clib_error_t *error = 0;
+
+  /* Get a line of input. */
+  if (!unformat_user (input, unformat_line_input, line_input))
+    return 0;
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (line_input, "%U - %U",
+                    unformat_ip4_address, &start_addr,
+                    unformat_ip4_address, &end_addr))
+        ;
+      else if (unformat (line_input, "tenant-vrf %u", &vrf_id))
+        ;
+      else if (unformat (line_input, "%U", unformat_ip4_address, &start_addr))
+        end_addr = start_addr;
+      else if (unformat (line_input, "del"))
+        is_add = 0;
+      else
+        {
+          error = clib_error_return (0, "unknown input '%U'",
+            format_unformat_error, line_input);
+          goto done;
+        }
+     }
+
+  if (sm->static_mapping_only)
+    {
+      error = clib_error_return (0, "static mapping only mode");
+      goto done;
+    }
+
+  start_host_order = clib_host_to_net_u32 (start_addr.as_u32);
+  end_host_order = clib_host_to_net_u32 (end_addr.as_u32);
+
+  if (end_host_order < start_host_order)
+    {
+      error = clib_error_return (0, "end address less than start address");
+      goto done;
+    }
+
+  count = (end_host_order - start_host_order) + 1;
+
+  if (count > 1024)
+    clib_warning ("%U - %U, %d addresses...",
+                  format_ip4_address, &start_addr,
+                  format_ip4_address, &end_addr,
+                  count);
+
+  this_addr = start_addr;
+
+  for (i = 0; i < count; i++)
+    {
+      if (is_add)
+        snat_add_address (sm, &this_addr, vrf_id);
+      else
+        rv = snat_del_address (sm, this_addr, 0);
+
+      switch (rv)
+        {
+        case VNET_API_ERROR_NO_SUCH_ENTRY:
+          error = clib_error_return (0, "S-NAT address not exist.");
+          goto done;
+        case VNET_API_ERROR_UNSPECIFIED:
+          error = clib_error_return (0, "S-NAT address used in static mapping.");
+          goto done;
+        default:
+          break;
+        }
+
+      increment_v4_address (&this_addr);
+    }
+
+done:
+  unformat_free (line_input);
+
+  return error;
+}
+
+VLIB_CLI_COMMAND (add_address_command, static) = {
+  .path = "nat44 add address",
+  .short_help = "nat44 add addresses <ip4-range-start> [- <ip4-range-end>] "
+                "[tenant-vrf <vrf-id>] [del]",
+  .function = add_address_command_fn,
+};
+
+static clib_error_t *
+snat_feature_command_fn (vlib_main_t * vm,
+                          unformat_input_t * input,
+                          vlib_cli_command_t * cmd)
+{
+  unformat_input_t _line_input, *line_input = &_line_input;
+  vnet_main_t * vnm = vnet_get_main();
+  clib_error_t * error = 0;
+  u32 sw_if_index;
+  u32 * inside_sw_if_indices = 0;
+  u32 * outside_sw_if_indices = 0;
+  u8 is_output_feature = 0;
+  int is_del = 0;
+  int i;
+
+  sw_if_index = ~0;
+
+  /* Get a line of input. */
+  if (!unformat_user (input, unformat_line_input, line_input))
+    return 0;
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (line_input, "in %U", unformat_vnet_sw_interface,
+                    vnm, &sw_if_index))
+        vec_add1 (inside_sw_if_indices, sw_if_index);
+      else if (unformat (line_input, "out %U", unformat_vnet_sw_interface,
+                         vnm, &sw_if_index))
+        vec_add1 (outside_sw_if_indices, sw_if_index);
+      else if (unformat (line_input, "output-feature"))
+        is_output_feature = 1;
+      else if (unformat (line_input, "del"))
+        is_del = 1;
+      else
+        {
+          error = clib_error_return (0, "unknown input '%U'",
+            format_unformat_error, line_input);
+          goto done;
+        }
+    }
+
+  if (vec_len (inside_sw_if_indices))
+    {
+      for (i = 0; i < vec_len(inside_sw_if_indices); i++)
+        {
+          sw_if_index = inside_sw_if_indices[i];
+          if (is_output_feature)
+            {
+              if (snat_interface_add_del_output_feature (sw_if_index, 1, is_del))
+                {
+                  error = clib_error_return (0, "%s %U failed",
+                                             is_del ? "del" : "add",
+                                             format_vnet_sw_interface_name, vnm,
+                                             vnet_get_sw_interface (vnm,
+                                                                    sw_if_index));
+                  goto done;
+                }
+            }
+          else
+            {
+              if (snat_interface_add_del (sw_if_index, 1, is_del))
+                {
+                  error = clib_error_return (0, "%s %U failed",
+                                             is_del ? "del" : "add",
+                                             format_vnet_sw_interface_name, vnm,
+                                             vnet_get_sw_interface (vnm,
+                                                                    sw_if_index));
+                  goto done;
+                }
+            }
+        }
+    }
+
+  if (vec_len (outside_sw_if_indices))
+    {
+      for (i = 0; i < vec_len(outside_sw_if_indices); i++)
+        {
+          sw_if_index = outside_sw_if_indices[i];
+          if (is_output_feature)
+            {
+              if (snat_interface_add_del_output_feature (sw_if_index, 0, is_del))
+                {
+                  error = clib_error_return (0, "%s %U failed",
+                                             is_del ? "del" : "add",
+                                             format_vnet_sw_interface_name, vnm,
+                                             vnet_get_sw_interface (vnm,
+                                                                    sw_if_index));
+                  goto done;
+                }
+            }
+          else
+            {
+              if (snat_interface_add_del (sw_if_index, 0, is_del))
+                {
+                  error = clib_error_return (0, "%s %U failed",
+                                             is_del ? "del" : "add",
+                                             format_vnet_sw_interface_name, vnm,
+                                             vnet_get_sw_interface (vnm,
+                                                                    sw_if_index));
+                  goto done;
+                }
+            }
+        }
+    }
+
+done:
+  unformat_free (line_input);
+  vec_free (inside_sw_if_indices);
+  vec_free (outside_sw_if_indices);
+
+  return error;
+}
+
+VLIB_CLI_COMMAND (set_interface_snat_command, static) = {
+  .path = "set interface nat44",
+  .function = snat_feature_command_fn,
+  .short_help = "set interface nat44 in <intfc> out <intfc> [output-feature] "
+                "[del]",
+};
+
+uword
+unformat_snat_protocol (unformat_input_t * input, va_list * args)
+{
+  u32 *r = va_arg (*args, u32 *);
+
+  if (0);
+#define _(N, i, n, s) else if (unformat (input, s)) *r = SNAT_PROTOCOL_##N;
+  foreach_snat_protocol
+#undef _
+  else
+    return 0;
+  return 1;
+}
+
+u8 *
+format_snat_protocol (u8 * s, va_list * args)
+{
+  u32 i = va_arg (*args, u32);
+  u8 *t = 0;
+
+  switch (i)
+    {
+#define _(N, j, n, str) case SNAT_PROTOCOL_##N: t = (u8 *) str; break;
+      foreach_snat_protocol
+#undef _
+    default:
+      s = format (s, "unknown");
+      return s;
+    }
+  s = format (s, "%s", t);
+  return s;
+}
+
+static clib_error_t *
+add_static_mapping_command_fn (vlib_main_t * vm,
+                               unformat_input_t * input,
+                               vlib_cli_command_t * cmd)
+{
+  unformat_input_t _line_input, *line_input = &_line_input;
+  clib_error_t * error = 0;
+  ip4_address_t l_addr, e_addr;
+  u32 l_port = 0, e_port = 0, vrf_id = ~0;
+  int is_add = 1;
+  int addr_only = 1;
+  u32 sw_if_index = ~0;
+  vnet_main_t * vnm = vnet_get_main();
+  int rv;
+  snat_protocol_t proto;
+  u8 proto_set = 0;
+
+  /* Get a line of input. */
+  if (!unformat_user (input, unformat_line_input, line_input))
+    return 0;
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (line_input, "local %U %u", unformat_ip4_address, &l_addr,
+                    &l_port))
+        addr_only = 0;
+      else if (unformat (line_input, "local %U", unformat_ip4_address, &l_addr))
+        ;
+      else if (unformat (line_input, "external %U %u", unformat_ip4_address,
+                         &e_addr, &e_port))
+        addr_only = 0;
+      else if (unformat (line_input, "external %U", unformat_ip4_address,
+                         &e_addr))
+        ;
+      else if (unformat (line_input, "external %U %u",
+                         unformat_vnet_sw_interface, vnm, &sw_if_index,
+                         &e_port))
+        addr_only = 0;
+
+      else if (unformat (line_input, "external %U",
+                         unformat_vnet_sw_interface, vnm, &sw_if_index))
+        ;
+      else if (unformat (line_input, "vrf %u", &vrf_id))
+        ;
+      else if (unformat (line_input, "%U", unformat_snat_protocol, &proto))
+        proto_set = 1;
+      else if (unformat (line_input, "del"))
+        is_add = 0;
+      else
+        {
+          error = clib_error_return (0, "unknown input: '%U'",
+            format_unformat_error, line_input);
+          goto done;
+        }
+    }
+
+  if (!addr_only && !proto_set)
+    {
+      error = clib_error_return (0, "missing protocol");
+      goto done;
+    }
+
+  rv = snat_add_static_mapping(l_addr, e_addr, (u16) l_port, (u16) e_port,
+                               vrf_id, addr_only, sw_if_index, proto, is_add);
+
+  switch (rv)
+    {
+    case VNET_API_ERROR_INVALID_VALUE:
+      error = clib_error_return (0, "External port already in use.");
+      goto done;
+    case VNET_API_ERROR_NO_SUCH_ENTRY:
+      if (is_add)
+        error = clib_error_return (0, "External addres must be allocated.");
+      else
+        error = clib_error_return (0, "Mapping not exist.");
+      goto done;
+    case VNET_API_ERROR_NO_SUCH_FIB:
+      error = clib_error_return (0, "No such VRF id.");
+      goto done;
+    case VNET_API_ERROR_VALUE_EXIST:
+      error = clib_error_return (0, "Mapping already exist.");
+      goto done;
+    default:
+      break;
+    }
+
+done:
+  unformat_free (line_input);
+
+  return error;
+}
+
+/*?
+ * @cliexpar
+ * @cliexstart{snat add static mapping}
+ * Static mapping allows hosts on the external network to initiate connection
+ * to to the local network host.
+ * To create static mapping between local host address 10.0.0.3 port 6303 and
+ * external address 4.4.4.4 port 3606 for TCP protocol use:
+ *  vpp# nat44 add static mapping local tcp 10.0.0.3 6303 external 4.4.4.4 3606
+ * If not runnig "static mapping only" NAT plugin mode use before:
+ *  vpp# nat44 add address 4.4.4.4
+ * To create static mapping between local and external address use:
+ *  vpp# nat44 add static mapping local 10.0.0.3 external 4.4.4.4
+ * @cliexend
+?*/
+VLIB_CLI_COMMAND (add_static_mapping_command, static) = {
+  .path = "nat44 add static mapping",
+  .function = add_static_mapping_command_fn,
+  .short_help =
+    "nat44 add static mapping local tcp|udp|icmp <addr> [<port>] external <addr> [<port>] [vrf <table-id>] [del]",
+};
+
+static clib_error_t *
+set_workers_command_fn (vlib_main_t * vm,
+                        unformat_input_t * input,
+                        vlib_cli_command_t * cmd)
+{
+  unformat_input_t _line_input, *line_input = &_line_input;
+  uword *bitmap = 0;
+  int rv = 0;
+  clib_error_t *error = 0;
+
+  /* Get a line of input. */
+  if (!unformat_user (input, unformat_line_input, line_input))
+    return 0;
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (line_input, "%U", unformat_bitmap_list, &bitmap))
+        ;
+      else
+        {
+          error = clib_error_return (0, "unknown input '%U'",
+            format_unformat_error, line_input);
+          goto done;
+        }
+     }
+
+  if (bitmap == 0)
+    {
+      error = clib_error_return (0, "List of workers must be specified.");
+      goto done;
+    }
+
+  rv = snat_set_workers(bitmap);
+
+  clib_bitmap_free (bitmap);
+
+  switch (rv)
+    {
+    case VNET_API_ERROR_INVALID_WORKER:
+      error = clib_error_return (0, "Invalid worker(s).");
+      goto done;
+    case VNET_API_ERROR_FEATURE_DISABLED:
+      error = clib_error_return (0,
+        "Supported only if 2 or more workes available.");
+      goto done;
+    default:
+      break;
+    }
+
+done:
+  unformat_free (line_input);
+
+  return error;
+}
+
+/*?
+ * @cliexpar
+ * @cliexstart{set snat workers}
+ * Set NAT workers if 2 or more workers available, use:
+ *  vpp# set snat workers 0-2,5
+ * @cliexend
+?*/
+VLIB_CLI_COMMAND (set_workers_command, static) = {
+  .path = "set nat workers",
+  .function = set_workers_command_fn,
+  .short_help =
+    "set nat workers <workers-list>",
+};
+
+static clib_error_t *
+snat_ipfix_logging_enable_disable_command_fn (vlib_main_t * vm,
+                                              unformat_input_t * input,
+                                              vlib_cli_command_t * cmd)
+{
+  unformat_input_t _line_input, *line_input = &_line_input;
+  u32 domain_id = 0;
+  u32 src_port = 0;
+  u8 enable = 1;
+  int rv = 0;
+  clib_error_t *error = 0;
+
+  /* Get a line of input. */
+  if (!unformat_user (input, unformat_line_input, line_input))
+    return 0;
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (line_input, "domain %d", &domain_id))
+        ;
+      else if (unformat (line_input, "src-port %d", &src_port))
+        ;
+      else if (unformat (line_input, "disable"))
+        enable = 0;
+      else
+        {
+          error = clib_error_return (0, "unknown input '%U'",
+            format_unformat_error, line_input);
+          goto done;
+        }
+     }
+
+  rv = snat_ipfix_logging_enable_disable (enable, domain_id, (u16) src_port);
+
+  if (rv)
+    {
+      error = clib_error_return (0, "ipfix logging enable failed");
+      goto done;
+    }
+
+done:
+  unformat_free (line_input);
+
+  return error;
+}
+
+/*?
+ * @cliexpar
+ * @cliexstart{snat ipfix logging}
+ * To enable NAT IPFIX logging use:
+ *  vpp# nat ipfix logging
+ * To set IPFIX exporter use:
+ *  vpp# set ipfix exporter collector 10.10.10.3 src 10.10.10.1
+ * @cliexend
+?*/
+VLIB_CLI_COMMAND (snat_ipfix_logging_enable_disable_command, static) = {
+  .path = "nat ipfix logging",
+  .function = snat_ipfix_logging_enable_disable_command_fn,
+  .short_help = "nat ipfix logging [domain <domain-id>] [src-port <port>] [disable]",
+};
+
+static u32
+snat_get_worker_in2out_cb (ip4_header_t * ip0, u32 rx_fib_index0)
+{
+  snat_main_t *sm = &snat_main;
+  snat_user_key_t key0;
+  clib_bihash_kv_8_8_t kv0, value0;
+  u32 next_worker_index = 0;
+
+  key0.addr = ip0->src_address;
+  key0.fib_index = rx_fib_index0;
+
+  kv0.key = key0.as_u64;
+
+  /* Ever heard of of the "user" before? */
+  if (clib_bihash_search_8_8 (&sm->worker_by_in, &kv0, &value0))
+    {
+      /* No, assign next available worker (RR) */
+      next_worker_index = sm->first_worker_index;
+      if (vec_len (sm->workers))
+        {
+          next_worker_index +=
+            sm->workers[sm->next_worker++ % _vec_len (sm->workers)];
+        }
+
+      /* add non-traslated packets worker lookup */
+      kv0.value = next_worker_index;
+      clib_bihash_add_del_8_8 (&sm->worker_by_in, &kv0, 1);
+    }
+  else
+    next_worker_index = value0.value;
+
+  return next_worker_index;
+}
+
+static u32
+snat_get_worker_out2in_cb (ip4_header_t * ip0, u32 rx_fib_index0)
+{
+  snat_main_t *sm = &snat_main;
+  snat_worker_key_t key0;
+  clib_bihash_kv_8_8_t kv0, value0;
+  udp_header_t * udp0;
+  u32 next_worker_index = 0;
+
+  udp0 = ip4_next_header (ip0);
+
+  key0.addr = ip0->dst_address;
+  key0.port = udp0->dst_port;
+  key0.fib_index = rx_fib_index0;
+
+  if (PREDICT_FALSE(ip0->protocol == IP_PROTOCOL_ICMP))
+    {
+      icmp46_header_t * icmp0 = (icmp46_header_t *) udp0;
+      icmp_echo_header_t *echo0 = (icmp_echo_header_t *)(icmp0+1);
+      key0.port = echo0->identifier;
+    }
+
+  kv0.key = key0.as_u64;
+
+  /* Ever heard of of the "user" before? */
+  if (clib_bihash_search_8_8 (&sm->worker_by_out, &kv0, &value0))
+    {
+      key0.port = 0;
+      kv0.key = key0.as_u64;
+
+      if (clib_bihash_search_8_8 (&sm->worker_by_out, &kv0, &value0))
+        {
+          /* No, assign next available worker (RR) */
+          next_worker_index = sm->first_worker_index;
+          if (vec_len (sm->workers))
+            {
+              next_worker_index +=
+                sm->workers[sm->next_worker++ % _vec_len (sm->workers)];
+            }
+        }
+      else
+        {
+          /* Static mapping without port */
+          next_worker_index = value0.value;
+        }
+
+      /* Add to translated packets worker lookup */
+      kv0.value = next_worker_index;
+      clib_bihash_add_del_8_8 (&sm->worker_by_out, &kv0, 1);
+    }
+  else
+    next_worker_index = value0.value;
+
+  return next_worker_index;
+}
+
+static clib_error_t *
+snat_config (vlib_main_t * vm, unformat_input_t * input)
+{
+  snat_main_t * sm = &snat_main;
+  u32 translation_buckets = 1024;
+  u32 translation_memory_size = 128<<20;
+  u32 user_buckets = 128;
+  u32 user_memory_size = 64<<20;
+  u32 max_translations_per_user = 100;
+  u32 outside_vrf_id = 0;
+  u32 inside_vrf_id = 0;
+  u32 static_mapping_buckets = 1024;
+  u32 static_mapping_memory_size = 64<<20;
+  u8 static_mapping_only = 0;
+  u8 static_mapping_connection_tracking = 0;
+
+  sm->deterministic = 0;
+
+  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (input, "translation hash buckets %d", &translation_buckets))
+        ;
+      else if (unformat (input, "translation hash memory %d",
+                         &translation_memory_size));
+      else if (unformat (input, "user hash buckets %d", &user_buckets))
+        ;
+      else if (unformat (input, "user hash memory %d",
+                         &user_memory_size))
+        ;
+      else if (unformat (input, "max translations per user %d",
+                         &max_translations_per_user))
+        ;
+      else if (unformat (input, "outside VRF id %d",
+                         &outside_vrf_id))
+        ;
+      else if (unformat (input, "inside VRF id %d",
+                         &inside_vrf_id))
+        ;
+      else if (unformat (input, "static mapping only"))
+        {
+          static_mapping_only = 1;
+          if (unformat (input, "connection tracking"))
+            static_mapping_connection_tracking = 1;
+        }
+      else if (unformat (input, "deterministic"))
+        sm->deterministic = 1;
+      else
+	return clib_error_return (0, "unknown input '%U'",
+				  format_unformat_error, input);
+    }
+
+  /* for show commands, etc. */
+  sm->translation_buckets = translation_buckets;
+  sm->translation_memory_size = translation_memory_size;
+  sm->user_buckets = user_buckets;
+  sm->user_memory_size = user_memory_size;
+  sm->max_translations_per_user = max_translations_per_user;
+  sm->outside_vrf_id = outside_vrf_id;
+  sm->outside_fib_index = fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4,
+                                                             outside_vrf_id);
+  sm->inside_vrf_id = inside_vrf_id;
+  sm->inside_fib_index = fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4,
+                                                            inside_vrf_id);
+  sm->static_mapping_only = static_mapping_only;
+  sm->static_mapping_connection_tracking = static_mapping_connection_tracking;
+
+  if (sm->deterministic)
+    {
+      sm->in2out_node_index = snat_det_in2out_node.index;
+      sm->in2out_output_node_index = ~0;
+      sm->out2in_node_index = snat_det_out2in_node.index;
+      sm->icmp_match_in2out_cb = icmp_match_in2out_det;
+      sm->icmp_match_out2in_cb = icmp_match_out2in_det;
+    }
+  else
+    {
+      sm->worker_in2out_cb = snat_get_worker_in2out_cb;
+      sm->worker_out2in_cb = snat_get_worker_out2in_cb;
+      sm->in2out_node_index = snat_in2out_node.index;
+      sm->in2out_output_node_index = snat_in2out_output_node.index;
+      sm->out2in_node_index = snat_out2in_node.index;
+      if (!static_mapping_only ||
+          (static_mapping_only && static_mapping_connection_tracking))
+        {
+          sm->icmp_match_in2out_cb = icmp_match_in2out_slow;
+          sm->icmp_match_out2in_cb = icmp_match_out2in_slow;
+
+          clib_bihash_init_8_8 (&sm->worker_by_in, "worker-by-in", user_buckets,
+                                user_memory_size);
+
+          clib_bihash_init_8_8 (&sm->worker_by_out, "worker-by-out", user_buckets,
+                                user_memory_size);
+
+          clib_bihash_init_8_8 (&sm->in2out, "in2out", translation_buckets,
+                                translation_memory_size);
+
+          clib_bihash_init_8_8 (&sm->out2in, "out2in", translation_buckets,
+                                translation_memory_size);
+
+          clib_bihash_init_8_8 (&sm->user_hash, "users", user_buckets,
+                                user_memory_size);
+
+          clib_bihash_init_16_8 (&sm->in2out_unk_proto, "in2out-unk-proto",
+                                 translation_buckets, translation_memory_size);
+
+          clib_bihash_init_16_8 (&sm->out2in_unk_proto, "out2in-unk-proto",
+                                 translation_buckets, translation_memory_size);
+        }
+      else
+        {
+          sm->icmp_match_in2out_cb = icmp_match_in2out_fast;
+          sm->icmp_match_out2in_cb = icmp_match_out2in_fast;
+        }
+      clib_bihash_init_8_8 (&sm->static_mapping_by_local,
+                            "static_mapping_by_local", static_mapping_buckets,
+                            static_mapping_memory_size);
+
+      clib_bihash_init_8_8 (&sm->static_mapping_by_external,
+                            "static_mapping_by_external", static_mapping_buckets,
+                            static_mapping_memory_size);
+    }
+
+  return 0;
+}
+
+VLIB_CONFIG_FUNCTION (snat_config, "nat");
+
+u8 * format_snat_session_state (u8 * s, va_list * args)
+{
+  u32 i = va_arg (*args, u32);
+  u8 *t = 0;
+
+  switch (i)
+    {
+#define _(v, N, str) case SNAT_SESSION_##N: t = (u8 *) str; break;
+    foreach_snat_session_state
+#undef _
+    default:
+      t = format (t, "unknown");
+    }
+  s = format (s, "%s", t);
+  return s;
+}
+
+u8 * format_snat_key (u8 * s, va_list * args)
+{
+  snat_session_key_t * key = va_arg (*args, snat_session_key_t *);
+  char * protocol_string = "unknown";
+  static char *protocol_strings[] = {
+      "UDP",
+      "TCP",
+      "ICMP",
+  };
+
+  if (key->protocol < ARRAY_LEN(protocol_strings))
+      protocol_string = protocol_strings[key->protocol];
+
+  s = format (s, "%U proto %s port %d fib %d",
+              format_ip4_address, &key->addr, protocol_string,
+              clib_net_to_host_u16 (key->port), key->fib_index);
+  return s;
+}
+
+u8 * format_snat_session (u8 * s, va_list * args)
+{
+  snat_main_t * sm __attribute__((unused)) = va_arg (*args, snat_main_t *);
+  snat_session_t * sess = va_arg (*args, snat_session_t *);
+
+  if (snat_is_unk_proto_session (sess))
+    {
+      s = format (s, "  i2o %U proto %u fib %u\n",
+                  format_ip4_address, &sess->in2out.addr, sess->in2out.port,
+                  sess->in2out.fib_index);
+      s = format (s, "    o2i %U proto %u fib %u\n",
+                  format_ip4_address, &sess->out2in.addr, sess->out2in.port,
+                  sess->out2in.fib_index);
+    }
+  else
+    {
+      s = format (s, "  i2o %U\n", format_snat_key, &sess->in2out);
+      s = format (s, "    o2i %U\n", format_snat_key, &sess->out2in);
+    }
+  s = format (s, "       last heard %.2f\n", sess->last_heard);
+  s = format (s, "       total pkts %d, total bytes %lld\n",
+              sess->total_pkts, sess->total_bytes);
+  if (snat_is_session_static (sess))
+    s = format (s, "       static translation\n");
+  else
+    s = format (s, "       dynamic translation\n");
+
+  return s;
+}
+
+u8 * format_snat_user (u8 * s, va_list * args)
+{
+  snat_main_per_thread_data_t * sm = va_arg (*args, snat_main_per_thread_data_t *);
+  snat_user_t * u = va_arg (*args, snat_user_t *);
+  int verbose = va_arg (*args, int);
+  dlist_elt_t * head, * elt;
+  u32 elt_index, head_index;
+  u32 session_index;
+  snat_session_t * sess;
+
+  s = format (s, "%U: %d dynamic translations, %d static translations\n",
+              format_ip4_address, &u->addr, u->nsessions, u->nstaticsessions);
+
+  if (verbose == 0)
+    return s;
+
+  if (u->nsessions || u->nstaticsessions)
+    {
+      head_index = u->sessions_per_user_list_head_index;
+      head = pool_elt_at_index (sm->list_pool, head_index);
+
+      elt_index = head->next;
+      elt = pool_elt_at_index (sm->list_pool, elt_index);
+      session_index = elt->value;
+
+      while (session_index != ~0)
+        {
+          sess = pool_elt_at_index (sm->sessions, session_index);
+
+          s = format (s, "  %U\n", format_snat_session, sm, sess);
+
+          elt_index = elt->next;
+          elt = pool_elt_at_index (sm->list_pool, elt_index);
+          session_index = elt->value;
+        }
+    }
+
+  return s;
+}
+
+u8 * format_snat_static_mapping (u8 * s, va_list * args)
+{
+  snat_static_mapping_t *m = va_arg (*args, snat_static_mapping_t *);
+
+  if (m->addr_only)
+      s = format (s, "local %U external %U vrf %d",
+                  format_ip4_address, &m->local_addr,
+                  format_ip4_address, &m->external_addr,
+                  m->vrf_id);
+  else
+      s = format (s, "%U local %U:%d external %U:%d vrf %d",
+                  format_snat_protocol, m->proto,
+                  format_ip4_address, &m->local_addr, m->local_port,
+                  format_ip4_address, &m->external_addr, m->external_port,
+                  m->vrf_id);
+
+  return s;
+}
+
+u8 * format_snat_static_map_to_resolve (u8 * s, va_list * args)
+{
+  snat_static_map_resolve_t *m = va_arg (*args, snat_static_map_resolve_t *);
+  vnet_main_t *vnm = vnet_get_main();
+
+  if (m->addr_only)
+      s = format (s, "local %U external %U vrf %d",
+                  format_ip4_address, &m->l_addr,
+                  format_vnet_sw_interface_name, vnm,
+                  vnet_get_sw_interface (vnm, m->sw_if_index),
+                  m->vrf_id);
+  else
+      s = format (s, "%U local %U:%d external %U:%d vrf %d",
+                  format_snat_protocol, m->proto,
+                  format_ip4_address, &m->l_addr, m->l_port,
+                  format_vnet_sw_interface_name, vnm,
+                  vnet_get_sw_interface (vnm, m->sw_if_index), m->e_port,
+                  m->vrf_id);
+
+  return s;
+}
+
+u8 * format_det_map_ses (u8 * s, va_list * args)
+{
+  snat_det_map_t * det_map = va_arg (*args, snat_det_map_t *);
+  ip4_address_t in_addr, out_addr;
+  u32 in_offset, out_offset;
+  snat_det_session_t * ses = va_arg (*args, snat_det_session_t *);
+  u32 * i = va_arg (*args, u32 *);
+
+  u32 user_index = *i / SNAT_DET_SES_PER_USER;
+  in_addr.as_u32 = clib_host_to_net_u32 (
+    clib_net_to_host_u32(det_map->in_addr.as_u32) + user_index);
+  in_offset = clib_net_to_host_u32(in_addr.as_u32) -
+    clib_net_to_host_u32(det_map->in_addr.as_u32);
+  out_offset = in_offset / det_map->sharing_ratio;
+  out_addr.as_u32 = clib_host_to_net_u32(
+    clib_net_to_host_u32(det_map->out_addr.as_u32) + out_offset);
+  s = format (s, "in %U:%d out %U:%d external host %U:%d state: %U expire: %d\n",
+              format_ip4_address, &in_addr,
+              clib_net_to_host_u16 (ses->in_port),
+              format_ip4_address, &out_addr,
+              clib_net_to_host_u16 (ses->out.out_port),
+              format_ip4_address, &ses->out.ext_host_addr,
+              clib_net_to_host_u16 (ses->out.ext_host_port),
+              format_snat_session_state, ses->state,
+              ses->expire);
+
+  return s;
+}
+
+static clib_error_t *
+show_snat_command_fn (vlib_main_t * vm,
+		 unformat_input_t * input,
+		 vlib_cli_command_t * cmd)
+{
+  int verbose = 0;
+  snat_main_t * sm = &snat_main;
+  snat_user_t * u;
+  snat_static_mapping_t *m;
+  snat_interface_t *i;
+  snat_address_t * ap;
+  vnet_main_t *vnm = vnet_get_main();
+  snat_main_per_thread_data_t *tsm;
+  u32 users_num = 0, sessions_num = 0, *worker, *sw_if_index;
+  uword j = 0;
+  snat_static_map_resolve_t *rp;
+  snat_det_map_t * dm;
+  snat_det_session_t * ses;
+
+  if (unformat (input, "detail"))
+    verbose = 1;
+  else if (unformat (input, "verbose"))
+    verbose = 2;
+
+  if (sm->static_mapping_only)
+    {
+      if (sm->static_mapping_connection_tracking)
+        vlib_cli_output (vm, "NAT plugin mode: static mapping only connection "
+                         "tracking");
+      else
+        vlib_cli_output (vm, "NAT plugin mode: static mapping only");
+    }
+  else if (sm->deterministic)
+    {
+      vlib_cli_output (vm, "NAT plugin mode: deterministic mapping");
+    }
+  else
+    {
+      vlib_cli_output (vm, "NAT plugin mode: dynamic translations enabled");
+    }
+
+  if (verbose > 0)
+    {
+      pool_foreach (i, sm->interfaces,
+      ({
+        vlib_cli_output (vm, "%U %s", format_vnet_sw_interface_name, vnm,
+                         vnet_get_sw_interface (vnm, i->sw_if_index),
+                         i->is_inside ? "in" : "out");
+      }));
+
+      pool_foreach (i, sm->output_feature_interfaces,
+      ({
+        vlib_cli_output (vm, "%U output-feature %s",
+                         format_vnet_sw_interface_name, vnm,
+                         vnet_get_sw_interface (vnm, i->sw_if_index),
+                         i->is_inside ? "in" : "out");
+      }));
+
+      if (vec_len (sm->auto_add_sw_if_indices))
+        {
+          vlib_cli_output (vm, "NAT44 pool addresses interfaces:");
+          vec_foreach (sw_if_index, sm->auto_add_sw_if_indices)
+            {
+              vlib_cli_output (vm, "%U", format_vnet_sw_interface_name, vnm,
+                               vnet_get_sw_interface (vnm, *sw_if_index));
+            }
+        }
+
+      vec_foreach (ap, sm->addresses)
+        {
+          vlib_cli_output (vm, "%U", format_ip4_address, &ap->addr);
+          if (ap->fib_index != ~0)
+              vlib_cli_output (vm, "  tenant VRF: %u",
+                               ip4_fib_get(ap->fib_index)->table_id);
+          else
+            vlib_cli_output (vm, "  tenant VRF independent");
+#define _(N, i, n, s) \
+          vlib_cli_output (vm, "  %d busy %s ports", ap->busy_##n##_ports, s);
+          foreach_snat_protocol
+#undef _
+        }
+    }
+
+  if (sm->num_workers > 1)
+    {
+      vlib_cli_output (vm, "%d workers", vec_len (sm->workers));
+      if (verbose > 0)
+        {
+          vec_foreach (worker, sm->workers)
+            {
+              vlib_worker_thread_t *w =
+                vlib_worker_threads + *worker + sm->first_worker_index;
+              vlib_cli_output (vm, "  %s", w->name);
+            }
+        }
+    }
+
+  if (sm->deterministic)
+    {
+      vlib_cli_output (vm, "udp timeout: %dsec", sm->udp_timeout);
+      vlib_cli_output (vm, "tcp-established timeout: %dsec",
+                       sm->tcp_established_timeout);
+      vlib_cli_output (vm, "tcp-transitory timeout: %dsec",
+                       sm->tcp_transitory_timeout);
+      vlib_cli_output (vm, "icmp timeout: %dsec", sm->icmp_timeout);
+      vlib_cli_output (vm, "%d deterministic mappings",
+                       pool_elts (sm->det_maps));
+      if (verbose > 0)
+        {
+          pool_foreach (dm, sm->det_maps,
+          ({
+            vlib_cli_output (vm, "in %U/%d out %U/%d\n",
+                             format_ip4_address, &dm->in_addr, dm->in_plen,
+                             format_ip4_address, &dm->out_addr, dm->out_plen);
+            vlib_cli_output (vm, " outside address sharing ratio: %d\n",
+                             dm->sharing_ratio);
+            vlib_cli_output (vm, " number of ports per inside host: %d\n",
+                             dm->ports_per_host);
+            vlib_cli_output (vm, " sessions number: %d\n", dm->ses_num);
+            if (verbose > 1)
+              {
+                vec_foreach_index (j, dm->sessions)
+                  {
+                    ses = vec_elt_at_index (dm->sessions, j);
+                    if (ses->in_port)
+                      vlib_cli_output (vm, "  %U", format_det_map_ses, dm, ses,
+                                       &j);
+                  }
+              }
+          }));
+        }
+    }
+  else
+    {
+      if (sm->static_mapping_only && !(sm->static_mapping_connection_tracking))
+        {
+          vlib_cli_output (vm, "%d static mappings",
+                           pool_elts (sm->static_mappings));
+
+          if (verbose > 0)
+            {
+              pool_foreach (m, sm->static_mappings,
+              ({
+                vlib_cli_output (vm, "%U", format_snat_static_mapping, m);
+              }));
+            }
+        }
+      else
+        {
+          vec_foreach (tsm, sm->per_thread_data)
+            {
+              users_num += pool_elts (tsm->users);
+              sessions_num += pool_elts (tsm->sessions);
+            }
+
+          vlib_cli_output (vm, "%d users, %d outside addresses, %d active sessions,"
+                           " %d static mappings",
+                           users_num,
+                           vec_len (sm->addresses),
+                           sessions_num,
+                           pool_elts (sm->static_mappings));
+
+          if (verbose > 0)
+            {
+              vlib_cli_output (vm, "%U", format_bihash_8_8, &sm->in2out,
+                               verbose - 1);
+              vlib_cli_output (vm, "%U", format_bihash_8_8, &sm->out2in,
+                               verbose - 1);
+              vlib_cli_output (vm, "%U", format_bihash_8_8, &sm->worker_by_in,
+                               verbose - 1);
+              vlib_cli_output (vm, "%U", format_bihash_8_8, &sm->worker_by_out,
+                               verbose - 1);
+              vec_foreach_index (j, sm->per_thread_data)
+                {
+                  tsm = vec_elt_at_index (sm->per_thread_data, j);
+
+                  if (pool_elts (tsm->users) == 0)
+                    continue;
+
+                  vlib_worker_thread_t *w = vlib_worker_threads + j;
+                  vlib_cli_output (vm, "Thread %d (%s at lcore %u):", j, w->name,
+                                   w->lcore_id);
+                  vlib_cli_output (vm, "  %d list pool elements",
+                                   pool_elts (tsm->list_pool));
+
+                  pool_foreach (u, tsm->users,
+                  ({
+                    vlib_cli_output (vm, "  %U", format_snat_user, tsm, u,
+                                     verbose - 1);
+                  }));
+                }
+
+              if (pool_elts (sm->static_mappings))
+                {
+                  vlib_cli_output (vm, "static mappings:");
+                  pool_foreach (m, sm->static_mappings,
+                  ({
+                    vlib_cli_output (vm, "%U", format_snat_static_mapping, m);
+                  }));
+                  for (j = 0; j < vec_len (sm->to_resolve); j++)
+                    {
+                      rp = sm->to_resolve + j;
+                      vlib_cli_output (vm, "%U",
+                                       format_snat_static_map_to_resolve, rp);
+                    }
+                }
+            }
+        }
+    }
+  return 0;
+}
+
+VLIB_CLI_COMMAND (show_snat_command, static) = {
+    .path = "show nat44",
+    .short_help = "show nat44",
+    .function = show_snat_command_fn,
+};
+
+
+static void
+snat_ip4_add_del_interface_address_cb (ip4_main_t * im,
+                                       uword opaque,
+                                       u32 sw_if_index,
+                                       ip4_address_t * address,
+                                       u32 address_length,
+                                       u32 if_address_index,
+                                       u32 is_delete)
+{
+  snat_main_t *sm = &snat_main;
+  snat_static_map_resolve_t *rp;
+  u32 *indices_to_delete = 0;
+  int i, j;
+  int rv;
+
+  for (i = 0; i < vec_len(sm->auto_add_sw_if_indices); i++)
+    {
+      if (sw_if_index == sm->auto_add_sw_if_indices[i])
+        {
+          if (!is_delete)
+            {
+              /* Don't trip over lease renewal, static config */
+              for (j = 0; j < vec_len(sm->addresses); j++)
+                if (sm->addresses[j].addr.as_u32 == address->as_u32)
+                  return;
+
+              snat_add_address (sm, address, ~0);
+              /* Scan static map resolution vector */
+              for (j = 0; j < vec_len (sm->to_resolve); j++)
+                {
+                  rp = sm->to_resolve + j;
+                  /* On this interface? */
+                  if (rp->sw_if_index == sw_if_index)
+                    {
+                      /* Add the static mapping */
+                      rv = snat_add_static_mapping (rp->l_addr,
+                                                    address[0],
+                                                    rp->l_port,
+                                                    rp->e_port,
+                                                    rp->vrf_id,
+                                                    rp->addr_only,
+                                                    ~0 /* sw_if_index */,
+                                                    rp->proto,
+                                                    rp->is_add);
+                      if (rv)
+                        clib_warning ("snat_add_static_mapping returned %d", 
+                                      rv);
+                      vec_add1 (indices_to_delete, j);
+                    }
+                }
+              /* If we resolved any of the outstanding static mappings */
+              if (vec_len(indices_to_delete))
+                {
+                  /* Delete them */
+                  for (j = vec_len(indices_to_delete)-1; j >= 0; j--)
+                    vec_delete(sm->to_resolve, 1, j);
+                  vec_free(indices_to_delete);
+                }
+              return;
+            }
+          else
+            {
+              (void) snat_del_address(sm, address[0], 1);
+              return;
+            }
+        }
+    }
+}
+
+
+int snat_add_interface_address (snat_main_t *sm, u32 sw_if_index, int is_del)
+{
+  ip4_main_t * ip4_main = sm->ip4_main;
+  ip4_address_t * first_int_addr;
+  snat_static_map_resolve_t *rp;
+  u32 *indices_to_delete = 0;
+  int i, j;
+
+  first_int_addr = ip4_interface_first_address (ip4_main, sw_if_index,
+                                                0 /* just want the address*/);
+
+  for (i = 0; i < vec_len(sm->auto_add_sw_if_indices); i++)
+    {
+      if (sm->auto_add_sw_if_indices[i] == sw_if_index)
+        {
+          if (is_del)
+            {
+              /* if have address remove it */
+              if (first_int_addr)
+                  (void) snat_del_address (sm, first_int_addr[0], 1);
+              else
+                {
+                  for (j = 0; j < vec_len (sm->to_resolve); j++)
+                    {
+                      rp = sm->to_resolve + j;
+                      if (rp->sw_if_index == sw_if_index)
+                        vec_add1 (indices_to_delete, j);
+                    }
+                  if (vec_len(indices_to_delete))
+                    {
+                      for (j = vec_len(indices_to_delete)-1; j >= 0; j--)
+                        vec_del1(sm->to_resolve, j);
+                      vec_free(indices_to_delete);
+                    }
+                }
+              vec_del1(sm->auto_add_sw_if_indices, i);
+            }
+          else
+            return VNET_API_ERROR_VALUE_EXIST;
+
+          return 0;
+        }
+    }
+
+  if (is_del)
+    return VNET_API_ERROR_NO_SUCH_ENTRY;
+
+  /* add to the auto-address list */
+  vec_add1(sm->auto_add_sw_if_indices, sw_if_index);
+
+  /* If the address is already bound - or static - add it now */
+  if (first_int_addr)
+      snat_add_address (sm, first_int_addr, ~0);
+
+  return 0;
+}
+
+static clib_error_t *
+snat_add_interface_address_command_fn (vlib_main_t * vm,
+                                       unformat_input_t * input,
+                                       vlib_cli_command_t * cmd)
+{
+  snat_main_t *sm = &snat_main;
+  unformat_input_t _line_input, *line_input = &_line_input;
+  u32 sw_if_index;
+  int rv;
+  int is_del = 0;
+  clib_error_t *error = 0;
+
+  /* Get a line of input. */
+  if (!unformat_user (input, unformat_line_input, line_input))
+    return 0;
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (line_input, "%U", unformat_vnet_sw_interface,
+                    sm->vnet_main, &sw_if_index))
+        ;
+      else if (unformat (line_input, "del"))
+        is_del = 1;
+      else
+        {
+          error = clib_error_return (0, "unknown input '%U'",
+				     format_unformat_error, line_input);
+          goto done;
+        }
+    }
+
+  rv = snat_add_interface_address (sm, sw_if_index, is_del);
+
+  switch (rv)
+    {
+    case 0:
+      break;
+
+    default:
+      error = clib_error_return (0, "snat_add_interface_address returned %d",
+                                 rv);
+      goto done;
+    }
+
+done:
+  unformat_free (line_input);
+
+  return error;
+}
+
+VLIB_CLI_COMMAND (snat_add_interface_address_command, static) = {
+    .path = "nat44 add interface address",
+    .short_help = "nat44 add interface address <interface> [del]",
+    .function = snat_add_interface_address_command_fn,
+};
+
+static clib_error_t *
+snat_det_map_command_fn (vlib_main_t * vm,
+                         unformat_input_t * input,
+                         vlib_cli_command_t * cmd)
+{
+  snat_main_t *sm = &snat_main;
+  unformat_input_t _line_input, *line_input = &_line_input;
+  ip4_address_t in_addr, out_addr;
+  u32 in_plen, out_plen;
+  int is_add = 1, rv;
+  clib_error_t *error = 0;
+
+  /* Get a line of input. */
+  if (!unformat_user (input, unformat_line_input, line_input))
+    return 0;
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (line_input, "in %U/%u", unformat_ip4_address, &in_addr, &in_plen))
+        ;
+      else if (unformat (line_input, "out %U/%u", unformat_ip4_address, &out_addr, &out_plen))
+        ;
+      else if (unformat (line_input, "del"))
+        is_add = 0;
+      else
+        {
+          error = clib_error_return (0, "unknown input '%U'",
+                                     format_unformat_error, line_input);
+          goto done;
+        }
+    }
+
+  unformat_free (line_input);
+
+  rv = snat_det_add_map(sm, &in_addr, (u8) in_plen, &out_addr, (u8)out_plen,
+                        is_add);
+
+  if (rv)
+    {
+      error = clib_error_return (0, "snat_det_add_map return %d", rv);
+      goto done;
+    }
+
+done:
+  unformat_free (line_input);
+
+  return error;
+}
+
+/*?
+ * @cliexpar
+ * @cliexstart{snat deterministic add}
+ * Create bijective mapping of inside address to outside address and port range
+ * pairs, with the purpose of enabling deterministic NAT to reduce logging in
+ * CGN deployments.
+ * To create deterministic mapping between inside network 10.0.0.0/18 and
+ * outside network 1.1.1.0/30 use:
+ * # vpp# nat44 deterministic add in 10.0.0.0/18 out 1.1.1.0/30
+ * @cliexend
+?*/
+VLIB_CLI_COMMAND (snat_det_map_command, static) = {
+    .path = "nat44 deterministic add",
+    .short_help = "nat44 deterministic add in <addr>/<plen> out <addr>/<plen> [del]",
+    .function = snat_det_map_command_fn,
+};
+
+static clib_error_t *
+snat_det_forward_command_fn (vlib_main_t * vm,
+                             unformat_input_t * input,
+                             vlib_cli_command_t * cmd)
+{
+  snat_main_t *sm = &snat_main;
+  unformat_input_t _line_input, *line_input = &_line_input;
+  ip4_address_t in_addr, out_addr;
+  u16 lo_port;
+  snat_det_map_t * dm;
+  clib_error_t *error = 0;
+
+  /* Get a line of input. */
+  if (!unformat_user (input, unformat_line_input, line_input))
+    return 0;
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (line_input, "%U", unformat_ip4_address, &in_addr))
+        ;
+      else
+        {
+          error = clib_error_return (0, "unknown input '%U'",
+                                     format_unformat_error, line_input);
+          goto done;
+        }
+    }
+
+  unformat_free (line_input);
+
+  dm = snat_det_map_by_user(sm, &in_addr);
+  if (!dm)
+    vlib_cli_output (vm, "no match");
+  else
+    {
+      snat_det_forward (dm, &in_addr, &out_addr, &lo_port);
+      vlib_cli_output (vm, "%U:<%d-%d>", format_ip4_address, &out_addr,
+                       lo_port, lo_port + dm->ports_per_host - 1);
+    }
+
+done:
+  unformat_free (line_input);
+
+  return error;
+}
+
+/*?
+ * @cliexpar
+ * @cliexstart{snat deterministic forward}
+ * Return outside address and port range from inside address for deterministic
+ * NAT.
+ * To obtain outside address and port of inside host use:
+ *  vpp# nat44 deterministic forward 10.0.0.2
+ *  1.1.1.0:<1054-1068>
+ * @cliexend
+?*/
+VLIB_CLI_COMMAND (snat_det_forward_command, static) = {
+    .path = "nat44 deterministic forward",
+    .short_help = "nat44 deterministic forward <addr>",
+    .function = snat_det_forward_command_fn,
+};
+
+static clib_error_t *
+snat_det_reverse_command_fn (vlib_main_t * vm,
+                             unformat_input_t * input,
+                             vlib_cli_command_t * cmd)
+{
+  snat_main_t *sm = &snat_main;
+  unformat_input_t _line_input, *line_input = &_line_input;
+  ip4_address_t in_addr, out_addr;
+  u32 out_port;
+  snat_det_map_t * dm;
+  clib_error_t *error = 0;
+
+  /* Get a line of input. */
+  if (!unformat_user (input, unformat_line_input, line_input))
+    return 0;
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (line_input, "%U:%d", unformat_ip4_address, &out_addr, &out_port))
+        ;
+      else
+        {
+          error =  clib_error_return (0, "unknown input '%U'",
+                                      format_unformat_error, line_input);
+        }
+    }
+
+  unformat_free (line_input);
+
+  if (out_port < 1024 || out_port > 65535)
+    {
+      error = clib_error_return (0, "wrong port, must be <1024-65535>");
+      goto done;
+    }
+
+  dm = snat_det_map_by_out(sm, &out_addr);
+  if (!dm)
+    vlib_cli_output (vm, "no match");
+  else
+    {
+      snat_det_reverse (dm, &out_addr, (u16) out_port, &in_addr);
+      vlib_cli_output (vm, "%U", format_ip4_address, &in_addr);
+    }
+
+done:
+  unformat_free (line_input);
+
+  return error;
+}
+
+/*?
+ * @cliexpar
+ * @cliexstart{snat deterministic reverse}
+ * Return inside address from outside address and port for deterministic NAT.
+ * To obtain inside host address from outside address and port use:
+ *  #vpp nat44 deterministic reverse 1.1.1.1:1276
+ *  10.0.16.16
+ * @cliexend
+?*/
+VLIB_CLI_COMMAND (snat_det_reverse_command, static) = {
+    .path = "nat44 deterministic reverse",
+    .short_help = "nat44 deterministic reverse <addr>:<port>",
+    .function = snat_det_reverse_command_fn,
+};
+
+static clib_error_t *
+set_timeout_command_fn (vlib_main_t * vm,
+                        unformat_input_t * input,
+                        vlib_cli_command_t * cmd)
+{
+  snat_main_t *sm = &snat_main;
+  unformat_input_t _line_input, *line_input = &_line_input;
+  clib_error_t *error = 0;
+
+  /* Get a line of input. */
+  if (!unformat_user (input, unformat_line_input, line_input))
+    return 0;
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (line_input, "udp %u", &sm->udp_timeout))
+        ;
+      else if (unformat (line_input, "tcp-established %u",
+               &sm->tcp_established_timeout))
+        ;
+      else if (unformat (line_input, "tcp-transitory %u",
+               &sm->tcp_transitory_timeout))
+        ;
+      else if (unformat (line_input, "icmp %u", &sm->icmp_timeout))
+        ;
+      else if (unformat (line_input, "reset"))
+        {
+          sm->udp_timeout = SNAT_UDP_TIMEOUT;
+          sm->tcp_established_timeout = SNAT_TCP_ESTABLISHED_TIMEOUT;
+          sm->tcp_transitory_timeout = SNAT_TCP_TRANSITORY_TIMEOUT;
+          sm->icmp_timeout = SNAT_ICMP_TIMEOUT;
+        }
+      else
+        {
+          error = clib_error_return (0, "unknown input '%U'",
+                                     format_unformat_error, line_input);
+          goto done;
+        }
+    }
+
+  unformat_free (line_input);
+
+done:
+  unformat_free (line_input);
+
+  return error;
+}
+
+/*?
+ * @cliexpar
+ * @cliexstart{set snat deterministic timeout}
+ * Set values of timeouts for deterministic NAT (in seconds), use:
+ *  vpp# set nat44 deterministic timeout udp 120 tcp-established 7500
+ *  tcp-transitory 250 icmp 90
+ * To reset default values use:
+ *  vpp# set nat44 deterministic timeout reset
+ * @cliexend
+?*/
+VLIB_CLI_COMMAND (set_timeout_command, static) = {
+  .path = "set nat44 deterministic timeout",
+  .function = set_timeout_command_fn,
+  .short_help =
+    "set nat44 deterministic timeout [udp <sec> | tcp-established <sec> "
+    "tcp-transitory <sec> | icmp <sec> | reset]",
+};
+
+static clib_error_t *
+snat_det_close_session_out_fn (vlib_main_t *vm,
+                               unformat_input_t * input,
+                               vlib_cli_command_t * cmd)
+{
+  snat_main_t *sm = &snat_main;
+  unformat_input_t _line_input, *line_input = &_line_input;
+  ip4_address_t out_addr, ext_addr, in_addr;
+  u16 out_port, ext_port;
+  snat_det_map_t * dm;
+  snat_det_session_t * ses;
+  snat_det_out_key_t key;
+  clib_error_t *error = 0;
+
+  /* Get a line of input. */
+  if (!unformat_user (input, unformat_line_input, line_input))
+    return 0;
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (line_input, "%U:%d %U:%d",
+                    unformat_ip4_address, &out_addr, &out_port,
+                    unformat_ip4_address, &ext_addr, &ext_port))
+        ;
+      else
+        {
+          error = clib_error_return (0, "unknown input '%U'",
+                                     format_unformat_error, line_input);
+          goto done;
+        }
+    }
+
+  unformat_free (line_input);
+
+  dm = snat_det_map_by_out(sm, &out_addr);
+  if (!dm)
+    vlib_cli_output (vm, "no match");
+  else
+    {
+      snat_det_reverse(dm, &ext_addr, out_port, &in_addr);
+      key.ext_host_addr = out_addr;
+      key.ext_host_port = ntohs(ext_port);
+      key.out_port = ntohs(out_port);
+      ses = snat_det_get_ses_by_out(dm, &out_addr, key.as_u64);
+      if (!ses)
+        vlib_cli_output (vm, "no match");
+      else
+       snat_det_ses_close(dm, ses);
+    }
+
+done:
+  unformat_free (line_input);
+
+  return error;
+}
+
+/*?
+ * @cliexpar
+ * @cliexstart{snat deterministic close session out}
+ * Close session using outside ip address and port
+ * and external ip address and port, use:
+ *  vpp# nat44 deterministic close session out 1.1.1.1:1276 2.2.2.2:2387
+ * @cliexend
+?*/
+VLIB_CLI_COMMAND (snat_det_close_sesion_out_command, static) = {
+  .path = "nat44 deterministic close session out",
+  .short_help = "nat44 deterministic close session out "
+                "<out_addr>:<out_port> <ext_addr>:<ext_port>",
+  .function = snat_det_close_session_out_fn,
+};
+
+static clib_error_t *
+snat_det_close_session_in_fn (vlib_main_t *vm,
+                              unformat_input_t * input,
+                              vlib_cli_command_t * cmd)
+{
+  snat_main_t *sm = &snat_main;
+  unformat_input_t _line_input, *line_input = &_line_input;
+  ip4_address_t in_addr, ext_addr;
+  u16 in_port, ext_port;
+  snat_det_map_t * dm;
+  snat_det_session_t * ses;
+  snat_det_out_key_t key;
+  clib_error_t *error = 0;
+
+  /* Get a line of input. */
+  if (!unformat_user (input, unformat_line_input, line_input))
+    return 0;
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (line_input, "%U:%d %U:%d",
+                    unformat_ip4_address, &in_addr, &in_port,
+                    unformat_ip4_address, &ext_addr, &ext_port))
+        ;
+      else
+        {
+          error = clib_error_return (0, "unknown input '%U'",
+                                     format_unformat_error, line_input);
+          goto done;
+        }
+    }
+
+  unformat_free (line_input);
+
+  dm = snat_det_map_by_user (sm, &in_addr);
+  if (!dm)
+    vlib_cli_output (vm, "no match");
+  else
+    {
+      key.ext_host_addr = ext_addr;
+      key.ext_host_port = ntohs (ext_port);
+      ses = snat_det_find_ses_by_in (dm, &in_addr, ntohs(in_port), key);
+      if (!ses)
+        vlib_cli_output (vm, "no match");
+      else
+        snat_det_ses_close(dm, ses);
+    }
+
+done:
+  unformat_free(line_input);
+
+  return error;
+}
+
+/*?
+ * @cliexpar
+ * @cliexstart{snat deterministic close_session_in}
+ * Close session using inside ip address and port
+ * and external ip address and port, use:
+ *  vpp# nat44 deterministic close session in 3.3.3.3:3487 2.2.2.2:2387
+ * @cliexend
+?*/
+VLIB_CLI_COMMAND (snat_det_close_session_in_command, static) = {
+  .path = "nat44 deterministic close session in",
+  .short_help = "nat44 deterministic close session in "
+                "<in_addr>:<in_port> <ext_addr>:<ext_port>",
+  .function = snat_det_close_session_in_fn,
+};
diff --git a/src/plugins/nat/nat.h b/src/plugins/nat/nat.h
new file mode 100644
index 00000000000..04c466dc6f5
--- /dev/null
+++ b/src/plugins/nat/nat.h
@@ -0,0 +1,541 @@
+
+/*
+ * nat.h - NAT plugin definitions
+ *
+ * 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 __included_nat_h__
+#define __included_nat_h__
+
+#include <vnet/vnet.h>
+#include <vnet/ip/ip.h>
+#include <vnet/ethernet/ethernet.h>
+#include <vnet/ip/icmp46_packet.h>
+#include <vnet/api_errno.h>
+#include <vppinfra/bihash_8_8.h>
+#include <vppinfra/bihash_16_8.h>
+#include <vppinfra/dlist.h>
+#include <vppinfra/error.h>
+#include <vlibapi/api.h>
+
+
+#define SNAT_UDP_TIMEOUT 300
+#define SNAT_UDP_TIMEOUT_MIN 120
+#define SNAT_TCP_TRANSITORY_TIMEOUT 240
+#define SNAT_TCP_ESTABLISHED_TIMEOUT 7440
+#define SNAT_TCP_INCOMING_SYN 6
+#define SNAT_ICMP_TIMEOUT 60
+
+#define SNAT_FLAG_HAIRPINNING (1 << 0)
+
+/* Key */
+typedef struct {
+  union
+  {
+    struct
+    {
+      ip4_address_t addr;
+      u16 port;
+      u16 protocol:3,
+        fib_index:13;
+    };
+    u64 as_u64;
+  };
+} snat_session_key_t;
+
+typedef struct {
+  union
+  {
+    struct
+    {
+      ip4_address_t l_addr;
+      ip4_address_t r_addr;
+      u32 fib_index;
+      u8 proto;
+      u8 rsvd[3];
+    };
+    u64 as_u64[2];
+  };
+} snat_unk_proto_ses_key_t;
+
+typedef struct {
+  union
+  {
+    struct
+    {
+      ip4_address_t ext_host_addr;
+      u16 ext_host_port;
+      u16 out_port;
+    };
+    u64 as_u64;
+  };
+} snat_det_out_key_t;
+
+typedef struct {
+  union
+  {
+    struct
+    {
+      ip4_address_t addr;
+      u32 fib_index;
+    };
+    u64 as_u64;
+  };
+} snat_user_key_t;
+
+typedef struct {
+  union
+  {
+    struct
+    {
+      ip4_address_t addr;
+      u16 port;
+      u16 fib_index;
+    };
+    u64 as_u64;
+  };
+} snat_worker_key_t;
+
+
+#define foreach_snat_protocol \
+  _(UDP, 0, udp, "udp")       \
+  _(TCP, 1, tcp, "tcp")       \
+  _(ICMP, 2, icmp, "icmp")
+
+typedef enum {
+#define _(N, i, n, s) SNAT_PROTOCOL_##N = i,
+  foreach_snat_protocol
+#undef _
+} snat_protocol_t;
+
+
+#define foreach_snat_session_state          \
+  _(0, UNKNOWN, "unknown")                 \
+  _(1, UDP_ACTIVE, "udp-active")           \
+  _(2, TCP_SYN_SENT, "tcp-syn-sent")       \
+  _(3, TCP_ESTABLISHED, "tcp-established") \
+  _(4, TCP_FIN_WAIT, "tcp-fin-wait")       \
+  _(5, TCP_CLOSE_WAIT, "tcp-close-wait")   \
+  _(6, TCP_LAST_ACK, "tcp-last-ack")       \
+  _(7, ICMP_ACTIVE, "icmp-active")
+
+typedef enum {
+#define _(v, N, s) SNAT_SESSION_##N = v,
+  foreach_snat_session_state
+#undef _
+} snat_session_state_t;
+
+
+#define SNAT_SESSION_FLAG_STATIC_MAPPING 1
+#define SNAT_SESSION_FLAG_UNKNOWN_PROTO  2
+
+typedef CLIB_PACKED(struct {
+  snat_session_key_t out2in;    /* 0-15 */
+
+  snat_session_key_t in2out;    /* 16-31 */
+
+  u32 flags;                    /* 32-35 */
+
+  /* per-user translations */
+  u32 per_user_index;           /* 36-39 */
+
+  u32 per_user_list_head_index; /* 40-43 */
+
+  /* Last heard timer */
+  f64 last_heard;               /* 44-51 */
+
+  u64 total_bytes;              /* 52-59 */
+
+  u32 total_pkts;               /* 60-63 */
+
+  /* Outside address */
+  u32 outside_address_index;    /* 64-67 */
+
+  /* External host address */
+  ip4_address_t ext_host_addr;  /* 68-71 */
+
+}) snat_session_t;
+
+
+typedef struct {
+  ip4_address_t addr;
+  u32 fib_index;
+  u32 sessions_per_user_list_head_index;
+  u32 nsessions;
+  u32 nstaticsessions;
+} snat_user_t;
+
+typedef struct {
+  ip4_address_t addr;
+  u32 fib_index;
+#define _(N, i, n, s) \
+  u32 busy_##n##_ports; \
+  uword * busy_##n##_port_bitmap;
+  foreach_snat_protocol
+#undef _
+} snat_address_t;
+
+typedef struct {
+  u16 in_port;
+  snat_det_out_key_t out;
+  u8 state;
+  u32 expire;
+} snat_det_session_t;
+
+typedef struct {
+  ip4_address_t in_addr;
+  u8 in_plen;
+  ip4_address_t out_addr;
+  u8 out_plen;
+  u32 sharing_ratio;
+  u16 ports_per_host;
+  u32 ses_num;
+  /* vector of sessions */
+  snat_det_session_t * sessions;
+} snat_det_map_t;
+
+typedef struct {
+  ip4_address_t local_addr;
+  ip4_address_t external_addr;
+  u16 local_port;
+  u16 external_port;
+  u8 addr_only;
+  u32 vrf_id;
+  u32 fib_index;
+  snat_protocol_t proto;
+} snat_static_mapping_t;
+
+typedef struct {
+  u32 sw_if_index;
+  u8 is_inside;
+} snat_interface_t;
+
+typedef struct {
+  ip4_address_t l_addr;
+  u16 l_port;
+  u16 e_port;
+  u32 sw_if_index;
+  u32 vrf_id;
+  snat_protocol_t proto;
+  int addr_only;
+  int is_add;
+} snat_static_map_resolve_t;
+
+typedef struct {
+  /* User pool */
+  snat_user_t * users;
+
+  /* Session pool */
+  snat_session_t * sessions;
+
+  /* Pool of doubly-linked list elements */
+  dlist_elt_t * list_pool;
+
+  u32 snat_thread_index;
+} snat_main_per_thread_data_t;
+
+struct snat_main_s;
+
+typedef u32 snat_icmp_match_function_t (struct snat_main_s *sm,
+                                        vlib_node_runtime_t *node,
+                                        u32 thread_index,
+                                        vlib_buffer_t *b0,
+                                        u8 *p_proto,
+                                        snat_session_key_t *p_value,
+                                        u8 *p_dont_translate,
+                                        void *d,
+                                        void *e);
+
+typedef u32 (snat_get_worker_function_t) (ip4_header_t * ip, u32 rx_fib_index);
+
+typedef struct snat_main_s {
+  /* Main lookup tables */
+  clib_bihash_8_8_t out2in;
+  clib_bihash_8_8_t in2out;
+
+  /* Unknown protocol sessions lookup tables */
+  clib_bihash_16_8_t out2in_unk_proto;
+  clib_bihash_16_8_t in2out_unk_proto;
+
+  /* Find-a-user => src address lookup */
+  clib_bihash_8_8_t user_hash;
+
+  /* Non-translated packets worker lookup => src address + VRF */
+  clib_bihash_8_8_t worker_by_in;
+
+  /* Translated packets worker lookup => IP address + port number */
+  clib_bihash_8_8_t worker_by_out;
+
+  snat_icmp_match_function_t * icmp_match_in2out_cb;
+  snat_icmp_match_function_t * icmp_match_out2in_cb;
+
+  u32 num_workers;
+  u32 first_worker_index;
+  u32 next_worker;
+  u32 * workers;
+  snat_get_worker_function_t * worker_in2out_cb;
+  snat_get_worker_function_t * worker_out2in_cb;
+  u16 port_per_thread;
+  u32 num_snat_thread;
+
+  /* Per thread data */
+  snat_main_per_thread_data_t * per_thread_data;
+
+  /* Find a static mapping by local */
+  clib_bihash_8_8_t static_mapping_by_local;
+
+  /* Find a static mapping by external */
+  clib_bihash_8_8_t static_mapping_by_external;
+
+  /* Static mapping pool */
+  snat_static_mapping_t * static_mappings;
+
+  /* Interface pool */
+  snat_interface_t * interfaces;
+  snat_interface_t * output_feature_interfaces;
+
+  /* Vector of outside addresses */
+  snat_address_t * addresses;
+
+  /* sw_if_indices whose intfc addresses should be auto-added */
+  u32 * auto_add_sw_if_indices;
+
+  /* vector of interface address static mappings to resolve. */
+  snat_static_map_resolve_t *to_resolve;
+
+  /* Randomize port allocation order */
+  u32 random_seed;
+
+  /* Worker handoff index */
+  u32 fq_in2out_index;
+  u32 fq_in2out_output_index;
+  u32 fq_out2in_index;
+
+  /* in2out and out2in node index */
+  u32 in2out_node_index;
+  u32 in2out_output_node_index;
+  u32 out2in_node_index;
+
+  /* Deterministic NAT */
+  snat_det_map_t * det_maps;
+
+  /* Config parameters */
+  u8 static_mapping_only;
+  u8 static_mapping_connection_tracking;
+  u8 deterministic;
+  u32 translation_buckets;
+  u32 translation_memory_size;
+  u32 user_buckets;
+  u32 user_memory_size;
+  u32 max_translations_per_user;
+  u32 outside_vrf_id;
+  u32 outside_fib_index;
+  u32 inside_vrf_id;
+  u32 inside_fib_index;
+
+  /* tenant VRF aware address pool activation flag */
+  u8 vrf_mode;
+
+  /* values of various timeouts */
+  u32 udp_timeout;
+  u32 tcp_established_timeout;
+  u32 tcp_transitory_timeout;
+  u32 icmp_timeout;
+
+  /* API message ID base */
+  u16 msg_id_base;
+
+  /* convenience */
+  vlib_main_t * vlib_main;
+  vnet_main_t * vnet_main;
+  ip4_main_t * ip4_main;
+  ip_lookup_main_t * ip4_lookup_main;
+  api_main_t * api_main;
+} snat_main_t;
+
+extern snat_main_t snat_main;
+extern vlib_node_registration_t snat_in2out_node;
+extern vlib_node_registration_t snat_in2out_output_node;
+extern vlib_node_registration_t snat_out2in_node;
+extern vlib_node_registration_t snat_in2out_fast_node;
+extern vlib_node_registration_t snat_out2in_fast_node;
+extern vlib_node_registration_t snat_in2out_worker_handoff_node;
+extern vlib_node_registration_t snat_in2out_output_worker_handoff_node;
+extern vlib_node_registration_t snat_out2in_worker_handoff_node;
+extern vlib_node_registration_t snat_det_in2out_node;
+extern vlib_node_registration_t snat_det_out2in_node;
+extern vlib_node_registration_t snat_hairpin_dst_node;
+extern vlib_node_registration_t snat_hairpin_src_node;
+
+void snat_free_outside_address_and_port (snat_main_t * sm,
+                                         snat_session_key_t * k,
+                                         u32 address_index);
+
+int snat_alloc_outside_address_and_port (snat_main_t * sm,
+                                         u32 fib_index,
+                                         u32 thread_index,
+                                         snat_session_key_t * k,
+                                         u32 * address_indexp);
+
+int snat_static_mapping_match (snat_main_t * sm,
+                               snat_session_key_t match,
+                               snat_session_key_t * mapping,
+                               u8 by_external,
+                               u8 *is_addr_only);
+
+void snat_add_del_addr_to_fib (ip4_address_t * addr,
+                               u8 p_len,
+                               u32 sw_if_index,
+                               int is_add);
+
+format_function_t format_snat_user;
+
+typedef struct {
+  u32 cached_sw_if_index;
+  u32 cached_ip4_address;
+} snat_runtime_t;
+
+/** \brief Check if SNAT session is created from static mapping.
+    @param s SNAT session
+    @return 1 if SNAT session is created from static mapping otherwise 0
+*/
+#define snat_is_session_static(s) s->flags & SNAT_SESSION_FLAG_STATIC_MAPPING
+
+/** \brief Check if SNAT session for unknown protocol.
+    @param s SNAT session
+    @return 1 if SNAT session for unknown protocol otherwise 0
+*/
+#define snat_is_unk_proto_session(s) s->flags & SNAT_SESSION_FLAG_UNKNOWN_PROTO
+
+/*
+ * Why is this here? Because we don't need to touch this layer to
+ * simply reply to an icmp. We need to change id to a unique
+ * value to NAT an echo request/reply.
+ */
+
+typedef struct {
+  u16 identifier;
+  u16 sequence;
+} icmp_echo_header_t;
+
+always_inline u32
+ip_proto_to_snat_proto (u8 ip_proto)
+{
+  u32 snat_proto = ~0;
+
+  snat_proto = (ip_proto == IP_PROTOCOL_UDP) ? SNAT_PROTOCOL_UDP : snat_proto;
+  snat_proto = (ip_proto == IP_PROTOCOL_TCP) ? SNAT_PROTOCOL_TCP : snat_proto;
+  snat_proto = (ip_proto == IP_PROTOCOL_ICMP) ? SNAT_PROTOCOL_ICMP : snat_proto;
+  snat_proto = (ip_proto == IP_PROTOCOL_ICMP6) ? SNAT_PROTOCOL_ICMP : snat_proto;
+
+  return snat_proto;
+}
+
+always_inline u8
+snat_proto_to_ip_proto (snat_protocol_t snat_proto)
+{
+  u8 ip_proto = ~0;
+
+  ip_proto = (snat_proto == SNAT_PROTOCOL_UDP) ? IP_PROTOCOL_UDP : ip_proto;
+  ip_proto = (snat_proto == SNAT_PROTOCOL_TCP) ? IP_PROTOCOL_TCP : ip_proto;
+  ip_proto = (snat_proto == SNAT_PROTOCOL_ICMP) ? IP_PROTOCOL_ICMP : ip_proto;
+
+  return ip_proto;
+}
+
+typedef struct {
+  u16 src_port, dst_port;
+} tcp_udp_header_t;
+
+u32 icmp_match_in2out_fast(snat_main_t *sm, vlib_node_runtime_t *node,
+                           u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
+                           snat_session_key_t *p_value,
+                           u8 *p_dont_translate, void *d, void *e);
+u32 icmp_match_in2out_slow(snat_main_t *sm, vlib_node_runtime_t *node,
+                           u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
+                           snat_session_key_t *p_value,
+                           u8 *p_dont_translate, void *d, void *e);
+u32 icmp_match_in2out_det(snat_main_t *sm, vlib_node_runtime_t *node,
+                          u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
+                          snat_session_key_t *p_value,
+                          u8 *p_dont_translate, void *d, void *e);
+u32 icmp_match_out2in_fast(snat_main_t *sm, vlib_node_runtime_t *node,
+                           u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
+                           snat_session_key_t *p_value,
+                           u8 *p_dont_translate, void *d, void *e);
+u32 icmp_match_out2in_slow(snat_main_t *sm, vlib_node_runtime_t *node,
+                           u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
+                           snat_session_key_t *p_value,
+                           u8 *p_dont_translate, void *d, void *e);
+u32 icmp_match_out2in_det(snat_main_t *sm, vlib_node_runtime_t *node,
+                          u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
+                          snat_session_key_t *p_value,
+                          u8 *p_dont_translate, void *d, void *e);
+void increment_v4_address(ip4_address_t * a);
+void snat_add_address(snat_main_t *sm, ip4_address_t *addr, u32 vrf_id);
+int snat_del_address(snat_main_t *sm, ip4_address_t addr, u8 delete_sm);
+int snat_add_static_mapping(ip4_address_t l_addr, ip4_address_t e_addr,
+                            u16 l_port, u16 e_port, u32 vrf_id, int addr_only,
+                            u32 sw_if_index, snat_protocol_t proto, int is_add);
+clib_error_t * snat_api_init(vlib_main_t * vm, snat_main_t * sm);
+int snat_set_workers (uword * bitmap);
+int snat_interface_add_del(u32 sw_if_index, u8 is_inside, int is_del);
+int snat_interface_add_del_output_feature(u32 sw_if_index, u8 is_inside,
+                                          int is_del);
+int snat_add_interface_address(snat_main_t *sm, u32 sw_if_index, int is_del);
+uword unformat_snat_protocol(unformat_input_t * input, va_list * args);
+u8 * format_snat_protocol(u8 * s, va_list * args);
+
+static_always_inline u8
+icmp_is_error_message (icmp46_header_t * icmp)
+{
+  switch(icmp->type)
+    {
+    case ICMP4_destination_unreachable:
+    case ICMP4_time_exceeded:
+    case ICMP4_parameter_problem:
+    case ICMP4_source_quench:
+    case ICMP4_redirect:
+    case ICMP4_alternate_host_address:
+      return 1;
+    }
+  return 0;
+}
+
+static_always_inline u8
+is_interface_addr(snat_main_t *sm, vlib_node_runtime_t *node, u32 sw_if_index0,
+                  u32 ip4_addr)
+{
+  snat_runtime_t *rt = (snat_runtime_t *) node->runtime_data;
+  ip4_address_t * first_int_addr;
+
+  if (PREDICT_FALSE(rt->cached_sw_if_index != sw_if_index0))
+    {
+      first_int_addr =
+        ip4_interface_first_address (sm->ip4_main, sw_if_index0,
+                                     0 /* just want the address */);
+      rt->cached_sw_if_index = sw_if_index0;
+      if (first_int_addr)
+        rt->cached_ip4_address = first_int_addr->as_u32;
+      else
+        rt->cached_ip4_address = 0;
+    }
+
+  if (PREDICT_FALSE(ip4_addr == rt->cached_ip4_address))
+    return 1;
+  else
+    return 0;
+}
+
+#endif /* __included_nat_h__ */
diff --git a/src/plugins/nat/nat64.c b/src/plugins/nat/nat64.c
new file mode 100644
index 00000000000..b04901fade4
--- /dev/null
+++ b/src/plugins/nat/nat64.c
@@ -0,0 +1,858 @@
+/*
+ * Copyright (c) 2017 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.
+ */
+/**
+ * @file
+ * @brief NAT64 implementation
+ */
+
+#include <nat/nat64.h>
+#include <nat/nat64_db.h>
+#include <vnet/fib/ip4_fib.h>
+
+
+nat64_main_t nat64_main;
+
+/* *INDENT-OFF* */
+
+/* Hook up input features */
+VNET_FEATURE_INIT (nat64_in2out, static) = {
+  .arc_name = "ip6-unicast",
+  .node_name = "nat64-in2out",
+  .runs_before = VNET_FEATURES ("ip6-lookup"),
+};
+VNET_FEATURE_INIT (nat64_out2in, static) = {
+  .arc_name = "ip4-unicast",
+  .node_name = "nat64-out2in",
+  .runs_before = VNET_FEATURES ("ip4-lookup"),
+};
+
+static u8 well_known_prefix[] = {
+  0x00, 0x64, 0xff, 0x9b,
+  0x00, 0x00, 0x00, 0x00,
+  0x00, 0x00, 0x00, 0x00,
+  0x00, 0x00, 0x00, 0x00
+};
+
+/* *INDENT-ON* */
+
+clib_error_t *
+nat64_init (vlib_main_t * vm)
+{
+  nat64_main_t *nm = &nat64_main;
+  clib_error_t *error = 0;
+  vlib_thread_main_t *tm = vlib_get_thread_main ();
+
+  nm->is_disabled = 0;
+
+  if (tm->n_vlib_mains > 1)
+    {
+      nm->is_disabled = 1;
+      goto error;
+    }
+
+  if (nat64_db_init (&nm->db))
+    {
+      error = clib_error_return (0, "NAT64 DB init failed");
+      goto error;
+    }
+
+  /* set session timeouts to default values */
+  nm->udp_timeout = SNAT_UDP_TIMEOUT;
+  nm->icmp_timeout = SNAT_ICMP_TIMEOUT;
+  nm->tcp_trans_timeout = SNAT_TCP_TRANSITORY_TIMEOUT;
+  nm->tcp_est_timeout = SNAT_TCP_ESTABLISHED_TIMEOUT;
+  nm->tcp_incoming_syn_timeout = SNAT_TCP_INCOMING_SYN;
+
+error:
+  return error;
+}
+
+int
+nat64_add_del_pool_addr (ip4_address_t * addr, u32 vrf_id, u8 is_add)
+{
+  nat64_main_t *nm = &nat64_main;
+  snat_address_t *a = 0;
+  snat_interface_t *interface;
+  int i;
+
+  /* Check if address already exists */
+  for (i = 0; i < vec_len (nm->addr_pool); i++)
+    {
+      if (nm->addr_pool[i].addr.as_u32 == addr->as_u32)
+	{
+	  a = nm->addr_pool + i;
+	  break;
+	}
+    }
+
+  if (is_add)
+    {
+      if (a)
+	return VNET_API_ERROR_VALUE_EXIST;
+
+      vec_add2 (nm->addr_pool, a, 1);
+      a->addr = *addr;
+      a->fib_index = 0;
+      if (vrf_id != ~0)
+	a->fib_index =
+	  fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP6, vrf_id);
+#define _(N, i, n, s) \
+      clib_bitmap_alloc (a->busy_##n##_port_bitmap, 65535);
+      foreach_snat_protocol
+#undef _
+    }
+  else
+    {
+      if (!a)
+	return VNET_API_ERROR_NO_SUCH_ENTRY;
+
+      if (a->fib_index)
+	fib_table_unlock (a->fib_index, FIB_PROTOCOL_IP6);
+
+#define _(N, id, n, s) \
+      clib_bitmap_free (a->busy_##n##_port_bitmap);
+      foreach_snat_protocol
+#undef _
+	/* Delete sessions using address */
+	nat64_db_free_out_addr (&nm->db, &a->addr);
+      vec_del1 (nm->addr_pool, i);
+    }
+
+  /* Add/del external address to FIB */
+  /* *INDENT-OFF* */
+  pool_foreach (interface, nm->interfaces,
+  ({
+    if (interface->is_inside)
+      continue;
+
+    snat_add_del_addr_to_fib (addr, 32, interface->sw_if_index, is_add);
+    break;
+  }));
+  /* *INDENT-ON* */
+
+  return 0;
+}
+
+void
+nat64_pool_addr_walk (nat64_pool_addr_walk_fn_t fn, void *ctx)
+{
+  nat64_main_t *nm = &nat64_main;
+  snat_address_t *a = 0;
+
+  /* *INDENT-OFF* */
+  vec_foreach (a, nm->addr_pool)
+    {
+      if (fn (a, ctx))
+        break;
+    };
+  /* *INDENT-ON* */
+}
+
+int
+nat64_add_del_interface (u32 sw_if_index, u8 is_inside, u8 is_add)
+{
+  nat64_main_t *nm = &nat64_main;
+  snat_interface_t *interface = 0, *i;
+  snat_address_t *ap;
+  const char *feature_name, *arc_name;
+
+  /* Check if address already exists */
+  /* *INDENT-OFF* */
+  pool_foreach (i, nm->interfaces,
+  ({
+    if (i->sw_if_index == sw_if_index)
+      {
+        interface = i;
+        break;
+      }
+  }));
+  /* *INDENT-ON* */
+
+  if (is_add)
+    {
+      if (interface)
+	return VNET_API_ERROR_VALUE_EXIST;
+
+      pool_get (nm->interfaces, interface);
+      interface->sw_if_index = sw_if_index;
+      interface->is_inside = is_inside;
+
+    }
+  else
+    {
+      if (!interface)
+	return VNET_API_ERROR_NO_SUCH_ENTRY;
+
+      pool_put (nm->interfaces, interface);
+    }
+
+  if (!is_inside)
+    {
+      /* *INDENT-OFF* */
+      vec_foreach (ap, nm->addr_pool)
+        snat_add_del_addr_to_fib(&ap->addr, 32, sw_if_index, is_add);
+      /* *INDENT-ON* */
+    }
+
+  arc_name = is_inside ? "ip6-unicast" : "ip4-unicast";
+  feature_name = is_inside ? "nat64-in2out" : "nat64-out2in";
+
+  return vnet_feature_enable_disable (arc_name, feature_name, sw_if_index,
+				      is_add, 0, 0);
+}
+
+void
+nat64_interfaces_walk (nat64_interface_walk_fn_t fn, void *ctx)
+{
+  nat64_main_t *nm = &nat64_main;
+  snat_interface_t *i = 0;
+
+  /* *INDENT-OFF* */
+  pool_foreach (i, nm->interfaces,
+  ({
+    if (fn (i, ctx))
+      break;
+  }));
+  /* *INDENT-ON* */
+}
+
+int
+nat64_alloc_out_addr_and_port (u32 fib_index, snat_protocol_t proto,
+			       ip4_address_t * addr, u16 * port)
+{
+  nat64_main_t *nm = &nat64_main;
+  snat_main_t *sm = &snat_main;
+  int i;
+  snat_address_t *a, *ga = 0;
+  u32 portnum;
+
+  for (i = 0; i < vec_len (nm->addr_pool); i++)
+    {
+      a = nm->addr_pool + i;
+      switch (proto)
+	{
+#define _(N, j, n, s) \
+        case SNAT_PROTOCOL_##N: \
+          if (a->busy_##n##_ports < (65535-1024)) \
+            { \
+              if (a->fib_index == fib_index) \
+                { \
+                  while (1) \
+                    { \
+                      portnum = random_u32 (&sm->random_seed); \
+                      portnum &= 0xFFFF; \
+                      if (portnum < 1024) \
+                        continue; \
+                      if (clib_bitmap_get_no_check (a->busy_##n##_port_bitmap, \
+                                                    portnum)) \
+                        continue; \
+                      clib_bitmap_set_no_check (a->busy_##n##_port_bitmap, \
+                                                portnum, 1); \
+                      a->busy_##n##_ports++; \
+                      *port = portnum; \
+                      addr->as_u32 = a->addr.as_u32; \
+                      return 0; \
+                    } \
+                 } \
+               else if (a->fib_index == 0) \
+                 ga = a; \
+            } \
+          break;
+	  foreach_snat_protocol
+#undef _
+	default:
+	  clib_warning ("unknown protocol");
+	  return 1;
+	}
+    }
+
+  if (ga)
+    {
+      switch (proto)
+	{
+#define _(N, j, n, s) \
+        case SNAT_PROTOCOL_##N: \
+          while (1) \
+            { \
+              portnum = random_u32 (&sm->random_seed); \
+              portnum &= 0xFFFF; \
+              if (portnum < 1024) \
+                continue; \
+              if (clib_bitmap_get_no_check (a->busy_##n##_port_bitmap, \
+                                            portnum)) \
+                continue; \
+              clib_bitmap_set_no_check (a->busy_##n##_port_bitmap, \
+                                        portnum, 1); \
+              a->busy_##n##_ports++; \
+              *port = portnum; \
+              addr->as_u32 = a->addr.as_u32; \
+              return 0; \
+            }
+	  break;
+	  foreach_snat_protocol
+#undef _
+	default:
+	  clib_warning ("unknown protocol");
+	  return 1;
+	}
+    }
+
+  /* Totally out of translations to use... */
+  //TODO: IPFix
+  return 1;
+}
+
+void
+nat64_free_out_addr_and_port (ip4_address_t * addr, u16 port,
+			      snat_protocol_t proto)
+{
+  nat64_main_t *nm = &nat64_main;
+  int i;
+  snat_address_t *a;
+
+  for (i = 0; i < vec_len (nm->addr_pool); i++)
+    {
+      a = nm->addr_pool + i;
+      if (addr->as_u32 != a->addr.as_u32)
+	continue;
+      switch (proto)
+	{
+#define _(N, j, n, s) \
+        case SNAT_PROTOCOL_##N: \
+          ASSERT (clib_bitmap_get_no_check (a->busy_##n##_port_bitmap, \
+                  port) == 1); \
+          clib_bitmap_set_no_check (a->busy_##n##_port_bitmap, port, 0); \
+          a->busy_##n##_ports--; \
+          break;
+	  foreach_snat_protocol
+#undef _
+	default:
+	  clib_warning ("unknown protocol");
+	  return;
+	}
+      break;
+    }
+}
+
+int
+nat64_add_del_static_bib_entry (ip6_address_t * in_addr,
+				ip4_address_t * out_addr, u16 in_port,
+				u16 out_port, u8 proto, u32 vrf_id, u8 is_add)
+{
+  nat64_main_t *nm = &nat64_main;
+  nat64_db_bib_entry_t *bibe;
+  u32 fib_index =
+    fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP6, vrf_id);
+  snat_protocol_t p = ip_proto_to_snat_proto (proto);
+  ip46_address_t addr;
+  int i;
+  snat_address_t *a;
+
+  addr.as_u64[0] = in_addr->as_u64[0];
+  addr.as_u64[1] = in_addr->as_u64[1];
+  bibe =
+    nat64_db_bib_entry_find (&nm->db, &addr, clib_host_to_net_u16 (in_port),
+			     proto, fib_index, 1);
+
+  if (is_add)
+    {
+      if (bibe)
+	return VNET_API_ERROR_VALUE_EXIST;
+
+      for (i = 0; i < vec_len (nm->addr_pool); i++)
+	{
+	  a = nm->addr_pool + i;
+	  if (out_addr->as_u32 != a->addr.as_u32)
+	    continue;
+	  switch (p)
+	    {
+#define _(N, j, n, s) \
+            case SNAT_PROTOCOL_##N: \
+              if (clib_bitmap_get_no_check (a->busy_##n##_port_bitmap, \
+                                            out_port)) \
+                return VNET_API_ERROR_INVALID_VALUE; \
+              clib_bitmap_set_no_check (a->busy_##n##_port_bitmap, \
+                                        out_port, 1); \
+              if (out_port > 1024) \
+                a->busy_##n##_ports++; \
+              break;
+	      foreach_snat_protocol
+#undef _
+	    default:
+	      memset (&addr, 0, sizeof (addr));
+	      addr.ip4.as_u32 = out_addr->as_u32;
+	      if (nat64_db_bib_entry_find
+		  (&nm->db, &addr, 0, proto, fib_index, 0))
+		return VNET_API_ERROR_INVALID_VALUE;
+	    }
+	  break;
+	}
+      bibe =
+	nat64_db_bib_entry_create (&nm->db, in_addr, out_addr,
+				   clib_host_to_net_u16 (in_port),
+				   clib_host_to_net_u16 (out_port), fib_index,
+				   proto, 1);
+      if (!bibe)
+	return VNET_API_ERROR_UNSPECIFIED;
+    }
+  else
+    {
+      if (!bibe)
+	return VNET_API_ERROR_NO_SUCH_ENTRY;
+
+      nat64_free_out_addr_and_port (out_addr, out_port, p);
+      nat64_db_bib_entry_free (&nm->db, bibe);
+    }
+
+  return 0;
+}
+
+int
+nat64_set_udp_timeout (u32 timeout)
+{
+  nat64_main_t *nm = &nat64_main;
+
+  if (timeout == 0)
+    nm->udp_timeout = SNAT_UDP_TIMEOUT;
+  else if (timeout < SNAT_UDP_TIMEOUT_MIN)
+    return VNET_API_ERROR_INVALID_VALUE;
+  else
+    nm->udp_timeout = timeout;
+
+  return 0;
+}
+
+u32
+nat64_get_udp_timeout (void)
+{
+  nat64_main_t *nm = &nat64_main;
+
+  return nm->udp_timeout;
+}
+
+int
+nat64_set_icmp_timeout (u32 timeout)
+{
+  nat64_main_t *nm = &nat64_main;
+
+  if (timeout == 0)
+    nm->icmp_timeout = SNAT_ICMP_TIMEOUT;
+  else
+    nm->icmp_timeout = timeout;
+
+  return 0;
+}
+
+u32
+nat64_get_icmp_timeout (void)
+{
+  nat64_main_t *nm = &nat64_main;
+
+  return nm->icmp_timeout;
+}
+
+int
+nat64_set_tcp_timeouts (u32 trans, u32 est, u32 incoming_syn)
+{
+  nat64_main_t *nm = &nat64_main;
+
+  if (trans == 0)
+    nm->tcp_trans_timeout = SNAT_TCP_TRANSITORY_TIMEOUT;
+  else
+    nm->tcp_trans_timeout = trans;
+
+  if (est == 0)
+    nm->tcp_est_timeout = SNAT_TCP_ESTABLISHED_TIMEOUT;
+  else
+    nm->tcp_est_timeout = est;
+
+  if (incoming_syn == 0)
+    nm->tcp_incoming_syn_timeout = SNAT_TCP_INCOMING_SYN;
+  else
+    nm->tcp_incoming_syn_timeout = incoming_syn;
+
+  return 0;
+}
+
+u32
+nat64_get_tcp_trans_timeout (void)
+{
+  nat64_main_t *nm = &nat64_main;
+
+  return nm->tcp_trans_timeout;
+}
+
+u32
+nat64_get_tcp_est_timeout (void)
+{
+  nat64_main_t *nm = &nat64_main;
+
+  return nm->tcp_est_timeout;
+}
+
+u32
+nat64_get_tcp_incoming_syn_timeout (void)
+{
+  nat64_main_t *nm = &nat64_main;
+
+  return nm->tcp_incoming_syn_timeout;
+}
+
+void
+nat64_session_reset_timeout (nat64_db_st_entry_t * ste, vlib_main_t * vm)
+{
+  nat64_main_t *nm = &nat64_main;
+  u32 now = (u32) vlib_time_now (vm);
+
+  switch (ip_proto_to_snat_proto (ste->proto))
+    {
+    case SNAT_PROTOCOL_ICMP:
+      ste->expire = now + nm->icmp_timeout;
+      return;
+    case SNAT_PROTOCOL_TCP:
+      {
+	switch (ste->tcp_state)
+	  {
+	  case NAT64_TCP_STATE_V4_INIT:
+	  case NAT64_TCP_STATE_V6_INIT:
+	  case NAT64_TCP_STATE_V4_FIN_RCV:
+	  case NAT64_TCP_STATE_V6_FIN_RCV:
+	  case NAT64_TCP_STATE_V6_FIN_V4_FIN_RCV:
+	  case NAT64_TCP_STATE_TRANS:
+	    ste->expire = now + nm->tcp_trans_timeout;
+	    return;
+	  case NAT64_TCP_STATE_ESTABLISHED:
+	    ste->expire = now + nm->tcp_est_timeout;
+	    return;
+	  default:
+	    return;
+	  }
+      }
+    case SNAT_PROTOCOL_UDP:
+      ste->expire = now + nm->udp_timeout;
+      return;
+    default:
+      ste->expire = now + nm->udp_timeout;
+      return;
+    }
+}
+
+void
+nat64_tcp_session_set_state (nat64_db_st_entry_t * ste, tcp_header_t * tcp,
+			     u8 is_ip6)
+{
+  switch (ste->tcp_state)
+    {
+    case NAT64_TCP_STATE_CLOSED:
+      {
+	if (tcp->flags & TCP_FLAG_SYN)
+	  {
+	    if (is_ip6)
+	      ste->tcp_state = NAT64_TCP_STATE_V6_INIT;
+	    else
+	      ste->tcp_state = NAT64_TCP_STATE_V4_INIT;
+	  }
+	return;
+      }
+    case NAT64_TCP_STATE_V4_INIT:
+      {
+	if (is_ip6 && (tcp->flags & TCP_FLAG_SYN))
+	  ste->tcp_state = NAT64_TCP_STATE_ESTABLISHED;
+	return;
+      }
+    case NAT64_TCP_STATE_V6_INIT:
+      {
+	if (!is_ip6 && (tcp->flags & TCP_FLAG_SYN))
+	  ste->tcp_state = NAT64_TCP_STATE_ESTABLISHED;
+	return;
+      }
+    case NAT64_TCP_STATE_ESTABLISHED:
+      {
+	if (tcp->flags & TCP_FLAG_FIN)
+	  {
+	    if (is_ip6)
+	      ste->tcp_state = NAT64_TCP_STATE_V6_FIN_RCV;
+	    else
+	      ste->tcp_state = NAT64_TCP_STATE_V4_FIN_RCV;
+	  }
+	else if (tcp->flags & TCP_FLAG_RST)
+	  {
+	    ste->tcp_state = NAT64_TCP_STATE_TRANS;
+	  }
+	return;
+      }
+    case NAT64_TCP_STATE_V4_FIN_RCV:
+      {
+	if (is_ip6 && (tcp->flags & TCP_FLAG_FIN))
+	  ste->tcp_state = NAT64_TCP_STATE_V6_FIN_V4_FIN_RCV;
+	return;
+      }
+    case NAT64_TCP_STATE_V6_FIN_RCV:
+      {
+	if (!is_ip6 && (tcp->flags & TCP_FLAG_FIN))
+	  ste->tcp_state = NAT64_TCP_STATE_V6_FIN_V4_FIN_RCV;
+	return;
+      }
+    case NAT64_TCP_STATE_TRANS:
+      {
+	if (!(tcp->flags & TCP_FLAG_RST))
+	  ste->tcp_state = NAT64_TCP_STATE_ESTABLISHED;
+	return;
+      }
+    default:
+      return;
+    }
+}
+
+int
+nat64_add_del_prefix (ip6_address_t * prefix, u8 plen, u32 vrf_id, u8 is_add)
+{
+  nat64_main_t *nm = &nat64_main;
+  nat64_prefix_t *p = 0;
+  int i;
+
+  /* Verify prefix length */
+  if (plen != 32 && plen != 40 && plen != 48 && plen != 56 && plen != 64
+      && plen != 96)
+    return VNET_API_ERROR_INVALID_VALUE;
+
+  /* Check if tenant already have prefix */
+  for (i = 0; i < vec_len (nm->pref64); i++)
+    {
+      if (nm->pref64[i].vrf_id == vrf_id)
+	{
+	  p = nm->pref64 + i;
+	  break;
+	}
+    }
+
+  if (is_add)
+    {
+      if (!p)
+	{
+	  vec_add2 (nm->pref64, p, 1);
+	  p->fib_index =
+	    fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP6, vrf_id);
+	  p->vrf_id = vrf_id;
+	}
+
+      p->prefix.as_u64[0] = prefix->as_u64[0];
+      p->prefix.as_u64[1] = prefix->as_u64[1];
+      p->plen = plen;
+    }
+  else
+    {
+      if (!p)
+	return VNET_API_ERROR_NO_SUCH_ENTRY;
+
+      vec_del1 (nm->pref64, i);
+    }
+
+  return 0;
+}
+
+void
+nat64_prefix_walk (nat64_prefix_walk_fn_t fn, void *ctx)
+{
+  nat64_main_t *nm = &nat64_main;
+  nat64_prefix_t *p = 0;
+
+  /* *INDENT-OFF* */
+  vec_foreach (p, nm->pref64)
+    {
+      if (fn (p, ctx))
+        break;
+    };
+  /* *INDENT-ON* */
+}
+
+void
+nat64_compose_ip6 (ip6_address_t * ip6, ip4_address_t * ip4, u32 fib_index)
+{
+  nat64_main_t *nm = &nat64_main;
+  nat64_prefix_t *p, *gp = 0, *prefix = 0;
+
+  /* *INDENT-OFF* */
+  vec_foreach (p, nm->pref64)
+    {
+      if (p->fib_index == fib_index)
+        {
+          prefix = p;
+          break;
+        }
+
+      if (p->fib_index == 0)
+        gp = p;
+    };
+  /* *INDENT-ON* */
+
+  if (!prefix)
+    prefix = gp;
+
+  if (prefix)
+    {
+      memset (ip6, 0, 16);
+      memcpy (ip6, &p->prefix, p->plen);
+      switch (p->plen)
+	{
+	case 32:
+	  ip6->as_u32[1] = ip4->as_u32;
+	  break;
+	case 40:
+	  ip6->as_u8[5] = ip4->as_u8[0];
+	  ip6->as_u8[6] = ip4->as_u8[1];
+	  ip6->as_u8[7] = ip4->as_u8[2];
+	  ip6->as_u8[9] = ip4->as_u8[3];
+	  break;
+	case 48:
+	  ip6->as_u8[6] = ip4->as_u8[0];
+	  ip6->as_u8[7] = ip4->as_u8[1];
+	  ip6->as_u8[9] = ip4->as_u8[2];
+	  ip6->as_u8[10] = ip4->as_u8[3];
+	  break;
+	case 56:
+	  ip6->as_u8[7] = ip4->as_u8[0];
+	  ip6->as_u8[9] = ip4->as_u8[1];
+	  ip6->as_u8[10] = ip4->as_u8[2];
+	  ip6->as_u8[11] = ip4->as_u8[3];
+	  break;
+	case 64:
+	  ip6->as_u8[9] = ip4->as_u8[0];
+	  ip6->as_u8[10] = ip4->as_u8[1];
+	  ip6->as_u8[11] = ip4->as_u8[2];
+	  ip6->as_u8[12] = ip4->as_u8[3];
+	  break;
+	case 96:
+	  ip6->as_u32[3] = ip4->as_u32;
+	  break;
+	default:
+	  clib_warning ("invalid prefix length");
+	  break;
+	}
+    }
+  else
+    {
+      memcpy (ip6, well_known_prefix, 16);
+      ip6->as_u32[3] = ip4->as_u32;
+    }
+}
+
+void
+nat64_extract_ip4 (ip6_address_t * ip6, ip4_address_t * ip4, u32 fib_index)
+{
+  nat64_main_t *nm = &nat64_main;
+  nat64_prefix_t *p, *gp = 0;
+  u8 plen = 0;
+
+  /* *INDENT-OFF* */
+  vec_foreach (p, nm->pref64)
+    {
+      if (p->fib_index == fib_index)
+        {
+          plen = p->plen;
+          break;
+        }
+
+      if (p->vrf_id == 0)
+        gp = p;
+    };
+  /* *INDENT-ON* */
+
+  if (!plen)
+    {
+      if (gp)
+	plen = gp->plen;
+      else
+	plen = 96;
+    }
+
+  switch (plen)
+    {
+    case 32:
+      ip4->as_u32 = ip6->as_u32[1];
+      break;
+    case 40:
+      ip4->as_u8[0] = ip6->as_u8[5];
+      ip4->as_u8[1] = ip6->as_u8[6];
+      ip4->as_u8[2] = ip6->as_u8[7];
+      ip4->as_u8[3] = ip6->as_u8[9];
+      break;
+    case 48:
+      ip4->as_u8[0] = ip6->as_u8[6];
+      ip4->as_u8[1] = ip6->as_u8[7];
+      ip4->as_u8[2] = ip6->as_u8[9];
+      ip4->as_u8[3] = ip6->as_u8[10];
+      break;
+    case 56:
+      ip4->as_u8[0] = ip6->as_u8[7];
+      ip4->as_u8[1] = ip6->as_u8[9];
+      ip4->as_u8[2] = ip6->as_u8[10];
+      ip4->as_u8[3] = ip6->as_u8[11];
+      break;
+    case 64:
+      ip4->as_u8[0] = ip6->as_u8[9];
+      ip4->as_u8[1] = ip6->as_u8[10];
+      ip4->as_u8[2] = ip6->as_u8[11];
+      ip4->as_u8[3] = ip6->as_u8[12];
+      break;
+    case 96:
+      ip4->as_u32 = ip6->as_u32[3];
+      break;
+    default:
+      clib_warning ("invalid prefix length");
+      break;
+    }
+}
+
+/**
+ * @brief The 'nat64-expire-walk' process's main loop.
+ *
+ * Check expire time for NAT64 sessions.
+ */
+static uword
+nat64_expire_walk_fn (vlib_main_t * vm, vlib_node_runtime_t * rt,
+		      vlib_frame_t * f)
+{
+  nat64_main_t *nm = &nat64_main;
+
+  while (!nm->is_disabled)
+    {
+      vlib_process_wait_for_event_or_clock (vm, 10.0);
+      vlib_process_get_events (vm, NULL);
+      u32 now = (u32) vlib_time_now (vm);
+
+      nad64_db_st_free_expired (&nm->db, now);
+    }
+
+  return 0;
+}
+
+static vlib_node_registration_t nat64_expire_walk_node;
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (nat64_expire_walk_node, static) = {
+    .function = nat64_expire_walk_fn,
+    .type = VLIB_NODE_TYPE_PROCESS,
+    .name = "nat64-expire-walk",
+};
+/* *INDENT-ON* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/plugins/nat/nat64.h b/src/plugins/nat/nat64.h
new file mode 100644
index 00000000000..68224cab013
--- /dev/null
+++ b/src/plugins/nat/nat64.h
@@ -0,0 +1,322 @@
+/*
+ * Copyright (c) 2017 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.
+ */
+/**
+ * @file
+ * @brief NAT64 global declarations
+ */
+#ifndef __included_nat64_h__
+#define __included_nat64_h__
+
+#include <nat/nat.h>
+#include <nat/nat64_db.h>
+
+#define foreach_nat64_tcp_ses_state            \
+  _(0, CLOSED, "closed")                       \
+  _(1, V4_INIT, "v4-init")                     \
+  _(2, V6_INIT, "v6-init")                     \
+  _(3, ESTABLISHED, "established")             \
+  _(4, V4_FIN_RCV, "v4-fin-rcv")               \
+  _(5, V6_FIN_RCV, "v6-fin-rcv")               \
+  _(6, V6_FIN_V4_FIN_RCV, "v6-fin-v4-fin-rcv") \
+  _(7, TRANS, "trans")
+
+typedef enum
+{
+#define _(v, N, s) NAT64_TCP_STATE_##N = v,
+  foreach_nat64_tcp_ses_state
+#undef _
+} nat64_tcp_ses_state_t;
+
+typedef struct
+{
+  ip6_address_t prefix;
+  u8 plen;
+  u32 vrf_id;
+  u32 fib_index;
+} nat64_prefix_t;
+
+typedef struct
+{
+  /** Interface pool */
+  snat_interface_t *interfaces;
+
+  /** Address pool vector */
+  snat_address_t *addr_pool;
+
+  /** Pref64 vector */
+  nat64_prefix_t *pref64;
+
+  /** BIB and session DB */
+  nat64_db_t db;
+
+  /* values of various timeouts */
+  u32 udp_timeout;
+  u32 icmp_timeout;
+  u32 tcp_trans_timeout;
+  u32 tcp_est_timeout;
+  u32 tcp_incoming_syn_timeout;
+
+  u8 is_disabled;
+
+  snat_main_t *sm;
+} nat64_main_t;
+
+extern nat64_main_t nat64_main;
+extern vlib_node_registration_t nat64_in2out_node;
+extern vlib_node_registration_t nat64_out2in_node;
+
+/**
+ * @brief Add/delete address to NAT64 pool.
+ *
+ * @param addr   IPv4 address.
+ * @param vrf_id VRF id of tenant, ~0 means independent of VRF.
+ * @param is_add 1 if add, 0 if delete.
+ *
+ * @returns 0 on success, non-zero value otherwise.
+ */
+int nat64_add_del_pool_addr (ip4_address_t * addr, u32 vrf_id, u8 is_add);
+
+/**
+ * @brief Call back function when walking addresses in NAT64 pool, non-zero
+ * return value stop walk.
+ */
+typedef int (*nat64_pool_addr_walk_fn_t) (snat_address_t * addr, void *ctx);
+
+/**
+ * @brief Walk NAT64 pool.
+ *
+ * @param fn The function to invoke on each entry visited.
+ * @param ctx A context passed in the visit function.
+ */
+void nat64_pool_addr_walk (nat64_pool_addr_walk_fn_t fn, void *ctx);
+
+/**
+ * @brief Enable/disable NAT64 feature on the interface.
+ *
+ * @param sw_if_index Index of the interface.
+ * @param is_inside   1 if inside, 0 if outside.
+ * @param is_add      1 if add, 0 if delete.
+ *
+ * @returns 0 on success, non-zero value otherwise.
+ */
+int nat64_add_del_interface (u32 sw_if_index, u8 is_inside, u8 is_add);
+
+/**
+ * @brief Call back function when walking interfaces with NAT64 feature,
+ * non-zero return value stop walk.
+ */
+typedef int (*nat64_interface_walk_fn_t) (snat_interface_t * i, void *ctx);
+
+/**
+ * @brief Walk NAT64 interfaces.
+ *
+ * @param fn The function to invoke on each entry visited.
+ * @param ctx A context passed in the visit function.
+ */
+void nat64_interfaces_walk (nat64_interface_walk_fn_t fn, void *ctx);
+
+/**
+ * @brief Initialize NAT64.
+ *
+ * @param vm vlib main.
+ *
+ * @return error code.
+ */
+clib_error_t *nat64_init (vlib_main_t * vm);
+
+/**
+ * @brief Add/delete static NAT64 BIB entry.
+ *
+ * @param in_addr  Inside IPv6 address.
+ * @param out_addr Outside IPv4 address.
+ * @param in_port  Inside port number.
+ * @param out_port Outside port number.
+ * @param proto    L4 protocol.
+ * @param vrf_id   VRF id of tenant.
+ * @param is_add   1 if add, 0 if delete.
+ *
+ * @returns 0 on success, non-zero value otherwise.
+ */
+int nat64_add_del_static_bib_entry (ip6_address_t * in_addr,
+				    ip4_address_t * out_addr, u16 in_port,
+				    u16 out_port, u8 proto, u32 vrf_id,
+				    u8 is_add);
+
+/**
+ * @brief Alloce IPv4 address and port pair from NAT64 pool.
+ *
+ * @param fib_index FIB index of tenant.
+ * @param proto     L4 protocol.
+ * @param addr      Allocated IPv4 address.
+ * @param port      Allocated port number.
+ *
+ * @returns 0 on success, non-zero value otherwise.
+ */
+int nat64_alloc_out_addr_and_port (u32 fib_index, snat_protocol_t proto,
+				   ip4_address_t * addr, u16 * port);
+
+/**
+ * @brief Free IPv4 address and port pair from NAT64 pool.
+ *
+ * @param addr  IPv4 address to free.
+ * @param port  Port number to free.
+ * @param proto L4 protocol.
+ *
+ * @returns 0 on success, non-zero value otherwise.
+ */
+void nat64_free_out_addr_and_port (ip4_address_t * addr, u16 port,
+				   snat_protocol_t proto);
+
+/**
+ * @brief Set UDP session timeout.
+ *
+ * @param timeout Timeout value in seconds (if 0 reset to default value 300sec).
+ *
+ * @returns 0 on success, non-zero value otherwise.
+ */
+int nat64_set_udp_timeout (u32 timeout);
+
+/**
+ * @brief Get UDP session timeout.
+ *
+ * @returns UDP session timeout in seconds.
+ */
+u32 nat64_get_udp_timeout (void);
+
+/**
+ * @brief Set ICMP session timeout.
+ *
+ * @param timeout Timeout value in seconds (if 0 reset to default value 60sec).
+ *
+ * @returns 0 on success, non-zero value otherwise.
+ */
+int nat64_set_icmp_timeout (u32 timeout);
+
+/**
+ * @brief Get ICMP session timeout.
+ *
+ * @returns ICMP session timeout in seconds.
+ */
+u32 nat64_get_icmp_timeout (void);
+
+/**
+ * @brief Set TCP session timeouts.
+ *
+ * @param trans Transitory timeout in seconds (if 0 reset to default value 240sec).
+ * @param est Established timeout in seconds (if 0 reset to default value 7440sec).
+ * @param incoming_syn Incoming SYN timeout in seconds (if 0 reset to default value 6sec).
+ *
+ * @returns 0 on success, non-zero value otherwise.
+ */
+int nat64_set_tcp_timeouts (u32 trans, u32 est, u32 incoming_syn);
+
+/**
+ * @brief Get TCP transitory timeout.
+ *
+ * @returns TCP transitory timeout in seconds.
+ */
+u32 nat64_get_tcp_trans_timeout (void);
+
+/**
+ * @brief Get TCP established timeout.
+ *
+ * @returns TCP established timeout in seconds.
+ */
+u32 nat64_get_tcp_est_timeout (void);
+
+/**
+ * @brief Get TCP incoming SYN timeout.
+ *
+ * @returns TCP incoming SYN timeout in seconds.
+ */
+u32 nat64_get_tcp_incoming_syn_timeout (void);
+
+/**
+ * @brief Reset NAT64 session timeout.
+ *
+ * @param ste Session table entry.
+ * @param vm VLIB main.
+ **/
+void nat64_session_reset_timeout (nat64_db_st_entry_t * ste,
+				  vlib_main_t * vm);
+
+/**
+ * @brief Set NAT64 TCP session state.
+ *
+ * @param ste Session table entry.
+ * @param tcp TCP header.
+ * @param is_ip6 1 if IPv6 packet, 0 if IPv4.
+ */
+void nat64_tcp_session_set_state (nat64_db_st_entry_t * ste,
+				  tcp_header_t * tcp, u8 is_ip6);
+
+/**
+ * @brief Add/delete NAT64 prefix.
+ *
+ * @param prefix NAT64 prefix.
+ * @param plen Prefix length.
+ * @param vrf_id VRF id of tenant.
+ * @param is_add 1 if add, 0 if delete.
+ *
+ * @returns 0 on success, non-zero value otherwise.
+ */
+int nat64_add_del_prefix (ip6_address_t * prefix, u8 plen, u32 vrf_id,
+			  u8 is_add);
+
+/**
+ * @brief Call back function when walking addresses in NAT64 prefixes, non-zero
+ * return value stop walk.
+ */
+typedef int (*nat64_prefix_walk_fn_t) (nat64_prefix_t * pref64, void *ctx);
+
+/**
+ * @brief Walk NAT64 prefixes.
+ *
+ * @param fn The function to invoke on each entry visited.
+ * @param ctx A context passed in the visit function.
+ */
+void nat64_prefix_walk (nat64_prefix_walk_fn_t fn, void *ctx);
+
+/**
+ * Compose IPv4-embedded IPv6 addresses.
+ * @param ip6 IPv4-embedded IPv6 addresses.
+ * @param ip4 IPv4 address.
+ * @param fib_index Tenant FIB index.
+ */
+void nat64_compose_ip6 (ip6_address_t * ip6, ip4_address_t * ip4,
+			u32 fib_index);
+
+/**
+ * Extract IPv4 address from the IPv4-embedded IPv6 addresses.
+ *
+ * @param ip6 IPv4-embedded IPv6 addresses.
+ * @param ip4 IPv4 address.
+ * @param fib_index Tenant FIB index.
+ */
+void nat64_extract_ip4 (ip6_address_t * ip6, ip4_address_t * ip4,
+			u32 fib_index);
+
+#define u8_ptr_add(ptr, index) (((u8 *)ptr) + index)
+#define u16_net_add(u, val) clib_host_to_net_u16(clib_net_to_host_u16(u) + (val))
+
+#endif /* __included_nat64_h__ */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/plugins/nat/nat64_cli.c b/src/plugins/nat/nat64_cli.c
new file mode 100644
index 00000000000..bb62ecf2967
--- /dev/null
+++ b/src/plugins/nat/nat64_cli.c
@@ -0,0 +1,983 @@
+/*
+ * Copyright (c) 2017 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.
+ */
+/**
+ * @file
+ * @brief NAT64 CLI
+ */
+
+#include <nat/nat64.h>
+#include <nat/nat.h>
+#include <vnet/fib/fib_table.h>
+
+static clib_error_t *
+nat64_add_del_pool_addr_command_fn (vlib_main_t * vm,
+				    unformat_input_t * input,
+				    vlib_cli_command_t * cmd)
+{
+  nat64_main_t *nm = &nat64_main;
+  unformat_input_t _line_input, *line_input = &_line_input;
+  ip4_address_t start_addr, end_addr, this_addr;
+  u32 start_host_order, end_host_order;
+  int i, count, rv;
+  u32 vrf_id = ~0;
+  u8 is_add = 1;
+  clib_error_t *error = 0;
+
+  if (nm->is_disabled)
+    return clib_error_return (0,
+			      "NAT64 disabled, multi thread not supported");
+
+  /* Get a line of input. */
+  if (!unformat_user (input, unformat_line_input, line_input))
+    return 0;
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (line_input, "%U - %U",
+		    unformat_ip4_address, &start_addr,
+		    unformat_ip4_address, &end_addr))
+	;
+      else if (unformat (line_input, "tenant-vrf %u", &vrf_id))
+	;
+      else if (unformat (line_input, "%U", unformat_ip4_address, &start_addr))
+	end_addr = start_addr;
+      else if (unformat (line_input, "del"))
+	is_add = 0;
+      else
+	{
+	  error = clib_error_return (0, "unknown input '%U'",
+				     format_unformat_error, line_input);
+	  goto done;
+	}
+    }
+
+  start_host_order = clib_host_to_net_u32 (start_addr.as_u32);
+  end_host_order = clib_host_to_net_u32 (end_addr.as_u32);
+
+  if (end_host_order < start_host_order)
+    {
+      error = clib_error_return (0, "end address less than start address");
+      goto done;
+    }
+
+  count = (end_host_order - start_host_order) + 1;
+  this_addr = start_addr;
+
+  for (i = 0; i < count; i++)
+    {
+      rv = nat64_add_del_pool_addr (&this_addr, vrf_id, is_add);
+
+      switch (rv)
+	{
+	case VNET_API_ERROR_NO_SUCH_ENTRY:
+	  error =
+	    clib_error_return (0, "NAT64 pool address %U not exist.",
+			       format_ip4_address, &this_addr);
+	  goto done;
+	case VNET_API_ERROR_VALUE_EXIST:
+	  error =
+	    clib_error_return (0, "NAT64 pool address %U exist.",
+			       format_ip4_address, &this_addr);
+	  goto done;
+	default:
+	  break;
+
+	}
+      increment_v4_address (&this_addr);
+    }
+
+done:
+  unformat_free (line_input);
+
+  return error;
+}
+
+static int
+nat64_cli_pool_walk (snat_address_t * ap, void *ctx)
+{
+  vlib_main_t *vm = ctx;
+
+  if (ap->fib_index != ~0)
+    {
+      fib_table_t *fib;
+      fib = fib_table_get (ap->fib_index, FIB_PROTOCOL_IP6);
+      if (!fib)
+	return -1;
+      vlib_cli_output (vm, " %U tenant VRF: %u", format_ip4_address,
+		       &ap->addr, fib->ft_table_id);
+    }
+  else
+    vlib_cli_output (vm, " %U", format_ip4_address, &ap->addr);
+
+  return 0;
+}
+
+static clib_error_t *
+nat64_show_pool_command_fn (vlib_main_t * vm,
+			    unformat_input_t * input,
+			    vlib_cli_command_t * cmd)
+{
+  nat64_main_t *nm = &nat64_main;
+
+  if (nm->is_disabled)
+    return clib_error_return (0,
+			      "NAT64 disabled, multi thread not supported");
+
+  vlib_cli_output (vm, "NAT64 pool:");
+  nat64_pool_addr_walk (nat64_cli_pool_walk, vm);
+
+  return 0;
+}
+
+static clib_error_t *
+nat64_interface_feature_command_fn (vlib_main_t * vm,
+				    unformat_input_t *
+				    input, vlib_cli_command_t * cmd)
+{
+  nat64_main_t *nm = &nat64_main;
+  unformat_input_t _line_input, *line_input = &_line_input;
+  vnet_main_t *vnm = vnet_get_main ();
+  clib_error_t *error = 0;
+  u32 sw_if_index;
+  u32 *inside_sw_if_indices = 0;
+  u32 *outside_sw_if_indices = 0;
+  u8 is_add = 1;
+  int i, rv;
+
+  if (nm->is_disabled)
+    return clib_error_return (0,
+			      "NAT64 disabled, multi thread not supported");
+
+  /* Get a line of input. */
+  if (!unformat_user (input, unformat_line_input, line_input))
+    return 0;
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (line_input, "in %U", unformat_vnet_sw_interface,
+		    vnm, &sw_if_index))
+	vec_add1 (inside_sw_if_indices, sw_if_index);
+      else if (unformat (line_input, "out %U", unformat_vnet_sw_interface,
+			 vnm, &sw_if_index))
+	vec_add1 (outside_sw_if_indices, sw_if_index);
+      else if (unformat (line_input, "del"))
+	is_add = 0;
+      else
+	{
+	  error = clib_error_return (0, "unknown input '%U'",
+				     format_unformat_error, line_input);
+	  goto done;
+	}
+    }
+
+  if (vec_len (inside_sw_if_indices))
+    {
+      for (i = 0; i < vec_len (inside_sw_if_indices); i++)
+	{
+	  sw_if_index = inside_sw_if_indices[i];
+	  rv = nat64_add_del_interface (sw_if_index, 1, is_add);
+	  switch (rv)
+	    {
+	    case VNET_API_ERROR_NO_SUCH_ENTRY:
+	      error =
+		clib_error_return (0, "%U NAT64 feature not enabled.",
+				   format_vnet_sw_interface_name, vnm,
+				   vnet_get_sw_interface (vnm, sw_if_index));
+	      goto done;
+	    case VNET_API_ERROR_VALUE_EXIST:
+	      error =
+		clib_error_return (0, "%U NAT64 feature already enabled.",
+				   format_vnet_sw_interface_name, vnm,
+				   vnet_get_sw_interface (vnm, sw_if_index));
+	      goto done;
+	    case VNET_API_ERROR_INVALID_VALUE:
+	    case VNET_API_ERROR_INVALID_VALUE_2:
+	      error =
+		clib_error_return (0,
+				   "%U NAT64 feature enable/disable failed.",
+				   format_vnet_sw_interface_name, vnm,
+				   vnet_get_sw_interface (vnm, sw_if_index));
+	      goto done;
+	    default:
+	      break;
+
+	    }
+	}
+    }
+
+  if (vec_len (outside_sw_if_indices))
+    {
+      for (i = 0; i < vec_len (outside_sw_if_indices); i++)
+	{
+	  sw_if_index = outside_sw_if_indices[i];
+	  rv = nat64_add_del_interface (sw_if_index, 0, is_add);
+	  switch (rv)
+	    {
+	    case VNET_API_ERROR_NO_SUCH_ENTRY:
+	      error =
+		clib_error_return (0, "%U NAT64 feature not enabled.",
+				   format_vnet_sw_interface_name, vnm,
+				   vnet_get_sw_interface (vnm, sw_if_index));
+	      goto done;
+	    case VNET_API_ERROR_VALUE_EXIST:
+	      error =
+		clib_error_return (0, "%U NAT64 feature already enabled.",
+				   format_vnet_sw_interface_name, vnm,
+				   vnet_get_sw_interface (vnm, sw_if_index));
+	      goto done;
+	    case VNET_API_ERROR_INVALID_VALUE:
+	    case VNET_API_ERROR_INVALID_VALUE_2:
+	      error =
+		clib_error_return (0,
+				   "%U NAT64 feature enable/disable failed.",
+				   format_vnet_sw_interface_name, vnm,
+				   vnet_get_sw_interface (vnm, sw_if_index));
+	      goto done;
+	    default:
+	      break;
+
+	    }
+	}
+    }
+
+done:
+  unformat_free (line_input);
+  vec_free (inside_sw_if_indices);
+  vec_free (outside_sw_if_indices);
+
+  return error;
+}
+
+static int
+nat64_cli_interface_walk (snat_interface_t * i, void *ctx)
+{
+  vlib_main_t *vm = ctx;
+  vnet_main_t *vnm = vnet_get_main ();
+
+  vlib_cli_output (vm, " %U %s", format_vnet_sw_interface_name, vnm,
+		   vnet_get_sw_interface (vnm, i->sw_if_index),
+		   i->is_inside ? "in" : "out");
+  return 0;
+}
+
+static clib_error_t *
+nat64_show_interfaces_command_fn (vlib_main_t * vm,
+				  unformat_input_t *
+				  input, vlib_cli_command_t * cmd)
+{
+  nat64_main_t *nm = &nat64_main;
+
+  if (nm->is_disabled)
+    return clib_error_return (0,
+			      "NAT64 disabled, multi thread not supported");
+
+  vlib_cli_output (vm, "NAT64 interfaces:");
+  nat64_interfaces_walk (nat64_cli_interface_walk, vm);
+
+  return 0;
+}
+
+static clib_error_t *
+nat64_add_del_static_bib_command_fn (vlib_main_t *
+				     vm,
+				     unformat_input_t
+				     * input, vlib_cli_command_t * cmd)
+{
+  nat64_main_t *nm = &nat64_main;
+  unformat_input_t _line_input, *line_input = &_line_input;
+  clib_error_t *error = 0;
+  u8 is_add = 1;
+  ip6_address_t in_addr;
+  ip4_address_t out_addr;
+  u16 in_port = 0;
+  u16 out_port = 0;
+  u32 vrf_id = 0, protocol;
+  snat_protocol_t proto = 0;
+  u8 p = 0;
+  int rv;
+
+  if (nm->is_disabled)
+    return clib_error_return (0,
+			      "NAT64 disabled, multi thread not supported");
+
+  if (!unformat_user (input, unformat_line_input, line_input))
+    return 0;
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (line_input, "%U %u", unformat_ip6_address,
+		    &in_addr, &in_port))
+	;
+      else if (unformat (line_input, "%U %u", unformat_ip4_address,
+			 &out_addr, &out_port))
+	;
+      else if (unformat (line_input, "vrf %u", &vrf_id))
+	;
+      else if (unformat (line_input, "%U", unformat_snat_protocol, &proto))
+	;
+      else
+	if (unformat
+	    (line_input, "%U %U %u", unformat_ip6_address, &in_addr,
+	     unformat_ip4_address, &out_addr, &protocol))
+	p = (u8) protocol;
+      else if (unformat (line_input, "del"))
+	is_add = 0;
+      else
+	{
+	  error = clib_error_return (0, "unknown input: '%U'",
+				     format_unformat_error, line_input);
+	  goto done;
+	}
+    }
+
+  if (!p)
+    {
+      if (!in_port)
+	{
+	  error =
+	    clib_error_return (0, "inside port and address  must be set");
+	  goto done;
+	}
+
+      if (!out_port)
+	{
+	  error =
+	    clib_error_return (0, "outside port and address  must be set");
+	  goto done;
+	}
+
+      p = snat_proto_to_ip_proto (proto);
+    }
+
+  rv =
+    nat64_add_del_static_bib_entry (&in_addr, &out_addr, in_port, out_port, p,
+				    vrf_id, is_add);
+
+  switch (rv)
+    {
+    case VNET_API_ERROR_NO_SUCH_ENTRY:
+      error = clib_error_return (0, "NAT64 BIB entry not exist.");
+      goto done;
+    case VNET_API_ERROR_VALUE_EXIST:
+      error = clib_error_return (0, "NAT64 BIB entry exist.");
+      goto done;
+    case VNET_API_ERROR_UNSPECIFIED:
+      error = clib_error_return (0, "Crerate NAT64 BIB entry failed.");
+      goto done;
+    case VNET_API_ERROR_INVALID_VALUE:
+      error =
+	clib_error_return (0, "Outside addres %U and port %u already in use.",
+			   format_ip4_address, &out_addr, out_port);
+      goto done;
+    default:
+      break;
+    }
+
+done:
+  unformat_free (line_input);
+
+  return error;
+}
+
+static int
+nat64_cli_bib_walk (nat64_db_bib_entry_t * bibe, void *ctx)
+{
+  vlib_main_t *vm = ctx;
+  fib_table_t *fib;
+
+  fib = fib_table_get (bibe->fib_index, FIB_PROTOCOL_IP6);
+  if (!fib)
+    return -1;
+
+  switch (bibe->proto)
+    {
+    case IP_PROTOCOL_ICMP:
+    case IP_PROTOCOL_TCP:
+    case IP_PROTOCOL_UDP:
+      vlib_cli_output (vm, " %U %u %U %u protocol %U vrf %u %s %u sessions",
+		       format_ip6_address, &bibe->in_addr,
+		       clib_net_to_host_u16 (bibe->in_port),
+		       format_ip4_address, &bibe->out_addr,
+		       clib_net_to_host_u16 (bibe->out_port),
+		       format_snat_protocol,
+		       ip_proto_to_snat_proto (bibe->proto), fib->ft_table_id,
+		       bibe->is_static ? "static" : "dynamic", bibe->ses_num);
+      break;
+    default:
+      vlib_cli_output (vm, " %U %U protocol %u vrf %u %s %u sessions",
+		       format_ip6_address, &bibe->in_addr,
+		       format_ip4_address, &bibe->out_addr,
+		       bibe->proto, fib->ft_table_id,
+		       bibe->is_static ? "static" : "dynamic", bibe->ses_num);
+    }
+  return 0;
+}
+
+static clib_error_t *
+nat64_show_bib_command_fn (vlib_main_t * vm,
+			   unformat_input_t * input, vlib_cli_command_t * cmd)
+{
+  nat64_main_t *nm = &nat64_main;
+  unformat_input_t _line_input, *line_input = &_line_input;
+  clib_error_t *error = 0;
+  u32 proto = ~0;
+  u8 p = 255;
+
+  if (nm->is_disabled)
+    return clib_error_return (0,
+			      "NAT64 disabled, multi thread not supported");
+
+  if (!unformat_user (input, unformat_line_input, line_input))
+    return 0;
+
+  if (unformat (line_input, "%U", unformat_snat_protocol, &proto))
+    p = snat_proto_to_ip_proto (proto);
+  else if (unformat (line_input, "unknown"))
+    p = 0;
+  else if (unformat (line_input, "all"))
+    ;
+  else
+    {
+      error = clib_error_return (0, "unknown input: '%U'",
+				 format_unformat_error, line_input);
+      goto done;
+    }
+
+  if (p == 255)
+    vlib_cli_output (vm, "NAT64 BIB entries:");
+  else
+    vlib_cli_output (vm, "NAT64 %U BIB entries:", format_snat_protocol,
+		     proto);
+  nat64_db_bib_walk (&nm->db, p, nat64_cli_bib_walk, vm);
+
+done:
+  unformat_free (line_input);
+
+  return error;
+}
+
+static clib_error_t *
+nat64_set_timeouts_command_fn (vlib_main_t * vm, unformat_input_t * input,
+			       vlib_cli_command_t * cmd)
+{
+  nat64_main_t *nm = &nat64_main;
+  unformat_input_t _line_input, *line_input = &_line_input;
+  clib_error_t *error = 0;
+  u32 timeout, tcp_trans, tcp_est, tcp_incoming_syn;
+
+  tcp_trans = nat64_get_tcp_trans_timeout ();
+  tcp_est = nat64_get_tcp_est_timeout ();
+  tcp_incoming_syn = nat64_get_tcp_incoming_syn_timeout ();
+
+  if (nm->is_disabled)
+    return clib_error_return (0,
+			      "NAT64 disabled, multi thread not supported");
+
+  if (!unformat_user (input, unformat_line_input, line_input))
+    return 0;
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (line_input, "udp %u", &timeout))
+	{
+	  if (nat64_set_udp_timeout (timeout))
+	    {
+	      error = clib_error_return (0, "Invalid UDP timeout value");
+	      goto done;
+	    }
+	}
+      else if (unformat (line_input, "icmp %u", &timeout))
+	{
+	  if (nat64_set_icmp_timeout (timeout))
+	    {
+	      error = clib_error_return (0, "Invalid ICMP timeout value");
+	      goto done;
+	    }
+	}
+      else if (unformat (line_input, "tcp-trans %u", &tcp_trans))
+	{
+	  if (nat64_set_tcp_timeouts (tcp_trans, tcp_est, tcp_incoming_syn))
+	    {
+	      error =
+		clib_error_return (0, "Invalid TCP transitory tiemout value");
+	      goto done;
+	    }
+	}
+      else if (unformat (line_input, "tcp-est %u", &tcp_est))
+	{
+	  if (nat64_set_tcp_timeouts (tcp_trans, tcp_est, tcp_incoming_syn))
+	    {
+	      error =
+		clib_error_return (0,
+				   "Invalid TCP established tiemout value");
+	      goto done;
+	    }
+	}
+      else
+	if (unformat (line_input, "tcp-incoming-syn %u", &tcp_incoming_syn))
+	{
+	  if (nat64_set_tcp_timeouts (tcp_trans, tcp_est, tcp_incoming_syn))
+	    {
+	      error =
+		clib_error_return (0,
+				   "Invalid TCP incoming SYN tiemout value");
+	      goto done;
+	    }
+	}
+      else if (unformat (line_input, "reset"))
+	{
+	  nat64_set_udp_timeout (0);
+	  nat64_set_icmp_timeout (0);
+	  nat64_set_tcp_timeouts (0, 0, 0);
+	}
+      else
+	{
+	  error = clib_error_return (0, "unknown input '%U'",
+				     format_unformat_error, line_input);
+	  goto done;
+	}
+    }
+
+done:
+  unformat_free (line_input);
+
+  return error;
+}
+
+static clib_error_t *
+nat64_show_timeouts_command_fn (vlib_main_t * vm, unformat_input_t * input,
+				vlib_cli_command_t * cmd)
+{
+  nat64_main_t *nm = &nat64_main;
+
+  if (nm->is_disabled)
+    return clib_error_return (0,
+			      "NAT64 disabled, multi thread not supported");
+
+  vlib_cli_output (vm, "NAT64 session timeouts:");
+  vlib_cli_output (vm, " UDP %usec", nat64_get_udp_timeout ());
+  vlib_cli_output (vm, " ICMP %usec", nat64_get_icmp_timeout ());
+  vlib_cli_output (vm, " TCP transitory %usec",
+		   nat64_get_tcp_trans_timeout ());
+  vlib_cli_output (vm, " TCP established %usec",
+		   nat64_get_tcp_est_timeout ());
+  vlib_cli_output (vm, " TCP incoming SYN %usec",
+		   nat64_get_tcp_incoming_syn_timeout ());
+
+  return 0;
+}
+
+static int
+nat64_cli_st_walk (nat64_db_st_entry_t * ste, void *ctx)
+{
+  vlib_main_t *vm = ctx;
+  nat64_main_t *nm = &nat64_main;
+  nat64_db_bib_entry_t *bibe;
+  fib_table_t *fib;
+
+  bibe = nat64_db_bib_entry_by_index (&nm->db, ste->proto, ste->bibe_index);
+  if (!bibe)
+    return -1;
+
+  fib = fib_table_get (bibe->fib_index, FIB_PROTOCOL_IP6);
+  if (!fib)
+    return -1;
+
+  u32 vrf_id = fib->ft_table_id;
+
+  if (ste->proto == IP_PROTOCOL_ICMP)
+    vlib_cli_output (vm, " %U %U %u %U %U %u protocol %U vrf %u",
+		     format_ip6_address, &bibe->in_addr,
+		     format_ip6_address, &ste->in_r_addr,
+		     clib_net_to_host_u16 (bibe->in_port),
+		     format_ip4_address, &bibe->out_addr,
+		     format_ip4_address, &ste->out_r_addr,
+		     clib_net_to_host_u16 (bibe->out_port),
+		     format_snat_protocol,
+		     ip_proto_to_snat_proto (bibe->proto), vrf_id);
+  else if (ste->proto == IP_PROTOCOL_TCP || ste->proto == IP_PROTOCOL_UDP)
+    vlib_cli_output (vm, " %U %u %U %u %U %u %U %u protcol %U vrf %u",
+		     format_ip6_address, &bibe->in_addr,
+		     clib_net_to_host_u16 (bibe->in_port),
+		     format_ip6_address, &ste->in_r_addr,
+		     clib_net_to_host_u16 (ste->r_port),
+		     format_ip4_address, &bibe->out_addr,
+		     clib_net_to_host_u16 (bibe->out_port),
+		     format_ip4_address, &ste->out_r_addr,
+		     clib_net_to_host_u16 (ste->r_port),
+		     format_snat_protocol,
+		     ip_proto_to_snat_proto (bibe->proto), vrf_id);
+  else
+    vlib_cli_output (vm, " %U %U %U %U protocol %u vrf %u",
+		     format_ip6_address, &bibe->in_addr,
+		     format_ip6_address, &ste->in_r_addr,
+		     format_ip4_address, &bibe->out_addr,
+		     format_ip4_address, &ste->out_r_addr,
+		     bibe->proto, vrf_id);
+
+  return 0;
+}
+
+static clib_error_t *
+nat64_show_st_command_fn (vlib_main_t * vm,
+			  unformat_input_t * input, vlib_cli_command_t * cmd)
+{
+  nat64_main_t *nm = &nat64_main;
+  unformat_input_t _line_input, *line_input = &_line_input;
+  clib_error_t *error = 0;
+  u32 proto = ~0;
+  u8 p = 255;
+
+  if (nm->is_disabled)
+    return clib_error_return (0,
+			      "NAT64 disabled, multi thread not supported");
+
+  if (!unformat_user (input, unformat_line_input, line_input))
+    return 0;
+
+  if (unformat (line_input, "%U", unformat_snat_protocol, &proto))
+    p = snat_proto_to_ip_proto (proto);
+  else if (unformat (line_input, "unknown"))
+    p = 0;
+  else if (unformat (line_input, "all"))
+    ;
+  else
+    {
+      error = clib_error_return (0, "unknown input: '%U'",
+				 format_unformat_error, line_input);
+      goto done;
+    }
+
+  if (p == 255)
+    vlib_cli_output (vm, "NAT64 sessions:");
+  else
+    vlib_cli_output (vm, "NAT64 %U sessions:", format_snat_protocol, proto);
+  nat64_db_st_walk (&nm->db, p, nat64_cli_st_walk, vm);
+
+done:
+  unformat_free (line_input);
+
+  return error;
+}
+
+static clib_error_t *
+nat64_add_del_prefix_command_fn (vlib_main_t * vm, unformat_input_t * input,
+				 vlib_cli_command_t * cmd)
+{
+  nat64_main_t *nm = &nat64_main;
+  clib_error_t *error = 0;
+  unformat_input_t _line_input, *line_input = &_line_input;
+  u8 is_add = 1;
+  u32 vrf_id = 0;
+  ip6_address_t prefix;
+  u32 plen = 0;
+  int rv;
+
+  if (nm->is_disabled)
+    return clib_error_return (0,
+			      "NAT64 disabled, multi thread not supported");
+
+  if (!unformat_user (input, unformat_line_input, line_input))
+    return 0;
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat
+	  (line_input, "%U/%u", unformat_ip6_address, &prefix, &plen))
+	;
+      else if (unformat (line_input, "tenant-vrf %u", &vrf_id))
+	;
+      else if (unformat (line_input, "del"))
+	is_add = 0;
+      else
+	{
+	  error = clib_error_return (0, "unknown input: '%U'",
+				     format_unformat_error, line_input);
+	  goto done;
+	}
+    }
+
+  if (!plen)
+    {
+      error = clib_error_return (0, "NAT64 prefix must be set.");
+      goto done;
+    }
+
+  rv = nat64_add_del_prefix (&prefix, (u8) plen, vrf_id, is_add);
+
+  switch (rv)
+    {
+    case VNET_API_ERROR_NO_SUCH_ENTRY:
+      error = clib_error_return (0, "NAT64 prefix not exist.");
+      goto done;
+    case VNET_API_ERROR_INVALID_VALUE:
+      error = clib_error_return (0, "Invalid prefix length.");
+      goto done;
+    default:
+      break;
+    }
+
+done:
+  unformat_free (line_input);
+
+  return error;
+}
+
+static int
+nat64_cli_prefix_walk (nat64_prefix_t * p, void *ctx)
+{
+  vlib_main_t *vm = ctx;
+
+  vlib_cli_output (vm, " %U/%u tenant-vrf %u",
+		   format_ip6_address, &p->prefix, p->plen, p->vrf_id);
+
+  return 0;
+}
+
+static clib_error_t *
+nat64_show_prefix_command_fn (vlib_main_t * vm, unformat_input_t * input,
+			      vlib_cli_command_t * cmd)
+{
+  nat64_main_t *nm = &nat64_main;
+
+  if (nm->is_disabled)
+    return clib_error_return (0,
+			      "NAT64 disabled, multi thread not supported");
+
+  vlib_cli_output (vm, "NAT64 prefix:");
+  nat64_prefix_walk (nat64_cli_prefix_walk, vm);
+
+  return 0;
+}
+
+/* *INDENT-OFF* */
+
+/*?
+ * @cliexpar
+ * @cliexstart{nat64 add pool address}
+ * Add/delete NAT64 pool address.
+ * To add single NAT64 pool address use:
+ *  vpp# nat64 add pool address 10.1.1.10
+ * To add NAT64 pool address range use:
+ *  vpp# nat64 add pool address 10.1.1.2 - 10.1.1.5
+ * To add NAT64 pool address for specific tenant use:
+ *  vpp# nat64 add pool address 10.1.1.100 tenant-vrf 100
+ * @cliexend
+?*/
+VLIB_CLI_COMMAND (nat64_add_pool_address_command, static) = {
+  .path = "nat64 add pool address",
+  .short_help = "nat64 add pool address <ip4-range-start> [- <ip4-range-end>] "
+                "[tenant-vrf <vrf-id>] [del]",
+  .function = nat64_add_del_pool_addr_command_fn,
+};
+
+/*?
+ * @cliexpar
+ * @cliexstart{show nat64 pool}
+ * Show NAT64 pool.
+ *  vpp# show nat64 pool
+ *  NAT64 pool:
+ *   10.1.1.3 tenant VRF: 0
+ *   10.1.1.10 tenant VRF: 10
+ * @cliexend
+?*/
+VLIB_CLI_COMMAND (show_nat64_pool_command, static) = {
+  .path = "show nat64 pool",
+  .short_help = "show nat64 pool",
+  .function = nat64_show_pool_command_fn,
+};
+
+/*?
+ * @cliexpar
+ * @cliexstart{set interface nat64}
+ * Enable/disable NAT64 feature on the interface.
+ * To enable NAT64 feature with local (IPv6) network interface
+ * GigabitEthernet0/8/0 and external (IPv4) network interface
+ * GigabitEthernet0/a/0 use:
+ *  vpp# set interface nat64 in GigabitEthernet0/8/0 out GigabitEthernet0/a/0
+ * @cliexend
+?*/
+VLIB_CLI_COMMAND (set_interface_nat64_command, static) = {
+  .path = "set interface nat64",
+  .short_help = "set interface nat64 in|out <intfc> [del]",
+  .function = nat64_interface_feature_command_fn,
+};
+
+/*?
+ * @cliexpar
+ * @cliexstart{show nat64 interfaces}
+ * Show interfaces with NAT64 feature.
+ * To show interfaces with NAT64 feature use:
+ *  vpp# show nat64 interfaces
+ *  NAT64 interfaces:
+ *   GigabitEthernet0/8/0 in
+ *   GigabitEthernet0/a/0 out
+ * @cliexend
+?*/
+VLIB_CLI_COMMAND (show_nat64_interfaces_command, static) = {
+  .path = "show nat64 interfaces",
+  .short_help = "show nat64 interfaces",
+  .function = nat64_show_interfaces_command_fn,
+};
+
+/*?
+ * @cliexpar
+ * @cliexstart{nat64 add static bib}
+ * Add/delete NAT64 static BIB entry.
+ * To create NAT64 satatic BIB entry use:
+ *  vpp# nat64 add static bib 2001:db8:c000:221:: 1234 10.1.1.3 5678 tcp
+ *  vpp# nat64 add static bib 2001:db8:c000:221:: 1234 10.1.1.3 5678 udp vrf 10
+ * @cliexend
+?*/
+VLIB_CLI_COMMAND (nat64_add_del_static_bib_command, static) = {
+  .path = "nat64 add static bib",
+  .short_help = "nat64 add static bib <ip6-addr> <port> <ip4-addr> <port> "
+                "tcp|udp|icmp [vfr <table-id>] [del]",
+  .function = nat64_add_del_static_bib_command_fn,
+};
+
+/*?
+ * @cliexpar
+ * @cliexstart{show nat64 bib}
+ * Show NAT64 BIB entries.
+ * To show NAT64 TCP BIB entries use:
+ *  vpp# show nat64 bib tcp
+ *  NAT64 tcp BIB:
+ *   fd01:1::2 6303 10.0.0.3 62303 tcp vrf 0 dynamic 1 sessions
+ *   2001:db8:c000:221:: 1234 10.1.1.3 5678 tcp vrf 0 static 2 sessions
+ * To show NAT64 UDP BIB entries use:
+ *  vpp# show nat64 bib udp
+ *  NAT64 udp BIB:
+ *   fd01:1::2 6304 10.0.0.3 10546 udp vrf 0 dynamic 10 sessions
+ *   2001:db8:c000:221:: 1234 10.1.1.3 5678 udp vrf 10 static 0 sessions
+ * To show NAT64 ICMP BIB entries use:
+ *  vpp# show nat64 bib icmp
+ *  NAT64 icmp BIB:
+ *   fd01:1::2 6305 10.0.0.3 63209 icmp vrf 10 dynamic 1 sessions
+ * @cliexend
+?*/
+VLIB_CLI_COMMAND (show_nat64_bib_command, static) = {
+  .path = "show nat64 bib",
+  .short_help = "show nat64 bib all|tcp|udp|icmp|unknown",
+  .function = nat64_show_bib_command_fn,
+};
+
+/*?
+ * @cliexpar
+ * @cliexstart{set nat64 timeouts}
+ * Set NAT64 session timeouts (in seconds).
+ * To set NAT64 session timeoutes use use:
+ *  vpp# set nat64 timeouts udp 200 icmp 30 tcp-trans 250 tcp-est 7450
+ * To reset NAT64 session timeoutes to default values use:
+ *  vpp# set nat64 timeouts reset
+ * @cliexend
+?*/
+VLIB_CLI_COMMAND (set_nat64_timeouts_command, static) = {
+  .path = "set nat64 timeouts",
+  .short_help = "set nat64 timeouts udp <sec> icmp <sec> tcp-trans <sec> "
+                "tcp-est <sec> tcp-incoming-syn <sec> | reset",
+  .function = nat64_set_timeouts_command_fn,
+};
+
+/*?
+ * @cliexpar
+ * @cliexstart{show nat64 tiemouts}
+ * Show NAT64 session timeouts:
+ *  vpp# show nat64 tiemouts
+ *  NAT64 session timeouts:
+ *   UDP 300sec
+ *   ICMP 60sec
+ *   TCP transitory 240sec
+ *   TCP established 7440sec
+ *   TCP incoming SYN 6sec
+ * @cliexend
+?*/
+VLIB_CLI_COMMAND (show_nat64_timeouts_command, static) = {
+  .path = "show nat64 tiemouts",
+  .short_help = "show nat64 tiemouts",
+  .function = nat64_show_timeouts_command_fn,
+};
+
+/*?
+ * @cliexpar
+ * @cliexstart{show nat64 session table}
+ * Show NAT64 session table.
+ * To show NAT64 TCP session table use:
+ *  vpp# show nat64 session table tcp
+ *  NAT64 tcp session table:
+ *   fd01:1::2 6303 64:ff9b::ac10:202 20 10.0.0.3 62303 172.16.2.2 20 tcp vrf 0
+ *   fd01:3::2 6303 64:ff9b::ac10:202 20 10.0.10.3 21300 172.16.2.2 20 tcp vrf 10
+ * To show NAT64 UDP session table use:
+ * #vpp show nat64 session table udp
+ * NAT64 udp session table:
+ *  fd01:1::2 6304 64:ff9b::ac10:202 20 10.0.0.3 10546 172.16.2.2 20 udp vrf 0
+ *  fd01:3::2 6304 64:ff9b::ac10:202 20 10.0.10.3 58627 172.16.2.2 20 udp vrf 10
+ *  fd01:1::2 1235 64:ff9b::a00:3 4023 10.0.0.3 24488 10.0.0.3 4023 udp vrf 0
+ *  fd01:1::3 23 64:ff9b::a00:3 24488 10.0.0.3 4023 10.0.0.3 24488 udp vrf 0
+ * To show NAT64 ICMP session table use:
+ * #vpp show nat64 session table icmp
+ * NAT64 icmp session table:
+ *  fd01:1::2 64:ff9b::ac10:202 6305 10.0.0.3 172.16.2.2 63209 icmp vrf 0
+ * @cliexend
+?*/
+VLIB_CLI_COMMAND (show_nat64_st_command, static) = {
+  .path = "show nat64 session table",
+  .short_help = "show nat64 session table all|tcp|udp|icmp|unknown",
+  .function = nat64_show_st_command_fn,
+};
+
+/*?
+ * @cliexpar
+ * @cliexstart{nat64 add prefix}
+ * Set NAT64 prefix for generating IPv6 representations of IPv4 addresses.
+ * To set NAT64 global prefix use:
+ *  vpp# nat64 add prefix 2001:db8::/32
+ * To set NAT64 prefix for specific tenant use:
+ *  vpp# nat64 add prefix 2001:db8:122:300::/56 tenant-vrf 10
+ * @cliexend
+?*/
+VLIB_CLI_COMMAND (nat64_add_del_prefix_command, static) = {
+  .path = "nat64 add prefix",
+  .short_help = "nat64 add prefix <ip6-prefix>/<plen> [tenant-vrf <vrf-id>] "
+                "[del]",
+  .function = nat64_add_del_prefix_command_fn,
+};
+
+/*?
+ * @cliexpar
+ * @cliexstart{show nat64 prefix}
+ * Show NAT64 prefix.
+ * To show NAT64 prefix use:
+ *  vpp# show nat64 prefix
+ *  NAT64 prefix:
+ *   2001:db8::/32 tenant-vrf 0
+ *   2001:db8:122:300::/56 tenant-vrf 10
+ * @cliexend
+?*/
+VLIB_CLI_COMMAND (show_nat64_prefix_command, static) = {
+  .path = "show nat64 prefix",
+  .short_help = "show nat64 prefix",
+  .function = nat64_show_prefix_command_fn,
+};
+
+/* *INDENT-ON* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/plugins/nat/nat64_db.c b/src/plugins/nat/nat64_db.c
new file mode 100644
index 00000000000..da73ceee2d1
--- /dev/null
+++ b/src/plugins/nat/nat64_db.c
@@ -0,0 +1,603 @@
+/*
+ * Copyright (c) 2017 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.
+ */
+/**
+ * @file
+ * @brief NAT64 DB
+ */
+#include <nat/nat64_db.h>
+
+int
+nat64_db_init (nat64_db_t * db)
+{
+  u32 bib_buckets = 1024;
+  u32 bib_memory_size = 128 << 20;
+  u32 st_buckets = 2048;
+  u32 st_memory_size = 256 << 20;
+
+  clib_bihash_init_24_8 (&db->bib.in2out, "bib-in2out", bib_buckets,
+			 bib_memory_size);
+
+  clib_bihash_init_24_8 (&db->bib.out2in, "bib-out2in", bib_buckets,
+			 bib_memory_size);
+
+  clib_bihash_init_48_8 (&db->st.in2out, "st-in2out", st_buckets,
+			 st_memory_size);
+
+  clib_bihash_init_48_8 (&db->st.out2in, "st-out2in", st_buckets,
+			 st_memory_size);
+
+  return 0;
+}
+
+nat64_db_bib_entry_t *
+nat64_db_bib_entry_create (nat64_db_t * db, ip6_address_t * in_addr,
+			   ip4_address_t * out_addr, u16 in_port,
+			   u16 out_port, u32 fib_index, u8 proto,
+			   u8 is_static)
+{
+  nat64_db_bib_entry_t *bibe;
+  nat64_db_bib_entry_key_t bibe_key;
+  clib_bihash_kv_24_8_t kv;
+
+  /* create pool entry */
+  switch (ip_proto_to_snat_proto (proto))
+    {
+/* *INDENT-OFF* */
+#define _(N, i, n, s) \
+    case SNAT_PROTOCOL_##N: \
+      pool_get (db->bib._##n##_bib, bibe); \
+      kv.value = bibe - db->bib._##n##_bib; \
+      break;
+      foreach_snat_protocol
+#undef _
+/* *INDENT-ON* */
+    default:
+      pool_get (db->bib._unk_proto_bib, bibe);
+      kv.value = bibe - db->bib._unk_proto_bib;
+      break;
+    }
+  memset (bibe, 0, sizeof (*bibe));
+  bibe->in_addr.as_u64[0] = in_addr->as_u64[0];
+  bibe->in_addr.as_u64[1] = in_addr->as_u64[1];
+  bibe->in_port = in_port;
+  bibe->out_addr.as_u32 = out_addr->as_u32;
+  bibe->out_port = out_port;
+  bibe->fib_index = fib_index;
+  bibe->proto = proto;
+  bibe->is_static = is_static;
+
+  /* create hash lookup */
+  bibe_key.addr.as_u64[0] = bibe->in_addr.as_u64[0];
+  bibe_key.addr.as_u64[1] = bibe->in_addr.as_u64[1];
+  bibe_key.fib_index = bibe->fib_index;
+  bibe_key.port = bibe->in_port;
+  bibe_key.proto = bibe->proto;
+  bibe_key.rsvd = 0;
+  kv.key[0] = bibe_key.as_u64[0];
+  kv.key[1] = bibe_key.as_u64[1];
+  kv.key[2] = bibe_key.as_u64[2];
+  clib_bihash_add_del_24_8 (&db->bib.in2out, &kv, 1);
+
+  memset (&bibe_key.addr, 0, sizeof (bibe_key.addr));
+  bibe_key.addr.ip4.as_u32 = bibe->out_addr.as_u32;
+  bibe_key.fib_index = 0;
+  bibe_key.port = bibe->out_port;
+  kv.key[0] = bibe_key.as_u64[0];
+  kv.key[1] = bibe_key.as_u64[1];
+  kv.key[2] = bibe_key.as_u64[2];
+  clib_bihash_add_del_24_8 (&db->bib.out2in, &kv, 1);
+
+  return bibe;
+}
+
+void
+nat64_db_bib_entry_free (nat64_db_t * db, nat64_db_bib_entry_t * bibe)
+{
+  nat64_db_bib_entry_key_t bibe_key;
+  clib_bihash_kv_24_8_t kv;
+  nat64_db_bib_entry_t *bib;
+  u32 *ste_to_be_free = 0, *ste_index, bibe_index;
+  nat64_db_st_entry_t *st, *ste;
+
+  switch (ip_proto_to_snat_proto (bibe->proto))
+    {
+/* *INDENT-OFF* */
+#define _(N, i, n, s) \
+    case SNAT_PROTOCOL_##N: \
+      bib = db->bib._##n##_bib; \
+      st = db->st._##n##_st; \
+      break;
+      foreach_snat_protocol
+#undef _
+/* *INDENT-ON* */
+    default:
+      bib = db->bib._unk_proto_bib;
+      st = db->st._unk_proto_st;
+      break;
+    }
+
+  bibe_index = bibe - bib;
+
+  /* delete ST entries for static BIB entry */
+  if (bibe->is_static)
+    {
+      pool_foreach (ste, st, (
+			       {
+			       if (ste->bibe_index == bibe_index)
+			       vec_add1 (ste_to_be_free, ste - st);}
+		    ));
+      vec_foreach (ste_index, ste_to_be_free)
+	nat64_db_st_entry_free (db, pool_elt_at_index (st, ste_index[0]));
+      vec_free (ste_to_be_free);
+    }
+
+  /* delete hash lookup */
+  bibe_key.addr.as_u64[0] = bibe->in_addr.as_u64[0];
+  bibe_key.addr.as_u64[1] = bibe->in_addr.as_u64[1];
+  bibe_key.fib_index = bibe->fib_index;
+  bibe_key.port = bibe->in_port;
+  bibe_key.proto = bibe->proto;
+  bibe_key.rsvd = 0;
+  kv.key[0] = bibe_key.as_u64[0];
+  kv.key[1] = bibe_key.as_u64[1];
+  kv.key[2] = bibe_key.as_u64[2];
+  clib_bihash_add_del_24_8 (&db->bib.in2out, &kv, 0);
+
+  memset (&bibe_key.addr, 0, sizeof (bibe_key.addr));
+  bibe_key.addr.ip4.as_u32 = bibe->out_addr.as_u32;
+  bibe_key.fib_index = 0;
+  bibe_key.port = bibe->out_port;
+  kv.key[0] = bibe_key.as_u64[0];
+  kv.key[1] = bibe_key.as_u64[1];
+  kv.key[2] = bibe_key.as_u64[2];
+  clib_bihash_add_del_24_8 (&db->bib.out2in, &kv, 0);
+
+  /* delete from pool */
+  pool_put (bib, bibe);
+
+}
+
+nat64_db_bib_entry_t *
+nat64_db_bib_entry_find (nat64_db_t * db, ip46_address_t * addr, u16 port,
+			 u8 proto, u32 fib_index, u8 is_ip6)
+{
+  nat64_db_bib_entry_t *bibe = 0;
+  nat64_db_bib_entry_key_t bibe_key;
+  clib_bihash_kv_24_8_t kv, value;
+  nat64_db_bib_entry_t *bib;
+
+  switch (ip_proto_to_snat_proto (proto))
+    {
+/* *INDENT-OFF* */
+#define _(N, i, n, s) \
+    case SNAT_PROTOCOL_##N: \
+      bib = db->bib._##n##_bib; \
+      break;
+      foreach_snat_protocol
+#undef _
+/* *INDENT-ON* */
+    default:
+      bib = db->bib._unk_proto_bib;
+      break;
+    }
+
+  bibe_key.addr.as_u64[0] = addr->as_u64[0];
+  bibe_key.addr.as_u64[1] = addr->as_u64[1];
+  bibe_key.fib_index = fib_index;
+  bibe_key.port = port;
+  bibe_key.proto = proto;
+  bibe_key.rsvd = 0;
+
+  kv.key[0] = bibe_key.as_u64[0];
+  kv.key[1] = bibe_key.as_u64[1];
+  kv.key[2] = bibe_key.as_u64[2];
+
+  if (!clib_bihash_search_24_8
+      (is_ip6 ? &db->bib.in2out : &db->bib.out2in, &kv, &value))
+    bibe = pool_elt_at_index (bib, value.value);
+
+  return bibe;
+}
+
+void
+nat64_db_bib_walk (nat64_db_t * db, u8 proto,
+		   nat64_db_bib_walk_fn_t fn, void *ctx)
+{
+  nat64_db_bib_entry_t *bib, *bibe;
+
+  if (proto == 255)
+    {
+    /* *INDENT-OFF* */
+    #define _(N, i, n, s) \
+      bib = db->bib._##n##_bib; \
+      pool_foreach (bibe, bib, ({ \
+        if (fn (bibe, ctx)) \
+          return; \
+      }));
+      foreach_snat_protocol
+    #undef _
+      bib = db->bib._unk_proto_bib;
+      pool_foreach (bibe, bib, ({
+        if (fn (bibe, ctx))
+          return;
+      }));
+    /* *INDENT-ON* */
+    }
+  else
+    {
+      switch (ip_proto_to_snat_proto (proto))
+	{
+    /* *INDENT-OFF* */
+    #define _(N, i, n, s) \
+        case SNAT_PROTOCOL_##N: \
+          bib = db->bib._##n##_bib; \
+          break;
+          foreach_snat_protocol
+    #undef _
+    /* *INDENT-ON* */
+	default:
+	  bib = db->bib._unk_proto_bib;
+	  break;
+	}
+
+      /* *INDENT-OFF* */
+      pool_foreach (bibe, bib,
+      ({
+        if (fn (bibe, ctx))
+          return;
+      }));
+      /* *INDENT-ON* */
+    }
+}
+
+nat64_db_bib_entry_t *
+nat64_db_bib_entry_by_index (nat64_db_t * db, u8 proto, u32 bibe_index)
+{
+  nat64_db_bib_entry_t *bib;
+
+  switch (ip_proto_to_snat_proto (proto))
+    {
+/* *INDENT-OFF* */
+#define _(N, i, n, s) \
+    case SNAT_PROTOCOL_##N: \
+      bib = db->bib._##n##_bib; \
+      break;
+      foreach_snat_protocol
+#undef _
+/* *INDENT-ON* */
+    default:
+      bib = db->bib._unk_proto_bib;
+      break;
+    }
+
+  return pool_elt_at_index (bib, bibe_index);
+}
+
+void
+nat64_db_st_walk (nat64_db_t * db, u8 proto,
+		  nat64_db_st_walk_fn_t fn, void *ctx)
+{
+  nat64_db_st_entry_t *st, *ste;
+
+  if (proto == 255)
+    {
+    /* *INDENT-OFF* */
+    #define _(N, i, n, s) \
+      st = db->st._##n##_st; \
+      pool_foreach (ste, st, ({ \
+        if (fn (ste, ctx)) \
+          return; \
+      }));
+      foreach_snat_protocol
+    #undef _
+      st = db->st._unk_proto_st;
+      pool_foreach (ste, st, ({
+        if (fn (ste, ctx))
+          return;
+      }));
+    /* *INDENT-ON* */
+    }
+  else
+    {
+      switch (ip_proto_to_snat_proto (proto))
+	{
+    /* *INDENT-OFF* */
+    #define _(N, i, n, s) \
+        case SNAT_PROTOCOL_##N: \
+          st = db->st._##n##_st; \
+          break;
+          foreach_snat_protocol
+    #undef _
+    /* *INDENT-ON* */
+	default:
+	  st = db->st._unk_proto_st;
+	  break;
+	}
+
+      /* *INDENT-OFF* */
+      pool_foreach (ste, st,
+      ({
+        if (fn (ste, ctx))
+          return;
+      }));
+      /* *INDENT-ON* */
+    }
+}
+
+nat64_db_st_entry_t *
+nat64_db_st_entry_create (nat64_db_t * db, nat64_db_bib_entry_t * bibe,
+			  ip6_address_t * in_r_addr,
+			  ip4_address_t * out_r_addr, u16 r_port)
+{
+  nat64_db_st_entry_t *ste;
+  nat64_db_bib_entry_t *bib;
+  nat64_db_st_entry_key_t ste_key;
+  clib_bihash_kv_48_8_t kv;
+
+  /* create pool entry */
+  switch (ip_proto_to_snat_proto (bibe->proto))
+    {
+/* *INDENT-OFF* */
+#define _(N, i, n, s) \
+    case SNAT_PROTOCOL_##N: \
+      pool_get (db->st._##n##_st, ste); \
+      kv.value = ste - db->st._##n##_st; \
+      bib = db->bib._##n##_bib; \
+      break;
+      foreach_snat_protocol
+#undef _
+/* *INDENT-ON* */
+    default:
+      pool_get (db->st._unk_proto_st, ste);
+      kv.value = ste - db->st._unk_proto_st;
+      bib = db->bib._unk_proto_bib;
+      break;
+    }
+  memset (ste, 0, sizeof (*ste));
+  ste->in_r_addr.as_u64[0] = in_r_addr->as_u64[0];
+  ste->in_r_addr.as_u64[1] = in_r_addr->as_u64[1];
+  ste->out_r_addr.as_u32 = out_r_addr->as_u32;
+  ste->r_port = r_port;
+  ste->bibe_index = bibe - bib;
+  ste->proto = bibe->proto;
+
+  /* increment session number for BIB entry */
+  bibe->ses_num++;
+
+  /* create hash lookup */
+  memset (&ste_key, 0, sizeof (ste_key));
+  ste_key.l_addr.as_u64[0] = bibe->in_addr.as_u64[0];
+  ste_key.l_addr.as_u64[1] = bibe->in_addr.as_u64[1];
+  ste_key.r_addr.as_u64[0] = ste->in_r_addr.as_u64[0];
+  ste_key.r_addr.as_u64[1] = ste->in_r_addr.as_u64[1];
+  ste_key.fib_index = bibe->fib_index;
+  ste_key.l_port = bibe->in_port;
+  ste_key.r_port = ste->r_port;
+  ste_key.proto = ste->proto;
+  kv.key[0] = ste_key.as_u64[0];
+  kv.key[1] = ste_key.as_u64[1];
+  kv.key[2] = ste_key.as_u64[2];
+  kv.key[3] = ste_key.as_u64[3];
+  kv.key[4] = ste_key.as_u64[4];
+  kv.key[5] = ste_key.as_u64[5];
+  clib_bihash_add_del_48_8 (&db->st.in2out, &kv, 1);
+
+  memset (&ste_key, 0, sizeof (ste_key));
+  ste_key.l_addr.ip4.as_u32 = bibe->out_addr.as_u32;
+  ste_key.r_addr.ip4.as_u32 = ste->out_r_addr.as_u32;
+  ste_key.l_port = bibe->out_port;
+  ste_key.r_port = ste->r_port;
+  ste_key.proto = ste->proto;
+  kv.key[0] = ste_key.as_u64[0];
+  kv.key[1] = ste_key.as_u64[1];
+  kv.key[2] = ste_key.as_u64[2];
+  kv.key[3] = ste_key.as_u64[3];
+  kv.key[4] = ste_key.as_u64[4];
+  kv.key[5] = ste_key.as_u64[5];
+  clib_bihash_add_del_48_8 (&db->st.out2in, &kv, 1);
+
+  return ste;
+}
+
+void
+nat64_db_st_entry_free (nat64_db_t * db, nat64_db_st_entry_t * ste)
+{
+  nat64_db_st_entry_t *st;
+  nat64_db_bib_entry_t *bib, *bibe;
+  nat64_db_st_entry_key_t ste_key;
+  clib_bihash_kv_48_8_t kv;
+
+  switch (ip_proto_to_snat_proto (ste->proto))
+    {
+/* *INDENT-OFF* */
+#define _(N, i, n, s) \
+    case SNAT_PROTOCOL_##N: \
+      st = db->st._##n##_st; \
+      bib = db->bib._##n##_bib; \
+      break;
+      foreach_snat_protocol
+#undef _
+/* *INDENT-ON* */
+    default:
+      st = db->st._unk_proto_st;
+      bib = db->bib._unk_proto_bib;
+      break;
+    }
+
+  bibe = pool_elt_at_index (bib, ste->bibe_index);
+
+  /* delete hash lookup */
+  memset (&ste_key, 0, sizeof (ste_key));
+  ste_key.l_addr.as_u64[0] = bibe->in_addr.as_u64[0];
+  ste_key.l_addr.as_u64[1] = bibe->in_addr.as_u64[1];
+  ste_key.r_addr.as_u64[0] = ste->in_r_addr.as_u64[0];
+  ste_key.r_addr.as_u64[1] = ste->in_r_addr.as_u64[1];
+  ste_key.fib_index = bibe->fib_index;
+  ste_key.l_port = bibe->in_port;
+  ste_key.r_port = ste->r_port;
+  ste_key.proto = ste->proto;
+  kv.key[0] = ste_key.as_u64[0];
+  kv.key[1] = ste_key.as_u64[1];
+  kv.key[2] = ste_key.as_u64[2];
+  kv.key[3] = ste_key.as_u64[3];
+  kv.key[4] = ste_key.as_u64[4];
+  kv.key[5] = ste_key.as_u64[5];
+  clib_bihash_add_del_48_8 (&db->st.in2out, &kv, 0);
+
+  memset (&ste_key, 0, sizeof (ste_key));
+  ste_key.l_addr.ip4.as_u32 = bibe->out_addr.as_u32;
+  ste_key.r_addr.ip4.as_u32 = ste->out_r_addr.as_u32;
+  ste_key.l_port = bibe->out_port;
+  ste_key.r_port = ste->r_port;
+  ste_key.proto = ste->proto;
+  kv.key[0] = ste_key.as_u64[0];
+  kv.key[1] = ste_key.as_u64[1];
+  kv.key[2] = ste_key.as_u64[2];
+  kv.key[3] = ste_key.as_u64[3];
+  kv.key[4] = ste_key.as_u64[4];
+  kv.key[5] = ste_key.as_u64[5];
+  clib_bihash_add_del_48_8 (&db->st.out2in, &kv, 0);
+
+  /* delete from pool */
+  pool_put (st, ste);
+
+  /* decrement session number for BIB entry */
+  bibe->ses_num--;
+
+  /* delete BIB entry if last session and dynamic */
+  if (!bibe->is_static && !bibe->ses_num)
+    nat64_db_bib_entry_free (db, bibe);
+}
+
+nat64_db_st_entry_t *
+nat64_db_st_entry_find (nat64_db_t * db, ip46_address_t * l_addr,
+			ip46_address_t * r_addr, u16 l_port, u16 r_port,
+			u8 proto, u32 fib_index, u8 is_ip6)
+{
+  nat64_db_st_entry_t *ste = 0;
+  nat64_db_st_entry_t *st;
+  nat64_db_st_entry_key_t ste_key;
+  clib_bihash_kv_48_8_t kv, value;
+
+  switch (ip_proto_to_snat_proto (proto))
+    {
+/* *INDENT-OFF* */
+#define _(N, i, n, s) \
+    case SNAT_PROTOCOL_##N: \
+      st = db->st._##n##_st; \
+      break;
+      foreach_snat_protocol
+#undef _
+/* *INDENT-ON* */
+    default:
+      st = db->st._unk_proto_st;
+      break;
+    }
+
+  memset (&ste_key, 0, sizeof (ste_key));
+  ste_key.l_addr.as_u64[0] = l_addr->as_u64[0];
+  ste_key.l_addr.as_u64[1] = l_addr->as_u64[1];
+  ste_key.r_addr.as_u64[0] = r_addr->as_u64[0];
+  ste_key.r_addr.as_u64[1] = r_addr->as_u64[1];
+  ste_key.fib_index = fib_index;
+  ste_key.l_port = l_port;
+  ste_key.r_port = r_port;
+  ste_key.proto = proto;
+  kv.key[0] = ste_key.as_u64[0];
+  kv.key[1] = ste_key.as_u64[1];
+  kv.key[2] = ste_key.as_u64[2];
+  kv.key[3] = ste_key.as_u64[3];
+  kv.key[4] = ste_key.as_u64[4];
+  kv.key[5] = ste_key.as_u64[5];
+
+  if (!clib_bihash_search_48_8
+      (is_ip6 ? &db->st.in2out : &db->st.out2in, &kv, &value))
+    ste = pool_elt_at_index (st, value.value);
+
+  return ste;
+}
+
+void
+nad64_db_st_free_expired (nat64_db_t * db, u32 now)
+{
+  u32 *ste_to_be_free = 0, *ste_index;
+  nat64_db_st_entry_t *st, *ste;
+
+/* *INDENT-OFF* */
+#define _(N, i, n, s) \
+  st = db->st._##n##_st; \
+  pool_foreach (ste, st, ({\
+    if (i == SNAT_PROTOCOL_TCP && !ste->tcp_state) \
+      continue; \
+    if (ste->expire < now) \
+      vec_add1 (ste_to_be_free, ste - st); \
+  })); \
+  vec_foreach (ste_index, ste_to_be_free) \
+    nat64_db_st_entry_free (db, pool_elt_at_index(st, ste_index[0])); \
+  vec_free (ste_to_be_free); \
+  ste_to_be_free = 0;
+  foreach_snat_protocol
+#undef _
+  st = db->st._unk_proto_st;
+  pool_foreach (ste, st, ({
+    if (ste->expire < now)
+      vec_add1 (ste_to_be_free, ste - st);
+  }));
+  vec_foreach (ste_index, ste_to_be_free)
+    nat64_db_st_entry_free (db, pool_elt_at_index(st, ste_index[0]));
+  vec_free (ste_to_be_free);
+/* *INDENT-ON* */
+}
+
+void
+nat64_db_free_out_addr (nat64_db_t * db, ip4_address_t * out_addr)
+{
+  u32 *ste_to_be_free = 0, *ste_index;
+  nat64_db_st_entry_t *st, *ste;
+  nat64_db_bib_entry_t *bibe;
+
+/* *INDENT-OFF* */
+#define _(N, i, n, s) \
+  st = db->st._##n##_st; \
+  pool_foreach (ste, st, ({ \
+    bibe = pool_elt_at_index (db->bib._##n##_bib, ste->bibe_index); \
+    if (bibe->out_addr.as_u32 == out_addr->as_u32) \
+      vec_add1 (ste_to_be_free, ste - st); \
+  })); \
+  vec_foreach (ste_index, ste_to_be_free) \
+    nat64_db_st_entry_free (db, pool_elt_at_index(st, ste_index[0])); \
+  vec_free (ste_to_be_free); \
+  ste_to_be_free = 0;
+  foreach_snat_protocol
+#undef _
+  st = db->st._unk_proto_st;
+  pool_foreach (ste, st, ({
+    bibe = pool_elt_at_index (db->bib._unk_proto_bib, ste->bibe_index);
+    if (bibe->out_addr.as_u32 == out_addr->as_u32)
+      vec_add1 (ste_to_be_free, ste - st);
+  }));
+  vec_foreach (ste_index, ste_to_be_free)
+    nat64_db_st_entry_free (db, pool_elt_at_index(st, ste_index[0]));
+  vec_free (ste_to_be_free);
+/* *INDENT-ON* */
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/plugins/nat/nat64_db.h b/src/plugins/nat/nat64_db.h
new file mode 100644
index 00000000000..394ca875bbb
--- /dev/null
+++ b/src/plugins/nat/nat64_db.h
@@ -0,0 +1,307 @@
+/*
+ * Copyright (c) 2017 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.
+ */
+/**
+ * @file
+ * @brief NAT64 DB
+ */
+#ifndef __included_nat64_db_h__
+#define __included_nat64_db_h__
+
+#include <vppinfra/bihash_24_8.h>
+#include <vppinfra/bihash_48_8.h>
+#include <nat/nat.h>
+
+
+typedef struct
+{
+  union
+  {
+    struct
+    {
+      ip46_address_t addr;
+      u32 fib_index;
+      u16 port;
+      u8 proto;
+      u8 rsvd;
+    };
+    u64 as_u64[3];
+  };
+} nat64_db_bib_entry_key_t;
+
+/* *INDENT-OFF* */
+typedef CLIB_PACKED(struct
+{
+  ip6_address_t in_addr;
+  u16 in_port;
+  ip4_address_t out_addr;
+  u16 out_port;
+  u32 fib_index;
+  u32 ses_num;
+  u8 proto;
+  u8 is_static;
+}) nat64_db_bib_entry_t;
+/* *INDENT-ON* */
+
+typedef struct
+{
+  /* BIBs */
+/* *INDENT-OFF* */
+#define _(N, i, n, s) \
+  nat64_db_bib_entry_t *_##n##_bib;
+  foreach_snat_protocol
+#undef _
+/* *INDENT-ON* */
+  nat64_db_bib_entry_t *_unk_proto_bib;
+
+  /* BIB lookup */
+  clib_bihash_24_8_t in2out;
+  clib_bihash_24_8_t out2in;
+} nat64_db_bib_t;
+
+typedef struct
+{
+  union
+  {
+    struct
+    {
+      ip46_address_t l_addr;
+      ip46_address_t r_addr;
+      u32 fib_index;
+      u16 l_port;
+      u16 r_port;
+      u8 proto;
+      u8 rsvd[7];
+    };
+    u64 as_u64[6];
+  };
+} nat64_db_st_entry_key_t;
+
+/* *INDENT-OFF* */
+typedef CLIB_PACKED(struct
+{
+  ip6_address_t in_r_addr;
+  ip4_address_t out_r_addr;
+  u16 r_port;
+  u32 bibe_index;
+  u32 expire;
+  u8 proto;
+  u8 tcp_state;
+}) nat64_db_st_entry_t;
+/* *INDENT-ON* */
+
+typedef struct
+{
+  /* session tables */
+/* *INDENT-OFF* */
+#define _(N, i, n, s) \
+  nat64_db_st_entry_t *_##n##_st;
+  foreach_snat_protocol
+#undef _
+/* *INDENT-ON* */
+  nat64_db_st_entry_t *_unk_proto_st;
+
+  /* session lookup */
+  clib_bihash_48_8_t in2out;
+  clib_bihash_48_8_t out2in;
+} nat64_db_st_t;
+
+typedef struct
+{
+  nat64_db_bib_t bib;
+  nat64_db_st_t st;
+} nat64_db_t;
+
+/**
+ * @brief Initialize NAT64 DB.
+ *
+ * @param db NAT64 DB.
+ *
+ * @returns 0 on success, non-zero value otherwise.
+ */
+int nat64_db_init (nat64_db_t * db);
+
+/**
+ * @brief Create new NAT64 BIB entry.
+ *
+ * @param db NAT64 DB.
+ * @param in_addr Inside IPv6 address.
+ * @param out_addr Outside IPv4 address.
+ * @param in_port Inside port number.
+ * @param out_port Outside port number.
+ * @param fib_index FIB index.
+ * @param proto L4 protocol.
+ * @param is_static 1 if static, 0 if dynamic.
+ *
+ * @returns BIB entry on success, 0 otherwise.
+ */
+nat64_db_bib_entry_t *nat64_db_bib_entry_create (nat64_db_t * db,
+						 ip6_address_t * in_addr,
+						 ip4_address_t * out_addr,
+						 u16 in_port, u16 out_port,
+						 u32 fib_index,
+						 u8 proto, u8 is_static);
+
+/**
+ * @brief Free NAT64 BIB entry.
+ *
+ * @param db NAT64 DB.
+ * @param bibe BIB entry.
+ */
+void nat64_db_bib_entry_free (nat64_db_t * db, nat64_db_bib_entry_t * bibe);
+
+/**
+ * @brief Call back function when walking NAT64 BIB, non-zero
+ * return value stop walk.
+ */
+typedef int (*nat64_db_bib_walk_fn_t) (nat64_db_bib_entry_t * bibe,
+				       void *ctx);
+/**
+ * @brief Walk NAT64 BIB.
+ *
+ * @param db NAT64 DB.
+ * @param proto BIB L4 protocol:
+ *  - 255 all BIBs
+ *  - 6 TCP BIB
+ *  - 17 UDP BIB
+ *  - 1/58 ICMP BIB
+ *  - otherwise "unknown" protocol BIB
+ * @param fn The function to invoke on each entry visited.
+ * @param ctx A context passed in the visit function.
+ */
+void nat64_db_bib_walk (nat64_db_t * db, u8 proto,
+			nat64_db_bib_walk_fn_t fn, void *ctx);
+
+/**
+ * @brief Find NAT64 BIB entry.
+ *
+ * @param db NAT64 DB.
+ * @param addr IP address.
+ * @param port Port number.
+ * @param proto L4 protocol.
+ * @param fib_index FIB index.
+ * @param is_ip6 1 if find by IPv6 (inside) address, 0 by IPv4 (outside).
+ *
+ * @return BIB entry if found.
+ */
+nat64_db_bib_entry_t *nat64_db_bib_entry_find (nat64_db_t * db,
+					       ip46_address_t * addr,
+					       u16 port,
+					       u8 proto,
+					       u32 fib_index, u8 is_ip6);
+
+/**
+ * @brief Get BIB entry by index and protocol.
+ *
+ * @param db NAT64 DB.
+ * @param proto L4 protocol.
+ * @param bibe_index BIB entry index.
+ *
+ * @return BIB entry if found.
+ */
+nat64_db_bib_entry_t *nat64_db_bib_entry_by_index (nat64_db_t * db,
+						   u8 proto, u32 bibe_index);
+/**
+ * @brief Create new NAT64 session table entry.
+ *
+ * @param db NAT64 DB.
+ * @param bibe Corresponding BIB entry.
+ * @param in_r_addr Inside IPv6 address of the remote host.
+ * @param out_r_addr Outside IPv4 address of the remote host.
+ * @param r_port Remote host port number.
+ *
+ * @returns BIB entry on success, 0 otherwise.
+ */
+nat64_db_st_entry_t *nat64_db_st_entry_create (nat64_db_t * db,
+					       nat64_db_bib_entry_t * bibe,
+					       ip6_address_t * in_r_addr,
+					       ip4_address_t * out_r_addr,
+					       u16 r_port);
+
+/**
+ * @brief Free NAT64 session table entry.
+ *
+ * @param db NAT64 DB.
+ * @param ste Session table entry.
+ */
+void nat64_db_st_entry_free (nat64_db_t * db, nat64_db_st_entry_t * ste);
+
+/**
+ * @brief Find NAT64 session table entry.
+ *
+ * @param db NAT64 DB.
+ * @param l_addr Local host address.
+ * @param r_addr Remote host address.
+ * @param l_port Local host port number.
+ * @param r_port Remote host port number.
+ * @param proto L4 protocol.
+ * @param fib_index FIB index.
+ * @param is_ip6 1 if find by IPv6 (inside) address, 0 by IPv4 (outside).
+ *
+ * @return BIB entry if found.
+ */
+nat64_db_st_entry_t *nat64_db_st_entry_find (nat64_db_t * db,
+					     ip46_address_t * l_addr,
+					     ip46_address_t * r_addr,
+					     u16 l_port, u16 r_port,
+					     u8 proto,
+					     u32 fib_index, u8 is_ip6);
+
+/**
+ * @brief Call back function when walking NAT64 session table, non-zero
+ * return value stop walk.
+ */
+typedef int (*nat64_db_st_walk_fn_t) (nat64_db_st_entry_t * ste, void *ctx);
+
+/**
+ * @brief Walk NAT64 session table.
+ *
+ * @param db NAT64 DB.
+ * @param proto L4 protocol:
+ *  - 255 all session tables
+ *  - 6 TCP session table
+ *  - 17 UDP session table
+ *  - 1/58 ICMP session table
+ *  - otherwise "unknown" protocol session table
+ * @param fn The function to invoke on each entry visited.
+ * @param ctx A context passed in the visit function.
+ */
+void nat64_db_st_walk (nat64_db_t * db, u8 proto,
+		       nat64_db_st_walk_fn_t fn, void *ctx);
+
+/**
+ * @brief Free expired session entries in session tables.
+ *
+ * @param db NAT64 DB.
+ * @param now Current time.
+ */
+void nad64_db_st_free_expired (nat64_db_t * db, u32 now);
+
+/**
+ * @brief Free sessions using specific outside address.
+ *
+ * @param db NAT64 DB.
+ * @param out_addr Outside address to match.
+ */
+void nat64_db_free_out_addr (nat64_db_t * db, ip4_address_t * out_addr);
+
+#endif /* __included_nat64_db_h__ */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/plugins/nat/nat64_doc.md b/src/plugins/nat/nat64_doc.md
new file mode 100644
index 00000000000..f94467dade1
--- /dev/null
+++ b/src/plugins/nat/nat64_doc.md
@@ -0,0 +1,73 @@
+# Stateful NAT64: Network Address and Protocol Translation from IPv6 Clients to IPv4 Servers {#nat64_doc}
+
+## Introduction
+
+Stateful NAT64 in VPP allows IPv6-only clients to contact IPv4 servers using unicast UDP, TCP, or ICMP based on RFC 6146.
+
+## Configuration
+
+### Enable/disable NAT64 feature on the interface
+
+> set interface nat64 in|out <intfc> [del]
+
+in: inside/local/IPv6 network
+out: outside/external/IPv4 network
+intfc: interface name
+
+### Add/delete NAT64 pool address
+
+One or more public IPv4 addresses assigned to a NAT64 are shared among several IPv6-only clients.
+
+> nat64 add pool address <ip4-range-start> [- <ip4-range-end>] [tenant-vrf <tenant-vrf-id>] [del]
+
+ip4-range-start: First IPv4 address of the range 
+ip4-range-end: Last IPv4 address of the range (optional, not used for single address)
+tenant-vrf-id: VRF id of the tenant associated with the pool address (optional, if not set pool address is global)
+
+### Add/delete static BIB entry
+
+Stateful NAT64 also supports IPv4-initiated communications to a subset of the IPv6 hosts through staticaly configured bindings.
+
+> nat64 add static bib <ip6-addr> <in-port> <ip4-addr> <out-port> tcp|udp|icmp [vfr <table-id>] [del]
+
+ip6-addr: inside IPv6 address of the host
+in-port: inside port or ICMPv6 identifier
+ip4-addr: outside IPv4 address of the host
+out-port: outside port or ICMPv4 identifier
+table-id: VRF id of the tenant associated with the BIB entry (optional, default use global VRF)
+
+### Set NAT64 session timeouts
+
+Session is deleted when timer expires. If all sessions corresponding to a dynamically create BIB entry are deleted, then the BIB entry is also deleted. When packets are flowing sessiom timer is refreshed to keep the session alive.
+
+> set nat64 timeouts udp <sec> icmp <sec> tcp-trans <sec> tcp-est <sec> tcp-incoming-syn <sec> | reset
+
+udp: UDP session timeout value (default 300sec)
+icmp: ICMP session timeout value (default 60sec)
+tcp-trans: transitory TCP session timeout value (default 240sec)
+tcp-est: established TCP session timeout value (default 7440sec)
+tcp-incoming-syn: incoming SYN TCP session timeout value (default 6sec)
+reset: reset timers to default values
+
+### Set NAT64 prefix 
+
+Stateful NAT64 support the algorithm for generating IPv6 representations of IPv4 addresses defined in RFC 6052. If no prefix is configured, Well-Known Prefix (64:ff9b::/96) is used. 
+
+> nat64 add prefix <ip6-prefix>/<plen> [tenant-vrf <vrf-id>] [del]
+
+ip6-prefix: IPv6 prefix
+plen: prefix length (valid values: 32, 40, 48, 56, 64, or 96)
+tenant-vrf: VRF id of the tenant associated with the prefix
+
+### Show commands
+
+> show nat64 pool
+> show nat64 interfaces
+> show nat64 bib tcp|udp|icmp
+> show nat64 session table tcp|udp|icmp
+> show nat64 tiemouts
+> show nat64 prefix
+
+## Notes
+
+Multi thread is not supported yet (CLI/API commands are disabled when VPP runs with multiple threads).
diff --git a/src/plugins/nat/nat64_in2out.c b/src/plugins/nat/nat64_in2out.c
new file mode 100644
index 00000000000..f78baff4e12
--- /dev/null
+++ b/src/plugins/nat/nat64_in2out.c
@@ -0,0 +1,1118 @@
+/*
+ * Copyright (c) 2017 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.
+ */
+/**
+ * @file
+ * @brief NAT64 IPv6 to IPv4 translation (inside to outside network)
+ */
+
+#include <nat/nat64.h>
+#include <vnet/ip/ip6_to_ip4.h>
+#include <vnet/fib/fib_table.h>
+
+typedef struct
+{
+  u32 sw_if_index;
+  u32 next_index;
+  u8 is_slow_path;
+} nat64_in2out_trace_t;
+
+static u8 *
+format_nat64_in2out_trace (u8 * s, va_list * args)
+{
+  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
+  nat64_in2out_trace_t *t = va_arg (*args, nat64_in2out_trace_t *);
+  char *tag;
+
+  tag = t->is_slow_path ? "NAT64-in2out-slowpath" : "NAT64-in2out";
+
+  s =
+    format (s, "%s: sw_if_index %d, next index %d", tag, t->sw_if_index,
+	    t->next_index);
+
+  return s;
+}
+
+vlib_node_registration_t nat64_in2out_node;
+vlib_node_registration_t nat64_in2out_slowpath_node;
+
+#define foreach_nat64_in2out_error                 \
+_(UNSUPPORTED_PROTOCOL, "unsupported protocol")    \
+_(IN2OUT_PACKETS, "good in2out packets processed") \
+_(NO_TRANSLATION, "no translation")                \
+_(UNKNOWN, "unknown")
+
+typedef enum
+{
+#define _(sym,str) NAT64_IN2OUT_ERROR_##sym,
+  foreach_nat64_in2out_error
+#undef _
+    NAT64_IN2OUT_N_ERROR,
+} nat64_in2out_error_t;
+
+static char *nat64_in2out_error_strings[] = {
+#define _(sym,string) string,
+  foreach_nat64_in2out_error
+#undef _
+};
+
+typedef enum
+{
+  NAT64_IN2OUT_NEXT_IP4_LOOKUP,
+  NAT64_IN2OUT_NEXT_IP6_LOOKUP,
+  NAT64_IN2OUT_NEXT_DROP,
+  NAT64_IN2OUT_NEXT_SLOWPATH,
+  NAT64_IN2OUT_N_NEXT,
+} nat64_in2out_next_t;
+
+typedef struct nat64_in2out_set_ctx_t_
+{
+  vlib_buffer_t *b;
+  vlib_main_t *vm;
+} nat64_in2out_set_ctx_t;
+
+/**
+ * @brief Check whether is a hairpinning.
+ *
+ * If the destination IP address of the packet is an IPv4 address assigned to
+ * the NAT64 itself, then the packet is a hairpin packet.
+ *
+ * param dst_addr Destination address of the packet.
+ *
+ * @returns 1 if hairpinning, otherwise 0.
+ */
+static_always_inline int
+is_hairpinning (ip6_address_t * dst_addr)
+{
+  nat64_main_t *nm = &nat64_main;
+  int i;
+
+  for (i = 0; i < vec_len (nm->addr_pool); i++)
+    {
+      if (nm->addr_pool[i].addr.as_u32 == dst_addr->as_u32[3])
+	return 1;
+    }
+
+  return 0;
+}
+
+static int
+nat64_in2out_tcp_udp_set_cb (ip6_header_t * ip6, ip4_header_t * ip4,
+			     void *arg)
+{
+  nat64_main_t *nm = &nat64_main;
+  nat64_in2out_set_ctx_t *ctx = arg;
+  nat64_db_bib_entry_t *bibe;
+  nat64_db_st_entry_t *ste;
+  ip46_address_t saddr, daddr;
+  u32 sw_if_index, fib_index;
+  udp_header_t *udp = ip6_next_header (ip6);
+  u8 proto = ip6->protocol;
+  u16 sport = udp->src_port;
+  u16 dport = udp->dst_port;
+
+  sw_if_index = vnet_buffer (ctx->b)->sw_if_index[VLIB_RX];
+  fib_index =
+    fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP6, sw_if_index);
+
+  saddr.as_u64[0] = ip6->src_address.as_u64[0];
+  saddr.as_u64[1] = ip6->src_address.as_u64[1];
+  daddr.as_u64[0] = ip6->dst_address.as_u64[0];
+  daddr.as_u64[1] = ip6->dst_address.as_u64[1];
+
+  ste =
+    nat64_db_st_entry_find (&nm->db, &saddr, &daddr, sport, dport, proto,
+			    fib_index, 1);
+
+  if (ste)
+    {
+      bibe = nat64_db_bib_entry_by_index (&nm->db, proto, ste->bibe_index);
+      if (!bibe)
+	return -1;
+    }
+  else
+    {
+      bibe =
+	nat64_db_bib_entry_find (&nm->db, &saddr, sport, proto, fib_index, 1);
+
+      if (!bibe)
+	{
+	  u16 out_port;
+	  ip4_address_t out_addr;
+	  if (nat64_alloc_out_addr_and_port
+	      (fib_index, ip_proto_to_snat_proto (proto), &out_addr,
+	       &out_port))
+	    return -1;
+
+	  bibe =
+	    nat64_db_bib_entry_create (&nm->db, &ip6->src_address, &out_addr,
+				       sport, clib_host_to_net_u16 (out_port),
+				       fib_index, proto, 0);
+	  if (!bibe)
+	    return -1;
+	}
+
+      nat64_extract_ip4 (&ip6->dst_address, &daddr.ip4, fib_index);
+      ste =
+	nat64_db_st_entry_create (&nm->db, bibe, &ip6->dst_address,
+				  &daddr.ip4, dport);
+      if (!ste)
+	return -1;
+    }
+
+  nat64_session_reset_timeout (ste, ctx->vm);
+
+  ip4->src_address.as_u32 = bibe->out_addr.as_u32;
+  udp->src_port = bibe->out_port;
+
+  ip4->dst_address.as_u32 = ste->out_r_addr.as_u32;
+
+  if (proto == IP_PROTOCOL_TCP)
+    {
+      u16 *checksum;
+      ip_csum_t csum;
+      tcp_header_t *tcp = ip6_next_header (ip6);
+
+      checksum = &tcp->checksum;
+      csum = ip_csum_sub_even (*checksum, sport);
+      csum = ip_csum_add_even (csum, udp->src_port);
+      *checksum = ip_csum_fold (csum);
+    }
+
+  return 0;
+}
+
+static int
+nat64_in2out_icmp_set_cb (ip6_header_t * ip6, ip4_header_t * ip4, void *arg)
+{
+  nat64_main_t *nm = &nat64_main;
+  nat64_in2out_set_ctx_t *ctx = arg;
+  nat64_db_bib_entry_t *bibe;
+  nat64_db_st_entry_t *ste;
+  ip46_address_t saddr, daddr;
+  u32 sw_if_index, fib_index;
+  icmp46_header_t *icmp = ip6_next_header (ip6);
+
+  sw_if_index = vnet_buffer (ctx->b)->sw_if_index[VLIB_RX];
+  fib_index =
+    fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP6, sw_if_index);
+
+  saddr.as_u64[0] = ip6->src_address.as_u64[0];
+  saddr.as_u64[1] = ip6->src_address.as_u64[1];
+  daddr.as_u64[0] = ip6->dst_address.as_u64[0];
+  daddr.as_u64[1] = ip6->dst_address.as_u64[1];
+
+  if (icmp->type == ICMP4_echo_request || icmp->type == ICMP4_echo_reply)
+    {
+      u16 in_id = ((u16 *) (icmp))[2];
+      ste =
+	nat64_db_st_entry_find (&nm->db, &saddr, &daddr, in_id, 0,
+				IP_PROTOCOL_ICMP, fib_index, 1);
+
+      if (ste)
+	{
+	  bibe =
+	    nat64_db_bib_entry_by_index (&nm->db, IP_PROTOCOL_ICMP,
+					 ste->bibe_index);
+	  if (!bibe)
+	    return -1;
+	}
+      else
+	{
+	  bibe =
+	    nat64_db_bib_entry_find (&nm->db, &saddr, in_id,
+				     IP_PROTOCOL_ICMP, fib_index, 1);
+
+	  if (!bibe)
+	    {
+	      u16 out_id;
+	      ip4_address_t out_addr;
+	      if (nat64_alloc_out_addr_and_port
+		  (fib_index, SNAT_PROTOCOL_ICMP, &out_addr, &out_id))
+		return -1;
+
+	      bibe =
+		nat64_db_bib_entry_create (&nm->db, &ip6->src_address,
+					   &out_addr, in_id,
+					   clib_host_to_net_u16 (out_id),
+					   fib_index, IP_PROTOCOL_ICMP, 0);
+	      if (!bibe)
+		return -1;
+	    }
+
+	  nat64_extract_ip4 (&ip6->dst_address, &daddr.ip4, fib_index);
+	  ste =
+	    nat64_db_st_entry_create (&nm->db, bibe, &ip6->dst_address,
+				      &daddr.ip4, 0);
+	  if (!ste)
+	    return -1;
+	}
+
+      nat64_session_reset_timeout (ste, ctx->vm);
+
+      ip4->src_address.as_u32 = bibe->out_addr.as_u32;
+      ((u16 *) (icmp))[2] = bibe->out_port;
+
+      ip4->dst_address.as_u32 = ste->out_r_addr.as_u32;
+    }
+  else
+    {
+      if (!vec_len (nm->addr_pool))
+	return -1;
+
+      ip4->src_address.as_u32 = nm->addr_pool[0].addr.as_u32;
+      nat64_extract_ip4 (&ip6->dst_address, &ip4->dst_address, fib_index);
+    }
+
+  return 0;
+}
+
+static int
+nat64_in2out_inner_icmp_set_cb (ip6_header_t * ip6, ip4_header_t * ip4,
+				void *arg)
+{
+  nat64_main_t *nm = &nat64_main;
+  nat64_in2out_set_ctx_t *ctx = arg;
+  nat64_db_st_entry_t *ste;
+  nat64_db_bib_entry_t *bibe;
+  ip46_address_t saddr, daddr;
+  u32 sw_if_index, fib_index;
+  u8 proto = ip6->protocol;
+
+  sw_if_index = vnet_buffer (ctx->b)->sw_if_index[VLIB_RX];
+  fib_index =
+    fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP6, sw_if_index);
+
+  saddr.as_u64[0] = ip6->src_address.as_u64[0];
+  saddr.as_u64[1] = ip6->src_address.as_u64[1];
+  daddr.as_u64[0] = ip6->dst_address.as_u64[0];
+  daddr.as_u64[1] = ip6->dst_address.as_u64[1];
+
+  if (proto == IP_PROTOCOL_ICMP6)
+    {
+      icmp46_header_t *icmp = ip6_next_header (ip6);
+      u16 in_id = ((u16 *) (icmp))[2];
+      proto = IP_PROTOCOL_ICMP;
+
+      if (!
+	  (icmp->type == ICMP4_echo_request
+	   || icmp->type == ICMP4_echo_reply))
+	return -1;
+
+      ste =
+	nat64_db_st_entry_find (&nm->db, &daddr, &saddr, in_id, 0, proto,
+				fib_index, 1);
+      if (!ste)
+	return -1;
+
+      bibe = nat64_db_bib_entry_by_index (&nm->db, proto, ste->bibe_index);
+      if (!bibe)
+	return -1;
+
+      ip4->dst_address.as_u32 = bibe->out_addr.as_u32;
+      ((u16 *) (icmp))[2] = bibe->out_port;
+      ip4->src_address.as_u32 = ste->out_r_addr.as_u32;
+    }
+  else
+    {
+      udp_header_t *udp = ip6_next_header (ip6);
+      tcp_header_t *tcp = ip6_next_header (ip6);
+      u16 *checksum;
+      ip_csum_t csum;
+
+      u16 sport = udp->src_port;
+      u16 dport = udp->dst_port;
+
+      ste =
+	nat64_db_st_entry_find (&nm->db, &daddr, &saddr, dport, sport, proto,
+				fib_index, 1);
+      if (!ste)
+	return -1;
+
+      bibe = nat64_db_bib_entry_by_index (&nm->db, proto, ste->bibe_index);
+      if (!bibe)
+	return -1;
+
+      ip4->dst_address.as_u32 = bibe->out_addr.as_u32;
+      udp->dst_port = bibe->out_port;
+      ip4->src_address.as_u32 = ste->out_r_addr.as_u32;
+
+      if (proto == IP_PROTOCOL_TCP)
+	checksum = &tcp->checksum;
+      else
+	checksum = &udp->checksum;
+      csum = ip_csum_sub_even (*checksum, dport);
+      csum = ip_csum_add_even (csum, udp->dst_port);
+      *checksum = ip_csum_fold (csum);
+    }
+
+  return 0;
+}
+
+typedef struct unk_proto_st_walk_ctx_t_
+{
+  ip6_address_t src_addr;
+  ip6_address_t dst_addr;
+  ip4_address_t out_addr;
+  u32 fib_index;
+  u8 proto;
+} unk_proto_st_walk_ctx_t;
+
+static int
+unk_proto_st_walk (nat64_db_st_entry_t * ste, void *arg)
+{
+  nat64_main_t *nm = &nat64_main;
+  unk_proto_st_walk_ctx_t *ctx = arg;
+  nat64_db_bib_entry_t *bibe;
+  ip46_address_t saddr, daddr;
+
+  if (ip46_address_is_equal (&ste->in_r_addr, &ctx->dst_addr))
+    {
+      bibe =
+	nat64_db_bib_entry_by_index (&nm->db, ste->proto, ste->bibe_index);
+      if (!bibe)
+	return -1;
+
+      if (ip46_address_is_equal (&bibe->in_addr, &ctx->src_addr)
+	  && bibe->fib_index == ctx->fib_index)
+	{
+	  memset (&saddr, 0, sizeof (saddr));
+	  saddr.ip4.as_u32 = bibe->out_addr.as_u32;
+	  memset (&daddr, 0, sizeof (daddr));
+	  nat64_extract_ip4 (&ctx->dst_addr, &daddr.ip4, ctx->fib_index);
+
+	  if (nat64_db_st_entry_find
+	      (&nm->db, &daddr, &saddr, 0, 0, ctx->proto, ctx->fib_index, 0))
+	    return -1;
+
+	  ctx->out_addr.as_u32 = bibe->out_addr.as_u32;
+	  return 1;
+	}
+    }
+
+  return 0;
+}
+
+static int
+nat64_in2out_unk_proto_set_cb (ip6_header_t * ip6, ip4_header_t * ip4,
+			       void *arg)
+{
+  nat64_main_t *nm = &nat64_main;
+  nat64_in2out_set_ctx_t *ctx = arg;
+  nat64_db_bib_entry_t *bibe;
+  nat64_db_st_entry_t *ste;
+  ip46_address_t saddr, daddr, addr;
+  u32 sw_if_index, fib_index;
+  u8 proto = ip6->protocol;
+  int i;
+
+  sw_if_index = vnet_buffer (ctx->b)->sw_if_index[VLIB_RX];
+  fib_index =
+    fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP6, sw_if_index);
+
+  saddr.as_u64[0] = ip6->src_address.as_u64[0];
+  saddr.as_u64[1] = ip6->src_address.as_u64[1];
+  daddr.as_u64[0] = ip6->dst_address.as_u64[0];
+  daddr.as_u64[1] = ip6->dst_address.as_u64[1];
+
+  ste =
+    nat64_db_st_entry_find (&nm->db, &saddr, &daddr, 0, 0, proto, fib_index,
+			    1);
+
+  if (ste)
+    {
+      bibe = nat64_db_bib_entry_by_index (&nm->db, proto, ste->bibe_index);
+      if (!bibe)
+	return -1;
+    }
+  else
+    {
+      bibe =
+	nat64_db_bib_entry_find (&nm->db, &saddr, 0, proto, fib_index, 1);
+
+      if (!bibe)
+	{
+	  /* Choose same out address as for TCP/UDP session to same dst */
+	  unk_proto_st_walk_ctx_t ctx = {
+	    .src_addr.as_u64[0] = ip6->src_address.as_u64[0],
+	    .src_addr.as_u64[1] = ip6->src_address.as_u64[1],
+	    .dst_addr.as_u64[0] = ip6->dst_address.as_u64[0],
+	    .dst_addr.as_u64[1] = ip6->dst_address.as_u64[1],
+	    .out_addr.as_u32 = 0,
+	    .fib_index = fib_index,
+	    .proto = proto,
+	  };
+
+	  nat64_db_st_walk (&nm->db, IP_PROTOCOL_TCP, unk_proto_st_walk,
+			    &ctx);
+
+	  if (!ctx.out_addr.as_u32)
+	    nat64_db_st_walk (&nm->db, IP_PROTOCOL_UDP, unk_proto_st_walk,
+			      &ctx);
+
+	  /* Verify if out address is not already in use for protocol */
+	  memset (&addr, 0, sizeof (addr));
+	  addr.ip4.as_u32 = ctx.out_addr.as_u32;
+	  if (nat64_db_bib_entry_find (&nm->db, &addr, 0, proto, 0, 0))
+	    ctx.out_addr.as_u32 = 0;
+
+	  if (!ctx.out_addr.as_u32)
+	    {
+	      for (i = 0; i < vec_len (nm->addr_pool); i++)
+		{
+		  addr.ip4.as_u32 = nm->addr_pool[i].addr.as_u32;
+		  if (!nat64_db_bib_entry_find
+		      (&nm->db, &addr, 0, proto, 0, 0))
+		    break;
+		}
+	    }
+
+	  if (!ctx.out_addr.as_u32)
+	    return -1;
+
+	  bibe =
+	    nat64_db_bib_entry_create (&nm->db, &ip6->src_address,
+				       &ctx.out_addr, 0, 0, fib_index, proto,
+				       0);
+	  if (!bibe)
+	    return -1;
+	}
+
+      nat64_extract_ip4 (&ip6->dst_address, &daddr.ip4, fib_index);
+      ste =
+	nat64_db_st_entry_create (&nm->db, bibe, &ip6->dst_address,
+				  &daddr.ip4, 0);
+      if (!ste)
+	return -1;
+    }
+
+  nat64_session_reset_timeout (ste, ctx->vm);
+
+  ip4->src_address.as_u32 = bibe->out_addr.as_u32;
+  ip4->dst_address.as_u32 = ste->out_r_addr.as_u32;
+
+  return 0;
+}
+
+
+
+static int
+nat64_in2out_tcp_udp_hairpinning (vlib_main_t * vm, vlib_buffer_t * b,
+				  ip6_header_t * ip6)
+{
+  nat64_main_t *nm = &nat64_main;
+  nat64_db_bib_entry_t *bibe;
+  nat64_db_st_entry_t *ste;
+  ip46_address_t saddr, daddr;
+  u32 sw_if_index, fib_index;
+  udp_header_t *udp = ip6_next_header (ip6);
+  tcp_header_t *tcp = ip6_next_header (ip6);
+  u8 proto = ip6->protocol;
+  u16 sport = udp->src_port;
+  u16 dport = udp->dst_port;
+  u16 *checksum;
+  ip_csum_t csum;
+
+  sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
+  fib_index =
+    fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP6, sw_if_index);
+
+  saddr.as_u64[0] = ip6->src_address.as_u64[0];
+  saddr.as_u64[1] = ip6->src_address.as_u64[1];
+  daddr.as_u64[0] = ip6->dst_address.as_u64[0];
+  daddr.as_u64[1] = ip6->dst_address.as_u64[1];
+
+  if (proto == IP_PROTOCOL_UDP)
+    checksum = &udp->checksum;
+  else
+    checksum = &tcp->checksum;
+
+  csum = ip_csum_sub_even (*checksum, ip6->src_address.as_u64[0]);
+  csum = ip_csum_sub_even (csum, ip6->src_address.as_u64[1]);
+  csum = ip_csum_sub_even (csum, ip6->dst_address.as_u64[0]);
+  csum = ip_csum_sub_even (csum, ip6->dst_address.as_u64[1]);
+  csum = ip_csum_sub_even (csum, sport);
+  csum = ip_csum_sub_even (csum, dport);
+
+  ste =
+    nat64_db_st_entry_find (&nm->db, &saddr, &daddr, sport, dport, proto,
+			    fib_index, 1);
+
+  if (ste)
+    {
+      bibe = nat64_db_bib_entry_by_index (&nm->db, proto, ste->bibe_index);
+      if (!bibe)
+	return -1;
+    }
+  else
+    {
+      bibe =
+	nat64_db_bib_entry_find (&nm->db, &saddr, sport, proto, fib_index, 1);
+
+      if (!bibe)
+	{
+	  u16 out_port;
+	  ip4_address_t out_addr;
+	  if (nat64_alloc_out_addr_and_port
+	      (fib_index, ip_proto_to_snat_proto (proto), &out_addr,
+	       &out_port))
+	    return -1;
+
+	  bibe =
+	    nat64_db_bib_entry_create (&nm->db, &ip6->src_address, &out_addr,
+				       sport, clib_host_to_net_u16 (out_port),
+				       fib_index, proto, 0);
+	  if (!bibe)
+	    return -1;
+	}
+
+      nat64_extract_ip4 (&ip6->dst_address, &daddr.ip4, fib_index);
+      ste =
+	nat64_db_st_entry_create (&nm->db, bibe, &ip6->dst_address,
+				  &daddr.ip4, dport);
+      if (!ste)
+	return -1;
+    }
+
+  nat64_session_reset_timeout (ste, vm);
+
+  sport = udp->src_port = bibe->out_port;
+  nat64_compose_ip6 (&ip6->src_address, &bibe->out_addr, fib_index);
+
+  memset (&saddr, 0, sizeof (saddr));
+  memset (&daddr, 0, sizeof (daddr));
+  saddr.ip4.as_u32 = bibe->out_addr.as_u32;
+  daddr.ip4.as_u32 = ste->out_r_addr.as_u32;
+
+  ste =
+    nat64_db_st_entry_find (&nm->db, &daddr, &saddr, dport, sport, proto, 0,
+			    0);
+
+  if (ste)
+    {
+      bibe = nat64_db_bib_entry_by_index (&nm->db, proto, ste->bibe_index);
+      if (!bibe)
+	return -1;
+    }
+  else
+    {
+      bibe = nat64_db_bib_entry_find (&nm->db, &daddr, dport, proto, 0, 0);
+
+      if (!bibe)
+	return -1;
+
+      ste =
+	nat64_db_st_entry_create (&nm->db, bibe, &ip6->src_address,
+				  &saddr.ip4, sport);
+    }
+
+  ip6->dst_address.as_u64[0] = bibe->in_addr.as_u64[0];
+  ip6->dst_address.as_u64[1] = bibe->in_addr.as_u64[1];
+  udp->dst_port = bibe->in_port;
+
+  csum = ip_csum_add_even (csum, ip6->src_address.as_u64[0]);
+  csum = ip_csum_add_even (csum, ip6->src_address.as_u64[1]);
+  csum = ip_csum_add_even (csum, ip6->dst_address.as_u64[0]);
+  csum = ip_csum_add_even (csum, ip6->dst_address.as_u64[1]);
+  csum = ip_csum_add_even (csum, udp->src_port);
+  csum = ip_csum_add_even (csum, udp->dst_port);
+  *checksum = ip_csum_fold (csum);
+
+  return 0;
+}
+
+static int
+nat64_in2out_icmp_hairpinning (vlib_main_t * vm, vlib_buffer_t * b,
+			       ip6_header_t * ip6)
+{
+  nat64_main_t *nm = &nat64_main;
+  nat64_db_bib_entry_t *bibe;
+  nat64_db_st_entry_t *ste;
+  icmp46_header_t *icmp = ip6_next_header (ip6);
+  ip6_header_t *inner_ip6;
+  ip46_address_t saddr, daddr;
+  u32 sw_if_index, fib_index;
+  u8 proto;
+  udp_header_t *udp;
+  tcp_header_t *tcp;
+  u16 *checksum, sport, dport;
+  ip_csum_t csum;
+
+  if (icmp->type == ICMP6_echo_request || icmp->type == ICMP6_echo_reply)
+    return -1;
+
+  inner_ip6 = (ip6_header_t *) u8_ptr_add (icmp, 8);
+
+  proto = inner_ip6->protocol;
+
+  if (proto == IP_PROTOCOL_ICMP6)
+    return -1;
+
+  sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
+  fib_index =
+    fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP6, sw_if_index);
+
+  saddr.as_u64[0] = inner_ip6->src_address.as_u64[0];
+  saddr.as_u64[1] = inner_ip6->src_address.as_u64[1];
+  daddr.as_u64[0] = inner_ip6->dst_address.as_u64[0];
+  daddr.as_u64[1] = inner_ip6->dst_address.as_u64[1];
+
+  udp = ip6_next_header (inner_ip6);
+  tcp = ip6_next_header (inner_ip6);
+
+  sport = udp->src_port;
+  dport = udp->dst_port;
+
+  if (proto == IP_PROTOCOL_UDP)
+    checksum = &udp->checksum;
+  else
+    checksum = &tcp->checksum;
+
+  csum = ip_csum_sub_even (*checksum, inner_ip6->src_address.as_u64[0]);
+  csum = ip_csum_sub_even (csum, inner_ip6->src_address.as_u64[1]);
+  csum = ip_csum_sub_even (csum, inner_ip6->dst_address.as_u64[0]);
+  csum = ip_csum_sub_even (csum, inner_ip6->dst_address.as_u64[1]);
+  csum = ip_csum_sub_even (csum, sport);
+  csum = ip_csum_sub_even (csum, dport);
+
+  ste =
+    nat64_db_st_entry_find (&nm->db, &daddr, &saddr, dport, sport, proto,
+			    fib_index, 1);
+  if (!ste)
+    return -1;
+
+  bibe = nat64_db_bib_entry_by_index (&nm->db, proto, ste->bibe_index);
+  if (!bibe)
+    return -1;
+
+  dport = udp->dst_port = bibe->out_port;
+  nat64_compose_ip6 (&inner_ip6->dst_address, &bibe->out_addr, fib_index);
+
+  memset (&saddr, 0, sizeof (saddr));
+  memset (&daddr, 0, sizeof (daddr));
+  saddr.ip4.as_u32 = ste->out_r_addr.as_u32;
+  daddr.ip4.as_u32 = bibe->out_addr.as_u32;
+
+  ste =
+    nat64_db_st_entry_find (&nm->db, &saddr, &daddr, sport, dport, proto, 0,
+			    0);
+  if (!ste)
+    return -1;
+
+  bibe = nat64_db_bib_entry_by_index (&nm->db, proto, ste->bibe_index);
+  if (!bibe)
+    return -1;
+
+  inner_ip6->src_address.as_u64[0] = bibe->in_addr.as_u64[0];
+  inner_ip6->src_address.as_u64[1] = bibe->in_addr.as_u64[1];
+  udp->src_port = bibe->in_port;
+
+  csum = ip_csum_add_even (csum, inner_ip6->src_address.as_u64[0]);
+  csum = ip_csum_add_even (csum, inner_ip6->src_address.as_u64[1]);
+  csum = ip_csum_add_even (csum, inner_ip6->dst_address.as_u64[0]);
+  csum = ip_csum_add_even (csum, inner_ip6->dst_address.as_u64[1]);
+  csum = ip_csum_add_even (csum, udp->src_port);
+  csum = ip_csum_add_even (csum, udp->dst_port);
+  *checksum = ip_csum_fold (csum);
+
+  if (!vec_len (nm->addr_pool))
+    return -1;
+
+  nat64_compose_ip6 (&ip6->src_address, &nm->addr_pool[0].addr, fib_index);
+  ip6->dst_address.as_u64[0] = inner_ip6->src_address.as_u64[0];
+  ip6->dst_address.as_u64[1] = inner_ip6->src_address.as_u64[1];
+
+  icmp->checksum = 0;
+  csum = ip_csum_with_carry (0, ip6->payload_length);
+  csum = ip_csum_with_carry (csum, clib_host_to_net_u16 (ip6->protocol));
+  csum = ip_csum_with_carry (csum, ip6->src_address.as_u64[0]);
+  csum = ip_csum_with_carry (csum, ip6->src_address.as_u64[1]);
+  csum = ip_csum_with_carry (csum, ip6->dst_address.as_u64[0]);
+  csum = ip_csum_with_carry (csum, ip6->dst_address.as_u64[1]);
+  csum =
+    ip_incremental_checksum (csum, icmp,
+			     clib_net_to_host_u16 (ip6->payload_length));
+  icmp->checksum = ~ip_csum_fold (csum);
+
+  return 0;
+}
+
+static int
+nat64_in2out_unk_proto_hairpinning (vlib_main_t * vm, vlib_buffer_t * b,
+				    ip6_header_t * ip6)
+{
+  nat64_main_t *nm = &nat64_main;
+  nat64_db_bib_entry_t *bibe;
+  nat64_db_st_entry_t *ste;
+  ip46_address_t saddr, daddr, addr;
+  u32 sw_if_index, fib_index;
+  u8 proto = ip6->protocol;
+  int i;
+
+  sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
+  fib_index =
+    fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP6, sw_if_index);
+
+  saddr.as_u64[0] = ip6->src_address.as_u64[0];
+  saddr.as_u64[1] = ip6->src_address.as_u64[1];
+  daddr.as_u64[0] = ip6->dst_address.as_u64[0];
+  daddr.as_u64[1] = ip6->dst_address.as_u64[1];
+
+  ste =
+    nat64_db_st_entry_find (&nm->db, &saddr, &daddr, 0, 0, proto, fib_index,
+			    1);
+
+  if (ste)
+    {
+      bibe = nat64_db_bib_entry_by_index (&nm->db, proto, ste->bibe_index);
+      if (!bibe)
+	return -1;
+    }
+  else
+    {
+      bibe =
+	nat64_db_bib_entry_find (&nm->db, &saddr, 0, proto, fib_index, 1);
+
+      if (!bibe)
+	{
+	  /* Choose same out address as for TCP/UDP session to same dst */
+	  unk_proto_st_walk_ctx_t ctx = {
+	    .src_addr.as_u64[0] = ip6->src_address.as_u64[0],
+	    .src_addr.as_u64[1] = ip6->src_address.as_u64[1],
+	    .dst_addr.as_u64[0] = ip6->dst_address.as_u64[0],
+	    .dst_addr.as_u64[1] = ip6->dst_address.as_u64[1],
+	    .out_addr.as_u32 = 0,
+	    .fib_index = fib_index,
+	    .proto = proto,
+	  };
+
+	  nat64_db_st_walk (&nm->db, IP_PROTOCOL_TCP, unk_proto_st_walk,
+			    &ctx);
+
+	  if (!ctx.out_addr.as_u32)
+	    nat64_db_st_walk (&nm->db, IP_PROTOCOL_UDP, unk_proto_st_walk,
+			      &ctx);
+
+	  /* Verify if out address is not already in use for protocol */
+	  memset (&addr, 0, sizeof (addr));
+	  addr.ip4.as_u32 = ctx.out_addr.as_u32;
+	  if (nat64_db_bib_entry_find (&nm->db, &addr, 0, proto, 0, 0))
+	    ctx.out_addr.as_u32 = 0;
+
+	  if (!ctx.out_addr.as_u32)
+	    {
+	      for (i = 0; i < vec_len (nm->addr_pool); i++)
+		{
+		  addr.ip4.as_u32 = nm->addr_pool[i].addr.as_u32;
+		  if (!nat64_db_bib_entry_find
+		      (&nm->db, &addr, 0, proto, 0, 0))
+		    break;
+		}
+	    }
+
+	  if (!ctx.out_addr.as_u32)
+	    return -1;
+
+	  bibe =
+	    nat64_db_bib_entry_create (&nm->db, &ip6->src_address,
+				       &ctx.out_addr, 0, 0, fib_index, proto,
+				       0);
+	  if (!bibe)
+	    return -1;
+	}
+
+      nat64_extract_ip4 (&ip6->dst_address, &daddr.ip4, fib_index);
+      ste =
+	nat64_db_st_entry_create (&nm->db, bibe, &ip6->dst_address,
+				  &daddr.ip4, 0);
+      if (!ste)
+	return -1;
+    }
+
+  nat64_session_reset_timeout (ste, vm);
+
+  nat64_compose_ip6 (&ip6->src_address, &bibe->out_addr, fib_index);
+
+  memset (&saddr, 0, sizeof (saddr));
+  memset (&daddr, 0, sizeof (daddr));
+  saddr.ip4.as_u32 = bibe->out_addr.as_u32;
+  daddr.ip4.as_u32 = ste->out_r_addr.as_u32;
+
+  ste = nat64_db_st_entry_find (&nm->db, &daddr, &saddr, 0, 0, proto, 0, 0);
+
+  if (ste)
+    {
+      bibe = nat64_db_bib_entry_by_index (&nm->db, proto, ste->bibe_index);
+      if (!bibe)
+	return -1;
+    }
+  else
+    {
+      bibe = nat64_db_bib_entry_find (&nm->db, &daddr, 0, proto, 0, 0);
+
+      if (!bibe)
+	return -1;
+
+      ste =
+	nat64_db_st_entry_create (&nm->db, bibe, &ip6->src_address,
+				  &saddr.ip4, 0);
+    }
+
+  ip6->dst_address.as_u64[0] = bibe->in_addr.as_u64[0];
+  ip6->dst_address.as_u64[1] = bibe->in_addr.as_u64[1];
+
+  return 0;
+}
+
+static inline uword
+nat64_in2out_node_fn_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
+			     vlib_frame_t * frame, u8 is_slow_path)
+{
+  u32 n_left_from, *from, *to_next;
+  nat64_in2out_next_t next_index;
+  u32 pkts_processed = 0;
+  u32 stats_node_index;
+
+  stats_node_index =
+    is_slow_path ? nat64_in2out_slowpath_node.index : nat64_in2out_node.index;
+
+  from = vlib_frame_vector_args (frame);
+  n_left_from = frame->n_vectors;
+  next_index = node->cached_next_index;
+
+  while (n_left_from > 0)
+    {
+      u32 n_left_to_next;
+
+      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+	  u32 bi0;
+	  vlib_buffer_t *b0;
+	  u32 next0;
+	  ip6_header_t *ip60;
+	  u16 l4_offset0, frag_offset0;
+	  u8 l4_protocol0;
+	  u32 proto0;
+	  nat64_in2out_set_ctx_t ctx0;
+
+	  /* speculatively enqueue b0 to the current next frame */
+	  bi0 = from[0];
+	  to_next[0] = bi0;
+	  from += 1;
+	  to_next += 1;
+	  n_left_from -= 1;
+	  n_left_to_next -= 1;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+	  ip60 = vlib_buffer_get_current (b0);
+
+	  ctx0.b = b0;
+	  ctx0.vm = vm;
+
+	  next0 = NAT64_IN2OUT_NEXT_IP4_LOOKUP;
+
+	  if (PREDICT_FALSE
+	      (ip6_parse
+	       (ip60, b0->current_length, &l4_protocol0, &l4_offset0,
+		&frag_offset0)))
+	    {
+	      next0 = NAT64_IN2OUT_NEXT_DROP;
+	      b0->error = node->errors[NAT64_IN2OUT_ERROR_UNKNOWN];
+	      goto trace0;
+	    }
+
+	  proto0 = ip_proto_to_snat_proto (l4_protocol0);
+	  if (frag_offset0 != 0)
+	    {
+	      next0 = NAT64_IN2OUT_NEXT_DROP;
+	      b0->error =
+		node->errors[NAT64_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL];
+	      goto trace0;
+	    }
+
+	  if (is_slow_path)
+	    {
+	      if (PREDICT_TRUE (proto0 == ~0))
+		{
+		  if (is_hairpinning (&ip60->dst_address))
+		    {
+		      next0 = NAT64_IN2OUT_NEXT_IP6_LOOKUP;
+		      if (nat64_in2out_unk_proto_hairpinning (vm, b0, ip60))
+			{
+			  next0 = NAT64_IN2OUT_NEXT_DROP;
+			  b0->error =
+			    node->errors[NAT64_IN2OUT_ERROR_NO_TRANSLATION];
+			}
+		      goto trace0;
+		    }
+
+		  if (ip6_to_ip4 (b0, nat64_in2out_unk_proto_set_cb, &ctx0))
+		    {
+		      next0 = NAT64_IN2OUT_NEXT_DROP;
+		      b0->error =
+			node->errors[NAT64_IN2OUT_ERROR_NO_TRANSLATION];
+		      goto trace0;
+		    }
+		}
+	      goto trace0;
+	    }
+	  else
+	    {
+	      if (PREDICT_FALSE (proto0 == ~0))
+		{
+		  next0 = NAT64_IN2OUT_NEXT_SLOWPATH;
+		  goto trace0;
+		}
+	    }
+
+	  if (proto0 == SNAT_PROTOCOL_ICMP)
+	    {
+	      if (is_hairpinning (&ip60->dst_address))
+		{
+		  next0 = NAT64_IN2OUT_NEXT_IP6_LOOKUP;
+		  if (nat64_in2out_icmp_hairpinning (vm, b0, ip60))
+		    {
+		      next0 = NAT64_IN2OUT_NEXT_DROP;
+		      b0->error =
+			node->errors[NAT64_IN2OUT_ERROR_NO_TRANSLATION];
+		    }
+		  goto trace0;
+		}
+
+	      if (icmp6_to_icmp
+		  (b0, nat64_in2out_icmp_set_cb, &ctx0,
+		   nat64_in2out_inner_icmp_set_cb, &ctx0))
+		{
+		  next0 = NAT64_IN2OUT_NEXT_DROP;
+		  b0->error = node->errors[NAT64_IN2OUT_ERROR_NO_TRANSLATION];
+		  goto trace0;
+		}
+	    }
+	  else if (proto0 == SNAT_PROTOCOL_TCP || proto0 == SNAT_PROTOCOL_UDP)
+	    {
+	      if (is_hairpinning (&ip60->dst_address))
+		{
+		  next0 = NAT64_IN2OUT_NEXT_IP6_LOOKUP;
+		  if (nat64_in2out_tcp_udp_hairpinning (vm, b0, ip60))
+		    {
+		      next0 = NAT64_IN2OUT_NEXT_DROP;
+		      b0->error =
+			node->errors[NAT64_IN2OUT_ERROR_NO_TRANSLATION];
+		    }
+		  goto trace0;
+		}
+
+	      if (ip6_to_ip4_tcp_udp
+		  (b0, nat64_in2out_tcp_udp_set_cb, &ctx0, 0))
+		{
+		  next0 = NAT64_IN2OUT_NEXT_DROP;
+		  b0->error = node->errors[NAT64_IN2OUT_ERROR_NO_TRANSLATION];
+		  goto trace0;
+		}
+	    }
+
+	trace0:
+	  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
+			     && (b0->flags & VLIB_BUFFER_IS_TRACED)))
+	    {
+	      nat64_in2out_trace_t *t =
+		vlib_add_trace (vm, node, b0, sizeof (*t));
+	      t->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
+	      t->next_index = next0;
+	      t->is_slow_path = is_slow_path;
+	    }
+
+	  pkts_processed += next0 != NAT64_IN2OUT_NEXT_DROP;
+
+	  /* verify speculative enqueue, maybe switch current next frame */
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
+					   n_left_to_next, bi0, next0);
+	}
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+  vlib_node_increment_counter (vm, stats_node_index,
+			       NAT64_IN2OUT_ERROR_IN2OUT_PACKETS,
+			       pkts_processed);
+  return frame->n_vectors;
+}
+
+static uword
+nat64_in2out_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
+		      vlib_frame_t * frame)
+{
+  return nat64_in2out_node_fn_inline (vm, node, frame, 0);
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (nat64_in2out_node) = {
+  .function = nat64_in2out_node_fn,
+  .name = "nat64-in2out",
+  .vector_size = sizeof (u32),
+  .format_trace = format_nat64_in2out_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN (nat64_in2out_error_strings),
+  .error_strings = nat64_in2out_error_strings,
+  .n_next_nodes = NAT64_IN2OUT_N_NEXT,
+  /* edit / add dispositions here */
+  .next_nodes = {
+    [NAT64_IN2OUT_NEXT_DROP] = "error-drop",
+    [NAT64_IN2OUT_NEXT_IP4_LOOKUP] = "ip4-lookup",
+    [NAT64_IN2OUT_NEXT_IP6_LOOKUP] = "ip6-lookup",
+    [NAT64_IN2OUT_NEXT_SLOWPATH] = "nat64-in2out-slowpath",
+  },
+};
+/* *INDENT-ON* */
+
+VLIB_NODE_FUNCTION_MULTIARCH (nat64_in2out_node, nat64_in2out_node_fn);
+
+static uword
+nat64_in2out_slowpath_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
+			       vlib_frame_t * frame)
+{
+  return nat64_in2out_node_fn_inline (vm, node, frame, 1);
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (nat64_in2out_slowpath_node) = {
+  .function = nat64_in2out_slowpath_node_fn,
+  .name = "nat64-in2out-slowpath",
+  .vector_size = sizeof (u32),
+  .format_trace = format_nat64_in2out_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN (nat64_in2out_error_strings),
+  .error_strings = nat64_in2out_error_strings,
+  .n_next_nodes = NAT64_IN2OUT_N_NEXT,
+  /* edit / add dispositions here */
+  .next_nodes = {
+    [NAT64_IN2OUT_NEXT_DROP] = "error-drop",
+    [NAT64_IN2OUT_NEXT_IP4_LOOKUP] = "ip4-lookup",
+    [NAT64_IN2OUT_NEXT_IP6_LOOKUP] = "ip6-lookup",
+    [NAT64_IN2OUT_NEXT_SLOWPATH] = "nat64-in2out-slowpath",
+  },
+};
+/* *INDENT-ON* */
+
+VLIB_NODE_FUNCTION_MULTIARCH (nat64_in2out_slowpath_node,
+			      nat64_in2out_slowpath_node_fn);
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/plugins/nat/nat64_out2in.c b/src/plugins/nat/nat64_out2in.c
new file mode 100644
index 00000000000..61e88a7f304
--- /dev/null
+++ b/src/plugins/nat/nat64_out2in.c
@@ -0,0 +1,494 @@
+/*
+ * Copyright (c) 2017 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.
+ */
+/**
+ * @file
+ * @brief NAT64 IPv4 to IPv6 translation (otside to inside network)
+ */
+
+#include <nat/nat64.h>
+#include <vnet/ip/ip4_to_ip6.h>
+#include <vnet/fib/ip4_fib.h>
+
+typedef struct
+{
+  u32 sw_if_index;
+  u32 next_index;
+} nat64_out2in_trace_t;
+
+static u8 *
+format_nat64_out2in_trace (u8 * s, va_list * args)
+{
+  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
+  nat64_out2in_trace_t *t = va_arg (*args, nat64_out2in_trace_t *);
+
+  s =
+    format (s, "NAT64-out2in: sw_if_index %d, next index %d", t->sw_if_index,
+	    t->next_index);
+
+  return s;
+}
+
+vlib_node_registration_t nat64_out2in_node;
+
+#define foreach_nat64_out2in_error                 \
+_(UNSUPPORTED_PROTOCOL, "Unsupported protocol")    \
+_(OUT2IN_PACKETS, "Good out2in packets processed") \
+_(NO_TRANSLATION, "No translation")                \
+_(UNKNOWN, "unknown")
+
+typedef enum
+{
+#define _(sym,str) NAT64_OUT2IN_ERROR_##sym,
+  foreach_nat64_out2in_error
+#undef _
+    NAT64_OUT2IN_N_ERROR,
+} nat64_out2in_error_t;
+
+static char *nat64_out2in_error_strings[] = {
+#define _(sym,string) string,
+  foreach_nat64_out2in_error
+#undef _
+};
+
+typedef enum
+{
+  NAT64_OUT2IN_NEXT_LOOKUP,
+  NAT64_OUT2IN_NEXT_DROP,
+  NAT64_OUT2IN_N_NEXT,
+} nat64_out2in_next_t;
+
+typedef struct nat64_out2in_set_ctx_t_
+{
+  vlib_buffer_t *b;
+  vlib_main_t *vm;
+} nat64_out2in_set_ctx_t;
+
+static int
+nat64_out2in_tcp_udp_set_cb (ip4_header_t * ip4, ip6_header_t * ip6,
+			     void *arg)
+{
+  nat64_main_t *nm = &nat64_main;
+  nat64_out2in_set_ctx_t *ctx = arg;
+  nat64_db_bib_entry_t *bibe;
+  nat64_db_st_entry_t *ste;
+  ip46_address_t saddr, daddr;
+  ip6_address_t ip6_saddr;
+  udp_header_t *udp = ip4_next_header (ip4);
+  tcp_header_t *tcp = ip4_next_header (ip4);
+  u8 proto = ip4->protocol;
+  u16 dport = udp->dst_port;
+  u16 sport = udp->src_port;
+  u32 sw_if_index, fib_index;
+  u16 *checksum;
+  ip_csum_t csum;
+
+  sw_if_index = vnet_buffer (ctx->b)->sw_if_index[VLIB_RX];
+  fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
+
+  memset (&saddr, 0, sizeof (saddr));
+  saddr.ip4.as_u32 = ip4->src_address.as_u32;
+  memset (&daddr, 0, sizeof (daddr));
+  daddr.ip4.as_u32 = ip4->dst_address.as_u32;
+
+  ste =
+    nat64_db_st_entry_find (&nm->db, &daddr, &saddr, dport, sport, proto,
+			    fib_index, 0);
+  if (ste)
+    {
+      bibe = nat64_db_bib_entry_by_index (&nm->db, proto, ste->bibe_index);
+      if (!bibe)
+	return -1;
+    }
+  else
+    {
+      bibe =
+	nat64_db_bib_entry_find (&nm->db, &daddr, dport, proto, fib_index, 0);
+
+      if (!bibe)
+	return -1;
+
+      nat64_compose_ip6 (&ip6_saddr, &ip4->src_address, bibe->fib_index);
+      ste =
+	nat64_db_st_entry_create (&nm->db, bibe, &ip6_saddr, &saddr.ip4,
+				  sport);
+    }
+
+  nat64_session_reset_timeout (ste, ctx->vm);
+
+  ip6->src_address.as_u64[0] = ste->in_r_addr.as_u64[0];
+  ip6->src_address.as_u64[1] = ste->in_r_addr.as_u64[1];
+
+  ip6->dst_address.as_u64[0] = bibe->in_addr.as_u64[0];
+  ip6->dst_address.as_u64[1] = bibe->in_addr.as_u64[1];
+  udp->dst_port = bibe->in_port;
+
+  if (proto == IP_PROTOCOL_UDP)
+    checksum = &udp->checksum;
+  else
+    checksum = &tcp->checksum;
+  csum = ip_csum_sub_even (*checksum, dport);
+  csum = ip_csum_add_even (csum, udp->dst_port);
+  *checksum = ip_csum_fold (csum);
+
+  vnet_buffer (ctx->b)->sw_if_index[VLIB_TX] = bibe->fib_index;
+
+  return 0;
+}
+
+static int
+nat64_out2in_icmp_set_cb (ip4_header_t * ip4, ip6_header_t * ip6, void *arg)
+{
+  nat64_main_t *nm = &nat64_main;
+  nat64_out2in_set_ctx_t *ctx = arg;
+  nat64_db_bib_entry_t *bibe;
+  nat64_db_st_entry_t *ste;
+  ip46_address_t saddr, daddr;
+  ip6_address_t ip6_saddr;
+  u32 sw_if_index, fib_index;
+  icmp46_header_t *icmp = ip4_next_header (ip4);
+
+  sw_if_index = vnet_buffer (ctx->b)->sw_if_index[VLIB_RX];
+  fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
+
+  memset (&saddr, 0, sizeof (saddr));
+  saddr.ip4.as_u32 = ip4->src_address.as_u32;
+  memset (&daddr, 0, sizeof (daddr));
+  daddr.ip4.as_u32 = ip4->dst_address.as_u32;
+
+  if (icmp->type == ICMP6_echo_request || icmp->type == ICMP6_echo_reply)
+    {
+      u16 out_id = ((u16 *) (icmp))[2];
+      ste =
+	nat64_db_st_entry_find (&nm->db, &daddr, &saddr, out_id, 0,
+				IP_PROTOCOL_ICMP, fib_index, 0);
+
+      if (ste)
+	{
+	  bibe =
+	    nat64_db_bib_entry_by_index (&nm->db, IP_PROTOCOL_ICMP,
+					 ste->bibe_index);
+	  if (!bibe)
+	    return -1;
+	}
+      else
+	{
+	  bibe =
+	    nat64_db_bib_entry_find (&nm->db, &daddr, out_id,
+				     IP_PROTOCOL_ICMP, fib_index, 0);
+	  if (!bibe)
+	    return -1;
+
+	  nat64_compose_ip6 (&ip6_saddr, &ip4->src_address, bibe->fib_index);
+	  ste =
+	    nat64_db_st_entry_create (&nm->db, bibe, &ip6_saddr, &saddr.ip4,
+				      0);
+	}
+
+      nat64_session_reset_timeout (ste, ctx->vm);
+
+      ip6->src_address.as_u64[0] = ste->in_r_addr.as_u64[0];
+      ip6->src_address.as_u64[1] = ste->in_r_addr.as_u64[1];
+
+      ip6->dst_address.as_u64[0] = bibe->in_addr.as_u64[0];
+      ip6->dst_address.as_u64[1] = bibe->in_addr.as_u64[1];
+      ((u16 *) (icmp))[2] = bibe->in_port;
+
+      vnet_buffer (ctx->b)->sw_if_index[VLIB_TX] = bibe->fib_index;
+    }
+  else
+    {
+      ip6_header_t *inner_ip6 = (ip6_header_t *) u8_ptr_add (icmp, 8);
+
+      nat64_compose_ip6 (&ip6->src_address, &ip4->src_address,
+			 vnet_buffer (ctx->b)->sw_if_index[VLIB_TX]);
+      ip6->dst_address.as_u64[0] = inner_ip6->src_address.as_u64[0];
+      ip6->dst_address.as_u64[1] = inner_ip6->src_address.as_u64[1];
+    }
+
+  return 0;
+}
+
+static int
+nat64_out2in_inner_icmp_set_cb (ip4_header_t * ip4, ip6_header_t * ip6,
+				void *arg)
+{
+  nat64_main_t *nm = &nat64_main;
+  nat64_out2in_set_ctx_t *ctx = arg;
+  nat64_db_bib_entry_t *bibe;
+  nat64_db_st_entry_t *ste;
+  ip46_address_t saddr, daddr;
+  u32 sw_if_index, fib_index;
+  u8 proto = ip4->protocol;
+
+  sw_if_index = vnet_buffer (ctx->b)->sw_if_index[VLIB_RX];
+  fib_index =
+    fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP6, sw_if_index);
+
+  memset (&saddr, 0, sizeof (saddr));
+  saddr.ip4.as_u32 = ip4->src_address.as_u32;
+  memset (&daddr, 0, sizeof (daddr));
+  daddr.ip4.as_u32 = ip4->dst_address.as_u32;
+
+  if (proto == IP_PROTOCOL_ICMP6)
+    {
+      icmp46_header_t *icmp = ip4_next_header (ip4);
+      u16 out_id = ((u16 *) (icmp))[2];
+      proto = IP_PROTOCOL_ICMP;
+
+      if (!
+	  (icmp->type == ICMP6_echo_request
+	   || icmp->type == ICMP6_echo_reply))
+	return -1;
+
+      ste =
+	nat64_db_st_entry_find (&nm->db, &saddr, &daddr, out_id, 0, proto,
+				fib_index, 0);
+      if (!ste)
+	return -1;
+
+      bibe = nat64_db_bib_entry_by_index (&nm->db, proto, ste->bibe_index);
+      if (!bibe)
+	return -1;
+
+      ip6->dst_address.as_u64[0] = ste->in_r_addr.as_u64[0];
+      ip6->dst_address.as_u64[1] = ste->in_r_addr.as_u64[1];
+      ip6->src_address.as_u64[0] = bibe->in_addr.as_u64[0];
+      ip6->src_address.as_u64[1] = bibe->in_addr.as_u64[1];
+      ((u16 *) (icmp))[2] = bibe->in_port;
+
+      vnet_buffer (ctx->b)->sw_if_index[VLIB_TX] = bibe->fib_index;
+    }
+  else
+    {
+      udp_header_t *udp = ip4_next_header (ip4);
+      tcp_header_t *tcp = ip4_next_header (ip4);
+      u16 dport = udp->dst_port;
+      u16 sport = udp->src_port;
+      u16 *checksum;
+      ip_csum_t csum;
+
+      ste =
+	nat64_db_st_entry_find (&nm->db, &saddr, &daddr, sport, dport, proto,
+				fib_index, 0);
+      if (!ste)
+	return -1;
+
+      bibe = nat64_db_bib_entry_by_index (&nm->db, proto, ste->bibe_index);
+      if (!bibe)
+	return -1;
+
+      nat64_compose_ip6 (&ip6->dst_address, &daddr.ip4, bibe->fib_index);
+      ip6->src_address.as_u64[0] = bibe->in_addr.as_u64[0];
+      ip6->src_address.as_u64[1] = bibe->in_addr.as_u64[1];
+      udp->src_port = bibe->in_port;
+
+      if (proto == IP_PROTOCOL_UDP)
+	checksum = &udp->checksum;
+      else
+	checksum = &tcp->checksum;
+      if (*checksum)
+	{
+	  csum = ip_csum_sub_even (*checksum, sport);
+	  csum = ip_csum_add_even (csum, udp->src_port);
+	  *checksum = ip_csum_fold (csum);
+	}
+
+      vnet_buffer (ctx->b)->sw_if_index[VLIB_TX] = bibe->fib_index;
+    }
+
+  return 0;
+}
+
+static int
+nat64_out2in_unk_proto_set_cb (ip4_header_t * ip4, ip6_header_t * ip6,
+			       void *arg)
+{
+  nat64_main_t *nm = &nat64_main;
+  nat64_out2in_set_ctx_t *ctx = arg;
+  nat64_db_bib_entry_t *bibe;
+  nat64_db_st_entry_t *ste;
+  ip46_address_t saddr, daddr;
+  ip6_address_t ip6_saddr;
+  u32 sw_if_index, fib_index;
+  u8 proto = ip4->protocol;
+
+  sw_if_index = vnet_buffer (ctx->b)->sw_if_index[VLIB_RX];
+  fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
+
+  memset (&saddr, 0, sizeof (saddr));
+  saddr.ip4.as_u32 = ip4->src_address.as_u32;
+  memset (&daddr, 0, sizeof (daddr));
+  daddr.ip4.as_u32 = ip4->dst_address.as_u32;
+
+  ste =
+    nat64_db_st_entry_find (&nm->db, &daddr, &saddr, 0, 0, proto, fib_index,
+			    0);
+  if (ste)
+    {
+      bibe = nat64_db_bib_entry_by_index (&nm->db, proto, ste->bibe_index);
+      if (!bibe)
+	return -1;
+    }
+  else
+    {
+      bibe =
+	nat64_db_bib_entry_find (&nm->db, &daddr, 0, proto, fib_index, 0);
+
+      if (!bibe)
+	return -1;
+
+      nat64_compose_ip6 (&ip6_saddr, &ip4->src_address, bibe->fib_index);
+      ste =
+	nat64_db_st_entry_create (&nm->db, bibe, &ip6_saddr, &saddr.ip4, 0);
+    }
+
+  nat64_session_reset_timeout (ste, ctx->vm);
+
+  ip6->src_address.as_u64[0] = ste->in_r_addr.as_u64[0];
+  ip6->src_address.as_u64[1] = ste->in_r_addr.as_u64[1];
+
+  ip6->dst_address.as_u64[0] = bibe->in_addr.as_u64[0];
+  ip6->dst_address.as_u64[1] = bibe->in_addr.as_u64[1];
+
+  vnet_buffer (ctx->b)->sw_if_index[VLIB_TX] = bibe->fib_index;
+
+  return 0;
+}
+
+static uword
+nat64_out2in_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
+		      vlib_frame_t * frame)
+{
+  u32 n_left_from, *from, *to_next;
+  nat64_out2in_next_t next_index;
+  u32 pkts_processed = 0;
+
+  from = vlib_frame_vector_args (frame);
+  n_left_from = frame->n_vectors;
+  next_index = node->cached_next_index;
+  while (n_left_from > 0)
+    {
+      u32 n_left_to_next;
+
+      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+	  u32 bi0;
+	  vlib_buffer_t *b0;
+	  u32 next0;
+	  ip4_header_t *ip40;
+	  u32 proto0;
+	  nat64_out2in_set_ctx_t ctx0;
+
+	  /* speculatively enqueue b0 to the current next frame */
+	  bi0 = from[0];
+	  to_next[0] = bi0;
+	  from += 1;
+	  to_next += 1;
+	  n_left_from -= 1;
+	  n_left_to_next -= 1;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+	  ip40 = vlib_buffer_get_current (b0);
+
+	  ctx0.b = b0;
+	  ctx0.vm = vm;
+
+	  next0 = NAT64_OUT2IN_NEXT_LOOKUP;
+
+	  proto0 = ip_proto_to_snat_proto (ip40->protocol);
+
+	  if (proto0 == SNAT_PROTOCOL_ICMP)
+	    {
+	      if (icmp_to_icmp6
+		  (b0, nat64_out2in_icmp_set_cb, &ctx0,
+		   nat64_out2in_inner_icmp_set_cb, &ctx0))
+		{
+		  next0 = NAT64_OUT2IN_NEXT_DROP;
+		  b0->error = node->errors[NAT64_OUT2IN_ERROR_NO_TRANSLATION];
+		  goto trace0;
+		}
+	    }
+	  else if (proto0 == SNAT_PROTOCOL_TCP || proto0 == SNAT_PROTOCOL_UDP)
+	    {
+	      if (ip4_to_ip6_tcp_udp (b0, nat64_out2in_tcp_udp_set_cb, &ctx0))
+		{
+		  next0 = NAT64_OUT2IN_NEXT_DROP;
+		  b0->error = node->errors[NAT64_OUT2IN_ERROR_NO_TRANSLATION];
+		  goto trace0;
+		}
+	    }
+	  else
+	    {
+	      if (ip4_to_ip6 (b0, nat64_out2in_unk_proto_set_cb, &ctx0))
+		{
+		  next0 = NAT64_OUT2IN_NEXT_DROP;
+		  b0->error = node->errors[NAT64_OUT2IN_ERROR_NO_TRANSLATION];
+		  goto trace0;
+		}
+	    }
+
+	trace0:
+	  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
+			     && (b0->flags & VLIB_BUFFER_IS_TRACED)))
+	    {
+	      nat64_out2in_trace_t *t =
+		vlib_add_trace (vm, node, b0, sizeof (*t));
+	      t->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
+	      t->next_index = next0;
+	    }
+
+	  pkts_processed += next0 != NAT64_OUT2IN_NEXT_DROP;
+
+	  /* verify speculative enqueue, maybe switch current next frame */
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
+					   n_left_to_next, bi0, next0);
+	}
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+  vlib_node_increment_counter (vm, nat64_out2in_node.index,
+			       NAT64_OUT2IN_ERROR_OUT2IN_PACKETS,
+			       pkts_processed);
+  return frame->n_vectors;
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (nat64_out2in_node) = {
+  .function = nat64_out2in_node_fn,
+  .name = "nat64-out2in",
+  .vector_size = sizeof (u32),
+  .format_trace = format_nat64_out2in_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN (nat64_out2in_error_strings),
+  .error_strings = nat64_out2in_error_strings,.n_next_nodes = 2,
+  /* edit / add dispositions here */
+  .next_nodes = {
+    [NAT64_OUT2IN_NEXT_DROP] = "error-drop",
+    [NAT64_OUT2IN_NEXT_LOOKUP] = "ip6-lookup",
+  },
+};
+/* *INDENT-ON* */
+
+VLIB_NODE_FUNCTION_MULTIARCH (nat64_out2in_node, nat64_out2in_node_fn);
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/plugins/nat/nat_all_api_h.h b/src/plugins/nat/nat_all_api_h.h
new file mode 100644
index 00000000000..acd9ba1cac9
--- /dev/null
+++ b/src/plugins/nat/nat_all_api_h.h
@@ -0,0 +1,19 @@
+
+/*
+ * nat_all_api_h.h - skeleton vpp engine plug-in api #include file
+ *
+ * Copyright (c) <current-year> <your-organization>
+ * 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 the generated file, see BUILT_SOURCES in Makefile.am */
+#include <nat/nat.api.h>
diff --git a/src/plugins/nat/nat_api.c b/src/plugins/nat/nat_api.c
new file mode 100644
index 00000000000..0a2141f2a05
--- /dev/null
+++ b/src/plugins/nat/nat_api.c
@@ -0,0 +1,3255 @@
+/*
+ * Copyright (c) 2017 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.
+ */
+/**
+ * @file
+ * @brief NAT plugin API implementation
+ */
+
+#include <nat/nat.h>
+#include <nat/nat_det.h>
+#include <nat/nat64.h>
+#include <vlibapi/api.h>
+#include <vlibmemory/api.h>
+#include <vlibsocket/api.h>
+#include <nat/nat_msg_enum.h>
+#include <vnet/fib/fib_table.h>
+
+/* define message structures */
+#define vl_typedefs
+#include <nat/nat_all_api_h.h>
+#undef vl_typedefs
+
+/* define generated endian-swappers */
+#define vl_endianfun
+#include <nat/nat_all_api_h.h>
+#undef vl_endianfun
+
+#define vl_print(handle, ...) vlib_cli_output (handle, __VA_ARGS__)
+
+#define REPLY_MSG_ID_BASE sm->msg_id_base
+#include <vlibapi/api_helper_macros.h>
+
+/* Get the API version number */
+#define vl_api_version(n,v) static u32 api_version=(v);
+#include <nat/nat_all_api_h.h>
+#undef vl_api_version
+
+/* Macro to finish up custom dump fns */
+#define FINISH                                  \
+    vec_add1 (s, 0);                            \
+    vl_print (handle, (char *)s);               \
+    vec_free (s);                               \
+    return handle;
+
+static void
+  vl_api_snat_add_address_range_t_handler
+  (vl_api_snat_add_address_range_t * mp)
+{
+  snat_main_t *sm = &snat_main;
+  vl_api_snat_add_address_range_reply_t *rmp;
+  ip4_address_t this_addr;
+  u32 start_host_order, end_host_order;
+  u32 vrf_id;
+  int i, count;
+  int rv = 0;
+  u32 *tmp;
+
+  if (mp->is_ip4 != 1)
+    {
+      rv = VNET_API_ERROR_UNIMPLEMENTED;
+      goto send_reply;
+    }
+
+  if (sm->static_mapping_only)
+    {
+      rv = VNET_API_ERROR_FEATURE_DISABLED;
+      goto send_reply;
+    }
+
+  tmp = (u32 *) mp->first_ip_address;
+  start_host_order = clib_host_to_net_u32 (tmp[0]);
+  tmp = (u32 *) mp->last_ip_address;
+  end_host_order = clib_host_to_net_u32 (tmp[0]);
+
+  count = (end_host_order - start_host_order) + 1;
+
+  vrf_id = clib_host_to_net_u32 (mp->vrf_id);
+
+  if (count > 1024)
+    clib_warning ("%U - %U, %d addresses...",
+		  format_ip4_address, mp->first_ip_address,
+		  format_ip4_address, mp->last_ip_address, count);
+
+  memcpy (&this_addr.as_u8, mp->first_ip_address, 4);
+
+  for (i = 0; i < count; i++)
+    {
+      if (mp->is_add)
+	snat_add_address (sm, &this_addr, vrf_id);
+      else
+	rv = snat_del_address (sm, this_addr, 0);
+
+      if (rv)
+	goto send_reply;
+
+      increment_v4_address (&this_addr);
+    }
+
+send_reply:
+  REPLY_MACRO (VL_API_SNAT_ADD_ADDRESS_RANGE_REPLY);
+}
+
+static void *vl_api_snat_add_address_range_t_print
+  (vl_api_snat_add_address_range_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: snat_add_address_range ");
+  s = format (s, "%U ", format_ip4_address, mp->first_ip_address);
+  if (memcmp (mp->first_ip_address, mp->last_ip_address, 4))
+    {
+      s = format (s, " - %U ", format_ip4_address, mp->last_ip_address);
+    }
+  FINISH;
+}
+
+static void
+  send_snat_address_details
+  (snat_address_t * a, unix_shared_memory_queue_t * q, u32 context)
+{
+  vl_api_snat_address_details_t *rmp;
+  snat_main_t *sm = &snat_main;
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+  rmp->_vl_msg_id = ntohs (VL_API_SNAT_ADDRESS_DETAILS + sm->msg_id_base);
+  rmp->is_ip4 = 1;
+  clib_memcpy (rmp->ip_address, &(a->addr), 4);
+  if (a->fib_index != ~0)
+    {
+      fib_table_t *fib = fib_table_get (a->fib_index, FIB_PROTOCOL_IP4);
+      rmp->vrf_id = ntohl (fib->ft_table_id);
+    }
+  else
+    rmp->vrf_id = ~0;
+  rmp->context = context;
+
+  vl_msg_api_send_shmem (q, (u8 *) & rmp);
+}
+
+static void
+vl_api_snat_address_dump_t_handler (vl_api_snat_address_dump_t * mp)
+{
+  unix_shared_memory_queue_t *q;
+  snat_main_t *sm = &snat_main;
+  snat_address_t *a;
+
+  q = vl_api_client_index_to_input_queue (mp->client_index);
+  if (q == 0)
+    return;
+
+  /* *INDENT-OFF* */
+  vec_foreach (a, sm->addresses)
+    send_snat_address_details (a, q, mp->context);
+  /* *INDENT-ON* */
+}
+
+static void *vl_api_snat_address_dump_t_print
+  (vl_api_snat_address_dump_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: snat_address_dump ");
+
+  FINISH;
+}
+
+static void
+  vl_api_snat_interface_add_del_feature_t_handler
+  (vl_api_snat_interface_add_del_feature_t * mp)
+{
+  snat_main_t *sm = &snat_main;
+  vl_api_snat_interface_add_del_feature_reply_t *rmp;
+  u8 is_del = mp->is_add == 0;
+  u32 sw_if_index = ntohl (mp->sw_if_index);
+  int rv = 0;
+
+  VALIDATE_SW_IF_INDEX (mp);
+
+  rv = snat_interface_add_del (sw_if_index, mp->is_inside, is_del);
+
+  BAD_SW_IF_INDEX_LABEL;
+
+  REPLY_MACRO (VL_API_SNAT_INTERFACE_ADD_DEL_FEATURE_REPLY);
+}
+
+static void *vl_api_snat_interface_add_del_feature_t_print
+  (vl_api_snat_interface_add_del_feature_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: snat_interface_add_del_feature ");
+  s = format (s, "sw_if_index %d %s %s",
+	      clib_host_to_net_u32 (mp->sw_if_index),
+	      mp->is_inside ? "in" : "out", mp->is_add ? "" : "del");
+
+  FINISH;
+}
+
+static void
+  send_snat_interface_details
+  (snat_interface_t * i, unix_shared_memory_queue_t * q, u32 context)
+{
+  vl_api_snat_interface_details_t *rmp;
+  snat_main_t *sm = &snat_main;
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+  rmp->_vl_msg_id = ntohs (VL_API_SNAT_INTERFACE_DETAILS + sm->msg_id_base);
+  rmp->sw_if_index = ntohl (i->sw_if_index);
+  rmp->is_inside = i->is_inside;
+  rmp->context = context;
+
+  vl_msg_api_send_shmem (q, (u8 *) & rmp);
+}
+
+static void
+vl_api_snat_interface_dump_t_handler (vl_api_snat_interface_dump_t * mp)
+{
+  unix_shared_memory_queue_t *q;
+  snat_main_t *sm = &snat_main;
+  snat_interface_t *i;
+
+  q = vl_api_client_index_to_input_queue (mp->client_index);
+  if (q == 0)
+    return;
+
+  /* *INDENT-OFF* */
+  pool_foreach (i, sm->interfaces,
+  ({
+    send_snat_interface_details(i, q, mp->context);
+  }));
+  /* *INDENT-ON* */
+}
+
+static void *vl_api_snat_interface_dump_t_print
+  (vl_api_snat_interface_dump_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: snat_interface_dump ");
+
+  FINISH;
+}
+
+static void
+  vl_api_snat_interface_add_del_output_feature_t_handler
+  (vl_api_snat_interface_add_del_output_feature_t * mp)
+{
+  snat_main_t *sm = &snat_main;
+  vl_api_snat_interface_add_del_output_feature_reply_t *rmp;
+  u8 is_del = mp->is_add == 0;
+  u32 sw_if_index = ntohl (mp->sw_if_index);
+  int rv = 0;
+
+  VALIDATE_SW_IF_INDEX (mp);
+
+  rv = snat_interface_add_del_output_feature (sw_if_index, mp->is_inside,
+					      is_del);
+
+  BAD_SW_IF_INDEX_LABEL;
+
+  REPLY_MACRO (VL_API_SNAT_INTERFACE_ADD_DEL_OUTPUT_FEATURE_REPLY);
+}
+
+static void *vl_api_snat_interface_add_del_output_feature_t_print
+  (vl_api_snat_interface_add_del_output_feature_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: snat_interface_add_del_output_feature ");
+  s = format (s, "sw_if_index %d %s %s",
+	      clib_host_to_net_u32 (mp->sw_if_index),
+	      mp->is_inside ? "in" : "out", mp->is_add ? "" : "del");
+
+  FINISH;
+}
+
+static void
+send_snat_interface_output_feature_details (snat_interface_t * i,
+					    unix_shared_memory_queue_t * q,
+					    u32 context)
+{
+  vl_api_snat_interface_output_feature_details_t *rmp;
+  snat_main_t *sm = &snat_main;
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+  rmp->_vl_msg_id =
+    ntohs (VL_API_SNAT_INTERFACE_OUTPUT_FEATURE_DETAILS + sm->msg_id_base);
+  rmp->sw_if_index = ntohl (i->sw_if_index);
+  rmp->context = context;
+  rmp->is_inside = i->is_inside;
+
+  vl_msg_api_send_shmem (q, (u8 *) & rmp);
+}
+
+static void
+  vl_api_snat_interface_output_feature_dump_t_handler
+  (vl_api_snat_interface_output_feature_dump_t * mp)
+{
+  unix_shared_memory_queue_t *q;
+  snat_main_t *sm = &snat_main;
+  snat_interface_t *i;
+
+  q = vl_api_client_index_to_input_queue (mp->client_index);
+  if (q == 0)
+    return;
+
+  /* *INDENT-OFF* */
+  pool_foreach (i, sm->output_feature_interfaces,
+  ({
+    send_snat_interface_output_feature_details(i, q, mp->context);
+  }));
+  /* *INDENT-ON* */
+}
+
+static void *vl_api_snat_interface_output_feature_dump_t_print
+  (vl_api_snat_interface_output_feature_dump_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: snat_interface_output_feature_dump ");
+
+  FINISH;
+}
+
+static void
+  vl_api_snat_add_static_mapping_t_handler
+  (vl_api_snat_add_static_mapping_t * mp)
+{
+  snat_main_t *sm = &snat_main;
+  vl_api_snat_add_static_mapping_reply_t *rmp;
+  ip4_address_t local_addr, external_addr;
+  u16 local_port = 0, external_port = 0;
+  u32 vrf_id, external_sw_if_index;
+  int rv = 0;
+  snat_protocol_t proto;
+
+  if (mp->is_ip4 != 1)
+    {
+      rv = VNET_API_ERROR_UNIMPLEMENTED;
+      goto send_reply;
+    }
+
+  memcpy (&local_addr.as_u8, mp->local_ip_address, 4);
+  memcpy (&external_addr.as_u8, mp->external_ip_address, 4);
+  if (mp->addr_only == 0)
+    {
+      local_port = clib_net_to_host_u16 (mp->local_port);
+      external_port = clib_net_to_host_u16 (mp->external_port);
+    }
+  vrf_id = clib_net_to_host_u32 (mp->vrf_id);
+  external_sw_if_index = clib_net_to_host_u32 (mp->external_sw_if_index);
+  proto = ip_proto_to_snat_proto (mp->protocol);
+
+  rv = snat_add_static_mapping (local_addr, external_addr, local_port,
+				external_port, vrf_id, mp->addr_only,
+				external_sw_if_index, proto, mp->is_add);
+
+send_reply:
+  REPLY_MACRO (VL_API_SNAT_ADD_ADDRESS_RANGE_REPLY);
+}
+
+static void *vl_api_snat_add_static_mapping_t_print
+  (vl_api_snat_add_static_mapping_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: snat_add_static_mapping ");
+  s = format (s, "protocol %d local_addr %U external_addr %U ",
+	      mp->protocol,
+	      format_ip4_address, mp->local_ip_address,
+	      format_ip4_address, mp->external_ip_address);
+
+  if (mp->addr_only == 0)
+    s = format (s, "local_port %d external_port %d ",
+		clib_net_to_host_u16 (mp->local_port),
+		clib_net_to_host_u16 (mp->external_port));
+
+  if (mp->vrf_id != ~0)
+    s = format (s, "vrf %d", clib_net_to_host_u32 (mp->vrf_id));
+
+  if (mp->external_sw_if_index != ~0)
+    s = format (s, "external_sw_if_index %d",
+		clib_net_to_host_u32 (mp->external_sw_if_index));
+  FINISH;
+}
+
+static void
+  send_snat_static_mapping_details
+  (snat_static_mapping_t * m, unix_shared_memory_queue_t * q, u32 context)
+{
+  vl_api_snat_static_mapping_details_t *rmp;
+  snat_main_t *sm = &snat_main;
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+  rmp->_vl_msg_id =
+    ntohs (VL_API_SNAT_STATIC_MAPPING_DETAILS + sm->msg_id_base);
+  rmp->is_ip4 = 1;
+  rmp->addr_only = m->addr_only;
+  clib_memcpy (rmp->local_ip_address, &(m->local_addr), 4);
+  clib_memcpy (rmp->external_ip_address, &(m->external_addr), 4);
+  rmp->local_port = htons (m->local_port);
+  rmp->external_port = htons (m->external_port);
+  rmp->external_sw_if_index = ~0;
+  rmp->vrf_id = htonl (m->vrf_id);
+  rmp->protocol = snat_proto_to_ip_proto (m->proto);
+  rmp->context = context;
+
+  vl_msg_api_send_shmem (q, (u8 *) & rmp);
+}
+
+static void
+  send_snat_static_map_resolve_details
+  (snat_static_map_resolve_t * m, unix_shared_memory_queue_t * q, u32 context)
+{
+  vl_api_snat_static_mapping_details_t *rmp;
+  snat_main_t *sm = &snat_main;
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+  rmp->_vl_msg_id =
+    ntohs (VL_API_SNAT_STATIC_MAPPING_DETAILS + sm->msg_id_base);
+  rmp->is_ip4 = 1;
+  rmp->addr_only = m->addr_only;
+  clib_memcpy (rmp->local_ip_address, &(m->l_addr), 4);
+  rmp->local_port = htons (m->l_port);
+  rmp->external_port = htons (m->e_port);
+  rmp->external_sw_if_index = htonl (m->sw_if_index);
+  rmp->vrf_id = htonl (m->vrf_id);
+  rmp->protocol = snat_proto_to_ip_proto (m->proto);
+  rmp->context = context;
+
+  vl_msg_api_send_shmem (q, (u8 *) & rmp);
+}
+
+static void
+  vl_api_snat_static_mapping_dump_t_handler
+  (vl_api_snat_static_mapping_dump_t * mp)
+{
+  unix_shared_memory_queue_t *q;
+  snat_main_t *sm = &snat_main;
+  snat_static_mapping_t *m;
+  snat_static_map_resolve_t *rp;
+  int j;
+
+  q = vl_api_client_index_to_input_queue (mp->client_index);
+  if (q == 0)
+    return;
+
+  /* *INDENT-OFF* */
+  pool_foreach (m, sm->static_mappings,
+  ({
+      send_snat_static_mapping_details (m, q, mp->context);
+  }));
+  /* *INDENT-ON* */
+
+  for (j = 0; j < vec_len (sm->to_resolve); j++)
+    {
+      rp = sm->to_resolve + j;
+      send_snat_static_map_resolve_details (rp, q, mp->context);
+    }
+}
+
+static void *vl_api_snat_static_mapping_dump_t_print
+  (vl_api_snat_static_mapping_dump_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: snat_static_mapping_dump ");
+
+  FINISH;
+}
+
+static void
+vl_api_snat_control_ping_t_handler (vl_api_snat_control_ping_t * mp)
+{
+  vl_api_snat_control_ping_reply_t *rmp;
+  snat_main_t *sm = &snat_main;
+  int rv = 0;
+
+  /* *INDENT-OFF* */
+  REPLY_MACRO2 (VL_API_SNAT_CONTROL_PING_REPLY,
+  ({
+    rmp->vpe_pid = ntohl (getpid ());
+  }));
+  /* *INDENT-ON* */
+}
+
+static void *vl_api_snat_control_ping_t_print
+  (vl_api_snat_control_ping_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: snat_control_ping ");
+
+  FINISH;
+}
+
+static void
+vl_api_snat_show_config_t_handler (vl_api_snat_show_config_t * mp)
+{
+  vl_api_snat_show_config_reply_t *rmp;
+  snat_main_t *sm = &snat_main;
+  int rv = 0;
+
+  /* *INDENT-OFF* */
+  REPLY_MACRO2 (VL_API_SNAT_SHOW_CONFIG_REPLY,
+  ({
+    rmp->translation_buckets = htonl (sm->translation_buckets);
+    rmp->translation_memory_size = htonl (sm->translation_memory_size);
+    rmp->user_buckets = htonl (sm->user_buckets);
+    rmp->user_memory_size = htonl (sm->user_memory_size);
+    rmp->max_translations_per_user = htonl (sm->max_translations_per_user);
+    rmp->outside_vrf_id = htonl (sm->outside_vrf_id);
+    rmp->inside_vrf_id = htonl (sm->inside_vrf_id);
+    rmp->static_mapping_only = sm->static_mapping_only;
+    rmp->static_mapping_connection_tracking =
+      sm->static_mapping_connection_tracking;
+    rmp->deterministic = sm->deterministic;
+  }));
+  /* *INDENT-ON* */
+}
+
+static void *vl_api_snat_show_config_t_print
+  (vl_api_snat_show_config_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: snat_show_config ");
+
+  FINISH;
+}
+
+static void
+vl_api_snat_set_workers_t_handler (vl_api_snat_set_workers_t * mp)
+{
+  snat_main_t *sm = &snat_main;
+  vl_api_snat_set_workers_reply_t *rmp;
+  int rv = 0;
+  uword *bitmap = 0;
+  u64 mask = clib_net_to_host_u64 (mp->worker_mask);
+
+  if (sm->num_workers < 2)
+    {
+      rv = VNET_API_ERROR_FEATURE_DISABLED;
+      goto send_reply;
+    }
+
+  bitmap = clib_bitmap_set_multiple (bitmap, 0, mask, BITS (mask));
+  rv = snat_set_workers (bitmap);
+  clib_bitmap_free (bitmap);
+
+send_reply:
+  REPLY_MACRO (VL_API_SNAT_SET_WORKERS_REPLY);
+}
+
+static void *vl_api_snat_set_workers_t_print
+  (vl_api_snat_set_workers_t * mp, void *handle)
+{
+  u8 *s;
+  uword *bitmap = 0;
+  u8 first = 1;
+  int i;
+  u64 mask = clib_net_to_host_u64 (mp->worker_mask);
+
+  s = format (0, "SCRIPT: snat_set_workers ");
+  bitmap = clib_bitmap_set_multiple (bitmap, 0, mask, BITS (mask));
+  /* *INDENT-OFF* */
+  clib_bitmap_foreach (i, bitmap,
+    ({
+      if (first)
+        s = format (s, "%d", i);
+      else
+        s = format (s, ",%d", i);
+      first = 0;
+    }));
+  /* *INDENT-ON* */
+  clib_bitmap_free (bitmap);
+  FINISH;
+}
+
+static void
+  send_snat_worker_details
+  (u32 worker_index, unix_shared_memory_queue_t * q, u32 context)
+{
+  vl_api_snat_worker_details_t *rmp;
+  snat_main_t *sm = &snat_main;
+  vlib_worker_thread_t *w =
+    vlib_worker_threads + worker_index + sm->first_worker_index;
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+  rmp->_vl_msg_id = ntohs (VL_API_SNAT_WORKER_DETAILS + sm->msg_id_base);
+  rmp->context = context;
+  rmp->worker_index = htonl (worker_index);
+  rmp->lcore_id = htonl (w->lcore_id);
+  strncpy ((char *) rmp->name, (char *) w->name, ARRAY_LEN (rmp->name) - 1);
+
+  vl_msg_api_send_shmem (q, (u8 *) & rmp);
+}
+
+static void
+vl_api_snat_worker_dump_t_handler (vl_api_snat_worker_dump_t * mp)
+{
+  unix_shared_memory_queue_t *q;
+  snat_main_t *sm = &snat_main;
+  u32 *worker_index;
+
+  q = vl_api_client_index_to_input_queue (mp->client_index);
+  if (q == 0)
+    return;
+
+  /* *INDENT-OFF* */
+  vec_foreach (worker_index, sm->workers)
+    send_snat_worker_details(*worker_index, q, mp->context);
+  /* *INDENT-ON* */
+}
+
+static void *vl_api_snat_worker_dump_t_print
+  (vl_api_snat_worker_dump_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: snat_worker_dump ");
+
+  FINISH;
+}
+
+static void
+  vl_api_snat_add_del_interface_addr_t_handler
+  (vl_api_snat_add_del_interface_addr_t * mp)
+{
+  snat_main_t *sm = &snat_main;
+  vl_api_snat_add_del_interface_addr_reply_t *rmp;
+  u8 is_del = mp->is_add == 0;
+  u32 sw_if_index = ntohl (mp->sw_if_index);
+  int rv = 0;
+
+  VALIDATE_SW_IF_INDEX (mp);
+
+  rv = snat_add_interface_address (sm, sw_if_index, is_del);
+
+  BAD_SW_IF_INDEX_LABEL;
+
+  REPLY_MACRO (VL_API_SNAT_ADD_DEL_INTERFACE_ADDR_REPLY);
+}
+
+static void *vl_api_snat_add_del_interface_addr_t_print
+  (vl_api_snat_add_del_interface_addr_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: snat_add_del_interface_addr ");
+  s = format (s, "sw_if_index %d %s",
+	      clib_host_to_net_u32 (mp->sw_if_index),
+	      mp->is_add ? "" : "del");
+
+  FINISH;
+}
+
+static void
+  send_snat_interface_addr_details
+  (u32 sw_if_index, unix_shared_memory_queue_t * q, u32 context)
+{
+  vl_api_snat_interface_addr_details_t *rmp;
+  snat_main_t *sm = &snat_main;
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+  rmp->_vl_msg_id =
+    ntohs (VL_API_SNAT_INTERFACE_ADDR_DETAILS + sm->msg_id_base);
+  rmp->sw_if_index = ntohl (sw_if_index);
+  rmp->context = context;
+
+  vl_msg_api_send_shmem (q, (u8 *) & rmp);
+}
+
+static void
+  vl_api_snat_interface_addr_dump_t_handler
+  (vl_api_snat_interface_addr_dump_t * mp)
+{
+  unix_shared_memory_queue_t *q;
+  snat_main_t *sm = &snat_main;
+  u32 *i;
+
+  q = vl_api_client_index_to_input_queue (mp->client_index);
+  if (q == 0)
+    return;
+
+  /* *INDENT-OFF* */
+  vec_foreach (i, sm->auto_add_sw_if_indices)
+    send_snat_interface_addr_details(*i, q, mp->context);
+  /* *INDENT-ON* */
+}
+
+static void *vl_api_snat_interface_addr_dump_t_print
+  (vl_api_snat_interface_addr_dump_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: snat_interface_addr_dump ");
+
+  FINISH;
+}
+
+static void
+  vl_api_snat_ipfix_enable_disable_t_handler
+  (vl_api_snat_ipfix_enable_disable_t * mp)
+{
+  snat_main_t *sm = &snat_main;
+  vl_api_snat_ipfix_enable_disable_reply_t *rmp;
+  int rv = 0;
+
+  rv = snat_ipfix_logging_enable_disable (mp->enable,
+					  clib_host_to_net_u32
+					  (mp->domain_id),
+					  clib_host_to_net_u16
+					  (mp->src_port));
+
+  REPLY_MACRO (VL_API_SNAT_IPFIX_ENABLE_DISABLE_REPLY);
+}
+
+static void *vl_api_snat_ipfix_enable_disable_t_print
+  (vl_api_snat_ipfix_enable_disable_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: snat_ipfix_enable_disable ");
+  if (mp->domain_id)
+    s = format (s, "domain %d ", clib_net_to_host_u32 (mp->domain_id));
+  if (mp->src_port)
+    s = format (s, "src_port %d ", clib_net_to_host_u16 (mp->src_port));
+  if (!mp->enable)
+    s = format (s, "disable ");
+
+  FINISH;
+}
+
+static void
+  send_snat_user_details
+  (snat_user_t * u, unix_shared_memory_queue_t * q, u32 context)
+{
+  vl_api_snat_user_details_t *rmp;
+  snat_main_t *sm = &snat_main;
+  fib_table_t *fib = fib_table_get (u->fib_index, FIB_PROTOCOL_IP4);
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+  rmp->_vl_msg_id = ntohs (VL_API_SNAT_USER_DETAILS + sm->msg_id_base);
+
+  rmp->vrf_id = ntohl (fib->ft_table_id);
+
+  rmp->is_ip4 = 1;
+  clib_memcpy (rmp->ip_address, &(u->addr), 4);
+  rmp->nsessions = ntohl (u->nsessions);
+  rmp->nstaticsessions = ntohl (u->nstaticsessions);
+  rmp->context = context;
+
+  vl_msg_api_send_shmem (q, (u8 *) & rmp);
+}
+
+static void
+vl_api_snat_user_dump_t_handler (vl_api_snat_user_dump_t * mp)
+{
+  unix_shared_memory_queue_t *q;
+  snat_main_t *sm = &snat_main;
+  snat_main_per_thread_data_t *tsm;
+  snat_user_t *u;
+
+  q = vl_api_client_index_to_input_queue (mp->client_index);
+  if (q == 0)
+    return;
+
+  /* *INDENT-OFF* */
+  vec_foreach (tsm, sm->per_thread_data)
+    vec_foreach (u, tsm->users)
+      send_snat_user_details (u, q, mp->context);
+  /* *INDENT-ON* */
+}
+
+static void *vl_api_snat_user_dump_t_print
+  (vl_api_snat_user_dump_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: snat_user_dump ");
+
+  FINISH;
+}
+
+static void
+  send_snat_user_session_details
+  (snat_session_t * s, unix_shared_memory_queue_t * q, u32 context)
+{
+  vl_api_snat_user_session_details_t *rmp;
+  snat_main_t *sm = &snat_main;
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+  rmp->_vl_msg_id =
+    ntohs (VL_API_SNAT_USER_SESSION_DETAILS + sm->msg_id_base);
+  rmp->is_ip4 = 1;
+  clib_memcpy (rmp->outside_ip_address, (&s->out2in.addr), 4);
+  clib_memcpy (rmp->inside_ip_address, (&s->in2out.addr), 4);
+  rmp->is_static = s->flags & SNAT_SESSION_FLAG_STATIC_MAPPING ? 1 : 0;
+  rmp->last_heard = clib_host_to_net_u64 ((u64) s->last_heard);
+  rmp->total_bytes = clib_host_to_net_u64 (s->total_bytes);
+  rmp->total_pkts = ntohl (s->total_pkts);
+  rmp->context = context;
+  if (snat_is_unk_proto_session (s))
+    {
+      rmp->outside_port = 0;
+      rmp->inside_port = 0;
+      rmp->protocol = ntohs (s->in2out.port);
+    }
+  else
+    {
+      rmp->outside_port = s->out2in.port;
+      rmp->inside_port = s->in2out.port;
+      rmp->protocol = ntohs (snat_proto_to_ip_proto (s->in2out.protocol));
+    }
+
+  vl_msg_api_send_shmem (q, (u8 *) & rmp);
+}
+
+static void
+  vl_api_snat_user_session_dump_t_handler
+  (vl_api_snat_user_session_dump_t * mp)
+{
+  unix_shared_memory_queue_t *q;
+  snat_main_t *sm = &snat_main;
+  snat_main_per_thread_data_t *tsm;
+  snat_session_t *s;
+  clib_bihash_kv_8_8_t key, value;
+  snat_user_key_t ukey;
+  snat_user_t *u;
+  u32 session_index, head_index, elt_index;
+  dlist_elt_t *head, *elt;
+
+  q = vl_api_client_index_to_input_queue (mp->client_index);
+  if (q == 0)
+    return;
+  if (!mp->is_ip4)
+    return;
+
+  clib_memcpy (&ukey.addr, mp->ip_address, 4);
+  ukey.fib_index = fib_table_find (FIB_PROTOCOL_IP4, ntohl (mp->vrf_id));
+  key.key = ukey.as_u64;
+  if (!clib_bihash_search_8_8 (&sm->worker_by_in, &key, &value))
+    tsm = vec_elt_at_index (sm->per_thread_data, value.value);
+  else
+    tsm = vec_elt_at_index (sm->per_thread_data, sm->num_workers);
+  if (clib_bihash_search_8_8 (&sm->user_hash, &key, &value))
+    return;
+  u = pool_elt_at_index (tsm->users, value.value);
+  if (!u->nsessions && !u->nstaticsessions)
+    return;
+
+  head_index = u->sessions_per_user_list_head_index;
+  head = pool_elt_at_index (tsm->list_pool, head_index);
+  elt_index = head->next;
+  elt = pool_elt_at_index (tsm->list_pool, elt_index);
+  session_index = elt->value;
+  while (session_index != ~0)
+    {
+      s = pool_elt_at_index (tsm->sessions, session_index);
+
+      send_snat_user_session_details (s, q, mp->context);
+
+      elt_index = elt->next;
+      elt = pool_elt_at_index (tsm->list_pool, elt_index);
+      session_index = elt->value;
+    }
+}
+
+static void *vl_api_snat_user_session_dump_t_print
+  (vl_api_snat_user_session_dump_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: snat_user_session_dump ");
+  s = format (s, "ip_address %U vrf_id %d\n",
+	      format_ip4_address, mp->ip_address,
+	      clib_net_to_host_u32 (mp->vrf_id));
+
+  FINISH;
+}
+
+/******************************************************************/
+/*** detrministic NAT/CGN (old, will be deprecated after 17.10) ***/
+/******************************************************************/
+
+static void
+vl_api_snat_add_det_map_t_handler (vl_api_snat_add_det_map_t * mp)
+{
+  snat_main_t *sm = &snat_main;
+  vl_api_snat_add_det_map_reply_t *rmp;
+  int rv = 0;
+  ip4_address_t in_addr, out_addr;
+
+  clib_memcpy (&in_addr, mp->in_addr, 4);
+  clib_memcpy (&out_addr, mp->out_addr, 4);
+  rv = snat_det_add_map (sm, &in_addr, mp->in_plen, &out_addr,
+			 mp->out_plen, mp->is_add);
+
+  REPLY_MACRO (VL_API_SNAT_ADD_DET_MAP_REPLY);
+}
+
+static void *vl_api_snat_add_det_map_t_print
+  (vl_api_snat_add_det_map_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: snat_add_det_map ");
+  s = format (s, "inside address %U/%d outside address %U/%d\n",
+	      format_ip4_address, mp->in_addr, mp->in_plen,
+	      format_ip4_address, mp->out_addr, mp->out_plen);
+
+  FINISH;
+}
+
+static void
+vl_api_snat_det_forward_t_handler (vl_api_snat_det_forward_t * mp)
+{
+  snat_main_t *sm = &snat_main;
+  vl_api_snat_det_forward_reply_t *rmp;
+  int rv = 0;
+  u16 lo_port = 0, hi_port = 0;
+  snat_det_map_t *dm;
+  ip4_address_t in_addr, out_addr;
+
+  out_addr.as_u32 = 0;
+  clib_memcpy (&in_addr, mp->in_addr, 4);
+  dm = snat_det_map_by_user (sm, &in_addr);
+  if (!dm)
+    {
+      rv = VNET_API_ERROR_NO_SUCH_ENTRY;
+      goto send_reply;
+    }
+
+  snat_det_forward (dm, &in_addr, &out_addr, &lo_port);
+  hi_port = lo_port + dm->ports_per_host - 1;
+
+send_reply:
+  /* *INDENT-OFF* */
+  REPLY_MACRO2 (VL_API_SNAT_DET_FORWARD_REPLY,
+  ({
+    rmp->out_port_lo = ntohs (lo_port);
+    rmp->out_port_hi = ntohs (hi_port);
+    rmp->is_ip4 = 1;
+    memset (rmp->out_addr, 0, 16);
+    clib_memcpy (rmp->out_addr, &out_addr, 4);
+  }))
+  /* *INDENT-ON* */
+}
+
+static void *vl_api_snat_det_forward_t_print
+  (vl_api_snat_det_forward_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: smat_det_forward_t");
+  s = format (s, "inside ip address %U\n", format_ip4_address, mp->in_addr);
+
+  FINISH;
+}
+
+static void
+vl_api_snat_det_reverse_t_handler (vl_api_snat_det_reverse_t * mp)
+{
+  snat_main_t *sm = &snat_main;
+  vl_api_snat_det_reverse_reply_t *rmp;
+  int rv = 0;
+  ip4_address_t out_addr, in_addr;
+  snat_det_map_t *dm;
+
+  in_addr.as_u32 = 0;
+  clib_memcpy (&out_addr, mp->out_addr, 4);
+  dm = snat_det_map_by_out (sm, &out_addr);
+  if (!dm)
+    {
+      rv = VNET_API_ERROR_NO_SUCH_ENTRY;
+      goto send_reply;
+    }
+
+  snat_det_reverse (dm, &out_addr, htons (mp->out_port), &in_addr);
+
+send_reply:
+  /* *INDENT-OFF* */
+  REPLY_MACRO2 (VL_API_SNAT_DET_REVERSE_REPLY,
+  ({
+    rmp->is_ip4 = 1;
+    memset (rmp->in_addr, 0, 16);
+    clib_memcpy (rmp->in_addr, &in_addr, 4);
+  }))
+  /* *INDENT-ON* */
+}
+
+static void *vl_api_snat_det_reverse_t_print
+  (vl_api_snat_det_reverse_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: smat_det_reverse_t");
+  s = format (s, "outside ip address %U outside port %d",
+	      format_ip4_address, mp->out_addr, ntohs (mp->out_port));
+
+  FINISH;
+}
+
+static void
+  sent_snat_det_map_details
+  (snat_det_map_t * m, unix_shared_memory_queue_t * q, u32 context)
+{
+  vl_api_snat_det_map_details_t *rmp;
+  snat_main_t *sm = &snat_main;
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+  rmp->_vl_msg_id = ntohs (VL_API_SNAT_DET_MAP_DETAILS + sm->msg_id_base);
+  rmp->is_ip4 = 1;
+  clib_memcpy (rmp->in_addr, &m->in_addr, 4);
+  rmp->in_plen = m->in_plen;
+  clib_memcpy (rmp->out_addr, &m->out_addr, 4);
+  rmp->out_plen = m->out_plen;
+  rmp->sharing_ratio = htonl (m->sharing_ratio);
+  rmp->ports_per_host = htons (m->ports_per_host);
+  rmp->ses_num = htonl (m->ses_num);
+  rmp->context = context;
+
+  vl_msg_api_send_shmem (q, (u8 *) & rmp);
+}
+
+static void
+vl_api_snat_det_map_dump_t_handler (vl_api_snat_det_map_dump_t * mp)
+{
+  unix_shared_memory_queue_t *q;
+  snat_main_t *sm = &snat_main;
+  snat_det_map_t *m;
+
+  q = vl_api_client_index_to_input_queue (mp->client_index);
+  if (q == 0)
+    return;
+
+  /* *INDENT-OFF* */
+  vec_foreach(m, sm->det_maps)
+    sent_snat_det_map_details(m, q, mp->context);
+  /* *INDENT-ON* */
+}
+
+static void *vl_api_snat_det_map_dump_t_print
+  (vl_api_snat_det_map_dump_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: snat_det_map_dump ");
+
+  FINISH;
+}
+
+static void
+vl_api_snat_det_set_timeouts_t_handler (vl_api_snat_det_set_timeouts_t * mp)
+{
+  snat_main_t *sm = &snat_main;
+  vl_api_snat_det_set_timeouts_reply_t *rmp;
+  int rv = 0;
+
+  sm->udp_timeout = ntohl (mp->udp);
+  sm->tcp_established_timeout = ntohl (mp->tcp_established);
+  sm->tcp_transitory_timeout = ntohl (mp->tcp_transitory);
+  sm->icmp_timeout = ntohl (mp->icmp);
+
+  REPLY_MACRO (VL_API_SNAT_DET_SET_TIMEOUTS_REPLY);
+}
+
+static void *vl_api_snat_det_set_timeouts_t_print
+  (vl_api_snat_det_set_timeouts_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: snat_det_set_timeouts ");
+  s = format (s, "udp %d tcp_established %d tcp_transitory %d icmp %d\n",
+	      ntohl (mp->udp),
+	      ntohl (mp->tcp_established),
+	      ntohl (mp->tcp_transitory), ntohl (mp->icmp));
+
+  FINISH;
+}
+
+static void
+vl_api_snat_det_get_timeouts_t_handler (vl_api_snat_det_get_timeouts_t * mp)
+{
+  snat_main_t *sm = &snat_main;
+  vl_api_snat_det_get_timeouts_reply_t *rmp;
+  int rv = 0;
+
+  /* *INDENT-OFF* */
+  REPLY_MACRO2 (VL_API_SNAT_DET_GET_TIMEOUTS_REPLY,
+  ({
+    rmp->udp = htonl (sm->udp_timeout);
+    rmp->tcp_established = htonl (sm->tcp_established_timeout);
+    rmp->tcp_transitory = htonl (sm->tcp_transitory_timeout);
+    rmp->icmp = htonl (sm->icmp_timeout);
+  }))
+  /* *INDENT-ON* */
+}
+
+static void *vl_api_snat_det_get_timeouts_t_print
+  (vl_api_snat_det_get_timeouts_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: snat_det_get_timeouts");
+
+  FINISH;
+}
+
+static void
+  vl_api_snat_det_close_session_out_t_handler
+  (vl_api_snat_det_close_session_out_t * mp)
+{
+  snat_main_t *sm = &snat_main;
+  vl_api_snat_det_close_session_out_reply_t *rmp;
+  ip4_address_t out_addr, ext_addr, in_addr;
+  snat_det_out_key_t key;
+  snat_det_map_t *dm;
+  snat_det_session_t *ses;
+  int rv = 0;
+
+  clib_memcpy (&out_addr, mp->out_addr, 4);
+  clib_memcpy (&ext_addr, mp->ext_addr, 4);
+
+  dm = snat_det_map_by_out (sm, &out_addr);
+  if (!dm)
+    {
+      rv = VNET_API_ERROR_NO_SUCH_ENTRY;
+      goto send_reply;
+    }
+  snat_det_reverse (dm, &ext_addr, ntohs (mp->out_port), &in_addr);
+  key.ext_host_addr = ext_addr;
+  key.ext_host_port = mp->ext_port;
+  key.out_port = mp->out_port;
+  ses = snat_det_get_ses_by_out (dm, &in_addr, key.as_u64);
+  if (!ses)
+    {
+      rv = VNET_API_ERROR_NO_SUCH_ENTRY;
+      goto send_reply;
+    }
+  snat_det_ses_close (dm, ses);
+
+send_reply:
+  REPLY_MACRO (VL_API_SNAT_DET_CLOSE_SESSION_OUT_REPLY);
+}
+
+static void *vl_api_snat_det_close_session_out_t_print
+  (vl_api_snat_det_close_session_out_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: snat_det_close_session_out ");
+  s = format (s, "out_addr %U out_port %d "
+	      "ext_addr %U ext_port %d\n",
+	      format_ip4_address, mp->out_addr, ntohs (mp->out_port),
+	      format_ip4_address, mp->ext_addr, ntohs (mp->ext_port));
+
+  FINISH;
+}
+
+static void
+  vl_api_snat_det_close_session_in_t_handler
+  (vl_api_snat_det_close_session_in_t * mp)
+{
+  snat_main_t *sm = &snat_main;
+  vl_api_snat_det_close_session_in_reply_t *rmp;
+  ip4_address_t in_addr, ext_addr;
+  snat_det_out_key_t key;
+  snat_det_map_t *dm;
+  snat_det_session_t *ses;
+  int rv = 0;
+
+  clib_memcpy (&in_addr, mp->in_addr, 4);
+  clib_memcpy (&ext_addr, mp->ext_addr, 4);
+
+  dm = snat_det_map_by_user (sm, &in_addr);
+  if (!dm)
+    {
+      rv = VNET_API_ERROR_NO_SUCH_ENTRY;
+      goto send_reply;
+    }
+  key.ext_host_addr = ext_addr;
+  key.ext_host_port = mp->ext_port;
+  ses = snat_det_find_ses_by_in (dm, &in_addr, mp->in_port, key);
+  if (!ses)
+    {
+      rv = VNET_API_ERROR_NO_SUCH_ENTRY;
+      goto send_reply;
+    }
+  snat_det_ses_close (dm, ses);
+
+send_reply:
+  REPLY_MACRO (VL_API_SNAT_DET_CLOSE_SESSION_OUT_REPLY);
+}
+
+static void *vl_api_snat_det_close_session_in_t_print
+  (vl_api_snat_det_close_session_in_t * mp, void *handle)
+{
+  u8 *s;
+  s = format (0, "SCRIPT: snat_det_close_session_in ");
+  s = format (s, "in_addr %U in_port %d "
+	      "ext_addr %U ext_port %d\n",
+	      format_ip4_address, mp->in_addr, ntohs (mp->in_port),
+	      format_ip4_address, mp->ext_addr, ntohs (mp->ext_port));
+
+  FINISH;
+}
+
+static void
+  send_snat_det_session_details
+  (snat_det_session_t * s, unix_shared_memory_queue_t * q, u32 context)
+{
+  vl_api_snat_det_session_details_t *rmp;
+  snat_main_t *sm = &snat_main;
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+  rmp->_vl_msg_id = ntohs (VL_API_SNAT_DET_SESSION_DETAILS + sm->msg_id_base);
+  rmp->is_ip4 = 1;
+  rmp->in_port = s->in_port;
+  clib_memcpy (rmp->ext_addr, &s->out.ext_host_addr, 4);
+  rmp->ext_port = s->out.ext_host_port;
+  rmp->out_port = s->out.out_port;
+  rmp->state = s->state;
+  rmp->expire = ntohl (s->expire);
+  rmp->context = context;
+
+  vl_msg_api_send_shmem (q, (u8 *) & rmp);
+}
+
+static void
+vl_api_snat_det_session_dump_t_handler (vl_api_snat_det_session_dump_t * mp)
+{
+  unix_shared_memory_queue_t *q;
+  snat_main_t *sm = &snat_main;
+  ip4_address_t user_addr;
+  snat_det_map_t *dm;
+  snat_det_session_t *s, empty_ses;
+  u16 i;
+
+  q = vl_api_client_index_to_input_queue (mp->client_index);
+  if (q == 0)
+    return;
+  if (!mp->is_ip4)
+    return;
+
+  memset (&empty_ses, 0, sizeof (empty_ses));
+  clib_memcpy (&user_addr, mp->user_addr, 4);
+  dm = snat_det_map_by_user (sm, &user_addr);
+  if (!dm)
+    return;
+
+  s = dm->sessions + snat_det_user_ses_offset (&user_addr, dm->in_plen);
+  for (i = 0; i < SNAT_DET_SES_PER_USER; i++)
+    {
+      if (s->out.as_u64)
+	send_snat_det_session_details (s, q, mp->context);
+      s++;
+    }
+}
+
+static void *vl_api_snat_det_session_dump_t_print
+  (vl_api_snat_det_session_dump_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: snat_det_session_dump ");
+  s = format (s, "user_addr %U\n", format_ip4_address, mp->user_addr);
+
+  FINISH;
+}
+
+/******************************/
+/*** Common NAT plugin APIs ***/
+/******************************/
+
+static void
+vl_api_nat_control_ping_t_handler (vl_api_nat_control_ping_t * mp)
+{
+  vl_api_nat_control_ping_reply_t *rmp;
+  snat_main_t *sm = &snat_main;
+  int rv = 0;
+
+  /* *INDENT-OFF* */
+  REPLY_MACRO2 (VL_API_NAT_CONTROL_PING_REPLY,
+  ({
+    rmp->vpe_pid = ntohl (getpid ());
+  }));
+  /* *INDENT-ON* */
+}
+
+static void *
+vl_api_nat_control_ping_t_print (vl_api_nat_control_ping_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: nat_control_ping ");
+
+  FINISH;
+}
+
+static void
+vl_api_nat_show_config_t_handler (vl_api_nat_show_config_t * mp)
+{
+  vl_api_nat_show_config_reply_t *rmp;
+  snat_main_t *sm = &snat_main;
+  int rv = 0;
+
+  /* *INDENT-OFF* */
+  REPLY_MACRO2 (VL_API_NAT_SHOW_CONFIG_REPLY,
+  ({
+    rmp->translation_buckets = htonl (sm->translation_buckets);
+    rmp->translation_memory_size = htonl (sm->translation_memory_size);
+    rmp->user_buckets = htonl (sm->user_buckets);
+    rmp->user_memory_size = htonl (sm->user_memory_size);
+    rmp->max_translations_per_user = htonl (sm->max_translations_per_user);
+    rmp->outside_vrf_id = htonl (sm->outside_vrf_id);
+    rmp->inside_vrf_id = htonl (sm->inside_vrf_id);
+    rmp->static_mapping_only = sm->static_mapping_only;
+    rmp->static_mapping_connection_tracking =
+      sm->static_mapping_connection_tracking;
+    rmp->deterministic = sm->deterministic;
+  }));
+  /* *INDENT-ON* */
+}
+
+static void *
+vl_api_nat_show_config_t_print (vl_api_nat_show_config_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: nat_show_config ");
+
+  FINISH;
+}
+
+static void
+vl_api_nat_set_workers_t_handler (vl_api_nat_set_workers_t * mp)
+{
+  snat_main_t *sm = &snat_main;
+  vl_api_snat_set_workers_reply_t *rmp;
+  int rv = 0;
+  uword *bitmap = 0;
+  u64 mask = clib_net_to_host_u64 (mp->worker_mask);
+
+  if (sm->num_workers < 2)
+    {
+      rv = VNET_API_ERROR_FEATURE_DISABLED;
+      goto send_reply;
+    }
+
+  bitmap = clib_bitmap_set_multiple (bitmap, 0, mask, BITS (mask));
+  rv = snat_set_workers (bitmap);
+  clib_bitmap_free (bitmap);
+
+send_reply:
+  REPLY_MACRO (VL_API_NAT_SET_WORKERS_REPLY);
+}
+
+static void *
+vl_api_nat_set_workers_t_print (vl_api_nat_set_workers_t * mp, void *handle)
+{
+  u8 *s;
+  uword *bitmap = 0;
+  u8 first = 1;
+  int i;
+  u64 mask = clib_net_to_host_u64 (mp->worker_mask);
+
+  s = format (0, "SCRIPT: nat_set_workers ");
+  bitmap = clib_bitmap_set_multiple (bitmap, 0, mask, BITS (mask));
+  /* *INDENT-OFF* */
+  clib_bitmap_foreach (i, bitmap,
+    ({
+      if (first)
+        s = format (s, "%d", i);
+      else
+        s = format (s, ",%d", i);
+      first = 0;
+    }));
+  /* *INDENT-ON* */
+  clib_bitmap_free (bitmap);
+  FINISH;
+}
+
+static void
+send_nat_worker_details (u32 worker_index, unix_shared_memory_queue_t * q,
+			 u32 context)
+{
+  vl_api_nat_worker_details_t *rmp;
+  snat_main_t *sm = &snat_main;
+  vlib_worker_thread_t *w =
+    vlib_worker_threads + worker_index + sm->first_worker_index;
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+  rmp->_vl_msg_id = ntohs (VL_API_NAT_WORKER_DETAILS + sm->msg_id_base);
+  rmp->context = context;
+  rmp->worker_index = htonl (worker_index);
+  rmp->lcore_id = htonl (w->lcore_id);
+  strncpy ((char *) rmp->name, (char *) w->name, ARRAY_LEN (rmp->name) - 1);
+
+  vl_msg_api_send_shmem (q, (u8 *) & rmp);
+}
+
+static void
+vl_api_nat_worker_dump_t_handler (vl_api_nat_worker_dump_t * mp)
+{
+  unix_shared_memory_queue_t *q;
+  snat_main_t *sm = &snat_main;
+  u32 *worker_index;
+
+  q = vl_api_client_index_to_input_queue (mp->client_index);
+  if (q == 0)
+    return;
+
+  /* *INDENT-OFF* */
+  vec_foreach (worker_index, sm->workers)
+    send_nat_worker_details(*worker_index, q, mp->context);
+  /* *INDENT-ON* */
+}
+
+static void *
+vl_api_nat_worker_dump_t_print (vl_api_nat_worker_dump_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: nat_worker_dump ");
+
+  FINISH;
+}
+
+static void
+vl_api_nat_ipfix_enable_disable_t_handler (vl_api_nat_ipfix_enable_disable_t *
+					   mp)
+{
+  snat_main_t *sm = &snat_main;
+  vl_api_nat_ipfix_enable_disable_reply_t *rmp;
+  int rv = 0;
+
+  rv = snat_ipfix_logging_enable_disable (mp->enable,
+					  clib_host_to_net_u32
+					  (mp->domain_id),
+					  clib_host_to_net_u16
+					  (mp->src_port));
+
+  REPLY_MACRO (VL_API_NAT_IPFIX_ENABLE_DISABLE_REPLY);
+}
+
+static void *
+vl_api_nat_ipfix_enable_disable_t_print (vl_api_nat_ipfix_enable_disable_t *
+					 mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: nat_ipfix_enable_disable ");
+  if (mp->domain_id)
+    s = format (s, "domain %d ", clib_net_to_host_u32 (mp->domain_id));
+  if (mp->src_port)
+    s = format (s, "src_port %d ", clib_net_to_host_u16 (mp->src_port));
+  if (!mp->enable)
+    s = format (s, "disable ");
+
+  FINISH;
+}
+
+/*************/
+/*** NAT44 ***/
+/*************/
+static void
+  vl_api_nat44_add_del_address_range_t_handler
+  (vl_api_nat44_add_del_address_range_t * mp)
+{
+  snat_main_t *sm = &snat_main;
+  vl_api_nat44_add_del_address_range_reply_t *rmp;
+  ip4_address_t this_addr;
+  u32 start_host_order, end_host_order;
+  u32 vrf_id;
+  int i, count;
+  int rv = 0;
+  u32 *tmp;
+
+  if (sm->static_mapping_only)
+    {
+      rv = VNET_API_ERROR_FEATURE_DISABLED;
+      goto send_reply;
+    }
+
+  tmp = (u32 *) mp->first_ip_address;
+  start_host_order = clib_host_to_net_u32 (tmp[0]);
+  tmp = (u32 *) mp->last_ip_address;
+  end_host_order = clib_host_to_net_u32 (tmp[0]);
+
+  count = (end_host_order - start_host_order) + 1;
+
+  vrf_id = clib_host_to_net_u32 (mp->vrf_id);
+
+  if (count > 1024)
+    clib_warning ("%U - %U, %d addresses...",
+		  format_ip4_address, mp->first_ip_address,
+		  format_ip4_address, mp->last_ip_address, count);
+
+  memcpy (&this_addr.as_u8, mp->first_ip_address, 4);
+
+  for (i = 0; i < count; i++)
+    {
+      if (mp->is_add)
+	snat_add_address (sm, &this_addr, vrf_id);
+      else
+	rv = snat_del_address (sm, this_addr, 0);
+
+      if (rv)
+	goto send_reply;
+
+      increment_v4_address (&this_addr);
+    }
+
+send_reply:
+  REPLY_MACRO (VL_API_NAT44_ADD_DEL_ADDRESS_RANGE_REPLY);
+}
+
+static void *vl_api_nat44_add_del_address_range_t_print
+  (vl_api_nat44_add_del_address_range_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: nat44_add_address_range ");
+  s = format (s, "%U ", format_ip4_address, mp->first_ip_address);
+  if (memcmp (mp->first_ip_address, mp->last_ip_address, 4))
+    {
+      s = format (s, " - %U ", format_ip4_address, mp->last_ip_address);
+    }
+  FINISH;
+}
+
+static void
+send_nat44_address_details (snat_address_t * a,
+			    unix_shared_memory_queue_t * q, u32 context)
+{
+  vl_api_nat44_address_details_t *rmp;
+  snat_main_t *sm = &snat_main;
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+  rmp->_vl_msg_id = ntohs (VL_API_NAT44_ADDRESS_DETAILS + sm->msg_id_base);
+  clib_memcpy (rmp->ip_address, &(a->addr), 4);
+  if (a->fib_index != ~0)
+    {
+      fib_table_t *fib = fib_table_get (a->fib_index, FIB_PROTOCOL_IP4);
+      rmp->vrf_id = ntohl (fib->ft_table_id);
+    }
+  else
+    rmp->vrf_id = ~0;
+  rmp->context = context;
+
+  vl_msg_api_send_shmem (q, (u8 *) & rmp);
+}
+
+static void
+vl_api_nat44_address_dump_t_handler (vl_api_nat44_address_dump_t * mp)
+{
+  unix_shared_memory_queue_t *q;
+  snat_main_t *sm = &snat_main;
+  snat_address_t *a;
+
+  q = vl_api_client_index_to_input_queue (mp->client_index);
+  if (q == 0)
+    return;
+
+  /* *INDENT-OFF* */
+  vec_foreach (a, sm->addresses)
+    send_nat44_address_details (a, q, mp->context);
+  /* *INDENT-ON* */
+}
+
+static void *
+vl_api_nat44_address_dump_t_print (vl_api_nat44_address_dump_t * mp,
+				   void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: nat44_address_dump ");
+
+  FINISH;
+}
+
+static void
+  vl_api_nat44_interface_add_del_feature_t_handler
+  (vl_api_nat44_interface_add_del_feature_t * mp)
+{
+  snat_main_t *sm = &snat_main;
+  vl_api_nat44_interface_add_del_feature_reply_t *rmp;
+  u8 is_del = mp->is_add == 0;
+  u32 sw_if_index = ntohl (mp->sw_if_index);
+  int rv = 0;
+
+  VALIDATE_SW_IF_INDEX (mp);
+
+  rv = snat_interface_add_del (sw_if_index, mp->is_inside, is_del);
+
+  BAD_SW_IF_INDEX_LABEL;
+
+  REPLY_MACRO (VL_API_NAT44_INTERFACE_ADD_DEL_FEATURE_REPLY);
+}
+
+static void *vl_api_nat44_interface_add_del_feature_t_print
+  (vl_api_nat44_interface_add_del_feature_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: nat44_interface_add_del_feature ");
+  s = format (s, "sw_if_index %d %s %s",
+	      clib_host_to_net_u32 (mp->sw_if_index),
+	      mp->is_inside ? "in" : "out", mp->is_add ? "" : "del");
+
+  FINISH;
+}
+
+static void
+send_nat44_interface_details (snat_interface_t * i,
+			      unix_shared_memory_queue_t * q, u32 context)
+{
+  vl_api_nat44_interface_details_t *rmp;
+  snat_main_t *sm = &snat_main;
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+  rmp->_vl_msg_id = ntohs (VL_API_NAT44_INTERFACE_DETAILS + sm->msg_id_base);
+  rmp->sw_if_index = ntohl (i->sw_if_index);
+  rmp->is_inside = i->is_inside;
+  rmp->context = context;
+
+  vl_msg_api_send_shmem (q, (u8 *) & rmp);
+}
+
+static void
+vl_api_nat44_interface_dump_t_handler (vl_api_nat44_interface_dump_t * mp)
+{
+  unix_shared_memory_queue_t *q;
+  snat_main_t *sm = &snat_main;
+  snat_interface_t *i;
+
+  q = vl_api_client_index_to_input_queue (mp->client_index);
+  if (q == 0)
+    return;
+
+  /* *INDENT-OFF* */
+  pool_foreach (i, sm->interfaces,
+  ({
+    send_nat44_interface_details(i, q, mp->context);
+  }));
+  /* *INDENT-ON* */
+}
+
+static void *
+vl_api_nat44_interface_dump_t_print (vl_api_nat44_interface_dump_t * mp,
+				     void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: nat44_interface_dump ");
+
+  FINISH;
+}
+
+static void
+  vl_api_nat44_interface_add_del_output_feature_t_handler
+  (vl_api_nat44_interface_add_del_output_feature_t * mp)
+{
+  snat_main_t *sm = &snat_main;
+  vl_api_nat44_interface_add_del_output_feature_reply_t *rmp;
+  u8 is_del = mp->is_add == 0;
+  u32 sw_if_index = ntohl (mp->sw_if_index);
+  int rv = 0;
+
+  VALIDATE_SW_IF_INDEX (mp);
+
+  rv = snat_interface_add_del_output_feature (sw_if_index, mp->is_inside,
+					      is_del);
+
+  BAD_SW_IF_INDEX_LABEL;
+
+  REPLY_MACRO (VL_API_NAT44_INTERFACE_ADD_DEL_OUTPUT_FEATURE_REPLY);
+}
+
+static void *vl_api_nat44_interface_add_del_output_feature_t_print
+  (vl_api_nat44_interface_add_del_output_feature_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: nat44_interface_add_del_output_feature ");
+  s = format (s, "sw_if_index %d %s %s",
+	      clib_host_to_net_u32 (mp->sw_if_index),
+	      mp->is_inside ? "in" : "out", mp->is_add ? "" : "del");
+
+  FINISH;
+}
+
+static void
+send_nat44_interface_output_feature_details (snat_interface_t * i,
+					     unix_shared_memory_queue_t * q,
+					     u32 context)
+{
+  vl_api_nat44_interface_output_feature_details_t *rmp;
+  snat_main_t *sm = &snat_main;
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+  rmp->_vl_msg_id =
+    ntohs (VL_API_NAT44_INTERFACE_OUTPUT_FEATURE_DETAILS + sm->msg_id_base);
+  rmp->sw_if_index = ntohl (i->sw_if_index);
+  rmp->context = context;
+  rmp->is_inside = i->is_inside;
+
+  vl_msg_api_send_shmem (q, (u8 *) & rmp);
+}
+
+static void
+  vl_api_nat44_interface_output_feature_dump_t_handler
+  (vl_api_nat44_interface_output_feature_dump_t * mp)
+{
+  unix_shared_memory_queue_t *q;
+  snat_main_t *sm = &snat_main;
+  snat_interface_t *i;
+
+  q = vl_api_client_index_to_input_queue (mp->client_index);
+  if (q == 0)
+    return;
+
+  /* *INDENT-OFF* */
+  pool_foreach (i, sm->output_feature_interfaces,
+  ({
+    send_nat44_interface_output_feature_details(i, q, mp->context);
+  }));
+  /* *INDENT-ON* */
+}
+
+static void *vl_api_nat44_interface_output_feature_dump_t_print
+  (vl_api_nat44_interface_output_feature_dump_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: nat44_interface_output_feature_dump ");
+
+  FINISH;
+}
+
+static void
+  vl_api_nat44_add_del_static_mapping_t_handler
+  (vl_api_nat44_add_del_static_mapping_t * mp)
+{
+  snat_main_t *sm = &snat_main;
+  vl_api_nat44_add_del_static_mapping_reply_t *rmp;
+  ip4_address_t local_addr, external_addr;
+  u16 local_port = 0, external_port = 0;
+  u32 vrf_id, external_sw_if_index;
+  int rv = 0;
+  snat_protocol_t proto;
+
+  memcpy (&local_addr.as_u8, mp->local_ip_address, 4);
+  memcpy (&external_addr.as_u8, mp->external_ip_address, 4);
+  if (mp->addr_only == 0)
+    {
+      local_port = clib_net_to_host_u16 (mp->local_port);
+      external_port = clib_net_to_host_u16 (mp->external_port);
+    }
+  vrf_id = clib_net_to_host_u32 (mp->vrf_id);
+  external_sw_if_index = clib_net_to_host_u32 (mp->external_sw_if_index);
+  proto = ip_proto_to_snat_proto (mp->protocol);
+
+  rv = snat_add_static_mapping (local_addr, external_addr, local_port,
+				external_port, vrf_id, mp->addr_only,
+				external_sw_if_index, proto, mp->is_add);
+
+  REPLY_MACRO (VL_API_NAT44_ADD_DEL_STATIC_MAPPING_REPLY);
+}
+
+static void *vl_api_nat44_add_del_static_mapping_t_print
+  (vl_api_nat44_add_del_static_mapping_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: nat44_add_del_static_mapping ");
+  s = format (s, "protocol %d local_addr %U external_addr %U ",
+	      mp->protocol,
+	      format_ip4_address, mp->local_ip_address,
+	      format_ip4_address, mp->external_ip_address);
+
+  if (mp->addr_only == 0)
+    s = format (s, "local_port %d external_port %d ",
+		clib_net_to_host_u16 (mp->local_port),
+		clib_net_to_host_u16 (mp->external_port));
+
+  if (mp->vrf_id != ~0)
+    s = format (s, "vrf %d", clib_net_to_host_u32 (mp->vrf_id));
+
+  if (mp->external_sw_if_index != ~0)
+    s = format (s, "external_sw_if_index %d",
+		clib_net_to_host_u32 (mp->external_sw_if_index));
+  FINISH;
+}
+
+static void
+send_nat44_static_mapping_details (snat_static_mapping_t * m,
+				   unix_shared_memory_queue_t * q,
+				   u32 context)
+{
+  vl_api_nat44_static_mapping_details_t *rmp;
+  snat_main_t *sm = &snat_main;
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+  rmp->_vl_msg_id =
+    ntohs (VL_API_NAT44_STATIC_MAPPING_DETAILS + sm->msg_id_base);
+  rmp->addr_only = m->addr_only;
+  clib_memcpy (rmp->local_ip_address, &(m->local_addr), 4);
+  clib_memcpy (rmp->external_ip_address, &(m->external_addr), 4);
+  rmp->local_port = htons (m->local_port);
+  rmp->external_port = htons (m->external_port);
+  rmp->external_sw_if_index = ~0;
+  rmp->vrf_id = htonl (m->vrf_id);
+  rmp->protocol = snat_proto_to_ip_proto (m->proto);
+  rmp->context = context;
+
+  vl_msg_api_send_shmem (q, (u8 *) & rmp);
+}
+
+static void
+send_nat44_static_map_resolve_details (snat_static_map_resolve_t * m,
+				       unix_shared_memory_queue_t * q,
+				       u32 context)
+{
+  vl_api_nat44_static_mapping_details_t *rmp;
+  snat_main_t *sm = &snat_main;
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+  rmp->_vl_msg_id =
+    ntohs (VL_API_NAT44_STATIC_MAPPING_DETAILS + sm->msg_id_base);
+  rmp->addr_only = m->addr_only;
+  clib_memcpy (rmp->local_ip_address, &(m->l_addr), 4);
+  rmp->local_port = htons (m->l_port);
+  rmp->external_port = htons (m->e_port);
+  rmp->external_sw_if_index = htonl (m->sw_if_index);
+  rmp->vrf_id = htonl (m->vrf_id);
+  rmp->protocol = snat_proto_to_ip_proto (m->proto);
+  rmp->context = context;
+
+  vl_msg_api_send_shmem (q, (u8 *) & rmp);
+}
+
+static void
+vl_api_nat44_static_mapping_dump_t_handler (vl_api_nat44_static_mapping_dump_t
+					    * mp)
+{
+  unix_shared_memory_queue_t *q;
+  snat_main_t *sm = &snat_main;
+  snat_static_mapping_t *m;
+  snat_static_map_resolve_t *rp;
+  int j;
+
+  q = vl_api_client_index_to_input_queue (mp->client_index);
+  if (q == 0)
+    return;
+
+  /* *INDENT-OFF* */
+  pool_foreach (m, sm->static_mappings,
+  ({
+      send_nat44_static_mapping_details (m, q, mp->context);
+  }));
+  /* *INDENT-ON* */
+
+  for (j = 0; j < vec_len (sm->to_resolve); j++)
+    {
+      rp = sm->to_resolve + j;
+      send_nat44_static_map_resolve_details (rp, q, mp->context);
+    }
+}
+
+static void *
+vl_api_nat44_static_mapping_dump_t_print (vl_api_nat44_static_mapping_dump_t *
+					  mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: nat44_static_mapping_dump ");
+
+  FINISH;
+}
+
+static void
+  vl_api_nat44_add_del_interface_addr_t_handler
+  (vl_api_nat44_add_del_interface_addr_t * mp)
+{
+  snat_main_t *sm = &snat_main;
+  vl_api_nat44_add_del_interface_addr_reply_t *rmp;
+  u8 is_del = mp->is_add == 0;
+  u32 sw_if_index = ntohl (mp->sw_if_index);
+  int rv = 0;
+
+  VALIDATE_SW_IF_INDEX (mp);
+
+  rv = snat_add_interface_address (sm, sw_if_index, is_del);
+
+  BAD_SW_IF_INDEX_LABEL;
+
+  REPLY_MACRO (VL_API_NAT44_ADD_DEL_INTERFACE_ADDR_REPLY);
+}
+
+static void *vl_api_nat44_add_del_interface_addr_t_print
+  (vl_api_nat44_add_del_interface_addr_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: nat44_add_del_interface_addr ");
+  s = format (s, "sw_if_index %d %s",
+	      clib_host_to_net_u32 (mp->sw_if_index),
+	      mp->is_add ? "" : "del");
+
+  FINISH;
+}
+
+static void
+send_nat44_interface_addr_details (u32 sw_if_index,
+				   unix_shared_memory_queue_t * q,
+				   u32 context)
+{
+  vl_api_nat44_interface_addr_details_t *rmp;
+  snat_main_t *sm = &snat_main;
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+  rmp->_vl_msg_id =
+    ntohs (VL_API_NAT44_INTERFACE_ADDR_DETAILS + sm->msg_id_base);
+  rmp->sw_if_index = ntohl (sw_if_index);
+  rmp->context = context;
+
+  vl_msg_api_send_shmem (q, (u8 *) & rmp);
+}
+
+static void
+vl_api_nat44_interface_addr_dump_t_handler (vl_api_nat44_interface_addr_dump_t
+					    * mp)
+{
+  unix_shared_memory_queue_t *q;
+  snat_main_t *sm = &snat_main;
+  u32 *i;
+
+  q = vl_api_client_index_to_input_queue (mp->client_index);
+  if (q == 0)
+    return;
+
+  /* *INDENT-OFF* */
+  vec_foreach (i, sm->auto_add_sw_if_indices)
+    send_nat44_interface_addr_details(*i, q, mp->context);
+  /* *INDENT-ON* */
+}
+
+static void *
+vl_api_nat44_interface_addr_dump_t_print (vl_api_nat44_interface_addr_dump_t *
+					  mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: nat44_interface_addr_dump ");
+
+  FINISH;
+}
+
+static void
+send_nat44_user_details (snat_user_t * u, unix_shared_memory_queue_t * q,
+			 u32 context)
+{
+  vl_api_nat44_user_details_t *rmp;
+  snat_main_t *sm = &snat_main;
+  fib_table_t *fib = fib_table_get (u->fib_index, FIB_PROTOCOL_IP4);
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+  rmp->_vl_msg_id = ntohs (VL_API_NAT44_USER_DETAILS + sm->msg_id_base);
+
+  rmp->vrf_id = ntohl (fib->ft_table_id);
+
+  clib_memcpy (rmp->ip_address, &(u->addr), 4);
+  rmp->nsessions = ntohl (u->nsessions);
+  rmp->nstaticsessions = ntohl (u->nstaticsessions);
+  rmp->context = context;
+
+  vl_msg_api_send_shmem (q, (u8 *) & rmp);
+}
+
+static void
+vl_api_nat44_user_dump_t_handler (vl_api_nat44_user_dump_t * mp)
+{
+  unix_shared_memory_queue_t *q;
+  snat_main_t *sm = &snat_main;
+  snat_main_per_thread_data_t *tsm;
+  snat_user_t *u;
+
+  q = vl_api_client_index_to_input_queue (mp->client_index);
+  if (q == 0)
+    return;
+
+  /* *INDENT-OFF* */
+  vec_foreach (tsm, sm->per_thread_data)
+    vec_foreach (u, tsm->users)
+      send_nat44_user_details (u, q, mp->context);
+  /* *INDENT-ON* */
+}
+
+static void *
+vl_api_nat44_user_dump_t_print (vl_api_nat44_user_dump_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: nat44_user_dump ");
+
+  FINISH;
+}
+
+static void
+send_nat44_user_session_details (snat_session_t * s,
+				 unix_shared_memory_queue_t * q, u32 context)
+{
+  vl_api_nat44_user_session_details_t *rmp;
+  snat_main_t *sm = &snat_main;
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+  rmp->_vl_msg_id =
+    ntohs (VL_API_NAT44_USER_SESSION_DETAILS + sm->msg_id_base);
+  clib_memcpy (rmp->outside_ip_address, (&s->out2in.addr), 4);
+  clib_memcpy (rmp->inside_ip_address, (&s->in2out.addr), 4);
+  rmp->is_static = s->flags & SNAT_SESSION_FLAG_STATIC_MAPPING ? 1 : 0;
+  rmp->last_heard = clib_host_to_net_u64 ((u64) s->last_heard);
+  rmp->total_bytes = clib_host_to_net_u64 (s->total_bytes);
+  rmp->total_pkts = ntohl (s->total_pkts);
+  rmp->context = context;
+  if (snat_is_unk_proto_session (s))
+    {
+      rmp->outside_port = 0;
+      rmp->inside_port = 0;
+      rmp->protocol = ntohs (s->in2out.port);
+    }
+  else
+    {
+      rmp->outside_port = s->out2in.port;
+      rmp->inside_port = s->in2out.port;
+      rmp->protocol = ntohs (snat_proto_to_ip_proto (s->in2out.protocol));
+    }
+
+  vl_msg_api_send_shmem (q, (u8 *) & rmp);
+}
+
+static void
+vl_api_nat44_user_session_dump_t_handler (vl_api_nat44_user_session_dump_t *
+					  mp)
+{
+  unix_shared_memory_queue_t *q;
+  snat_main_t *sm = &snat_main;
+  snat_main_per_thread_data_t *tsm;
+  snat_session_t *s;
+  clib_bihash_kv_8_8_t key, value;
+  snat_user_key_t ukey;
+  snat_user_t *u;
+  u32 session_index, head_index, elt_index;
+  dlist_elt_t *head, *elt;
+
+  q = vl_api_client_index_to_input_queue (mp->client_index);
+  if (q == 0)
+    return;
+
+  clib_memcpy (&ukey.addr, mp->ip_address, 4);
+  ukey.fib_index = fib_table_find (FIB_PROTOCOL_IP4, ntohl (mp->vrf_id));
+  key.key = ukey.as_u64;
+  if (!clib_bihash_search_8_8 (&sm->worker_by_in, &key, &value))
+    tsm = vec_elt_at_index (sm->per_thread_data, value.value);
+  else
+    tsm = vec_elt_at_index (sm->per_thread_data, sm->num_workers);
+  if (clib_bihash_search_8_8 (&sm->user_hash, &key, &value))
+    return;
+  u = pool_elt_at_index (tsm->users, value.value);
+  if (!u->nsessions && !u->nstaticsessions)
+    return;
+
+  head_index = u->sessions_per_user_list_head_index;
+  head = pool_elt_at_index (tsm->list_pool, head_index);
+  elt_index = head->next;
+  elt = pool_elt_at_index (tsm->list_pool, elt_index);
+  session_index = elt->value;
+  while (session_index != ~0)
+    {
+      s = pool_elt_at_index (tsm->sessions, session_index);
+
+      send_nat44_user_session_details (s, q, mp->context);
+
+      elt_index = elt->next;
+      elt = pool_elt_at_index (tsm->list_pool, elt_index);
+      session_index = elt->value;
+    }
+}
+
+static void *
+vl_api_nat44_user_session_dump_t_print (vl_api_nat44_user_session_dump_t * mp,
+					void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: nat44_user_session_dump ");
+  s = format (s, "ip_address %U vrf_id %d\n",
+	      format_ip4_address, mp->ip_address,
+	      clib_net_to_host_u32 (mp->vrf_id));
+
+  FINISH;
+}
+
+/*******************************/
+/*** Deterministic NAT (CGN) ***/
+/*******************************/
+
+static void
+vl_api_nat_det_add_del_map_t_handler (vl_api_nat_det_add_del_map_t * mp)
+{
+  snat_main_t *sm = &snat_main;
+  vl_api_nat_det_add_del_map_reply_t *rmp;
+  int rv = 0;
+  ip4_address_t in_addr, out_addr;
+
+  if (!mp->is_nat44)
+    {
+      rv = VNET_API_ERROR_UNIMPLEMENTED;
+      goto send_reply;
+    }
+
+  clib_memcpy (&in_addr, mp->in_addr, 4);
+  clib_memcpy (&out_addr, mp->out_addr, 4);
+  rv = snat_det_add_map (sm, &in_addr, mp->in_plen, &out_addr,
+			 mp->out_plen, mp->is_add);
+
+send_reply:
+  REPLY_MACRO (VL_API_NAT_DET_ADD_DEL_MAP_REPLY);
+}
+
+static void *
+vl_api_nat_det_add_del_map_t_print (vl_api_nat_det_add_del_map_t * mp,
+				    void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: nat_det_add_del_map ");
+  s = format (s, "inside address %U/%d outside address %U/%d\n",
+	      format_ip4_address, mp->in_addr, mp->in_plen,
+	      format_ip4_address, mp->out_addr, mp->out_plen);
+
+  FINISH;
+}
+
+static void
+vl_api_nat_det_forward_t_handler (vl_api_nat_det_forward_t * mp)
+{
+  snat_main_t *sm = &snat_main;
+  vl_api_nat_det_forward_reply_t *rmp;
+  int rv = 0;
+  u16 lo_port = 0, hi_port = 0;
+  snat_det_map_t *dm;
+  ip4_address_t in_addr, out_addr;
+
+  if (!mp->is_nat44)
+    {
+      out_addr.as_u32 = 0;
+      rv = VNET_API_ERROR_UNIMPLEMENTED;
+      goto send_reply;
+    }
+
+  out_addr.as_u32 = 0;
+  clib_memcpy (&in_addr, mp->in_addr, 4);
+  dm = snat_det_map_by_user (sm, &in_addr);
+  if (!dm)
+    {
+      rv = VNET_API_ERROR_NO_SUCH_ENTRY;
+      goto send_reply;
+    }
+
+  snat_det_forward (dm, &in_addr, &out_addr, &lo_port);
+  hi_port = lo_port + dm->ports_per_host - 1;
+
+send_reply:
+  /* *INDENT-OFF* */
+  REPLY_MACRO2 (VL_API_NAT_DET_FORWARD_REPLY,
+  ({
+    rmp->out_port_lo = ntohs (lo_port);
+    rmp->out_port_hi = ntohs (hi_port);
+    clib_memcpy (rmp->out_addr, &out_addr, 4);
+  }))
+  /* *INDENT-ON* */
+}
+
+static void *
+vl_api_nat_det_forward_t_print (vl_api_nat_det_forward_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: nat_det_forward");
+  s = format (s, "inside ip address %U\n", format_ip4_address, mp->in_addr);
+
+  FINISH;
+}
+
+static void
+vl_api_nat_det_reverse_t_handler (vl_api_nat_det_reverse_t * mp)
+{
+  snat_main_t *sm = &snat_main;
+  vl_api_nat_det_reverse_reply_t *rmp;
+  int rv = 0;
+  ip4_address_t out_addr, in_addr;
+  snat_det_map_t *dm;
+
+  in_addr.as_u32 = 0;
+  clib_memcpy (&out_addr, mp->out_addr, 4);
+  dm = snat_det_map_by_out (sm, &out_addr);
+  if (!dm)
+    {
+      rv = VNET_API_ERROR_NO_SUCH_ENTRY;
+      goto send_reply;
+    }
+
+  snat_det_reverse (dm, &out_addr, htons (mp->out_port), &in_addr);
+
+send_reply:
+  /* *INDENT-OFF* */
+  REPLY_MACRO2 (VL_API_NAT_DET_REVERSE_REPLY,
+  ({
+    rmp->is_nat44 = 1;
+    memset (rmp->in_addr, 0, 16);
+    clib_memcpy (rmp->in_addr, &in_addr, 4);
+  }))
+  /* *INDENT-ON* */
+}
+
+static void *
+vl_api_nat_det_reverse_t_print (vl_api_nat_det_reverse_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: nat_det_reverse");
+  s = format (s, "outside ip address %U outside port %d",
+	      format_ip4_address, mp->out_addr, ntohs (mp->out_port));
+
+  FINISH;
+}
+
+static void
+sent_nat_det_map_details (snat_det_map_t * m, unix_shared_memory_queue_t * q,
+			  u32 context)
+{
+  vl_api_nat_det_map_details_t *rmp;
+  snat_main_t *sm = &snat_main;
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+  rmp->_vl_msg_id = ntohs (VL_API_NAT_DET_MAP_DETAILS + sm->msg_id_base);
+  rmp->is_nat44 = 1;
+  clib_memcpy (rmp->in_addr, &m->in_addr, 4);
+  rmp->in_plen = m->in_plen;
+  clib_memcpy (rmp->out_addr, &m->out_addr, 4);
+  rmp->out_plen = m->out_plen;
+  rmp->sharing_ratio = htonl (m->sharing_ratio);
+  rmp->ports_per_host = htons (m->ports_per_host);
+  rmp->ses_num = htonl (m->ses_num);
+  rmp->context = context;
+
+  vl_msg_api_send_shmem (q, (u8 *) & rmp);
+}
+
+static void
+vl_api_nat_det_map_dump_t_handler (vl_api_nat_det_map_dump_t * mp)
+{
+  unix_shared_memory_queue_t *q;
+  snat_main_t *sm = &snat_main;
+  snat_det_map_t *m;
+
+  q = vl_api_client_index_to_input_queue (mp->client_index);
+  if (q == 0)
+    return;
+
+  /* *INDENT-OFF* */
+  vec_foreach(m, sm->det_maps)
+    sent_nat_det_map_details(m, q, mp->context);
+  /* *INDENT-ON* */
+}
+
+static void *
+vl_api_nat_det_map_dump_t_print (vl_api_nat_det_map_dump_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: nat_det_map_dump ");
+
+  FINISH;
+}
+
+static void
+vl_api_nat_det_set_timeouts_t_handler (vl_api_nat_det_set_timeouts_t * mp)
+{
+  snat_main_t *sm = &snat_main;
+  vl_api_nat_det_set_timeouts_reply_t *rmp;
+  int rv = 0;
+
+  sm->udp_timeout = ntohl (mp->udp);
+  sm->tcp_established_timeout = ntohl (mp->tcp_established);
+  sm->tcp_transitory_timeout = ntohl (mp->tcp_transitory);
+  sm->icmp_timeout = ntohl (mp->icmp);
+
+  REPLY_MACRO (VL_API_NAT_DET_SET_TIMEOUTS_REPLY);
+}
+
+static void *
+vl_api_nat_det_set_timeouts_t_print (vl_api_nat_det_set_timeouts_t * mp,
+				     void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: nat_det_set_timeouts ");
+  s = format (s, "udp %d tcp_established %d tcp_transitory %d icmp %d\n",
+	      ntohl (mp->udp),
+	      ntohl (mp->tcp_established),
+	      ntohl (mp->tcp_transitory), ntohl (mp->icmp));
+
+  FINISH;
+}
+
+static void
+vl_api_nat_det_get_timeouts_t_handler (vl_api_nat_det_get_timeouts_t * mp)
+{
+  snat_main_t *sm = &snat_main;
+  vl_api_nat_det_get_timeouts_reply_t *rmp;
+  int rv = 0;
+
+  /* *INDENT-OFF* */
+  REPLY_MACRO2 (VL_API_NAT_DET_GET_TIMEOUTS_REPLY,
+  ({
+    rmp->udp = htonl (sm->udp_timeout);
+    rmp->tcp_established = htonl (sm->tcp_established_timeout);
+    rmp->tcp_transitory = htonl (sm->tcp_transitory_timeout);
+    rmp->icmp = htonl (sm->icmp_timeout);
+  }))
+  /* *INDENT-ON* */
+}
+
+static void *
+vl_api_nat_det_get_timeouts_t_print (vl_api_nat_det_get_timeouts_t * mp,
+				     void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: nat_det_get_timeouts");
+
+  FINISH;
+}
+
+static void
+vl_api_nat_det_close_session_out_t_handler (vl_api_nat_det_close_session_out_t
+					    * mp)
+{
+  snat_main_t *sm = &snat_main;
+  vl_api_nat_det_close_session_out_reply_t *rmp;
+  ip4_address_t out_addr, ext_addr, in_addr;
+  snat_det_out_key_t key;
+  snat_det_map_t *dm;
+  snat_det_session_t *ses;
+  int rv = 0;
+
+  clib_memcpy (&out_addr, mp->out_addr, 4);
+  clib_memcpy (&ext_addr, mp->ext_addr, 4);
+
+  dm = snat_det_map_by_out (sm, &out_addr);
+  if (!dm)
+    {
+      rv = VNET_API_ERROR_NO_SUCH_ENTRY;
+      goto send_reply;
+    }
+  snat_det_reverse (dm, &ext_addr, ntohs (mp->out_port), &in_addr);
+  key.ext_host_addr = ext_addr;
+  key.ext_host_port = mp->ext_port;
+  key.out_port = mp->out_port;
+  ses = snat_det_get_ses_by_out (dm, &in_addr, key.as_u64);
+  if (!ses)
+    {
+      rv = VNET_API_ERROR_NO_SUCH_ENTRY;
+      goto send_reply;
+    }
+  snat_det_ses_close (dm, ses);
+
+send_reply:
+  REPLY_MACRO (VL_API_NAT_DET_CLOSE_SESSION_OUT_REPLY);
+}
+
+static void *
+vl_api_nat_det_close_session_out_t_print (vl_api_nat_det_close_session_out_t *
+					  mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: nat_det_close_session_out ");
+  s = format (s, "out_addr %U out_port %d "
+	      "ext_addr %U ext_port %d\n",
+	      format_ip4_address, mp->out_addr, ntohs (mp->out_port),
+	      format_ip4_address, mp->ext_addr, ntohs (mp->ext_port));
+
+  FINISH;
+}
+
+static void
+vl_api_nat_det_close_session_in_t_handler (vl_api_nat_det_close_session_in_t *
+					   mp)
+{
+  snat_main_t *sm = &snat_main;
+  vl_api_nat_det_close_session_in_reply_t *rmp;
+  ip4_address_t in_addr, ext_addr;
+  snat_det_out_key_t key;
+  snat_det_map_t *dm;
+  snat_det_session_t *ses;
+  int rv = 0;
+
+  if (!mp->is_nat44)
+    {
+      rv = VNET_API_ERROR_UNIMPLEMENTED;
+      goto send_reply;
+    }
+
+  clib_memcpy (&in_addr, mp->in_addr, 4);
+  clib_memcpy (&ext_addr, mp->ext_addr, 4);
+
+  dm = snat_det_map_by_user (sm, &in_addr);
+  if (!dm)
+    {
+      rv = VNET_API_ERROR_NO_SUCH_ENTRY;
+      goto send_reply;
+    }
+  key.ext_host_addr = ext_addr;
+  key.ext_host_port = mp->ext_port;
+  ses = snat_det_find_ses_by_in (dm, &in_addr, mp->in_port, key);
+  if (!ses)
+    {
+      rv = VNET_API_ERROR_NO_SUCH_ENTRY;
+      goto send_reply;
+    }
+  snat_det_ses_close (dm, ses);
+
+send_reply:
+  REPLY_MACRO (VL_API_NAT_DET_CLOSE_SESSION_OUT_REPLY);
+}
+
+static void *
+vl_api_nat_det_close_session_in_t_print (vl_api_nat_det_close_session_in_t *
+					 mp, void *handle)
+{
+  u8 *s;
+  s = format (0, "SCRIPT: nat_det_close_session_in ");
+  s = format (s, "in_addr %U in_port %d ext_addr %U ext_port %d\n",
+	      format_ip4_address, mp->in_addr, ntohs (mp->in_port),
+	      format_ip4_address, mp->ext_addr, ntohs (mp->ext_port));
+
+  FINISH;
+}
+
+static void
+send_nat_det_session_details (snat_det_session_t * s,
+			      unix_shared_memory_queue_t * q, u32 context)
+{
+  vl_api_nat_det_session_details_t *rmp;
+  snat_main_t *sm = &snat_main;
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+  rmp->_vl_msg_id = ntohs (VL_API_NAT_DET_SESSION_DETAILS + sm->msg_id_base);
+  rmp->in_port = s->in_port;
+  clib_memcpy (rmp->ext_addr, &s->out.ext_host_addr, 4);
+  rmp->ext_port = s->out.ext_host_port;
+  rmp->out_port = s->out.out_port;
+  rmp->state = s->state;
+  rmp->expire = ntohl (s->expire);
+  rmp->context = context;
+
+  vl_msg_api_send_shmem (q, (u8 *) & rmp);
+}
+
+static void
+vl_api_nat_det_session_dump_t_handler (vl_api_nat_det_session_dump_t * mp)
+{
+  unix_shared_memory_queue_t *q;
+  snat_main_t *sm = &snat_main;
+  ip4_address_t user_addr;
+  snat_det_map_t *dm;
+  snat_det_session_t *s, empty_ses;
+  u16 i;
+
+  q = vl_api_client_index_to_input_queue (mp->client_index);
+  if (q == 0)
+    return;
+  if (!mp->is_nat44)
+    return;
+
+  memset (&empty_ses, 0, sizeof (empty_ses));
+  clib_memcpy (&user_addr, mp->user_addr, 4);
+  dm = snat_det_map_by_user (sm, &user_addr);
+  if (!dm)
+    return;
+
+  s = dm->sessions + snat_det_user_ses_offset (&user_addr, dm->in_plen);
+  for (i = 0; i < SNAT_DET_SES_PER_USER; i++)
+    {
+      if (s->out.as_u64)
+	send_nat_det_session_details (s, q, mp->context);
+      s++;
+    }
+}
+
+static void *
+vl_api_nat_det_session_dump_t_print (vl_api_nat_det_session_dump_t * mp,
+				     void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: nat_det_session_dump ");
+  s = format (s, "user_addr %U\n", format_ip4_address, mp->user_addr);
+
+  FINISH;
+}
+
+/*************/
+/*** NAT64 ***/
+/*************/
+
+static void
+  vl_api_nat64_add_del_pool_addr_range_t_handler
+  (vl_api_nat64_add_del_pool_addr_range_t * mp)
+{
+  vl_api_nat64_add_del_pool_addr_range_reply_t *rmp;
+  snat_main_t *sm = &snat_main;
+  nat64_main_t *nm = &nat64_main;
+  int rv = 0;
+  ip4_address_t this_addr;
+  u32 start_host_order, end_host_order;
+  u32 vrf_id;
+  int i, count;
+  u32 *tmp;
+
+  if (nm->is_disabled)
+    {
+      rv = VNET_API_ERROR_FEATURE_DISABLED;
+      goto send_reply;
+    }
+
+  tmp = (u32 *) mp->start_addr;
+  start_host_order = clib_host_to_net_u32 (tmp[0]);
+  tmp = (u32 *) mp->end_addr;
+  end_host_order = clib_host_to_net_u32 (tmp[0]);
+
+  count = (end_host_order - start_host_order) + 1;
+
+  vrf_id = clib_host_to_net_u32 (mp->vrf_id);
+
+  memcpy (&this_addr.as_u8, mp->start_addr, 4);
+
+  for (i = 0; i < count; i++)
+    {
+      if ((rv = nat64_add_del_pool_addr (&this_addr, vrf_id, mp->is_add)))
+	goto send_reply;
+
+      increment_v4_address (&this_addr);
+    }
+
+send_reply:
+  REPLY_MACRO (VL_API_NAT64_ADD_DEL_POOL_ADDR_RANGE_REPLY);
+}
+
+static void *vl_api_nat64_add_del_pool_addr_range_t_print
+  (vl_api_nat64_add_del_pool_addr_range_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: nat64_add_del_pool_addr_range ");
+  s = format (s, "%U - %U vrf_id %u %s\n",
+	      format_ip4_address, mp->start_addr,
+	      format_ip4_address, mp->end_addr,
+	      ntohl (mp->vrf_id), mp->is_add ? "" : "del");
+
+  FINISH;
+}
+
+typedef struct nat64_api_walk_ctx_t_
+{
+  unix_shared_memory_queue_t *q;
+  u32 context;
+} nat64_api_walk_ctx_t;
+
+static int
+nat64_api_pool_walk (snat_address_t * a, void *arg)
+{
+  vl_api_nat64_pool_addr_details_t *rmp;
+  snat_main_t *sm = &snat_main;
+  nat64_api_walk_ctx_t *ctx = arg;
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+  rmp->_vl_msg_id = ntohs (VL_API_NAT64_POOL_ADDR_DETAILS + sm->msg_id_base);
+  clib_memcpy (rmp->address, &(a->addr), 4);
+  if (a->fib_index != ~0)
+    {
+      fib_table_t *fib = fib_table_get (a->fib_index, FIB_PROTOCOL_IP6);
+      if (!fib)
+	return -1;
+      rmp->vrf_id = ntohl (fib->ft_table_id);
+    }
+  else
+    rmp->vrf_id = ~0;
+  rmp->context = ctx->context;
+
+  vl_msg_api_send_shmem (ctx->q, (u8 *) & rmp);
+
+  return 0;
+}
+
+static void
+vl_api_nat64_pool_addr_dump_t_handler (vl_api_nat64_pool_addr_dump_t * mp)
+{
+  unix_shared_memory_queue_t *q;
+  nat64_main_t *nm = &nat64_main;
+
+  if (nm->is_disabled)
+    return;
+
+  q = vl_api_client_index_to_input_queue (mp->client_index);
+  if (q == 0)
+    return;
+
+  nat64_api_walk_ctx_t ctx = {
+    .q = q,
+    .context = mp->context,
+  };
+
+  nat64_pool_addr_walk (nat64_api_pool_walk, &ctx);
+}
+
+static void *
+vl_api_nat64_pool_addr_dump_t_print (vl_api_nat64_pool_addr_dump_t * mp,
+				     void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: nat64_pool_addr_dump\n");
+
+  FINISH;
+}
+
+static void
+vl_api_nat64_add_del_interface_t_handler (vl_api_nat64_add_del_interface_t *
+					  mp)
+{
+  snat_main_t *sm = &snat_main;
+  nat64_main_t *nm = &nat64_main;
+  vl_api_nat64_add_del_interface_reply_t *rmp;
+  int rv = 0;
+
+  if (nm->is_disabled)
+    {
+      rv = VNET_API_ERROR_FEATURE_DISABLED;
+      goto send_reply;
+    }
+
+  VALIDATE_SW_IF_INDEX (mp);
+
+  rv =
+    nat64_add_del_interface (ntohl (mp->sw_if_index), mp->is_inside,
+			     mp->is_add);
+
+  BAD_SW_IF_INDEX_LABEL;
+
+send_reply:
+  REPLY_MACRO (VL_API_NAT64_ADD_DEL_INTERFACE_REPLY);
+}
+
+static void *
+vl_api_nat64_add_del_interface_t_print (vl_api_nat64_add_del_interface_t * mp,
+					void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: nat64_add_del_interface ");
+  s = format (s, "sw_if_index %d %s %s",
+	      clib_host_to_net_u32 (mp->sw_if_index),
+	      mp->is_inside ? "in" : "out", mp->is_add ? "" : "del");
+
+  FINISH;
+}
+
+static int
+nat64_api_interface_walk (snat_interface_t * i, void *arg)
+{
+  vl_api_nat64_interface_details_t *rmp;
+  snat_main_t *sm = &snat_main;
+  nat64_api_walk_ctx_t *ctx = arg;
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+  rmp->_vl_msg_id = ntohs (VL_API_NAT64_INTERFACE_DETAILS + sm->msg_id_base);
+  rmp->sw_if_index = ntohl (i->sw_if_index);
+  rmp->is_inside = i->is_inside;
+  rmp->context = ctx->context;
+
+  vl_msg_api_send_shmem (ctx->q, (u8 *) & rmp);
+
+  return 0;
+}
+
+static void
+vl_api_nat64_interface_dump_t_handler (vl_api_nat64_interface_dump_t * mp)
+{
+  unix_shared_memory_queue_t *q;
+  nat64_main_t *nm = &nat64_main;
+
+  if (nm->is_disabled)
+    return;
+
+  q = vl_api_client_index_to_input_queue (mp->client_index);
+  if (q == 0)
+    return;
+
+  nat64_api_walk_ctx_t ctx = {
+    .q = q,
+    .context = mp->context,
+  };
+
+  nat64_interfaces_walk (nat64_api_interface_walk, &ctx);
+}
+
+static void *
+vl_api_nat64_interface_dump_t_print (vl_api_nat64_interface_dump_t * mp,
+				     void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: snat_interface_dump ");
+
+  FINISH;
+}
+
+static void
+  vl_api_nat64_add_del_static_bib_t_handler
+  (vl_api_nat64_add_del_static_bib_t * mp)
+{
+  snat_main_t *sm = &snat_main;
+  nat64_main_t *nm = &nat64_main;
+  vl_api_nat64_add_del_static_bib_reply_t *rmp;
+  ip6_address_t in_addr;
+  ip4_address_t out_addr;
+  int rv = 0;
+
+  if (nm->is_disabled)
+    {
+      rv = VNET_API_ERROR_FEATURE_DISABLED;
+      goto send_reply;
+    }
+
+  memcpy (&in_addr.as_u8, mp->i_addr, 16);
+  memcpy (&out_addr.as_u8, mp->o_addr, 4);
+
+  rv =
+    nat64_add_del_static_bib_entry (&in_addr, &out_addr,
+				    clib_net_to_host_u16 (mp->i_port),
+				    clib_net_to_host_u16 (mp->o_port),
+				    mp->proto,
+				    clib_net_to_host_u32 (mp->vrf_id),
+				    mp->is_add);
+
+send_reply:
+  REPLY_MACRO (VL_API_NAT64_ADD_DEL_STATIC_BIB_REPLY);
+}
+
+static void *vl_api_nat64_add_del_static_bib_t_print
+  (vl_api_nat64_add_del_static_bib_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: nat64_add_del_static_bib ");
+  s = format (s, "protocol %d i_addr %U o_addr %U ",
+	      mp->proto,
+	      format_ip6_address, mp->i_addr, format_ip4_address, mp->o_addr);
+
+  if (mp->vrf_id != ~0)
+    s = format (s, "vrf %d", clib_net_to_host_u32 (mp->vrf_id));
+
+  FINISH;
+}
+
+static int
+nat64_api_bib_walk (nat64_db_bib_entry_t * bibe, void *arg)
+{
+  vl_api_nat64_bib_details_t *rmp;
+  snat_main_t *sm = &snat_main;
+  nat64_api_walk_ctx_t *ctx = arg;
+  fib_table_t *fib;
+
+  fib = fib_table_get (bibe->fib_index, FIB_PROTOCOL_IP6);
+  if (!fib)
+    return -1;
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+  rmp->_vl_msg_id = ntohs (VL_API_NAT64_BIB_DETAILS + sm->msg_id_base);
+  rmp->context = ctx->context;
+  clib_memcpy (rmp->i_addr, &(bibe->in_addr), 16);
+  clib_memcpy (rmp->o_addr, &(bibe->out_addr), 4);
+  rmp->i_port = bibe->in_port;
+  rmp->o_port = bibe->out_port;
+  rmp->vrf_id = ntohl (fib->ft_table_id);
+  rmp->proto = bibe->proto;
+  rmp->is_static = bibe->is_static;
+  rmp->ses_num = ntohl (bibe->ses_num);
+
+  vl_msg_api_send_shmem (ctx->q, (u8 *) & rmp);
+
+  return 0;
+}
+
+static void
+vl_api_nat64_bib_dump_t_handler (vl_api_nat64_bib_dump_t * mp)
+{
+  unix_shared_memory_queue_t *q;
+  nat64_main_t *nm = &nat64_main;
+
+  if (nm->is_disabled)
+    return;
+
+  q = vl_api_client_index_to_input_queue (mp->client_index);
+  if (q == 0)
+    return;
+
+  nat64_api_walk_ctx_t ctx = {
+    .q = q,
+    .context = mp->context,
+  };
+
+  nat64_db_bib_walk (&nm->db, mp->proto, nat64_api_bib_walk, &ctx);
+}
+
+static void *
+vl_api_nat64_bib_dump_t_print (vl_api_nat64_bib_dump_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: snat_bib_dump protocol %d", mp->proto);
+
+  FINISH;
+}
+
+static void
+vl_api_nat64_set_timeouts_t_handler (vl_api_nat64_set_timeouts_t * mp)
+{
+  snat_main_t *sm = &snat_main;
+  nat64_main_t *nm = &nat64_main;
+  vl_api_nat64_set_timeouts_reply_t *rmp;
+  int rv = 0;
+
+  if (nm->is_disabled)
+    {
+      rv = VNET_API_ERROR_FEATURE_DISABLED;
+      goto send_reply;
+    }
+
+  rv = nat64_set_icmp_timeout (ntohl (mp->icmp));
+  if (rv)
+    goto send_reply;
+  rv = nat64_set_udp_timeout (ntohl (mp->udp));
+  if (rv)
+    goto send_reply;
+  rv =
+    nat64_set_tcp_timeouts (ntohl (mp->tcp_trans), ntohl (mp->tcp_est),
+			    ntohl (mp->tcp_incoming_syn));
+
+send_reply:
+  REPLY_MACRO (VL_API_NAT64_SET_TIMEOUTS_REPLY);
+}
+
+static void *vl_api_nat64_set_timeouts_t_print
+  (vl_api_nat64_set_timeouts_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: nat64_set_timeouts ");
+  s =
+    format (s,
+	    "udp %d icmp %d, tcp_trans %d, tcp_est %d, tcp_incoming_syn %d\n",
+	    ntohl (mp->udp), ntohl (mp->icmp), ntohl (mp->tcp_trans),
+	    ntohl (mp->tcp_est), ntohl (mp->tcp_incoming_syn));
+
+  FINISH;
+}
+
+static void
+vl_api_nat64_get_timeouts_t_handler (vl_api_nat64_get_timeouts_t * mp)
+{
+  snat_main_t *sm = &snat_main;
+  nat64_main_t *nm = &nat64_main;
+  vl_api_nat64_get_timeouts_reply_t *rmp;
+  int rv = 0;
+
+  if (nm->is_disabled)
+    return;
+
+  /* *INDENT-OFF* */
+  REPLY_MACRO2 (VL_API_NAT64_GET_TIMEOUTS_REPLY,
+  ({
+    rmp->udp = htonl (nat64_get_udp_timeout());
+    rmp->icmp = htonl (nat64_get_icmp_timeout());
+    rmp->tcp_trans = htonl (nat64_get_tcp_trans_timeout());
+    rmp->tcp_est = htonl (nat64_get_tcp_est_timeout());
+    rmp->tcp_incoming_syn = htonl (nat64_get_tcp_incoming_syn_timeout());
+  }))
+  /* *INDENT-ON* */
+}
+
+static void *vl_api_nat64_get_timeouts_t_print
+  (vl_api_nat64_get_timeouts_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: nat64_get_timeouts");
+
+  FINISH;
+}
+
+static int
+nat64_api_st_walk (nat64_db_st_entry_t * ste, void *arg)
+{
+  vl_api_nat64_st_details_t *rmp;
+  snat_main_t *sm = &snat_main;
+  nat64_api_walk_ctx_t *ctx = arg;
+  nat64_main_t *nm = &nat64_main;
+  nat64_db_bib_entry_t *bibe;
+  fib_table_t *fib;
+
+  bibe = nat64_db_bib_entry_by_index (&nm->db, ste->proto, ste->bibe_index);
+  if (!bibe)
+    return -1;
+
+  fib = fib_table_get (bibe->fib_index, FIB_PROTOCOL_IP6);
+  if (!fib)
+    return -1;
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+  rmp->_vl_msg_id = ntohs (VL_API_NAT64_ST_DETAILS + sm->msg_id_base);
+  rmp->context = ctx->context;
+  clib_memcpy (rmp->il_addr, &(bibe->in_addr), 16);
+  clib_memcpy (rmp->ol_addr, &(bibe->out_addr), 4);
+  rmp->il_port = bibe->in_port;
+  rmp->ol_port = bibe->out_port;
+  clib_memcpy (rmp->ir_addr, &(ste->in_r_addr), 16);
+  clib_memcpy (rmp->or_addr, &(ste->out_r_addr), 4);
+  rmp->il_port = ste->r_port;
+  rmp->vrf_id = ntohl (fib->ft_table_id);
+  rmp->proto = ste->proto;
+
+  vl_msg_api_send_shmem (ctx->q, (u8 *) & rmp);
+
+  return 0;
+}
+
+static void
+vl_api_nat64_st_dump_t_handler (vl_api_nat64_st_dump_t * mp)
+{
+  unix_shared_memory_queue_t *q;
+  nat64_main_t *nm = &nat64_main;
+
+  if (nm->is_disabled)
+    return;
+
+  q = vl_api_client_index_to_input_queue (mp->client_index);
+  if (q == 0)
+    return;
+
+  nat64_api_walk_ctx_t ctx = {
+    .q = q,
+    .context = mp->context,
+  };
+
+  nat64_db_st_walk (&nm->db, mp->proto, nat64_api_st_walk, &ctx);
+}
+
+static void *
+vl_api_nat64_st_dump_t_print (vl_api_nat64_st_dump_t * mp, void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: snat_st_dump protocol %d", mp->proto);
+
+  FINISH;
+}
+
+static void
+vl_api_nat64_add_del_prefix_t_handler (vl_api_nat64_add_del_prefix_t * mp)
+{
+  vl_api_nat64_add_del_prefix_reply_t *rmp;
+  snat_main_t *sm = &snat_main;
+  nat64_main_t *nm = &nat64_main;
+  ip6_address_t prefix;
+  int rv = 0;
+
+  if (nm->is_disabled)
+    {
+      rv = VNET_API_ERROR_FEATURE_DISABLED;
+      goto send_reply;
+    }
+
+  memcpy (&prefix.as_u8, mp->prefix, 16);
+
+  rv =
+    nat64_add_del_prefix (&prefix, mp->prefix_len,
+			  clib_net_to_host_u32 (mp->vrf_id), mp->is_add);
+send_reply:
+  REPLY_MACRO (VL_API_NAT64_ADD_DEL_PREFIX_REPLY);
+}
+
+static void *
+vl_api_nat64_add_del_prefix_t_print (vl_api_nat64_add_del_prefix_t * mp,
+				     void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: nat64_add_del_prefix %U/%u vrf_id %u %s\n",
+	      format_ip6_address, mp->prefix, mp->prefix_len,
+	      ntohl (mp->vrf_id), mp->is_add ? "" : "del");
+
+  FINISH;
+}
+
+static int
+nat64_api_prefix_walk (nat64_prefix_t * p, void *arg)
+{
+  vl_api_nat64_prefix_details_t *rmp;
+  snat_main_t *sm = &snat_main;
+  nat64_api_walk_ctx_t *ctx = arg;
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+  rmp->_vl_msg_id = ntohs (VL_API_NAT64_PREFIX_DETAILS + sm->msg_id_base);
+  clib_memcpy (rmp->prefix, &(p->prefix), 16);
+  rmp->prefix_len = p->plen;
+  rmp->vrf_id = ntohl (p->vrf_id);
+  rmp->context = ctx->context;
+
+  vl_msg_api_send_shmem (ctx->q, (u8 *) & rmp);
+
+  return 0;
+}
+
+static void
+vl_api_nat64_prefix_dump_t_handler (vl_api_nat64_prefix_dump_t * mp)
+{
+  unix_shared_memory_queue_t *q;
+  nat64_main_t *nm = &nat64_main;
+
+  if (nm->is_disabled)
+    return;
+
+  q = vl_api_client_index_to_input_queue (mp->client_index);
+  if (q == 0)
+    return;
+
+  nat64_api_walk_ctx_t ctx = {
+    .q = q,
+    .context = mp->context,
+  };
+
+  nat64_prefix_walk (nat64_api_prefix_walk, &ctx);
+}
+
+static void *
+vl_api_nat64_prefix_dump_t_print (vl_api_nat64_prefix_dump_t * mp,
+				  void *handle)
+{
+  u8 *s;
+
+  s = format (0, "SCRIPT: nat64_prefix_dump\n");
+
+  FINISH;
+}
+
+/* List of message types that this plugin understands */
+#define foreach_snat_plugin_api_msg                                     \
+_(SNAT_ADD_ADDRESS_RANGE, snat_add_address_range)                       \
+_(SNAT_INTERFACE_ADD_DEL_FEATURE, snat_interface_add_del_feature)       \
+_(SNAT_ADD_STATIC_MAPPING, snat_add_static_mapping)                     \
+_(SNAT_CONTROL_PING, snat_control_ping)                                 \
+_(SNAT_STATIC_MAPPING_DUMP, snat_static_mapping_dump)                   \
+_(SNAT_SHOW_CONFIG, snat_show_config)                                   \
+_(SNAT_ADDRESS_DUMP, snat_address_dump)                                 \
+_(SNAT_INTERFACE_DUMP, snat_interface_dump)                             \
+_(SNAT_SET_WORKERS, snat_set_workers)                                   \
+_(SNAT_WORKER_DUMP, snat_worker_dump)                                   \
+_(SNAT_ADD_DEL_INTERFACE_ADDR, snat_add_del_interface_addr)             \
+_(SNAT_INTERFACE_ADDR_DUMP, snat_interface_addr_dump)                   \
+_(SNAT_IPFIX_ENABLE_DISABLE, snat_ipfix_enable_disable)                 \
+_(SNAT_USER_DUMP, snat_user_dump)                                       \
+_(SNAT_USER_SESSION_DUMP, snat_user_session_dump)                       \
+_(SNAT_INTERFACE_ADD_DEL_OUTPUT_FEATURE,                                \
+  snat_interface_add_del_output_feature)                                \
+_(SNAT_INTERFACE_OUTPUT_FEATURE_DUMP,                                   \
+  snat_interface_output_feature_dump)                                   \
+_(SNAT_ADD_DET_MAP, snat_add_det_map)                                   \
+_(SNAT_DET_FORWARD, snat_det_forward)                                   \
+_(SNAT_DET_REVERSE, snat_det_reverse)                                   \
+_(SNAT_DET_MAP_DUMP, snat_det_map_dump)                                 \
+_(SNAT_DET_SET_TIMEOUTS, snat_det_set_timeouts)                         \
+_(SNAT_DET_GET_TIMEOUTS, snat_det_get_timeouts)                         \
+_(SNAT_DET_CLOSE_SESSION_OUT, snat_det_close_session_out)               \
+_(SNAT_DET_CLOSE_SESSION_IN, snat_det_close_session_in)                 \
+_(SNAT_DET_SESSION_DUMP, snat_det_session_dump)                         \
+_(NAT_CONTROL_PING, nat_control_ping)                                   \
+_(NAT_SHOW_CONFIG, nat_show_config)                                     \
+_(NAT_SET_WORKERS, nat_set_workers)                                     \
+_(NAT_WORKER_DUMP, nat_worker_dump)                                     \
+_(NAT_IPFIX_ENABLE_DISABLE, nat_ipfix_enable_disable)                   \
+_(NAT44_ADD_DEL_ADDRESS_RANGE, nat44_add_del_address_range)             \
+_(NAT44_INTERFACE_ADD_DEL_FEATURE, nat44_interface_add_del_feature)     \
+_(NAT44_ADD_DEL_STATIC_MAPPING, nat44_add_del_static_mapping)           \
+_(NAT44_STATIC_MAPPING_DUMP, nat44_static_mapping_dump)                 \
+_(NAT44_ADDRESS_DUMP, nat44_address_dump)                               \
+_(NAT44_INTERFACE_DUMP, nat44_interface_dump)                           \
+_(NAT44_ADD_DEL_INTERFACE_ADDR, nat44_add_del_interface_addr)           \
+_(NAT44_INTERFACE_ADDR_DUMP, nat44_interface_addr_dump)                 \
+_(NAT44_USER_DUMP, nat44_user_dump)                                     \
+_(NAT44_USER_SESSION_DUMP, nat44_user_session_dump)                     \
+_(NAT44_INTERFACE_ADD_DEL_OUTPUT_FEATURE,                               \
+  nat44_interface_add_del_output_feature)                               \
+_(NAT44_INTERFACE_OUTPUT_FEATURE_DUMP,                                  \
+  nat44_interface_output_feature_dump)                                  \
+_(NAT_DET_ADD_DEL_MAP, nat_det_add_del_map)                             \
+_(NAT_DET_FORWARD, nat_det_forward)                                     \
+_(NAT_DET_REVERSE, nat_det_reverse)                                     \
+_(NAT_DET_MAP_DUMP, nat_det_map_dump)                                   \
+_(NAT_DET_SET_TIMEOUTS, nat_det_set_timeouts)                           \
+_(NAT_DET_GET_TIMEOUTS, nat_det_get_timeouts)                           \
+_(NAT_DET_CLOSE_SESSION_OUT, nat_det_close_session_out)                 \
+_(NAT_DET_CLOSE_SESSION_IN, nat_det_close_session_in)                   \
+_(NAT_DET_SESSION_DUMP, nat_det_session_dump)                           \
+_(NAT64_ADD_DEL_POOL_ADDR_RANGE, nat64_add_del_pool_addr_range)         \
+_(NAT64_POOL_ADDR_DUMP, nat64_pool_addr_dump)                           \
+_(NAT64_ADD_DEL_INTERFACE, nat64_add_del_interface)                     \
+_(NAT64_INTERFACE_DUMP, nat64_interface_dump)                           \
+_(NAT64_ADD_DEL_STATIC_BIB, nat64_add_del_static_bib)                   \
+_(NAT64_BIB_DUMP, nat64_bib_dump)                                       \
+_(NAT64_SET_TIMEOUTS, nat64_set_timeouts)                               \
+_(NAT64_GET_TIMEOUTS, nat64_get_timeouts)                               \
+_(NAT64_ST_DUMP, nat64_st_dump)                                         \
+_(NAT64_ADD_DEL_PREFIX, nat64_add_del_prefix)                           \
+_(NAT64_PREFIX_DUMP, nat64_prefix_dump)
+
+/* Set up the API message handling tables */
+static clib_error_t *
+snat_plugin_api_hookup (vlib_main_t * vm)
+{
+  snat_main_t *sm __attribute__ ((unused)) = &snat_main;
+#define _(N,n)                                                  \
+    vl_msg_api_set_handlers((VL_API_##N + sm->msg_id_base),     \
+                           #n,					\
+                           vl_api_##n##_t_handler,              \
+                           vl_noop_handler,                     \
+                           vl_api_##n##_t_endian,               \
+                           vl_api_##n##_t_print,                \
+                           sizeof(vl_api_##n##_t), 1);
+  foreach_snat_plugin_api_msg;
+#undef _
+
+  return 0;
+}
+
+#define vl_msg_name_crc_list
+#include <nat/nat_all_api_h.h>
+#undef vl_msg_name_crc_list
+
+static void
+setup_message_id_table (snat_main_t * sm, api_main_t * am)
+{
+#define _(id,n,crc) \
+  vl_msg_api_add_msg_name_crc (am, #n "_" #crc, id + sm->msg_id_base);
+  foreach_vl_msg_name_crc_nat;
+#undef _
+}
+
+static void
+plugin_custom_dump_configure (snat_main_t * sm)
+{
+#define _(n,f) sm->api_main->msg_print_handlers \
+  [VL_API_##n + sm->msg_id_base]                \
+    = (void *) vl_api_##f##_t_print;
+  foreach_snat_plugin_api_msg;
+#undef _
+}
+
+clib_error_t *
+snat_api_init (vlib_main_t * vm, snat_main_t * sm)
+{
+  u8 *name;
+  clib_error_t *error = 0;
+
+  name = format (0, "snat_%08x%c", api_version, 0);
+
+  /* Ask for a correctly-sized block of API message decode slots */
+  sm->msg_id_base =
+    vl_msg_api_get_msg_ids ((char *) name, VL_MSG_FIRST_AVAILABLE);
+
+  error = snat_plugin_api_hookup (vm);
+
+  /* Add our API messages to the global name_crc hash table */
+  setup_message_id_table (sm, sm->api_main);
+
+  plugin_custom_dump_configure (sm);
+
+  vec_free (name);
+
+  return error;
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/plugins/nat/nat_det.c b/src/plugins/nat/nat_det.c
new file mode 100644
index 00000000000..3af6698c09a
--- /dev/null
+++ b/src/plugins/nat/nat_det.c
@@ -0,0 +1,158 @@
+/*
+ * snat_det.c - deterministic NAT
+ *
+ * Copyright (c) 2017 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.
+ */
+/**
+ * @file
+ * @brief deterministic NAT
+ */
+
+#include <nat/nat_det.h>
+
+
+/**
+ * @brief Add/delete deterministic NAT mapping.
+ *
+ * Create bijective mapping of inside address to outside address and port range
+ * pairs, with the purpose of enabling deterministic NAT to reduce logging in
+ * CGN deployments.
+ *
+ * @param sm       SNAT main.
+ * @param in_addr  Inside network address.
+ * @param in_plen  Inside network prefix length.
+ * @param out_addr Outside network address.
+ * @param out_plen Outside network prefix length.
+ * @param is_add   If 0 delete, otherwise add.
+ */
+int
+snat_det_add_map (snat_main_t * sm, ip4_address_t * in_addr, u8 in_plen,
+		  ip4_address_t * out_addr, u8 out_plen, int is_add)
+{
+  snat_det_map_t *det_map;
+  static snat_det_session_t empty_snat_det_session = { 0 };
+  snat_interface_t *i;
+  ip4_address_t in_cmp, out_cmp;
+  u8 found = 0;
+
+  in_cmp.as_u32 = in_addr->as_u32 & ip4_main.fib_masks[in_plen];
+  out_cmp.as_u32 = out_addr->as_u32 & ip4_main.fib_masks[out_plen];
+  vec_foreach (det_map, sm->det_maps)
+  {
+    /* Checking for overlapping addresses to be added here */
+    if (det_map->in_addr.as_u32 == in_cmp.as_u32 &&
+	det_map->in_plen == in_plen &&
+	det_map->out_addr.as_u32 == out_cmp.as_u32 &&
+	det_map->out_plen == out_plen)
+      {
+	found = 1;
+	break;
+      }
+  }
+
+  /* If found, don't add again */
+  if (found && is_add)
+    return VNET_API_ERROR_VALUE_EXIST;
+
+  /* If not found, don't delete */
+  if (!found && !is_add)
+    return VNET_API_ERROR_NO_SUCH_ENTRY;
+
+  if (is_add)
+    {
+      pool_get (sm->det_maps, det_map);
+      memset (det_map, 0, sizeof (*det_map));
+      det_map->in_addr.as_u32 = in_cmp.as_u32;
+      det_map->in_plen = in_plen;
+      det_map->out_addr.as_u32 = out_cmp.as_u32;
+      det_map->out_plen = out_plen;
+      det_map->sharing_ratio = (1 << (32 - in_plen)) / (1 << (32 - out_plen));
+      det_map->ports_per_host = (65535 - 1023) / det_map->sharing_ratio;
+
+      vec_validate_init_empty (det_map->sessions,
+			       SNAT_DET_SES_PER_USER * (1 << (32 - in_plen)) -
+			       1, empty_snat_det_session);
+    }
+  else
+    {
+      vec_free (det_map->sessions);
+      vec_del1 (sm->det_maps, det_map - sm->det_maps);
+    }
+
+  /* Add/del external address range to FIB */
+  /* *INDENT-OFF* */
+  pool_foreach (i, sm->interfaces,
+  ({
+    if (i->is_inside)
+      continue;
+
+    snat_add_del_addr_to_fib(out_addr, out_plen, i->sw_if_index, is_add);
+    break;
+  }));
+  /* *INDENT-ON* */
+  return 0;
+}
+
+/**
+ * @brief The 'nat-det-expire-walk' process's main loop.
+ *
+ * Check expire time for active sessions.
+ */
+static uword
+snat_det_expire_walk_fn (vlib_main_t * vm, vlib_node_runtime_t * rt,
+			 vlib_frame_t * f)
+{
+  snat_main_t *sm = &snat_main;
+  snat_det_map_t *dm;
+  snat_det_session_t *ses;
+
+  while (sm->deterministic)
+    {
+      vlib_process_wait_for_event_or_clock (vm, 10.0);
+      vlib_process_get_events (vm, NULL);
+      u32 now = (u32) vlib_time_now (vm);
+      /* *INDENT-OFF* */
+      pool_foreach (dm, sm->det_maps,
+      ({
+        vec_foreach(ses, dm->sessions)
+          {
+            /* Delete if session expired */
+            if (ses->in_port && (ses->expire < now))
+              snat_det_ses_close (dm, ses);
+          }
+      }));
+      /* *INDENT-ON* */
+    }
+
+  return 0;
+}
+
+static vlib_node_registration_t snat_det_expire_walk_node;
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (snat_det_expire_walk_node, static) = {
+    .function = snat_det_expire_walk_fn,
+    .type = VLIB_NODE_TYPE_PROCESS,
+    .name =
+    "nat-det-expire-walk",
+};
+/* *INDENT-ON* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/plugins/nat/nat_det.h b/src/plugins/nat/nat_det.h
new file mode 100644
index 00000000000..2ab7f27eece
--- /dev/null
+++ b/src/plugins/nat/nat_det.h
@@ -0,0 +1,196 @@
+/*
+ * snat_det.h - deterministic NAT definitions
+ *
+ * Copyright (c) 2017 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.
+ */
+/**
+ * @file
+ * @brief deterministic NAT definitions
+ */
+
+#ifndef __included_nat_det_h__
+#define __included_nat_det_h__
+
+#include <vnet/ip/ip.h>
+#include <nat/nat.h>
+#include <nat/nat_ipfix_logging.h>
+
+
+#define SNAT_DET_SES_PER_USER 1000
+
+
+int snat_det_add_map (snat_main_t * sm, ip4_address_t * in_addr, u8 in_plen,
+		      ip4_address_t * out_addr, u8 out_plen, int is_add);
+
+always_inline int
+is_addr_in_net (ip4_address_t * addr, ip4_address_t * net, u8 plen)
+{
+  if (net->as_u32 == (addr->as_u32 & ip4_main.fib_masks[plen]))
+    return 1;
+  return 0;
+}
+
+always_inline snat_det_map_t *
+snat_det_map_by_user (snat_main_t * sm, ip4_address_t * user_addr)
+{
+  snat_det_map_t *dm;
+
+  /* *INDENT-OFF* */
+  pool_foreach (dm, sm->det_maps,
+  ({
+    if (is_addr_in_net(user_addr, &dm->in_addr, dm->in_plen))
+      return dm;
+  }));
+  /* *INDENT-ON* */
+  return 0;
+}
+
+always_inline snat_det_map_t *
+snat_det_map_by_out (snat_main_t * sm, ip4_address_t * out_addr)
+{
+  snat_det_map_t *dm;
+
+  /* *INDENT-OFF* */
+  pool_foreach (dm, sm->det_maps,
+  ({
+    if (is_addr_in_net(out_addr, &dm->out_addr, dm->out_plen))
+      return dm;
+  }));
+  /* *INDENT-ON* */
+  return 0;
+}
+
+always_inline void
+snat_det_forward (snat_det_map_t * dm, ip4_address_t * in_addr,
+		  ip4_address_t * out_addr, u16 * lo_port)
+{
+  u32 in_offset, out_offset;
+
+  in_offset = clib_net_to_host_u32 (in_addr->as_u32) -
+    clib_net_to_host_u32 (dm->in_addr.as_u32);
+  out_offset = in_offset / dm->sharing_ratio;
+  out_addr->as_u32 =
+    clib_host_to_net_u32 (clib_net_to_host_u32 (dm->out_addr.as_u32) +
+			  out_offset);
+  *lo_port = 1024 + dm->ports_per_host * (in_offset % dm->sharing_ratio);
+}
+
+always_inline void
+snat_det_reverse (snat_det_map_t * dm, ip4_address_t * out_addr, u16 out_port,
+		  ip4_address_t * in_addr)
+{
+  u32 in_offset1, in_offset2, out_offset;
+
+  out_offset = clib_net_to_host_u32 (out_addr->as_u32) -
+    clib_net_to_host_u32 (dm->out_addr.as_u32);
+  in_offset1 = out_offset * dm->sharing_ratio;
+  in_offset2 = (out_port - 1024) / dm->ports_per_host;
+  in_addr->as_u32 =
+    clib_host_to_net_u32 (clib_net_to_host_u32 (dm->in_addr.as_u32) +
+			  in_offset1 + in_offset2);
+}
+
+always_inline u32
+snat_det_user_ses_offset (ip4_address_t * addr, u8 plen)
+{
+  return (clib_net_to_host_u32 (addr->as_u32) & pow2_mask (32 - plen)) *
+    SNAT_DET_SES_PER_USER;
+}
+
+always_inline snat_det_session_t *
+snat_det_get_ses_by_out (snat_det_map_t * dm, ip4_address_t * in_addr,
+			 u64 out_key)
+{
+  u32 user_offset;
+  u16 i;
+
+  user_offset = snat_det_user_ses_offset (in_addr, dm->in_plen);
+  for (i = 0; i < SNAT_DET_SES_PER_USER; i++)
+    {
+      if (dm->sessions[i + user_offset].out.as_u64 == out_key)
+	return &dm->sessions[i + user_offset];
+    }
+
+  return 0;
+}
+
+always_inline snat_det_session_t *
+snat_det_find_ses_by_in (snat_det_map_t * dm, ip4_address_t * in_addr,
+			 u16 in_port, snat_det_out_key_t out_key)
+{
+  snat_det_session_t *ses;
+  u32 user_offset;
+  u16 i;
+
+  user_offset = snat_det_user_ses_offset (in_addr, dm->in_plen);
+  for (i = 0; i < SNAT_DET_SES_PER_USER; i++)
+    {
+      ses = &dm->sessions[i + user_offset];
+      if (ses->in_port == in_port &&
+	  ses->out.ext_host_addr.as_u32 == out_key.ext_host_addr.as_u32 &&
+	  ses->out.ext_host_port == out_key.ext_host_port)
+	return &dm->sessions[i + user_offset];
+    }
+
+  return 0;
+}
+
+always_inline snat_det_session_t *
+snat_det_ses_create (snat_det_map_t * dm, ip4_address_t * in_addr,
+		     u16 in_port, snat_det_out_key_t * out)
+{
+  u32 user_offset;
+  u16 i;
+
+  user_offset = snat_det_user_ses_offset (in_addr, dm->in_plen);
+
+  for (i = 0; i < SNAT_DET_SES_PER_USER; i++)
+    {
+      if (!dm->sessions[i + user_offset].in_port)
+	{
+	  if (__sync_bool_compare_and_swap
+	      (&dm->sessions[i + user_offset].in_port, 0, in_port))
+	    {
+	      dm->sessions[i + user_offset].out.as_u64 = out->as_u64;
+	      dm->sessions[i + user_offset].state = SNAT_SESSION_UNKNOWN;
+	      dm->sessions[i + user_offset].expire = 0;
+	      __sync_add_and_fetch (&dm->ses_num, 1);
+	      return &dm->sessions[i + user_offset];
+	    }
+	}
+    }
+
+  snat_ipfix_logging_max_entries_per_user (in_addr->as_u32);
+  return 0;
+}
+
+always_inline void
+snat_det_ses_close (snat_det_map_t * dm, snat_det_session_t * ses)
+{
+  if (__sync_bool_compare_and_swap (&ses->in_port, ses->in_port, 0))
+    {
+      ses->out.as_u64 = 0;
+      __sync_add_and_fetch (&dm->ses_num, -1);
+    }
+}
+
+#endif /* __included_nat_det_h__ */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/plugins/nat/nat_ipfix_logging.c b/src/plugins/nat/nat_ipfix_logging.c
new file mode 100644
index 00000000000..0cc0f82a337
--- /dev/null
+++ b/src/plugins/nat/nat_ipfix_logging.c
@@ -0,0 +1,835 @@
+/*
+ * nat_ipfix_logging.c - NAT Events IPFIX logging
+ *
+ * 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/flow/flow_report.h>
+#include <vlibmemory/api.h>
+#include <nat/nat.h>
+#include <nat/nat_ipfix_logging.h>
+
+snat_ipfix_logging_main_t snat_ipfix_logging_main;
+
+#define NAT44_SESSION_CREATE_LEN 26
+#define NAT_ADDRESSES_EXHAUTED_LEN 13
+#define MAX_ENTRIES_PER_USER_LEN 17
+
+#define NAT44_SESSION_CREATE_FIELD_COUNT 8
+#define NAT_ADDRESSES_EXHAUTED_FIELD_COUNT 3
+#define MAX_ENTRIES_PER_USER_FIELD_COUNT 4
+
+typedef struct {
+  u8 nat_event;
+  u32 src_ip;
+  u32 nat_src_ip;
+  snat_protocol_t snat_proto;
+  u16 src_port;
+  u16 nat_src_port;
+  u32 vrf_id;
+} snat_ipfix_logging_nat44_ses_args_t;
+
+typedef struct {
+  u32 pool_id;
+} snat_ipfix_logging_addr_exhausted_args_t;
+
+typedef struct {
+  u32 src_ip;
+} snat_ipfix_logging_max_entries_per_user_args_t;
+
+/**
+ * @brief Create an IPFIX template packet rewrite string
+ *
+ * @param frm               flow report main
+ * @param fr                flow report
+ * @param collector_address collector address
+ * @param src_address       source address
+ * @param collector_port    collector
+ * @param event             NAT event ID
+ * @param quota_event       NAT quota exceeded event ID
+ *
+ * @returns template packet
+ */
+static inline u8 *
+snat_template_rewrite (flow_report_main_t * frm,
+                       flow_report_t * fr,
+                       ip4_address_t * collector_address,
+                       ip4_address_t * src_address,
+                       u16 collector_port,
+                       nat_event_t event,
+                       quota_exceed_event_t quota_event)
+{
+  snat_ipfix_logging_main_t *silm = &snat_ipfix_logging_main;
+  ip4_header_t *ip;
+  udp_header_t *udp;
+  ipfix_message_header_t *h;
+  ipfix_set_header_t *s;
+  ipfix_template_header_t *t;
+  ipfix_field_specifier_t *f;
+  ipfix_field_specifier_t *first_field;
+  u8 *rewrite = 0;
+  ip4_ipfix_template_packet_t *tp;
+  u32 field_count = 0;
+  flow_report_stream_t *stream;
+
+  stream = &frm->streams[fr->stream_index];
+  silm->stream_index = fr->stream_index;
+
+  if (event == NAT_ADDRESSES_EXHAUTED)
+    {
+      field_count = NAT_ADDRESSES_EXHAUTED_FIELD_COUNT;
+      silm->addr_exhausted_template_id = fr->template_id;
+    }
+  else if (event == NAT44_SESSION_CREATE)
+    {
+      field_count = NAT44_SESSION_CREATE_FIELD_COUNT;
+      silm->nat44_session_template_id = fr->template_id;
+    }
+  else if (event == QUOTA_EXCEEDED)
+    {
+      if (quota_event == MAX_ENTRIES_PER_USER)
+        {
+          field_count = MAX_ENTRIES_PER_USER_FIELD_COUNT;
+          silm->max_entries_per_user_template_id = fr->template_id;
+        }
+    }
+
+  /* allocate rewrite space */
+  vec_validate_aligned (rewrite,
+			sizeof (ip4_ipfix_template_packet_t)
+			+ field_count * sizeof (ipfix_field_specifier_t) - 1,
+			CLIB_CACHE_LINE_BYTES);
+
+  tp = (ip4_ipfix_template_packet_t *) rewrite;
+  ip = (ip4_header_t *) & tp->ip4;
+  udp = (udp_header_t *) (ip + 1);
+  h = (ipfix_message_header_t *) (udp + 1);
+  s = (ipfix_set_header_t *) (h + 1);
+  t = (ipfix_template_header_t *) (s + 1);
+  first_field = f = (ipfix_field_specifier_t *) (t + 1);
+
+  ip->ip_version_and_header_length = 0x45;
+  ip->ttl = 254;
+  ip->protocol = IP_PROTOCOL_UDP;
+  ip->src_address.as_u32 = src_address->as_u32;
+  ip->dst_address.as_u32 = collector_address->as_u32;
+  udp->src_port = clib_host_to_net_u16 (stream->src_port);
+  udp->dst_port = clib_host_to_net_u16 (collector_port);
+  udp->length = clib_host_to_net_u16 (vec_len (rewrite) - sizeof (*ip));
+
+  /* FIXUP: message header export_time */
+  h->domain_id = clib_host_to_net_u32 (stream->domain_id);
+
+  /* Add TLVs to the template */
+  if (event == NAT_ADDRESSES_EXHAUTED)
+    {
+      f->e_id_length = ipfix_e_id_length (0, observationTimeMilliseconds, 8);
+      f++;
+      f->e_id_length = ipfix_e_id_length (0, natEvent, 1);
+      f++;
+      f->e_id_length = ipfix_e_id_length (0, natPoolId, 4);
+      f++;
+    }
+  else if (event == NAT44_SESSION_CREATE)
+    {
+      f->e_id_length = ipfix_e_id_length (0, observationTimeMilliseconds, 8);
+      f++;
+      f->e_id_length = ipfix_e_id_length (0, natEvent, 1);
+      f++;
+      f->e_id_length = ipfix_e_id_length (0, sourceIPv4Address, 4);
+      f++;
+      f->e_id_length = ipfix_e_id_length (0, postNATSourceIPv4Address, 4);
+      f++;
+      f->e_id_length = ipfix_e_id_length (0, protocolIdentifier, 1);
+      f++;
+      f->e_id_length = ipfix_e_id_length (0, sourceTransportPort, 2);
+      f++;
+      f->e_id_length = ipfix_e_id_length (0, postNAPTSourceTransportPort, 2);
+      f++;
+      f->e_id_length = ipfix_e_id_length (0, ingressVRFID, 4);
+      f++;
+    }
+  else if (event == QUOTA_EXCEEDED)
+    {
+      if (quota_event == MAX_ENTRIES_PER_USER)
+        {
+          f->e_id_length = ipfix_e_id_length (0, observationTimeMilliseconds,
+                                              8);
+          f++;
+          f->e_id_length = ipfix_e_id_length (0, natEvent, 1);
+          f++;
+          f->e_id_length = ipfix_e_id_length (0, natQuotaExceededEvent, 4);
+          f++;
+          f->e_id_length = ipfix_e_id_length (0, sourceIPv4Address, 4);
+          f++;
+        }
+    }
+
+  /* Back to the template packet... */
+  ip = (ip4_header_t *) & tp->ip4;
+  udp = (udp_header_t *) (ip + 1);
+
+  ASSERT (f - first_field);
+  /* Field count in this template */
+  t->id_count = ipfix_id_count (fr->template_id, f - first_field);
+
+  /* set length in octets */
+  s->set_id_length =
+    ipfix_set_id_length (2 /* set_id */ , (u8 *) f - (u8 *) s);
+
+  /* message length in octets */
+  h->version_length = version_length ((u8 *) f - (u8 *) h);
+
+  ip->length = clib_host_to_net_u16 ((u8 *) f - (u8 *) ip);
+  ip->checksum = ip4_header_checksum (ip);
+
+  return rewrite;
+}
+
+u8 *
+snat_template_rewrite_addr_exhausted (flow_report_main_t * frm,
+                                      flow_report_t * fr,
+                                      ip4_address_t * collector_address,
+                                      ip4_address_t * src_address,
+                                      u16 collector_port)
+{
+  return snat_template_rewrite (frm, fr, collector_address, src_address,
+                                collector_port, NAT_ADDRESSES_EXHAUTED, 0);
+}
+
+u8 *
+snat_template_rewrite_nat44_session (flow_report_main_t * frm,
+                                     flow_report_t * fr,
+                                     ip4_address_t * collector_address,
+                                     ip4_address_t * src_address,
+                                     u16 collector_port)
+{
+  return snat_template_rewrite (frm, fr, collector_address, src_address,
+                                collector_port, NAT44_SESSION_CREATE, 0);
+}
+
+u8 *
+snat_template_rewrite_max_entries_per_usr (flow_report_main_t * frm,
+                                           flow_report_t * fr,
+                                           ip4_address_t * collector_address,
+                                           ip4_address_t * src_address,
+                                           u16 collector_port)
+{
+  return snat_template_rewrite (frm, fr, collector_address, src_address,
+                                collector_port, QUOTA_EXCEEDED,
+                                MAX_ENTRIES_PER_USER);
+}
+
+static inline void
+snat_ipfix_header_create (flow_report_main_t * frm,
+                          vlib_buffer_t * b0,
+                          u32 * offset)
+{
+  snat_ipfix_logging_main_t *silm = &snat_ipfix_logging_main;
+  flow_report_stream_t *stream;
+  ip4_ipfix_template_packet_t * tp;
+  ipfix_message_header_t * h = 0;
+  ipfix_set_header_t * s = 0;
+  ip4_header_t * ip;
+  udp_header_t * udp;
+
+  stream = &frm->streams[silm->stream_index];
+
+  b0->current_data = 0;
+  b0->current_length = sizeof (*ip) + sizeof (*udp) + sizeof (*h) +
+                       sizeof (*s);
+  b0->flags |= (VLIB_BUFFER_TOTAL_LENGTH_VALID | VLIB_BUFFER_FLOW_REPORT);
+  vnet_buffer (b0)->sw_if_index[VLIB_RX] = 0;
+  vnet_buffer (b0)->sw_if_index[VLIB_TX] = frm->fib_index;
+  tp = vlib_buffer_get_current (b0);
+  ip = (ip4_header_t *) &tp->ip4;
+  udp = (udp_header_t *) (ip+1);
+  h = (ipfix_message_header_t *)(udp+1);
+  s = (ipfix_set_header_t *)(h+1);
+
+  ip->ip_version_and_header_length = 0x45;
+  ip->ttl = 254;
+  ip->protocol = IP_PROTOCOL_UDP;
+  ip->flags_and_fragment_offset = 0;
+  ip->src_address.as_u32 = frm->src_address.as_u32;
+  ip->dst_address.as_u32 = frm->ipfix_collector.as_u32;
+  udp->src_port = clib_host_to_net_u16 (stream->src_port);
+  udp->dst_port = clib_host_to_net_u16 (frm->collector_port);
+  udp->checksum = 0;
+
+  h->export_time = clib_host_to_net_u32 (
+    (u32) (((f64)frm->unix_time_0) + (vlib_time_now(frm->vlib_main) -
+    frm->vlib_time_0)));
+  h->sequence_number = clib_host_to_net_u32 (stream->sequence_number++);
+  h->domain_id = clib_host_to_net_u32 (stream->domain_id);
+
+  *offset = (u32) (((u8 *)(s+1)) - (u8 *)tp);
+}
+
+static inline void
+snat_ipfix_send (flow_report_main_t * frm,
+                 vlib_frame_t * f,
+                 vlib_buffer_t * b0,
+                 u16 template_id)
+{
+  ip4_ipfix_template_packet_t * tp;
+  ipfix_message_header_t * h = 0;
+  ipfix_set_header_t * s = 0;
+  ip4_header_t * ip;
+  udp_header_t * udp;
+  vlib_main_t * vm = frm->vlib_main;
+
+  tp = vlib_buffer_get_current (b0);
+  ip = (ip4_header_t *) & tp->ip4;
+  udp = (udp_header_t *) (ip + 1);
+  h = (ipfix_message_header_t *) (udp + 1);
+  s = (ipfix_set_header_t *) (h + 1);
+
+  s->set_id_length = ipfix_set_id_length (template_id,
+                                          b0->current_length -
+                                          (sizeof (*ip) + sizeof (*udp) +
+                                           sizeof (*h)));
+  h->version_length = version_length (b0->current_length -
+                                      (sizeof (*ip) + sizeof (*udp)));
+
+  ip->length = clib_host_to_net_u16 (b0->current_length);
+  ip->checksum = ip4_header_checksum (ip);
+  udp->length = clib_host_to_net_u16 (b0->current_length - sizeof (*ip));
+
+  if (frm->udp_checksum)
+    {
+      udp->checksum = ip4_tcp_udp_compute_checksum (vm, b0, ip);
+      if (udp->checksum == 0)
+        udp->checksum = 0xffff;
+    }
+
+  ASSERT (ip->checksum == ip4_header_checksum (ip));
+
+  vlib_put_frame_to_node (vm, ip4_lookup_node.index, f);
+}
+
+static void
+snat_ipfix_logging_nat44_ses (u8 nat_event, u32 src_ip, u32 nat_src_ip,
+                              snat_protocol_t snat_proto, u16 src_port,
+                              u16 nat_src_port, u32 vrf_id, int do_flush)
+{
+  snat_ipfix_logging_main_t *silm = &snat_ipfix_logging_main;
+  flow_report_main_t *frm = &flow_report_main;
+  vlib_frame_t *f;
+  vlib_buffer_t *b0 = 0;
+  u32 bi0 = ~0;
+  u32 offset;
+  vlib_main_t * vm = frm->vlib_main;
+  u64 now;
+  vlib_buffer_free_list_t *fl;
+  u8 proto = ~0;
+
+  if (!silm->enabled)
+    return;
+
+  proto = snat_proto_to_ip_proto (snat_proto);
+
+  now = (u64) ((vlib_time_now (vm) - silm->vlib_time_0) * 1e3);
+  now += silm->milisecond_time_0;
+
+  b0 = silm->nat44_session_buffer;
+
+  if (PREDICT_FALSE (b0 == 0))
+    {
+      if (do_flush)
+        return;
+
+      if (vlib_buffer_alloc (vm, &bi0, 1) != 1)
+        {
+          clib_warning ("can't allocate buffer for NAT IPFIX event");
+          return;
+        }
+
+      b0 = silm->nat44_session_buffer =
+        vlib_get_buffer (vm, bi0);
+      fl = vlib_buffer_get_free_list (vm, VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX);
+      vlib_buffer_init_for_free_list (b0, fl);
+      VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b0);
+      offset = 0;
+    }
+  else
+    {
+      bi0 = vlib_get_buffer_index (vm, b0);
+      offset = silm->nat44_session_next_record_offset;
+    }
+
+  f = silm->nat44_session_frame;
+  if (PREDICT_FALSE (f == 0))
+    {
+      u32 * to_next;
+      f = vlib_get_frame_to_node (vm, ip4_lookup_node.index);
+      silm->nat44_session_frame = f;
+      to_next = vlib_frame_vector_args (f);
+      to_next[0] = bi0;
+      f->n_vectors = 1;
+    }
+
+  if (PREDICT_FALSE (offset == 0))
+    snat_ipfix_header_create (frm, b0, &offset);
+
+  if (PREDICT_TRUE (do_flush == 0))
+    {
+      u64 time_stamp = clib_host_to_net_u64 (now);
+      clib_memcpy (b0->data + offset, &time_stamp, sizeof (time_stamp));
+      offset += sizeof (time_stamp);
+
+      clib_memcpy (b0->data + offset, &nat_event, sizeof (nat_event));
+      offset += sizeof (nat_event);
+
+      clib_memcpy (b0->data + offset, &src_ip, sizeof (src_ip));
+      offset += sizeof (src_ip);
+
+      clib_memcpy (b0->data + offset, &nat_src_ip, sizeof (nat_src_ip));
+      offset += sizeof (nat_src_ip);
+
+      clib_memcpy (b0->data + offset, &proto, sizeof (proto));
+      offset += sizeof (proto);
+
+      clib_memcpy (b0->data + offset, &src_port, sizeof (src_port));
+      offset += sizeof (src_port);
+
+      clib_memcpy (b0->data + offset, &nat_src_port, sizeof (nat_src_port));
+      offset += sizeof (nat_src_port);
+
+      clib_memcpy (b0->data + offset, &vrf_id, sizeof(vrf_id));
+      offset += sizeof (vrf_id);
+
+      b0->current_length += NAT44_SESSION_CREATE_LEN;
+    }
+
+  if (PREDICT_FALSE (do_flush || (offset + NAT44_SESSION_CREATE_LEN) > frm->path_mtu))
+    {
+      snat_ipfix_send (frm, f, b0, silm->nat44_session_template_id);
+      silm->nat44_session_frame = 0;
+      silm->nat44_session_buffer = 0;
+      offset = 0;
+    }
+  silm->nat44_session_next_record_offset = offset;
+ }
+
+static void
+snat_ipfix_logging_addr_exhausted (u32 pool_id, int do_flush)
+{
+  snat_ipfix_logging_main_t *silm = &snat_ipfix_logging_main;
+  flow_report_main_t *frm = &flow_report_main;
+  vlib_frame_t *f;
+  vlib_buffer_t *b0 = 0;
+  u32 bi0 = ~0;
+  u32 offset;
+  vlib_main_t * vm = frm->vlib_main;
+  u64 now;
+  vlib_buffer_free_list_t *fl;
+  u8 nat_event = NAT_ADDRESSES_EXHAUTED;
+
+  if (!silm->enabled)
+    return;
+
+  now = (u64) ((vlib_time_now (vm) - silm->vlib_time_0) * 1e3);
+  now += silm->milisecond_time_0;
+
+  b0 = silm->addr_exhausted_buffer;
+
+  if (PREDICT_FALSE (b0 == 0))
+    {
+      if (do_flush)
+        return;
+
+      if (vlib_buffer_alloc (vm, &bi0, 1) != 1)
+        {
+          clib_warning ("can't allocate buffer for NAT IPFIX event");
+          return;
+        }
+
+      b0 = silm->addr_exhausted_buffer =
+        vlib_get_buffer (vm, bi0);
+      fl = vlib_buffer_get_free_list (vm, VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX);
+      vlib_buffer_init_for_free_list (b0, fl);
+      VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b0);
+      offset = 0;
+    }
+  else
+    {
+      bi0 = vlib_get_buffer_index (vm, b0);
+      offset = silm->addr_exhausted_next_record_offset;
+    }
+
+  f = silm->addr_exhausted_frame;
+  if (PREDICT_FALSE (f == 0))
+    {
+      u32 * to_next;
+      f = vlib_get_frame_to_node (vm, ip4_lookup_node.index);
+      silm->addr_exhausted_frame = f;
+      to_next = vlib_frame_vector_args (f);
+      to_next[0] = bi0;
+      f->n_vectors = 1;
+    }
+
+  if (PREDICT_FALSE (offset == 0))
+    snat_ipfix_header_create (frm, b0, &offset);
+
+  if (PREDICT_TRUE (do_flush == 0))
+    {
+      u64 time_stamp = clib_host_to_net_u64 (now);
+      clib_memcpy (b0->data + offset, &time_stamp, sizeof (time_stamp));
+      offset += sizeof (time_stamp);
+
+      clib_memcpy (b0->data + offset, &nat_event, sizeof (nat_event));
+      offset += sizeof (nat_event);
+
+      clib_memcpy (b0->data + offset, &pool_id, sizeof(pool_id));
+      offset += sizeof (pool_id);
+
+      b0->current_length += NAT_ADDRESSES_EXHAUTED_LEN;
+    }
+
+  if (PREDICT_FALSE (do_flush || (offset + NAT_ADDRESSES_EXHAUTED_LEN) > frm->path_mtu))
+    {
+      snat_ipfix_send (frm, f, b0, silm->addr_exhausted_template_id);
+      silm->addr_exhausted_frame = 0;
+      silm->addr_exhausted_buffer = 0;
+      offset = 0;
+    }
+  silm->addr_exhausted_next_record_offset = offset;
+}
+
+static void
+snat_ipfix_logging_max_entries_per_usr (u32 src_ip, int do_flush)
+{
+  snat_ipfix_logging_main_t *silm = &snat_ipfix_logging_main;
+  flow_report_main_t *frm = &flow_report_main;
+  vlib_frame_t *f;
+  vlib_buffer_t *b0 = 0;
+  u32 bi0 = ~0;
+  u32 offset;
+  vlib_main_t * vm = frm->vlib_main;
+  u64 now;
+  vlib_buffer_free_list_t *fl;
+  u8 nat_event = QUOTA_EXCEEDED;
+  u32 quota_event = MAX_ENTRIES_PER_USER;
+
+  if (!silm->enabled)
+    return;
+
+  now = (u64) ((vlib_time_now (vm) - silm->vlib_time_0) * 1e3);
+  now += silm->milisecond_time_0;
+
+  b0 = silm->max_entries_per_user_buffer;
+
+  if (PREDICT_FALSE (b0 == 0))
+    {
+      if (do_flush)
+        return;
+
+      if (vlib_buffer_alloc (vm, &bi0, 1) != 1)
+        {
+          clib_warning ("can't allocate buffer for NAT IPFIX event");
+          return;
+        }
+
+      b0 = silm->max_entries_per_user_buffer =
+        vlib_get_buffer (vm, bi0);
+      fl = vlib_buffer_get_free_list (vm, VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX);
+      vlib_buffer_init_for_free_list (b0, fl);
+      VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b0);
+      offset = 0;
+    }
+  else
+    {
+      bi0 = vlib_get_buffer_index (vm, b0);
+      offset = silm->max_entries_per_user_next_record_offset;
+    }
+
+  f = silm->max_entries_per_user_frame;
+  if (PREDICT_FALSE (f == 0))
+    {
+      u32 * to_next;
+      f = vlib_get_frame_to_node (vm, ip4_lookup_node.index);
+      silm->max_entries_per_user_frame = f;
+      to_next = vlib_frame_vector_args (f);
+      to_next[0] = bi0;
+      f->n_vectors = 1;
+    }
+
+  if (PREDICT_FALSE (offset == 0))
+    snat_ipfix_header_create (frm, b0, &offset);
+
+  if (PREDICT_TRUE (do_flush == 0))
+    {
+      u64 time_stamp = clib_host_to_net_u64 (now);
+      clib_memcpy (b0->data + offset, &time_stamp, sizeof (time_stamp));
+      offset += sizeof (time_stamp);
+
+      clib_memcpy (b0->data + offset, &nat_event, sizeof (nat_event));
+      offset += sizeof (nat_event);
+
+      clib_memcpy (b0->data + offset, &quota_event, sizeof(quota_event));
+      offset += sizeof (quota_event);
+
+      clib_memcpy (b0->data + offset, &src_ip, sizeof (src_ip));
+      offset += sizeof (src_ip);
+
+      b0->current_length += MAX_ENTRIES_PER_USER_LEN;
+    }
+
+  if (PREDICT_FALSE (do_flush || (offset + MAX_ENTRIES_PER_USER_LEN) > frm->path_mtu))
+    {
+      snat_ipfix_send (frm, f, b0, silm->max_entries_per_user_template_id);
+      silm->max_entries_per_user_frame = 0;
+      silm->max_entries_per_user_buffer = 0;
+      offset = 0;
+    }
+  silm->max_entries_per_user_next_record_offset = offset;
+}
+
+static void
+snat_ipfix_logging_nat44_ses_rpc_cb (snat_ipfix_logging_nat44_ses_args_t *a)
+{
+  snat_ipfix_logging_nat44_ses(a->nat_event, a->src_ip, a->nat_src_ip,
+                               a->snat_proto, a->src_port, a->nat_src_port,
+                               a->vrf_id, 0);
+}
+
+/**
+ * @brief Generate NAT44 session create event
+ *
+ * @param src_ip       source IPv4 address
+ * @param nat_src_ip   transaltes source IPv4 address
+ * @param snat_proto   NAT transport protocol
+ * @param src_port     source port
+ * @param nat_src_port translated source port
+ * @param vrf_id       VRF ID
+ */
+void
+snat_ipfix_logging_nat44_ses_create (u32 src_ip,
+                                     u32 nat_src_ip,
+                                     snat_protocol_t snat_proto,
+                                     u16 src_port,
+                                     u16 nat_src_port,
+                                     u32 vrf_id)
+{
+  snat_ipfix_logging_nat44_ses_args_t a;
+
+  a.nat_event = NAT44_SESSION_CREATE;
+  a.src_ip = src_ip;
+  a.nat_src_ip = nat_src_ip;
+  a.snat_proto = snat_proto;
+  a.src_port = src_port;
+  a.nat_src_port = nat_src_port;
+  a.vrf_id = vrf_id;
+
+  vl_api_rpc_call_main_thread (snat_ipfix_logging_nat44_ses_rpc_cb, (u8 *) &a,
+                               sizeof (a));
+}
+
+/**
+ * @brief Generate NAT44 session delete event
+ *
+ * @param src_ip       source IPv4 address
+ * @param nat_src_ip   transaltes source IPv4 address
+ * @param snat_proto   NAT transport protocol
+ * @param src_port     source port
+ * @param nat_src_port translated source port
+ * @param vrf_id       VRF ID
+ */
+void
+snat_ipfix_logging_nat44_ses_delete (u32 src_ip,
+                                     u32 nat_src_ip,
+                                     snat_protocol_t snat_proto,
+                                     u16 src_port,
+                                     u16 nat_src_port,
+                                     u32 vrf_id)
+{
+  snat_ipfix_logging_nat44_ses_args_t a;
+
+  a.nat_event = NAT44_SESSION_DELETE;
+  a.src_ip = src_ip;
+  a.nat_src_ip = nat_src_ip;
+  a.snat_proto = snat_proto;
+  a.src_port = src_port;
+  a.nat_src_port = nat_src_port;
+  a.vrf_id = vrf_id;
+
+  vl_api_rpc_call_main_thread (snat_ipfix_logging_nat44_ses_rpc_cb, (u8 *) &a,
+                               sizeof (a));
+}
+
+vlib_frame_t *
+snat_data_callback_nat44_session (flow_report_main_t * frm,
+                                  flow_report_t * fr,
+                                  vlib_frame_t * f,
+                                  u32 * to_next,
+                                  u32 node_index)
+{
+  snat_ipfix_logging_nat44_ses(0, 0, 0, 0, 0, 0, 0, 1);
+  return f;
+}
+
+static void
+snat_ipfix_logging_addr_exhausted_rpc_cb
+ (snat_ipfix_logging_addr_exhausted_args_t * a)
+{
+  snat_ipfix_logging_addr_exhausted(a->pool_id, 0);
+}
+
+/**
+ * @brief Generate NAT addresses exhausted event
+ *
+ * @param pool_id NAT pool ID
+ */
+void
+snat_ipfix_logging_addresses_exhausted(u32 pool_id)
+{
+  //TODO: This event SHOULD be rate limited
+  snat_ipfix_logging_addr_exhausted_args_t a;
+
+  a.pool_id = pool_id;
+
+  vl_api_rpc_call_main_thread (snat_ipfix_logging_addr_exhausted_rpc_cb,
+                               (u8 *) &a, sizeof (a));
+}
+
+vlib_frame_t *
+snat_data_callback_addr_exhausted (flow_report_main_t * frm,
+                                   flow_report_t * fr,
+                                   vlib_frame_t * f,
+                                   u32 * to_next,
+                                   u32 node_index)
+{
+  snat_ipfix_logging_addr_exhausted(0, 1);
+  return f;
+}
+
+static void
+snat_ipfix_logging_max_entries_per_usr_rpc_cb
+ (snat_ipfix_logging_max_entries_per_user_args_t * a)
+{
+  snat_ipfix_logging_max_entries_per_usr(a->src_ip, 0);
+}
+
+/**
+ * @brief Generate maximum entries per user exceeded event
+ *
+ * @param src_ip source IPv4 address
+ */
+void
+snat_ipfix_logging_max_entries_per_user(u32 src_ip)
+{
+  //TODO: This event SHOULD be rate limited
+  snat_ipfix_logging_max_entries_per_user_args_t a;
+
+  a.src_ip = src_ip;
+
+  vl_api_rpc_call_main_thread (snat_ipfix_logging_max_entries_per_usr_rpc_cb,
+                               (u8 *) &a, sizeof (a));
+}
+
+vlib_frame_t *
+snat_data_callback_max_entries_per_usr (flow_report_main_t * frm,
+                                        flow_report_t * fr,
+                                        vlib_frame_t * f,
+                                        u32 * to_next,
+                                        u32 node_index)
+{
+  snat_ipfix_logging_max_entries_per_usr(0, 1);
+  return f;
+}
+
+/**
+ * @brief Enable/disable NAT plugin IPFIX logging
+ *
+ * @param enable    1 if enable, 0 if disable
+ * @param domain_id observation domain ID
+ * @param src_port  source port number
+ *
+ * @returns 0 if success
+ */
+int
+snat_ipfix_logging_enable_disable (int enable, u32 domain_id, u16 src_port)
+{
+  snat_main_t * sm = &snat_main;
+  snat_ipfix_logging_main_t *silm = &snat_ipfix_logging_main;
+  flow_report_main_t *frm = &flow_report_main;
+  vnet_flow_report_add_del_args_t a;
+  int rv;
+  u8 e = enable ? 1 : 0;
+
+  if (silm->enabled == e)
+    return 0;
+
+  silm->enabled = e;
+
+  memset (&a, 0, sizeof (a));
+  a.is_add = enable;
+  a.domain_id = domain_id ? domain_id : 1;
+  a.src_port = src_port ? src_port : UDP_DST_PORT_ipfix;
+
+  if (sm->deterministic)
+    {
+      a.rewrite_callback = snat_template_rewrite_max_entries_per_usr;
+      a.flow_data_callback = snat_data_callback_max_entries_per_usr;
+
+      rv = vnet_flow_report_add_del (frm, &a, NULL);
+      if (rv)
+        {
+          clib_warning ("vnet_flow_report_add_del returned %d", rv);
+          return -1;
+        }
+    }
+  else
+    {
+      a.rewrite_callback = snat_template_rewrite_nat44_session;
+      a.flow_data_callback = snat_data_callback_nat44_session;
+
+      rv = vnet_flow_report_add_del (frm, &a, NULL);
+      if (rv)
+        {
+          clib_warning ("vnet_flow_report_add_del returned %d", rv);
+          return -1;
+        }
+
+      a.rewrite_callback = snat_template_rewrite_addr_exhausted;
+      a.flow_data_callback = snat_data_callback_addr_exhausted;
+
+      rv = vnet_flow_report_add_del (frm, &a, NULL);
+      if (rv)
+        {
+          clib_warning ("vnet_flow_report_add_del returned %d", rv);
+          return -1;
+        }
+    }
+
+  return 0;
+}
+
+/**
+ * @brief Initialize NAT plugin IPFIX logging
+ *
+ * @param vm vlib main
+ */
+void
+snat_ipfix_logging_init (vlib_main_t * vm)
+{
+  snat_ipfix_logging_main_t *silm = &snat_ipfix_logging_main;
+
+  silm->enabled = 0;
+
+  /* Set up time reference pair */
+  silm->vlib_time_0 = vlib_time_now (vm);
+  silm->milisecond_time_0 = unix_time_now_nsec () * 1e-6;
+}
diff --git a/src/plugins/nat/nat_ipfix_logging.h b/src/plugins/nat/nat_ipfix_logging.h
new file mode 100644
index 00000000000..6dbf6627fba
--- /dev/null
+++ b/src/plugins/nat/nat_ipfix_logging.h
@@ -0,0 +1,79 @@
+/*
+ * nat_ipfix_logging.h - NAT Events IPFIX logging
+ *
+ * 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 __included_nat_ipfix_logging_h__
+#define __included_nat_ipfix_logging_h__
+
+typedef enum {
+  NAT_ADDRESSES_EXHAUTED = 3,
+  NAT44_SESSION_CREATE = 4,
+  NAT44_SESSION_DELETE = 5,
+  NAT_PORTS_EXHAUSTED = 12,
+  QUOTA_EXCEEDED = 13,
+} nat_event_t;
+
+typedef enum {
+  MAX_ENTRIES_PER_USER = 3,
+} quota_exceed_event_t;
+
+typedef struct {
+  /** NAT plugin IPFIX logging enabled */
+  u8 enabled;
+
+  /** ipfix buffers under construction */
+  vlib_buffer_t *nat44_session_buffer;
+  vlib_buffer_t *addr_exhausted_buffer;
+  vlib_buffer_t *max_entries_per_user_buffer;
+
+  /** frames containing ipfix buffers */
+  vlib_frame_t *nat44_session_frame;
+  vlib_frame_t *addr_exhausted_frame;
+  vlib_frame_t *max_entries_per_user_frame;
+
+  /** next record offset */
+  u32 nat44_session_next_record_offset;
+  u32 addr_exhausted_next_record_offset;
+  u32 max_entries_per_user_next_record_offset;
+
+  /** Time reference pair */
+  u64 milisecond_time_0;
+  f64 vlib_time_0;
+
+  /** template IDs */
+  u16 nat44_session_template_id;
+  u16 addr_exhausted_template_id;
+  u16 max_entries_per_user_template_id;
+
+  /** stream index */
+  u32 stream_index;
+} snat_ipfix_logging_main_t;
+
+extern snat_ipfix_logging_main_t snat_ipfix_logging_main;
+
+void snat_ipfix_logging_init (vlib_main_t * vm);
+int snat_ipfix_logging_enable_disable (int enable, u32 domain_id, u16 src_port);
+void snat_ipfix_logging_nat44_ses_create (u32 src_ip, u32 nat_src_ip,
+                                          snat_protocol_t snat_proto,
+                                          u16 src_port, u16 nat_src_port,
+                                          u32 vrf_id);
+void snat_ipfix_logging_nat44_ses_delete (u32 src_ip, u32 nat_src_ip,
+                                          snat_protocol_t snat_proto,
+                                          u16 src_port, u16 nat_src_port,
+                                          u32 vrf_id);
+void snat_ipfix_logging_addresses_exhausted(u32 pool_id);
+void snat_ipfix_logging_max_entries_per_user(u32 src_ip);
+
+#endif /* __included_nat_ipfix_logging_h__ */
diff --git a/src/plugins/nat/nat_msg_enum.h b/src/plugins/nat/nat_msg_enum.h
new file mode 100644
index 00000000000..710b631c73d
--- /dev/null
+++ b/src/plugins/nat/nat_msg_enum.h
@@ -0,0 +1,31 @@
+
+/*
+ * nat_msg_enum.h - skeleton vpp engine plug-in message enumeration
+ *
+ * Copyright (c) <current-year> <your-organization>
+ * 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 included_nat_msg_enum_h
+#define included_nat_msg_enum_h
+
+#include <vppinfra/byte_order.h>
+
+#define vl_msg_id(n,h) n,
+typedef enum {
+#include <nat/nat_all_api_h.h>
+    /* We'll want to know how many messages IDs we need... */
+    VL_MSG_FIRST_AVAILABLE,
+} vl_msg_id_t;
+#undef vl_msg_id
+
+#endif /* included_nat_msg_enum_h */
diff --git a/src/plugins/nat/nat_test.c b/src/plugins/nat/nat_test.c
new file mode 100644
index 00000000000..b653b77e40c
--- /dev/null
+++ b/src/plugins/nat/nat_test.c
@@ -0,0 +1,1167 @@
+
+/*
+ * nat.c - skeleton vpp-api-test plug-in
+ *
+ * Copyright (c) <current-year> <your-organization>
+ * 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 <vat/vat.h>
+#include <vlibapi/api.h>
+#include <vlibmemory/api.h>
+#include <vlibsocket/api.h>
+#include <vppinfra/error.h>
+#include <vnet/ip/ip.h>
+#include <nat/nat.h>
+
+#define __plugin_msg_base snat_test_main.msg_id_base
+#include <vlibapi/vat_helper_macros.h>
+
+uword unformat_sw_if_index (unformat_input_t * input, va_list * args);
+
+/* Declare message IDs */
+#include <nat/nat_msg_enum.h>
+
+/* define message structures */
+#define vl_typedefs
+#include <nat/nat_all_api_h.h>
+#undef vl_typedefs
+
+/* declare message handlers for each api */
+
+#define vl_endianfun             /* define message structures */
+#include <nat/nat_all_api_h.h>
+#undef vl_endianfun
+
+/* instantiate all the print functions we know about */
+#define vl_print(handle, ...)
+#define vl_printfun
+#include <nat/nat_all_api_h.h>
+#undef vl_printfun
+
+/* Get the API version number. */
+#define vl_api_version(n,v) static u32 api_version=(v);
+#include <nat/nat_all_api_h.h>
+#undef vl_api_version
+
+typedef struct {
+    /* API message ID base */
+    u16 msg_id_base;
+    vat_main_t *vat_main;
+} snat_test_main_t;
+
+snat_test_main_t snat_test_main;
+
+#define foreach_standard_reply_retval_handler   \
+_(snat_add_address_range_reply)                 \
+_(snat_interface_add_del_feature_reply)         \
+_(snat_add_static_mapping_reply)                \
+_(snat_set_workers_reply)                       \
+_(snat_add_del_interface_addr_reply)            \
+_(snat_ipfix_enable_disable_reply)              \
+_(snat_add_det_map_reply)                       \
+_(snat_det_set_timeouts_reply)                  \
+_(snat_det_close_session_out_reply)             \
+_(snat_det_close_session_in_reply)
+
+#define _(n)                                            \
+    static void vl_api_##n##_t_handler                  \
+    (vl_api_##n##_t * mp)                               \
+    {                                                   \
+        vat_main_t * vam = snat_test_main.vat_main;   \
+        i32 retval = ntohl(mp->retval);                 \
+        if (vam->async_mode) {                          \
+            vam->async_errors += (retval < 0);          \
+        } else {                                        \
+            vam->retval = retval;                       \
+            vam->result_ready = 1;                      \
+        }                                               \
+    }
+foreach_standard_reply_retval_handler;
+#undef _
+
+/* 
+ * Table of message reply handlers, must include boilerplate handlers
+ * we just generated
+ */
+#define foreach_vpe_api_reply_msg                               \
+_(SNAT_ADD_ADDRESS_RANGE_REPLY, snat_add_address_range_reply)   \
+_(SNAT_INTERFACE_ADD_DEL_FEATURE_REPLY,                         \
+  snat_interface_add_del_feature_reply)                         \
+_(SNAT_ADD_STATIC_MAPPING_REPLY, snat_add_static_mapping_reply) \
+_(SNAT_CONTROL_PING_REPLY, snat_control_ping_reply)             \
+_(SNAT_STATIC_MAPPING_DETAILS, snat_static_mapping_details)     \
+_(SNAT_SHOW_CONFIG_REPLY, snat_show_config_reply)               \
+_(SNAT_ADDRESS_DETAILS, snat_address_details)                   \
+_(SNAT_INTERFACE_DETAILS, snat_interface_details)               \
+_(SNAT_SET_WORKERS_REPLY, snat_set_workers_reply)               \
+_(SNAT_WORKER_DETAILS, snat_worker_details)                     \
+_(SNAT_ADD_DEL_INTERFACE_ADDR_REPLY,                            \
+  snat_add_del_interface_addr_reply)                            \
+_(SNAT_INTERFACE_ADDR_DETAILS, snat_interface_addr_details)     \
+_(SNAT_IPFIX_ENABLE_DISABLE_REPLY,                              \
+  snat_ipfix_enable_disable_reply)                              \
+_(SNAT_USER_DETAILS, snat_user_details)                         \
+_(SNAT_USER_SESSION_DETAILS, snat_user_session_details)         \
+_(SNAT_ADD_DET_MAP_REPLY, snat_add_det_map_reply)               \
+_(SNAT_DET_FORWARD_REPLY, snat_det_forward_reply)               \
+_(SNAT_DET_REVERSE_REPLY, snat_det_reverse_reply)               \
+_(SNAT_DET_MAP_DETAILS, snat_det_map_details)                   \
+_(SNAT_DET_SET_TIMEOUTS_REPLY, snat_det_set_timeouts_reply)     \
+_(SNAT_DET_GET_TIMEOUTS_REPLY, snat_det_get_timeouts_reply)     \
+_(SNAT_DET_CLOSE_SESSION_OUT_REPLY,                             \
+  snat_det_close_session_out_reply)                             \
+_(SNAT_DET_CLOSE_SESSION_IN_REPLY,                              \
+  snat_det_close_session_in_reply)                              \
+_(SNAT_DET_SESSION_DETAILS, snat_det_session_details)
+
+static int api_snat_add_address_range (vat_main_t * vam)
+{
+  unformat_input_t * i = vam->input;
+  ip4_address_t start_addr, end_addr;
+  u32 start_host_order, end_host_order;
+  vl_api_snat_add_address_range_t * mp;
+  u8 is_add = 1;
+  int count;
+  int ret;
+
+  while (unformat_check_input (i) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (i, "%U - %U",
+                    unformat_ip4_address, &start_addr,
+                    unformat_ip4_address, &end_addr))
+        ;
+      else if (unformat (i, "%U", unformat_ip4_address, &start_addr))
+        end_addr = start_addr;
+      else if (unformat (i, "del"))
+        is_add = 0;
+      else
+        {
+          clib_warning("unknown input '%U'", format_unformat_error, i);
+          return -99;
+        }
+    }
+
+  start_host_order = clib_host_to_net_u32 (start_addr.as_u32);
+  end_host_order = clib_host_to_net_u32 (end_addr.as_u32);
+  
+  if (end_host_order < start_host_order)
+    {
+      errmsg ("end address less than start address\n");
+      return -99;
+    }
+
+  count = (end_host_order - start_host_order) + 1;
+
+  if (count > 1024)
+    {
+    errmsg ("%U - %U, %d addresses...\n",
+           format_ip4_address, &start_addr,
+           format_ip4_address, &end_addr,
+           count);
+    }
+  
+  M(SNAT_ADD_ADDRESS_RANGE, mp);
+
+  memcpy (mp->first_ip_address, &start_addr, 4);
+  memcpy (mp->last_ip_address, &end_addr, 4);
+  mp->is_ip4 = 1;
+  mp->is_add = is_add;
+
+  S(mp);
+  W (ret);
+  return ret;
+}
+
+static int api_snat_interface_add_del_feature (vat_main_t * vam)
+{
+  unformat_input_t * i = vam->input;
+  vl_api_snat_interface_add_del_feature_t * mp;
+  u32 sw_if_index;
+  u8 sw_if_index_set = 0;
+  u8 is_inside = 1; 
+  u8 is_add = 1;
+  int ret;
+
+  while (unformat_check_input (i) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (i, "%U", unformat_sw_if_index, vam, &sw_if_index))
+        sw_if_index_set = 1;
+      else if (unformat (i, "sw_if_index %d", &sw_if_index))
+        sw_if_index_set = 1;
+      else if (unformat (i, "out"))
+        is_inside = 0;
+      else if (unformat (i, "in"))
+        is_inside = 1;
+      else if (unformat (i, "del"))
+        is_add = 0;
+      else
+        {
+          clib_warning("unknown input '%U'", format_unformat_error, i);
+          return -99;
+        }
+    }
+
+  if (sw_if_index_set == 0)
+    {
+      errmsg ("interface / sw_if_index required\n");
+      return -99;
+    }
+
+  M(SNAT_INTERFACE_ADD_DEL_FEATURE, mp);
+  mp->sw_if_index = ntohl(sw_if_index);
+  mp->is_add = is_add;
+  mp->is_inside = is_inside;
+  
+  S(mp);
+  W (ret);
+  return ret;
+}
+
+static int api_snat_add_static_mapping(vat_main_t * vam)
+{
+  unformat_input_t * i = vam->input;
+  vl_api_snat_add_static_mapping_t * mp;
+  u8 external_addr_set = 0;
+  u8 local_addr_set = 0;
+  u8 is_add = 1;
+  u8 addr_only = 1;
+  ip4_address_t local_addr, external_addr;
+  u32 local_port = 0, external_port = 0, vrf_id = ~0;
+  u32 sw_if_index = ~0;
+  u8 sw_if_index_set = 0;
+  u32 proto = ~0;
+  u8 proto_set = 0;
+  int ret;
+
+  while (unformat_check_input (i) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (i, "local_addr %U", unformat_ip4_address, &local_addr))
+        local_addr_set = 1;
+      else if (unformat (i, "external_addr %U", unformat_ip4_address,
+                         &external_addr))
+        external_addr_set = 1;
+      else if (unformat (i, "local_port %u", &local_port))
+        addr_only = 0;
+      else if (unformat (i, "external_port %u", &external_port))
+        addr_only = 0;
+      else if (unformat (i, "external_if %U", unformat_sw_if_index, vam,
+                         &sw_if_index))
+        sw_if_index_set = 1;
+      else if (unformat (i, "external_sw_if_index %d", &sw_if_index))
+        sw_if_index_set = 1;
+      else if (unformat (i, "vrf %u", &vrf_id))
+        ;
+      else if (unformat (i, "protocol %u", &proto))
+        proto_set = 1;
+      else if (unformat (i, "del"))
+        is_add = 0;
+      else
+        {
+          clib_warning("unknown input '%U'", format_unformat_error, i);
+          return -99;
+        }
+    }
+
+  if (!addr_only && !proto_set)
+    {
+      errmsg ("protocol required\n");
+      return -99;
+    }
+
+  if (!local_addr_set)
+    {
+      errmsg ("local addr required\n");
+      return -99;
+    }
+  if (!external_addr_set && !sw_if_index_set)
+    {
+      errmsg ("external addr or interface required\n");
+      return -99;
+    }
+
+  M(SNAT_ADD_STATIC_MAPPING, mp);
+  mp->is_add = is_add;
+  mp->is_ip4 = 1;
+  mp->addr_only = addr_only;
+  mp->local_port = ntohs ((u16) local_port);
+  mp->external_port = ntohs ((u16) external_port);
+  mp->external_sw_if_index = ntohl (sw_if_index);
+  mp->vrf_id = ntohl (vrf_id);
+  mp->protocol = (u8) proto;
+  memcpy (mp->local_ip_address, &local_addr, 4);
+  memcpy (mp->external_ip_address, &external_addr, 4);
+
+  S(mp);
+  W (ret);
+  return ret;
+}
+
+static void vl_api_snat_control_ping_reply_t_handler
+  (vl_api_snat_control_ping_reply_t * mp)
+{
+  vat_main_t *vam = &vat_main;
+  i32 retval = ntohl (mp->retval);
+  if (vam->async_mode)
+    {
+      vam->async_errors += (retval < 0);
+    }
+  else
+    {
+      vam->retval = retval;
+      vam->result_ready = 1;
+    }
+}
+
+static void vl_api_snat_static_mapping_details_t_handler
+  (vl_api_snat_static_mapping_details_t *mp)
+{
+  snat_test_main_t * sm = &snat_test_main;
+  vat_main_t *vam = sm->vat_main;
+
+  if (mp->addr_only && mp->external_sw_if_index != ~0)
+      fformat (vam->ofp, "%15U%6s%15d%6s%11d%6d\n",
+               format_ip4_address, &mp->local_ip_address, "",
+               ntohl (mp->external_sw_if_index), "",
+               ntohl (mp->vrf_id),
+               mp->protocol);
+  else if (mp->addr_only && mp->external_sw_if_index == ~0)
+      fformat (vam->ofp, "%15U%6s%15U%6s%11d%6d\n",
+               format_ip4_address, &mp->local_ip_address, "",
+               format_ip4_address, &mp->external_ip_address, "",
+               ntohl (mp->vrf_id),
+               mp->protocol);
+  else if (!mp->addr_only && mp->external_sw_if_index != ~0)
+      fformat (vam->ofp, "%15U%6d%15d%6d%11d%6d\n",
+               format_ip4_address, &mp->local_ip_address,
+               ntohs (mp->local_port),
+               ntohl (mp->external_sw_if_index),
+               ntohs (mp->external_port),
+               ntohl (mp->vrf_id),
+               mp->protocol);
+  else
+      fformat (vam->ofp, "%15U%6d%15U%6d%11d%6d\n",
+               format_ip4_address, &mp->local_ip_address,
+               ntohs (mp->local_port),
+               format_ip4_address, &mp->external_ip_address,
+               ntohs (mp->external_port),
+               ntohl (mp->vrf_id),
+               mp->protocol);
+
+}
+
+static int api_snat_static_mapping_dump(vat_main_t * vam)
+{
+  vl_api_snat_static_mapping_dump_t * mp;
+  vl_api_snat_control_ping_t *mp_ping;
+  int ret;
+
+  if (vam->json_output)
+    {
+      clib_warning ("JSON output not supported for snat_static_mapping_dump");
+      return -99;
+    }
+
+  fformat (vam->ofp, "%21s%21s\n", "local", "external");
+  fformat (vam->ofp, "%15s%6s%15s%6s%11s%6s\n", "address", "port",
+           "address/if_idx", "port", "vrf", "proto");
+
+  M(SNAT_STATIC_MAPPING_DUMP, mp);
+  S(mp);
+
+  /* Use a control ping for synchronization */
+  M(SNAT_CONTROL_PING, mp_ping);
+  S(mp_ping);
+
+  W (ret);
+  return ret;
+}
+
+static void vl_api_snat_show_config_reply_t_handler
+  (vl_api_snat_show_config_reply_t *mp)
+{
+  snat_test_main_t * sm = &snat_test_main;
+  vat_main_t *vam = sm->vat_main;
+  i32 retval = ntohl (mp->retval);
+
+  if (retval >= 0)
+    {
+      fformat (vam->ofp, "translation hash buckets %d\n",
+               ntohl (mp->translation_buckets));
+      fformat (vam->ofp, "translation hash memory %d\n",
+               ntohl (mp->translation_memory_size));
+      fformat (vam->ofp, "user hash buckets %d\n", ntohl (mp->user_buckets));
+      fformat (vam->ofp, "user hash memory %d\n", ntohl (mp->user_memory_size));
+      fformat (vam->ofp, "max translations per user %d\n",
+               ntohl (mp->max_translations_per_user));
+      fformat (vam->ofp, "outside VRF id %d\n", ntohl (mp->outside_vrf_id));
+      fformat (vam->ofp, "inside VRF id %d\n", ntohl (mp->inside_vrf_id));
+      if (mp->static_mapping_only)
+        {
+          fformat (vam->ofp, "static mapping only");
+          if (mp->static_mapping_connection_tracking)
+            fformat (vam->ofp, " connection tracking");
+          fformat (vam->ofp, "\n");
+        }
+    }
+  vam->retval = retval;
+  vam->result_ready = 1;
+}
+
+static int api_snat_show_config(vat_main_t * vam)
+{
+  vl_api_snat_show_config_t * mp;
+  int ret;
+
+  if (vam->json_output)
+    {
+      clib_warning ("JSON output not supported for snat_show_config");
+      return -99;
+    }
+
+  M(SNAT_SHOW_CONFIG, mp);
+  S(mp);
+  W (ret);
+  return ret;
+}
+
+static void vl_api_snat_address_details_t_handler
+  (vl_api_snat_address_details_t *mp)
+{
+  snat_test_main_t * sm = &snat_test_main;
+  vat_main_t *vam = sm->vat_main;
+
+  fformat (vam->ofp, "%U\n", format_ip4_address, &mp->ip_address);
+}
+
+static int api_snat_address_dump(vat_main_t * vam)
+{
+  vl_api_snat_address_dump_t * mp;
+  vl_api_snat_control_ping_t *mp_ping;
+  int ret;
+
+  if (vam->json_output)
+    {
+      clib_warning ("JSON output not supported for snat_address_dump");
+      return -99;
+    }
+
+  M(SNAT_ADDRESS_DUMP, mp);
+  S(mp);
+
+  /* Use a control ping for synchronization */
+  M(SNAT_CONTROL_PING, mp_ping);
+  S(mp_ping);
+
+  W (ret);
+  return ret;
+}
+
+static void vl_api_snat_interface_details_t_handler
+  (vl_api_snat_interface_details_t *mp)
+{
+  snat_test_main_t * sm = &snat_test_main;
+  vat_main_t *vam = sm->vat_main;
+
+  fformat (vam->ofp, "sw_if_index %d %s\n", ntohl (mp->sw_if_index),
+           mp->is_inside ? "in" : "out");
+}
+
+static int api_snat_interface_dump(vat_main_t * vam)
+{
+  vl_api_snat_interface_dump_t * mp;
+  vl_api_snat_control_ping_t *mp_ping;
+  int ret;
+
+  if (vam->json_output)
+    {
+      clib_warning ("JSON output not supported for snat_address_dump");
+      return -99;
+    }
+
+  M(SNAT_INTERFACE_DUMP, mp);
+  S(mp);
+
+  /* Use a control ping for synchronization */
+  M(SNAT_CONTROL_PING, mp_ping);
+  S(mp_ping);
+
+  W (ret);
+  return ret;
+}
+
+static int api_snat_set_workers (vat_main_t * vam)
+{
+  unformat_input_t * i = vam->input;
+  vl_api_snat_set_workers_t * mp;
+  uword *bitmap;
+  int ret;
+
+  while (unformat_check_input (i) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (i, "%U", unformat_bitmap_list, &bitmap))
+        ;
+      else
+        {
+          clib_warning("unknown input '%U'", format_unformat_error, i);
+          return -99;
+        }
+    }
+
+  M(SNAT_SET_WORKERS, mp);
+  mp->worker_mask = clib_host_to_net_u64 (bitmap[0]);
+
+  S(mp);
+  W (ret);
+  return ret;
+}
+
+static void vl_api_snat_worker_details_t_handler
+  (vl_api_snat_worker_details_t *mp)
+{
+  snat_test_main_t * sm = &snat_test_main;
+  vat_main_t *vam = sm->vat_main;
+
+  fformat (vam->ofp, "worker_index %d (%s at lcore %u)\n",
+           ntohl (mp->worker_index), mp->name, ntohl (mp->lcore_id));
+}
+
+static int api_snat_worker_dump(vat_main_t * vam)
+{
+  vl_api_snat_worker_dump_t * mp;
+  vl_api_snat_control_ping_t *mp_ping;
+  int ret;
+
+  if (vam->json_output)
+    {
+      clib_warning ("JSON output not supported for snat_address_dump");
+      return -99;
+    }
+
+  M(SNAT_WORKER_DUMP, mp);
+  S(mp);
+
+  /* Use a control ping for synchronization */
+  M(SNAT_CONTROL_PING, mp_ping);
+  S(mp_ping);
+
+  W (ret);
+  return ret;
+}
+
+static int api_snat_add_del_interface_addr (vat_main_t * vam)
+{
+  unformat_input_t * i = vam->input;
+  vl_api_snat_add_del_interface_addr_t * mp;
+  u32 sw_if_index;
+  u8 sw_if_index_set = 0;
+  u8 is_add = 1;
+  int ret;
+
+  while (unformat_check_input (i) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (i, "%U", unformat_sw_if_index, vam, &sw_if_index))
+        sw_if_index_set = 1;
+      else if (unformat (i, "sw_if_index %d", &sw_if_index))
+        sw_if_index_set = 1;
+      else if (unformat (i, "del"))
+        is_add = 0;
+      else
+        {
+          clib_warning("unknown input '%U'", format_unformat_error, i);
+          return -99;
+        }
+    }
+
+  if (sw_if_index_set == 0)
+    {
+      errmsg ("interface / sw_if_index required\n");
+      return -99;
+    }
+
+  M(SNAT_ADD_DEL_INTERFACE_ADDR, mp);
+  mp->sw_if_index = ntohl(sw_if_index);
+  mp->is_add = is_add;
+  
+  S(mp);
+  W (ret);
+  return ret;
+}
+
+static void vl_api_snat_interface_addr_details_t_handler
+  (vl_api_snat_interface_addr_details_t *mp)
+{
+  snat_test_main_t * sm = &snat_test_main;
+  vat_main_t *vam = sm->vat_main;
+
+  fformat (vam->ofp, "sw_if_index %d\n", ntohl (mp->sw_if_index));
+}
+
+static int api_snat_interface_addr_dump(vat_main_t * vam)
+{
+  vl_api_snat_interface_addr_dump_t * mp;
+  vl_api_snat_control_ping_t *mp_ping;
+  int ret;
+
+  if (vam->json_output)
+    {
+      clib_warning ("JSON output not supported for snat_address_dump");
+      return -99;
+    }
+
+  M(SNAT_INTERFACE_ADDR_DUMP, mp);
+  S(mp);
+
+  /* Use a control ping for synchronization */
+  M(SNAT_CONTROL_PING, mp_ping);
+  S(mp_ping);
+
+  W (ret);
+  return ret;
+}
+
+static int api_snat_ipfix_enable_disable (vat_main_t * vam)
+{
+  unformat_input_t * i = vam->input;
+  vl_api_snat_ipfix_enable_disable_t * mp;
+  u32 domain_id = 0;
+  u32 src_port = 0;
+  u8 enable = 1;
+  int ret;
+
+  while (unformat_check_input (i) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (i, "domain %d", &domain_id))
+        ;
+      else if (unformat (i, "src_port %d", &src_port))
+        ;
+      else if (unformat (i, "disable"))
+        enable = 0;
+      else
+        {
+          clib_warning("unknown input '%U'", format_unformat_error, i);
+          return -99;
+        }
+    }
+
+  M(SNAT_IPFIX_ENABLE_DISABLE, mp);
+  mp->domain_id = htonl(domain_id);
+  mp->src_port = htons((u16) src_port);
+  mp->enable = enable;
+
+  S(mp);
+  W (ret);
+  return ret;
+}
+
+static void vl_api_snat_user_session_details_t_handler
+  (vl_api_snat_user_session_details_t *mp)
+{
+  snat_test_main_t * sm = &snat_test_main;
+  vat_main_t *vam = sm->vat_main;
+
+  fformat(vam->ofp, "%s session %U:%d to %U:%d protocol id %d "
+                    "total packets %d total bytes %d\n",
+          mp->is_static ? "static" : "dynamic",
+          format_ip4_address, mp->inside_ip_address, ntohl(mp->inside_port),
+          format_ip4_address, mp->outside_ip_address, ntohl(mp->outside_port),
+          ntohl(mp->protocol), ntohl(mp->total_pkts), ntohl(mp->total_bytes));
+}
+
+static int api_snat_user_session_dump(vat_main_t * vam)
+{
+  unformat_input_t* i = vam->input;
+  vl_api_snat_user_session_dump_t * mp;
+  vl_api_snat_control_ping_t *mp_ping;
+  ip4_address_t addr;
+  u32 vrf_id = ~0;
+  int ret;
+
+  if (vam->json_output)
+    {
+      clib_warning ("JSON output not supported for snat_address_dump");
+      return -99;
+    }
+
+  if (unformat (i, "ip_address %U vrf_id %d",
+                unformat_ip4_address, &addr, &vrf_id))
+    ;
+  else
+    {
+      clib_warning("unknown input '%U'", format_unformat_error, i);
+      return -99;
+    }
+
+  M(SNAT_USER_SESSION_DUMP, mp);
+  S(mp);
+
+  /* Use a control ping for synchronization */
+  M(SNAT_CONTROL_PING, mp_ping);
+  memset(mp->ip_address, 0, 16);
+  clib_memcpy(mp->ip_address, &addr, 4);
+  mp->vrf_id = htonl(vrf_id);
+  mp->is_ip4 = 1;
+  S(mp_ping);
+
+  W (ret);
+  return ret;
+}
+
+static void vl_api_snat_user_details_t_handler
+  (vl_api_snat_user_details_t *mp)
+{
+  snat_test_main_t * sm = &snat_test_main;
+  vat_main_t *vam = sm->vat_main;
+
+  fformat(vam->ofp, "user with ip %U with vrf_id %d "
+                    "with %d sessions and %d static sessions\n",
+          format_ip4_address, mp->ip_address, ntohl(mp->vrf_id),
+          ntohl(mp->nsessions), ntohl(mp->nstaticsessions));
+}
+
+static int api_snat_user_dump(vat_main_t * vam)
+{
+  vl_api_snat_user_dump_t * mp;
+  vl_api_snat_control_ping_t *mp_ping;
+  int ret;
+
+  if (vam->json_output)
+    {
+      clib_warning ("JSON output not supported for snat_address_dump");
+      return -99;
+    }
+
+  M(SNAT_USER_DUMP, mp);
+  S(mp);
+
+  /* Use a control ping for synchronization */
+  M(SNAT_CONTROL_PING, mp_ping);
+  S(mp_ping);
+
+  W (ret);
+  return ret;
+}
+
+static int api_snat_add_det_map (vat_main_t * vam)
+{
+  unformat_input_t * i = vam->input;
+  vl_api_snat_add_det_map_t * mp;
+  ip4_address_t in_addr, out_addr;
+  u32 in_plen, out_plen;
+  u8 is_add = 1;
+  int ret;
+
+  if (unformat (i, "in %U/%d out %U/%d",
+                unformat_ip4_address, &in_addr, &in_plen,
+                unformat_ip4_address, &out_addr, &out_plen))
+    ;
+  else if (unformat (i, "del"))
+    is_add = 0;
+  else
+    {
+      clib_warning("unknown input '%U'", format_unformat_error, i);
+      return -99;
+    }
+
+  M(SNAT_ADD_DET_MAP, mp);
+  clib_memcpy(mp->in_addr, &in_addr, 4);
+  mp->in_plen = in_plen;
+  clib_memcpy(mp->out_addr, &out_addr, 4);
+  mp->out_plen = out_plen;
+  mp->is_add = is_add;
+
+  S(mp);
+  W (ret);
+  return ret;
+}
+
+static void vl_api_snat_det_forward_reply_t_handler
+  (vl_api_snat_det_forward_reply_t *mp)
+{
+  snat_test_main_t * sm = &snat_test_main;
+  vat_main_t *vam = sm->vat_main;
+  i32 retval = ntohl(mp->retval);
+
+  if (retval >= 0)
+  {
+    fformat (vam->ofp, "outside address %U", format_ip4_address, &mp->out_addr);
+    fformat (vam->ofp, " outside port range start %d", ntohs(mp->out_port_lo));
+    fformat (vam->ofp, " outside port range end %d\n", ntohs(mp->out_port_hi));
+  }
+
+  vam->retval = retval;
+  vam->result_ready = 1;
+}
+
+static int api_snat_det_forward (vat_main_t * vam)
+{
+  unformat_input_t * i = vam->input;
+  vl_api_snat_det_forward_t * mp;
+  ip4_address_t in_addr;
+  int ret;
+
+  if (unformat (i, "%U", unformat_ip4_address, &in_addr))
+    ;
+  else
+    {
+      clib_warning("unknown input '%U'", format_unformat_error, i);
+      return -99;
+    }
+
+  M(SNAT_DET_FORWARD, mp);
+  clib_memcpy(mp->in_addr, &in_addr, 4);
+
+  S(mp);
+  W(ret);
+  return ret;
+}
+
+static void vl_api_snat_det_reverse_reply_t_handler
+  (vl_api_snat_det_reverse_reply_t *mp)
+{
+  snat_test_main_t * sm = &snat_test_main;
+  vat_main_t *vam = sm->vat_main;
+  i32 retval = ntohl(mp->retval);
+
+  if (retval >= 0)
+  {
+    fformat (vam->ofp, "inside address %U\n", format_ip4_address, &mp->in_addr);
+  }
+
+  vam->retval = retval;
+  vam->result_ready = 1;
+}
+
+static int api_snat_det_reverse (vat_main_t * vam)
+{
+  unformat_input_t * i = vam->input;
+  vl_api_snat_det_reverse_t * mp;
+  ip4_address_t out_addr;
+  u16 out_port;
+  int ret;
+
+  if (unformat (i, "%U %d", unformat_ip4_address, &out_addr, &out_port))
+    ;
+  else
+    {
+      clib_warning("unknown input '%U'", format_unformat_error, i);
+      return -99;
+    }
+
+  M(SNAT_DET_REVERSE, mp);
+  clib_memcpy(mp->out_addr, &out_addr, 4);
+  mp->out_port = htons(out_port);
+
+  S(mp);
+  W(ret);
+  return ret;
+}
+
+static void vl_api_snat_det_map_details_t_handler
+  (vl_api_snat_det_map_details_t *mp)
+{
+  snat_test_main_t * sm = &snat_test_main;
+  vat_main_t *vam = sm->vat_main;
+
+  fformat (vam->ofp, "Deterministic S-NAT mapping in %U/%d out %U/%d "
+                     "ports per host %d sharing ratio %d "
+                     "number of sessions %d",
+           format_ip4_address, mp->in_addr, mp->in_plen,
+           format_ip4_address, mp->out_addr, mp->out_plen,
+           ntohs(mp->ports_per_host), ntohl(mp->sharing_ratio),
+           ntohl(mp->ses_num));
+}
+
+static int api_snat_det_map_dump(vat_main_t * vam)
+{
+  vl_api_snat_det_map_dump_t * mp;
+  vl_api_snat_control_ping_t *mp_ping;
+  int ret;
+
+  if (vam->json_output)
+    {
+      clib_warning ("JSON output not supported for snat_det_map_dump");
+      return -99;
+    }
+
+  M(SNAT_DET_MAP_DUMP, mp);
+  S(mp);
+
+  /* Use a control ping for synchronization */
+  M(SNAT_CONTROL_PING, mp_ping);
+  S(mp_ping);
+
+  W (ret);
+  return ret;
+}
+
+static int api_snat_det_set_timeouts (vat_main_t * vam)
+{
+  unformat_input_t * i = vam->input;
+  vl_api_snat_det_set_timeouts_t * mp;
+  u32 udp = SNAT_UDP_TIMEOUT;
+  u32 tcp_established = SNAT_TCP_ESTABLISHED_TIMEOUT;
+  u32 tcp_transitory = SNAT_TCP_TRANSITORY_TIMEOUT;
+  u32 icmp = SNAT_ICMP_TIMEOUT;
+  int ret;
+
+  if (unformat (i, "udp %d", &udp))
+    ;
+  else if (unformat (i, "tcp_established %d", &tcp_established))
+    ;
+  else if (unformat (i, "tcp_transitory %d", &tcp_transitory))
+    ;
+  else if (unformat (i, "icmp %d", &icmp))
+    ;
+  else
+    {
+      clib_warning("unknown input '%U'", format_unformat_error, i);
+      return -99;
+    }
+
+  M(SNAT_DET_SET_TIMEOUTS, mp);
+  mp->udp = htonl(udp);
+  mp->tcp_established = htonl(tcp_established);
+  mp->tcp_transitory = htonl(tcp_transitory);
+  mp->icmp = htonl(icmp);
+
+  S(mp);
+  W (ret);
+  return ret;
+}
+
+static void vl_api_snat_det_get_timeouts_reply_t_handler
+  (vl_api_snat_det_get_timeouts_reply_t *mp)
+{
+  snat_test_main_t * sm = &snat_test_main;
+  vat_main_t *vam = sm->vat_main;
+  i32 retval = ntohl (mp->retval);
+
+  if (retval >= 0)
+    {
+      fformat (vam->ofp, "udp timeout: %dsec\n", ntohl (mp->udp));
+      fformat (vam->ofp, "tcp-established timeout: %dsec",
+               ntohl (mp->tcp_established));
+      fformat (vam->ofp, "tcp-transitory timeout: %dsec",
+               ntohl (mp->tcp_transitory));
+      fformat (vam->ofp, "icmp timeout: %dsec", ntohl (mp->icmp));
+    }
+  vam->retval = retval;
+  vam->result_ready = 1;
+}
+
+static int api_snat_det_get_timeouts(vat_main_t * vam)
+{
+  vl_api_snat_det_get_timeouts_t * mp;
+  int ret;
+
+  if (vam->json_output)
+    {
+      clib_warning ("JSON output not supported for snat_show_config");
+      return -99;
+    }
+
+  M(SNAT_DET_GET_TIMEOUTS, mp);
+  S(mp);
+  W (ret);
+  return ret;
+}
+
+static int api_snat_det_close_session_out (vat_main_t * vam)
+{
+  unformat_input_t * i = vam->input;
+  vl_api_snat_det_close_session_out_t * mp;
+  ip4_address_t out_addr, ext_addr;
+  u16 out_port, ext_port;
+  int ret;
+
+  if (unformat (i, "%U:%d %U:%d",
+                unformat_ip4_address, &out_addr, &out_port,
+                unformat_ip4_address, &ext_addr, &ext_port))
+    ;
+  else
+    {
+      clib_warning("unknown input '%U'", format_unformat_error, i);
+      return -99;
+    }
+
+  M(SNAT_DET_CLOSE_SESSION_OUT, mp);
+  clib_memcpy(mp->out_addr, &out_addr, 4);
+  mp->out_port = ntohs(out_port);
+  clib_memcpy(mp->ext_addr, &ext_addr, 4);
+  mp->ext_port = ntohs(ext_port);
+
+  S(mp);
+  W (ret);
+  return ret;
+}
+
+static int api_snat_det_close_session_in (vat_main_t * vam)
+{
+  unformat_input_t * i = vam->input;
+  vl_api_snat_det_close_session_in_t * mp;
+  ip4_address_t in_addr, ext_addr;
+  u16 in_port, ext_port;
+  int ret;
+
+  if (unformat (i, "%U:%d %U:%d",
+                unformat_ip4_address, &in_addr, &in_port,
+                unformat_ip4_address, &ext_addr, &ext_port))
+    ;
+  else
+    {
+      clib_warning("unknown input '%U'", format_unformat_error, i);
+      return -99;
+    }
+
+  M(SNAT_DET_CLOSE_SESSION_IN, mp);
+  clib_memcpy(mp->in_addr, &in_addr, 4);
+  mp->in_port = ntohs(in_port);
+  clib_memcpy(mp->ext_addr, &ext_addr, 4);
+  mp->ext_port = ntohs(ext_port);
+
+  S(mp);
+  W (ret);
+  return ret;
+}
+
+static void vl_api_snat_det_session_details_t_handler
+  (vl_api_snat_det_session_details_t *mp)
+{
+  snat_test_main_t * sm = &snat_test_main;
+  vat_main_t *vam = sm->vat_main;
+
+  fformat(vam->ofp, "deterministic session, external host address %U, "
+                    "external host port %d, outer port %d, inside port %d",
+          format_ip4_address, mp->ext_addr, mp->ext_port,
+          mp->out_port, mp->in_port);
+}
+
+static int api_snat_det_session_dump(vat_main_t * vam)
+{
+  unformat_input_t* i = vam->input;
+  vl_api_snat_det_session_dump_t * mp;
+  vl_api_snat_control_ping_t *mp_ping;
+  ip4_address_t user_addr;
+  int ret;
+
+  if (vam->json_output)
+    {
+      clib_warning ("JSON output not supported for snat_det_session_dump");
+      return -99;
+    }
+
+  if (unformat (i, "user_addr %U", unformat_ip4_address, &user_addr))
+    ;
+  else
+    {
+      clib_warning ("unknown input '%U'", format_unformat_error, i);
+      return -99;
+    }
+
+  M(SNAT_DET_SESSION_DUMP, mp);
+  clib_memcpy (&mp->user_addr, &user_addr, 4);
+  S(mp);
+
+  /* Use a control ping for synchronization */
+  M(SNAT_CONTROL_PING, mp_ping);
+  S(mp_ping);
+
+  W (ret);
+  return ret;
+}
+
+/* 
+ * List of messages that the api test plugin sends,
+ * and that the data plane plugin processes
+ */
+#define foreach_vpe_api_msg                                      \
+_(snat_add_address_range, "<start-addr> [- <end-addr] [del]")    \
+_(snat_interface_add_del_feature,                                \
+  "<intfc> | sw_if_index <id> [in] [out] [del]")                 \
+_(snat_add_static_mapping, "local_addr <ip> (external_addr <ip>" \
+  " | external_if <intfc> | external_sw_if_ndex <id>) "          \
+  "[local_port <n>] [external_port <n>] [vrf <table-id>] [del] " \
+  "protocol <n>")                                                \
+_(snat_set_workers, "<wokrers_bitmap>")                          \
+_(snat_static_mapping_dump, "")                                  \
+_(snat_show_config, "")                                          \
+_(snat_address_dump, "")                                         \
+_(snat_interface_dump, "")                                       \
+_(snat_worker_dump, "")                                          \
+_(snat_add_del_interface_addr,                                   \
+  "<intfc> | sw_if_index <id> [del]")                            \
+_(snat_interface_addr_dump, "")                                  \
+_(snat_ipfix_enable_disable, "[domain <id>] [src_port <n>] "     \
+  "[disable]")                                                   \
+_(snat_user_dump, "")                                            \
+_(snat_user_session_dump, "ip_address <ip> vrf_id <table-id>")   \
+_(snat_add_det_map, "in <in_addr>/<in_plen> out "                \
+  "<out_addr>/<out_plen> [del]")                                 \
+_(snat_det_forward, "<in_addr>")                                 \
+_(snat_det_reverse, "<out_addr> <out_port>")                     \
+_(snat_det_map_dump, "")                                         \
+_(snat_det_set_timeouts, "[udp <sec> | tcp_established <sec> | " \
+  "tcp_transitory <sec> | icmp <sec>]")                          \
+_(snat_det_get_timeouts, "")                                     \
+_(snat_det_close_session_out, "<out_addr>:<out_port> "           \
+  "<ext_addr>:<ext_port>")                                       \
+_(snat_det_close_session_in, "<in_addr>:<in_port> "              \
+  "<out_addr>:<out_port>")                                       \
+_(snat_det_session_dump, "ip_address <user_addr>")
+
+static void 
+snat_vat_api_hookup (vat_main_t *vam)
+{
+  snat_test_main_t * sm __attribute__((unused)) = &snat_test_main;
+  /* Hook up handlers for replies from the data plane plug-in */
+#define _(N,n)                                                  \
+  vl_msg_api_set_handlers((VL_API_##N + sm->msg_id_base),       \
+                          #n,                                   \
+                          vl_api_##n##_t_handler,               \
+                          vl_noop_handler,                      \
+                          vl_api_##n##_t_endian,                \
+                          vl_api_##n##_t_print,                 \
+                          sizeof(vl_api_##n##_t), 1); 
+  foreach_vpe_api_reply_msg;
+#undef _
+
+  /* API messages we can send */
+#define _(n,h)                                          \
+  hash_set_mem (vam->function_by_name, #n, api_##n);
+  foreach_vpe_api_msg;
+#undef _    
+    
+  /* Help strings */
+#define _(n,h) hash_set_mem (vam->help_by_name, #n, h);
+  foreach_vpe_api_msg;
+#undef _
+}
+
+clib_error_t * vat_plugin_register (vat_main_t *vam)
+{
+  snat_test_main_t * sm = &snat_test_main;
+  u8 * name;
+
+  sm->vat_main = vam;
+
+  /* Ask the vpp engine for the first assigned message-id */
+  name = format (0, "snat_%08x%c", api_version, 0);
+  sm->msg_id_base = vl_client_get_first_plugin_msg_id ((char *) name);
+
+  if (sm->msg_id_base != (u16) ~0)
+    snat_vat_api_hookup (vam);
+  
+  vec_free(name);
+  
+  return 0;
+}
diff --git a/src/plugins/nat/out2in.c b/src/plugins/nat/out2in.c
new file mode 100644
index 00000000000..679500668c5
--- /dev/null
+++ b/src/plugins/nat/out2in.c
@@ -0,0 +1,2294 @@
+/*
+ * 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/pg/pg.h>
+#include <vnet/handoff.h>
+
+#include <vnet/ip/ip.h>
+#include <vnet/udp/udp.h>
+#include <vnet/ethernet/ethernet.h>
+#include <vnet/fib/ip4_fib.h>
+#include <nat/nat.h>
+#include <nat/nat_ipfix_logging.h>
+#include <nat/nat_det.h>
+
+#include <vppinfra/hash.h>
+#include <vppinfra/error.h>
+#include <vppinfra/elog.h>
+
+typedef struct {
+  u32 sw_if_index;
+  u32 next_index;
+  u32 session_index;
+} snat_out2in_trace_t;
+
+typedef struct {
+  u32 next_worker_index;
+  u8 do_handoff;
+} snat_out2in_worker_handoff_trace_t;
+
+/* packet trace format function */
+static u8 * format_snat_out2in_trace (u8 * s, va_list * args)
+{
+  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
+  snat_out2in_trace_t * t = va_arg (*args, snat_out2in_trace_t *);
+
+  s = format (s, "NAT44_OUT2IN: sw_if_index %d, next index %d, session index %d",
+              t->sw_if_index, t->next_index, t->session_index);
+  return s;
+}
+
+static u8 * format_snat_out2in_fast_trace (u8 * s, va_list * args)
+{
+  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
+  snat_out2in_trace_t * t = va_arg (*args, snat_out2in_trace_t *);
+
+  s = format (s, "NAT44_OUT2IN_FAST: sw_if_index %d, next index %d",
+              t->sw_if_index, t->next_index);
+  return s;
+}
+
+static u8 * format_snat_out2in_worker_handoff_trace (u8 * s, va_list * args)
+{
+  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
+  snat_out2in_worker_handoff_trace_t * t =
+    va_arg (*args, snat_out2in_worker_handoff_trace_t *);
+  char * m;
+
+  m = t->do_handoff ? "next worker" : "same worker";
+  s = format (s, "NAT44_OUT2IN_WORKER_HANDOFF: %s %d", m, t->next_worker_index);
+
+  return s;
+}
+
+vlib_node_registration_t snat_out2in_node;
+vlib_node_registration_t snat_out2in_fast_node;
+vlib_node_registration_t snat_out2in_worker_handoff_node;
+vlib_node_registration_t snat_det_out2in_node;
+
+#define foreach_snat_out2in_error                       \
+_(UNSUPPORTED_PROTOCOL, "Unsupported protocol")         \
+_(OUT2IN_PACKETS, "Good out2in packets processed")      \
+_(BAD_ICMP_TYPE, "unsupported ICMP type")               \
+_(NO_TRANSLATION, "No translation")
+
+typedef enum {
+#define _(sym,str) SNAT_OUT2IN_ERROR_##sym,
+  foreach_snat_out2in_error
+#undef _
+  SNAT_OUT2IN_N_ERROR,
+} snat_out2in_error_t;
+
+static char * snat_out2in_error_strings[] = {
+#define _(sym,string) string,
+  foreach_snat_out2in_error
+#undef _
+};
+
+typedef enum {
+  SNAT_OUT2IN_NEXT_DROP,
+  SNAT_OUT2IN_NEXT_LOOKUP,
+  SNAT_OUT2IN_NEXT_ICMP_ERROR,
+  SNAT_OUT2IN_N_NEXT,
+} snat_out2in_next_t;
+
+/**
+ * @brief Create session for static mapping.
+ *
+ * Create NAT session initiated by host from external network with static
+ * mapping.
+ *
+ * @param sm     NAT main.
+ * @param b0     Vlib buffer.
+ * @param in2out In2out NAT44 session key.
+ * @param out2in Out2in NAT44 session key.
+ * @param node   Vlib node.
+ *
+ * @returns SNAT session if successfully created otherwise 0.
+ */
+static inline snat_session_t *
+create_session_for_static_mapping (snat_main_t *sm,
+                                   vlib_buffer_t *b0,
+                                   snat_session_key_t in2out,
+                                   snat_session_key_t out2in,
+                                   vlib_node_runtime_t * node,
+                                   u32 thread_index)
+{
+  snat_user_t *u;
+  snat_user_key_t user_key;
+  snat_session_t *s;
+  clib_bihash_kv_8_8_t kv0, value0;
+  dlist_elt_t * per_user_translation_list_elt;
+  dlist_elt_t * per_user_list_head_elt;
+  ip4_header_t *ip0;
+
+  ip0 = vlib_buffer_get_current (b0);
+
+  user_key.addr = in2out.addr;
+  user_key.fib_index = in2out.fib_index;
+  kv0.key = user_key.as_u64;
+
+  /* Ever heard of the "user" = inside ip4 address before? */
+  if (clib_bihash_search_8_8 (&sm->user_hash, &kv0, &value0))
+    {
+      /* no, make a new one */
+      pool_get (sm->per_thread_data[thread_index].users, u);
+      memset (u, 0, sizeof (*u));
+      u->addr = in2out.addr;
+      u->fib_index = in2out.fib_index;
+
+      pool_get (sm->per_thread_data[thread_index].list_pool,
+                per_user_list_head_elt);
+
+      u->sessions_per_user_list_head_index = per_user_list_head_elt -
+        sm->per_thread_data[thread_index].list_pool;
+
+      clib_dlist_init (sm->per_thread_data[thread_index].list_pool,
+                       u->sessions_per_user_list_head_index);
+
+      kv0.value = u - sm->per_thread_data[thread_index].users;
+
+      /* add user */
+      clib_bihash_add_del_8_8 (&sm->user_hash, &kv0, 1 /* is_add */);
+
+      /* add non-traslated packets worker lookup */
+      kv0.value = thread_index;
+      clib_bihash_add_del_8_8 (&sm->worker_by_in, &kv0, 1);
+    }
+  else
+    {
+      u = pool_elt_at_index (sm->per_thread_data[thread_index].users,
+                             value0.value);
+    }
+
+  pool_get (sm->per_thread_data[thread_index].sessions, s);
+  memset (s, 0, sizeof (*s));
+
+  s->outside_address_index = ~0;
+  s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
+  s->ext_host_addr.as_u32 = ip0->dst_address.as_u32;
+  u->nstaticsessions++;
+
+  /* Create list elts */
+  pool_get (sm->per_thread_data[thread_index].list_pool,
+            per_user_translation_list_elt);
+  clib_dlist_init (sm->per_thread_data[thread_index].list_pool,
+                   per_user_translation_list_elt -
+                   sm->per_thread_data[thread_index].list_pool);
+
+  per_user_translation_list_elt->value =
+    s - sm->per_thread_data[thread_index].sessions;
+  s->per_user_index =
+    per_user_translation_list_elt - sm->per_thread_data[thread_index].list_pool;
+  s->per_user_list_head_index = u->sessions_per_user_list_head_index;
+
+  clib_dlist_addtail (sm->per_thread_data[thread_index].list_pool,
+                      s->per_user_list_head_index,
+                      per_user_translation_list_elt -
+                      sm->per_thread_data[thread_index].list_pool);
+
+  s->in2out = in2out;
+  s->out2in = out2in;
+  s->in2out.protocol = out2in.protocol;
+
+  /* Add to translation hashes */
+  kv0.key = s->in2out.as_u64;
+  kv0.value = s - sm->per_thread_data[thread_index].sessions;
+  if (clib_bihash_add_del_8_8 (&sm->in2out, &kv0, 1 /* is_add */))
+      clib_warning ("in2out key add failed");
+
+  kv0.key = s->out2in.as_u64;
+  kv0.value = s - sm->per_thread_data[thread_index].sessions;
+
+  if (clib_bihash_add_del_8_8 (&sm->out2in, &kv0, 1 /* is_add */))
+      clib_warning ("out2in key add failed");
+
+  /* log NAT event */
+  snat_ipfix_logging_nat44_ses_create(s->in2out.addr.as_u32,
+                                      s->out2in.addr.as_u32,
+                                      s->in2out.protocol,
+                                      s->in2out.port,
+                                      s->out2in.port,
+                                      s->in2out.fib_index);
+   return s;
+}
+
+static_always_inline
+snat_out2in_error_t icmp_get_key(ip4_header_t *ip0,
+                                 snat_session_key_t *p_key0)
+{
+  icmp46_header_t *icmp0;
+  snat_session_key_t key0;
+  icmp_echo_header_t *echo0, *inner_echo0 = 0;
+  ip4_header_t *inner_ip0;
+  void *l4_header = 0;
+  icmp46_header_t *inner_icmp0;
+
+  icmp0 = (icmp46_header_t *) ip4_next_header (ip0);
+  echo0 = (icmp_echo_header_t *)(icmp0+1);
+
+  if (!icmp_is_error_message (icmp0))
+    {
+      key0.protocol = SNAT_PROTOCOL_ICMP;
+      key0.addr = ip0->dst_address;
+      key0.port = echo0->identifier;
+    }
+  else
+    {
+      inner_ip0 = (ip4_header_t *)(echo0+1);
+      l4_header = ip4_next_header (inner_ip0);
+      key0.protocol = ip_proto_to_snat_proto (inner_ip0->protocol);
+      key0.addr = inner_ip0->src_address;
+      switch (key0.protocol)
+        {
+        case SNAT_PROTOCOL_ICMP:
+          inner_icmp0 = (icmp46_header_t*)l4_header;
+          inner_echo0 = (icmp_echo_header_t *)(inner_icmp0+1);
+          key0.port = inner_echo0->identifier;
+          break;
+        case SNAT_PROTOCOL_UDP:
+        case SNAT_PROTOCOL_TCP:
+          key0.port = ((tcp_udp_header_t*)l4_header)->src_port;
+          break;
+        default:
+          return SNAT_OUT2IN_ERROR_UNSUPPORTED_PROTOCOL;
+        }
+    }
+  *p_key0 = key0;
+  return -1; /* success */
+}
+
+/**
+ * Get address and port values to be used for ICMP packet translation
+ * and create session if needed
+ *
+ * @param[in,out] sm             NAT main
+ * @param[in,out] node           NAT node runtime
+ * @param[in] thread_index       thread index
+ * @param[in,out] b0             buffer containing packet to be translated
+ * @param[out] p_proto           protocol used for matching
+ * @param[out] p_value           address and port after NAT translation
+ * @param[out] p_dont_translate  if packet should not be translated
+ * @param d                      optional parameter
+ * @param e                      optional parameter
+ */
+u32 icmp_match_out2in_slow(snat_main_t *sm, vlib_node_runtime_t *node,
+                           u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
+                           snat_session_key_t *p_value,
+                           u8 *p_dont_translate, void *d, void *e)
+{
+  ip4_header_t *ip0;
+  icmp46_header_t *icmp0;
+  u32 sw_if_index0;
+  u32 rx_fib_index0;
+  snat_session_key_t key0;
+  snat_session_key_t sm0;
+  snat_session_t *s0 = 0;
+  u8 dont_translate = 0;
+  clib_bihash_kv_8_8_t kv0, value0;
+  u8 is_addr_only;
+  u32 next0 = ~0;
+  int err;
+
+  ip0 = vlib_buffer_get_current (b0);
+  icmp0 = (icmp46_header_t *) ip4_next_header (ip0);
+  sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
+  rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index (sw_if_index0);
+
+  key0.protocol = 0;
+
+  err = icmp_get_key (ip0, &key0);
+  if (err != -1)
+    {
+      b0->error = node->errors[SNAT_OUT2IN_ERROR_UNSUPPORTED_PROTOCOL];
+      next0 = SNAT_OUT2IN_NEXT_DROP;
+      goto out;
+    }
+  key0.fib_index = rx_fib_index0;
+
+  kv0.key = key0.as_u64;
+
+  if (clib_bihash_search_8_8 (&sm->out2in, &kv0, &value0))
+    {
+      /* Try to match static mapping by external address and port,
+         destination address and port in packet */
+      if (snat_static_mapping_match(sm, key0, &sm0, 1, &is_addr_only))
+        {
+          /* Don't NAT packet aimed at the intfc address */
+          if (PREDICT_FALSE(is_interface_addr(sm, node, sw_if_index0,
+                                              ip0->dst_address.as_u32)))
+            {
+              dont_translate = 1;
+              goto out;
+            }
+          b0->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION];
+          next0 = SNAT_OUT2IN_NEXT_DROP;
+          goto out;
+        }
+
+      if (PREDICT_FALSE(icmp0->type != ICMP4_echo_reply &&
+                        (icmp0->type != ICMP4_echo_request || !is_addr_only)))
+        {
+          b0->error = node->errors[SNAT_OUT2IN_ERROR_BAD_ICMP_TYPE];
+          next0 = SNAT_OUT2IN_NEXT_DROP;
+          goto out;
+        }
+
+      /* Create session initiated by host from external network */
+      s0 = create_session_for_static_mapping(sm, b0, sm0, key0,
+                                             node, thread_index);
+
+      if (!s0)
+        {
+          next0 = SNAT_OUT2IN_NEXT_DROP;
+          goto out;
+        }
+    }
+  else
+    {
+      if (PREDICT_FALSE(icmp0->type != ICMP4_echo_reply &&
+                        icmp0->type != ICMP4_echo_request &&
+                        !icmp_is_error_message (icmp0)))
+        {
+          b0->error = node->errors[SNAT_OUT2IN_ERROR_BAD_ICMP_TYPE];
+          next0 = SNAT_OUT2IN_NEXT_DROP;
+          goto out;
+        }
+
+      s0 = pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
+                              value0.value);
+    }
+
+out:
+  *p_proto = key0.protocol;
+  if (s0)
+    *p_value = s0->in2out;
+  *p_dont_translate = dont_translate;
+  if (d)
+    *(snat_session_t**)d = s0;
+  return next0;
+}
+
+/**
+ * Get address and port values to be used for ICMP packet translation
+ *
+ * @param[in] sm                 NAT main
+ * @param[in,out] node           NAT node runtime
+ * @param[in] thread_index       thread index
+ * @param[in,out] b0             buffer containing packet to be translated
+ * @param[out] p_proto           protocol used for matching
+ * @param[out] p_value           address and port after NAT translation
+ * @param[out] p_dont_translate  if packet should not be translated
+ * @param d                      optional parameter
+ * @param e                      optional parameter
+ */
+u32 icmp_match_out2in_fast(snat_main_t *sm, vlib_node_runtime_t *node,
+                           u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
+                           snat_session_key_t *p_value,
+                           u8 *p_dont_translate, void *d, void *e)
+{
+  ip4_header_t *ip0;
+  icmp46_header_t *icmp0;
+  u32 sw_if_index0;
+  u32 rx_fib_index0;
+  snat_session_key_t key0;
+  snat_session_key_t sm0;
+  u8 dont_translate = 0;
+  u8 is_addr_only;
+  u32 next0 = ~0;
+  int err;
+
+  ip0 = vlib_buffer_get_current (b0);
+  icmp0 = (icmp46_header_t *) ip4_next_header (ip0);
+  sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
+  rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index (sw_if_index0);
+
+  err = icmp_get_key (ip0, &key0);
+  if (err != -1)
+    {
+      b0->error = node->errors[err];
+      next0 = SNAT_OUT2IN_NEXT_DROP;
+      goto out2;
+    }
+  key0.fib_index = rx_fib_index0;
+
+  if (snat_static_mapping_match(sm, key0, &sm0, 1, &is_addr_only))
+    {
+      /* Don't NAT packet aimed at the intfc address */
+      if (is_interface_addr(sm, node, sw_if_index0, ip0->dst_address.as_u32))
+        {
+          dont_translate = 1;
+          goto out;
+        }
+      b0->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION];
+      next0 = SNAT_OUT2IN_NEXT_DROP;
+      goto out;
+    }
+
+  if (PREDICT_FALSE(icmp0->type != ICMP4_echo_reply &&
+                    (icmp0->type != ICMP4_echo_request || !is_addr_only) &&
+                    !icmp_is_error_message (icmp0)))
+    {
+      b0->error = node->errors[SNAT_OUT2IN_ERROR_BAD_ICMP_TYPE];
+      next0 = SNAT_OUT2IN_NEXT_DROP;
+      goto out;
+    }
+
+out:
+  *p_value = sm0;
+out2:
+  *p_proto = key0.protocol;
+  *p_dont_translate = dont_translate;
+  return next0;
+}
+
+static inline u32 icmp_out2in (snat_main_t *sm,
+                               vlib_buffer_t * b0,
+                               ip4_header_t * ip0,
+                               icmp46_header_t * icmp0,
+                               u32 sw_if_index0,
+                               u32 rx_fib_index0,
+                               vlib_node_runtime_t * node,
+                               u32 next0,
+                               u32 thread_index,
+                               void *d,
+                               void *e)
+{
+  snat_session_key_t sm0;
+  u8 protocol;
+  icmp_echo_header_t *echo0, *inner_echo0 = 0;
+  ip4_header_t *inner_ip0 = 0;
+  void *l4_header = 0;
+  icmp46_header_t *inner_icmp0;
+  u8 dont_translate;
+  u32 new_addr0, old_addr0;
+  u16 old_id0, new_id0;
+  ip_csum_t sum0;
+  u16 checksum0;
+  u32 next0_tmp;
+
+  echo0 = (icmp_echo_header_t *)(icmp0+1);
+
+  next0_tmp = sm->icmp_match_out2in_cb(sm, node, thread_index, b0,
+                                       &protocol, &sm0, &dont_translate, d, e);
+  if (next0_tmp != ~0)
+    next0 = next0_tmp;
+  if (next0 == SNAT_OUT2IN_NEXT_DROP || dont_translate)
+    goto out;
+
+  sum0 = ip_incremental_checksum (0, icmp0,
+                                  ntohs(ip0->length) - ip4_header_bytes (ip0));
+  checksum0 = ~ip_csum_fold (sum0);
+  if (checksum0 != 0 && checksum0 != 0xffff)
+    {
+      next0 = SNAT_OUT2IN_NEXT_DROP;
+      goto out;
+    }
+
+  old_addr0 = ip0->dst_address.as_u32;
+  new_addr0 = ip0->dst_address.as_u32 = sm0.addr.as_u32;
+  vnet_buffer(b0)->sw_if_index[VLIB_TX] = sm0.fib_index;
+
+  sum0 = ip0->checksum;
+  sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
+                         dst_address /* changed member */);
+  ip0->checksum = ip_csum_fold (sum0);
+
+  if (!icmp_is_error_message (icmp0))
+    {
+      new_id0 = sm0.port;
+      if (PREDICT_FALSE(new_id0 != echo0->identifier))
+        {
+          old_id0 = echo0->identifier;
+          new_id0 = sm0.port;
+          echo0->identifier = new_id0;
+
+          sum0 = icmp0->checksum;
+          sum0 = ip_csum_update (sum0, old_id0, new_id0, icmp_echo_header_t,
+                                 identifier /* changed member */);
+          icmp0->checksum = ip_csum_fold (sum0);
+        }
+    }
+  else
+    {
+      inner_ip0 = (ip4_header_t *)(echo0+1);
+      l4_header = ip4_next_header (inner_ip0);
+
+      if (!ip4_header_checksum_is_valid (inner_ip0))
+        {
+          next0 = SNAT_OUT2IN_NEXT_DROP;
+          goto out;
+        }
+
+      old_addr0 = inner_ip0->src_address.as_u32;
+      inner_ip0->src_address = sm0.addr;
+      new_addr0 = inner_ip0->src_address.as_u32;
+
+      sum0 = icmp0->checksum;
+      sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
+                             src_address /* changed member */);
+      icmp0->checksum = ip_csum_fold (sum0);
+
+      switch (protocol)
+        {
+        case SNAT_PROTOCOL_ICMP:
+          inner_icmp0 = (icmp46_header_t*)l4_header;
+          inner_echo0 = (icmp_echo_header_t *)(inner_icmp0+1);
+
+          old_id0 = inner_echo0->identifier;
+          new_id0 = sm0.port;
+          inner_echo0->identifier = new_id0;
+
+          sum0 = icmp0->checksum;
+          sum0 = ip_csum_update (sum0, old_id0, new_id0, icmp_echo_header_t,
+                                 identifier);
+          icmp0->checksum = ip_csum_fold (sum0);
+          break;
+        case SNAT_PROTOCOL_UDP:
+        case SNAT_PROTOCOL_TCP:
+          old_id0 = ((tcp_udp_header_t*)l4_header)->src_port;
+          new_id0 = sm0.port;
+          ((tcp_udp_header_t*)l4_header)->src_port = new_id0;
+
+          sum0 = icmp0->checksum;
+          sum0 = ip_csum_update (sum0, old_id0, new_id0, tcp_udp_header_t,
+                                 src_port);
+          icmp0->checksum = ip_csum_fold (sum0);
+          break;
+        default:
+          ASSERT(0);
+        }
+    }
+
+out:
+  return next0;
+}
+
+
+static inline u32 icmp_out2in_slow_path (snat_main_t *sm,
+                                         vlib_buffer_t * b0,
+                                         ip4_header_t * ip0,
+                                         icmp46_header_t * icmp0,
+                                         u32 sw_if_index0,
+                                         u32 rx_fib_index0,
+                                         vlib_node_runtime_t * node,
+                                         u32 next0, f64 now,
+                                         u32 thread_index,
+                                         snat_session_t ** p_s0)
+{
+  next0 = icmp_out2in(sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
+                      next0, thread_index, p_s0, 0);
+  snat_session_t * s0 = *p_s0;
+  if (PREDICT_TRUE(next0 != SNAT_OUT2IN_NEXT_DROP && s0))
+    {
+      /* Accounting */
+      s0->last_heard = now;
+      s0->total_pkts++;
+      s0->total_bytes += vlib_buffer_length_in_chain (sm->vlib_main, b0);
+      /* Per-user LRU list maintenance for dynamic translation */
+      if (!snat_is_session_static (s0))
+        {
+          clib_dlist_remove (sm->per_thread_data[thread_index].list_pool,
+                             s0->per_user_index);
+          clib_dlist_addtail (sm->per_thread_data[thread_index].list_pool,
+                              s0->per_user_list_head_index,
+                              s0->per_user_index);
+        }
+    }
+  return next0;
+}
+
+static void
+snat_out2in_unknown_proto (snat_main_t *sm,
+                           vlib_buffer_t * b,
+                           ip4_header_t * ip,
+                           u32 rx_fib_index,
+                           u32 thread_index,
+                           f64 now,
+                           vlib_main_t * vm)
+{
+  clib_bihash_kv_8_8_t kv, value;
+  clib_bihash_kv_16_8_t s_kv, s_value;
+  snat_static_mapping_t *m;
+  snat_session_key_t m_key;
+  u32 old_addr, new_addr;
+  ip_csum_t sum;
+  snat_unk_proto_ses_key_t key;
+  snat_session_t * s;
+  snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
+  snat_user_key_t u_key;
+  snat_user_t *u;
+  dlist_elt_t *head, *elt;
+
+  old_addr = ip->dst_address.as_u32;
+
+  key.l_addr = ip->dst_address;
+  key.r_addr = ip->src_address;
+  key.fib_index = rx_fib_index;
+  key.proto = ip->protocol;
+  key.rsvd[0] = key.rsvd[1] = key.rsvd[2] = 0;
+  s_kv.key[0] = key.as_u64[0];
+  s_kv.key[1] = key.as_u64[1];
+
+  if (!clib_bihash_search_16_8 (&sm->out2in_unk_proto, &s_kv, &s_value))
+    {
+      s = pool_elt_at_index (tsm->sessions, s_value.value);
+      new_addr = ip->dst_address.as_u32 = s->in2out.addr.as_u32;
+    }
+  else
+    {
+      m_key.addr = ip->dst_address;
+      m_key.port = 0;
+      m_key.protocol = 0;
+      m_key.fib_index = rx_fib_index;
+      kv.key = m_key.as_u64;
+      if (clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv, &value))
+        return;
+
+      m = pool_elt_at_index (sm->static_mappings, value.value);
+
+      new_addr = ip->dst_address.as_u32 = m->local_addr.as_u32;
+
+      u_key.addr = ip->src_address;
+      u_key.fib_index = m->fib_index;
+      kv.key = u_key.as_u64;
+
+      /* Ever heard of the "user" = src ip4 address before? */
+      if (clib_bihash_search_8_8 (&sm->user_hash, &kv, &value))
+        {
+          /* no, make a new one */
+          pool_get (tsm->users, u);
+          memset (u, 0, sizeof (*u));
+          u->addr = ip->src_address;
+          u->fib_index = rx_fib_index;
+
+          pool_get (tsm->list_pool, head);
+          u->sessions_per_user_list_head_index = head - tsm->list_pool;
+
+          clib_dlist_init (tsm->list_pool,
+                           u->sessions_per_user_list_head_index);
+
+          kv.value = u - tsm->users;
+
+          /* add user */
+          clib_bihash_add_del_8_8 (&sm->user_hash, &kv, 1);
+        }
+      else
+        {
+          u = pool_elt_at_index (tsm->users, value.value);
+        }
+
+      /* Create a new session */
+      pool_get (tsm->sessions, s);
+      memset (s, 0, sizeof (*s));
+
+      s->ext_host_addr.as_u32 = ip->src_address.as_u32;
+      s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
+      s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
+      s->outside_address_index = ~0;
+      s->out2in.addr.as_u32 = old_addr;
+      s->out2in.fib_index = rx_fib_index;
+      s->in2out.addr.as_u32 = new_addr;
+      s->in2out.fib_index = m->fib_index;
+      s->in2out.port = s->out2in.port = ip->protocol;
+      u->nstaticsessions++;
+
+      /* Create list elts */
+      pool_get (tsm->list_pool, elt);
+      clib_dlist_init (tsm->list_pool, elt - tsm->list_pool);
+      elt->value = s - tsm->sessions;
+      s->per_user_index = elt - tsm->list_pool;
+      s->per_user_list_head_index = u->sessions_per_user_list_head_index;
+      clib_dlist_addtail (tsm->list_pool, s->per_user_list_head_index,
+                          s->per_user_index);
+
+      /* Add to lookup tables */
+      s_kv.value = s - tsm->sessions;
+      if (clib_bihash_add_del_16_8 (&sm->out2in_unk_proto, &s_kv, 1))
+        clib_warning ("out2in key add failed");
+
+      key.l_addr = ip->dst_address;
+      key.fib_index = m->fib_index;
+      s_kv.key[0] = key.as_u64[0];
+      s_kv.key[1] = key.as_u64[1];
+      if (clib_bihash_add_del_16_8 (&sm->in2out_unk_proto, &s_kv, 1))
+        clib_warning ("in2out key add failed");
+   }
+
+  /* Update IP checksum */
+  sum = ip->checksum;
+  sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, dst_address);
+  ip->checksum = ip_csum_fold (sum);
+
+  vnet_buffer(b)->sw_if_index[VLIB_TX] = s->in2out.fib_index;
+
+  /* Accounting */
+  s->last_heard = now;
+  s->total_pkts++;
+  s->total_bytes += vlib_buffer_length_in_chain (vm, b);
+  /* Per-user LRU list maintenance */
+  clib_dlist_remove (tsm->list_pool, s->per_user_index);
+  clib_dlist_addtail (tsm->list_pool, s->per_user_list_head_index,
+                      s->per_user_index);
+}
+
+static uword
+snat_out2in_node_fn (vlib_main_t * vm,
+		  vlib_node_runtime_t * node,
+		  vlib_frame_t * frame)
+{
+  u32 n_left_from, * from, * to_next;
+  snat_out2in_next_t next_index;
+  u32 pkts_processed = 0;
+  snat_main_t * sm = &snat_main;
+  f64 now = vlib_time_now (vm);
+  u32 thread_index = vlib_get_thread_index ();
+
+  from = vlib_frame_vector_args (frame);
+  n_left_from = frame->n_vectors;
+  next_index = node->cached_next_index;
+
+  while (n_left_from > 0)
+    {
+      u32 n_left_to_next;
+
+      vlib_get_next_frame (vm, node, next_index,
+			   to_next, n_left_to_next);
+
+      while (n_left_from >= 4 && n_left_to_next >= 2)
+	{
+          u32 bi0, bi1;
+	  vlib_buffer_t * b0, * b1;
+          u32 next0 = SNAT_OUT2IN_NEXT_LOOKUP;
+          u32 next1 = SNAT_OUT2IN_NEXT_LOOKUP;
+          u32 sw_if_index0, sw_if_index1;
+          ip4_header_t * ip0, *ip1;
+          ip_csum_t sum0, sum1;
+          u32 new_addr0, old_addr0;
+          u16 new_port0, old_port0;
+          u32 new_addr1, old_addr1;
+          u16 new_port1, old_port1;
+          udp_header_t * udp0, * udp1;
+          tcp_header_t * tcp0, * tcp1;
+          icmp46_header_t * icmp0, * icmp1;
+          snat_session_key_t key0, key1, sm0, sm1;
+          u32 rx_fib_index0, rx_fib_index1;
+          u32 proto0, proto1;
+          snat_session_t * s0 = 0, * s1 = 0;
+          clib_bihash_kv_8_8_t kv0, kv1, value0, value1;
+
+	  /* Prefetch next iteration. */
+	  {
+	    vlib_buffer_t * p2, * p3;
+
+	    p2 = vlib_get_buffer (vm, from[2]);
+	    p3 = vlib_get_buffer (vm, from[3]);
+
+	    vlib_prefetch_buffer_header (p2, LOAD);
+	    vlib_prefetch_buffer_header (p3, LOAD);
+
+	    CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, STORE);
+	    CLIB_PREFETCH (p3->data, CLIB_CACHE_LINE_BYTES, STORE);
+	  }
+
+          /* speculatively enqueue b0 and b1 to the current next frame */
+	  to_next[0] = bi0 = from[0];
+	  to_next[1] = bi1 = from[1];
+	  from += 2;
+	  to_next += 2;
+	  n_left_from -= 2;
+	  n_left_to_next -= 2;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+	  b1 = vlib_get_buffer (vm, bi1);
+
+          vnet_buffer (b0)->snat.flags = 0;
+          vnet_buffer (b1)->snat.flags = 0;
+
+          ip0 = vlib_buffer_get_current (b0);
+          udp0 = ip4_next_header (ip0);
+          tcp0 = (tcp_header_t *) udp0;
+          icmp0 = (icmp46_header_t *) udp0;
+
+          sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
+	  rx_fib_index0 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index,
+                                   sw_if_index0);
+
+          if (PREDICT_FALSE(ip0->ttl == 1))
+            {
+              vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+              icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
+                                           ICMP4_time_exceeded_ttl_exceeded_in_transit,
+                                           0);
+              next0 = SNAT_OUT2IN_NEXT_ICMP_ERROR;
+              goto trace0;
+            }
+
+          proto0 = ip_proto_to_snat_proto (ip0->protocol);
+
+          if (PREDICT_FALSE (proto0 == ~0))
+            {
+              snat_out2in_unknown_proto(sm, b0, ip0, rx_fib_index0,
+                                        thread_index, now, vm);
+              goto trace0;
+            }
+
+          if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
+            {
+              next0 = icmp_out2in_slow_path
+                (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
+                 next0, now, thread_index, &s0);
+              goto trace0;
+            }
+
+          key0.addr = ip0->dst_address;
+          key0.port = udp0->dst_port;
+          key0.protocol = proto0;
+          key0.fib_index = rx_fib_index0;
+
+          kv0.key = key0.as_u64;
+
+          if (clib_bihash_search_8_8 (&sm->out2in, &kv0, &value0))
+            {
+              /* Try to match static mapping by external address and port,
+                 destination address and port in packet */
+              if (snat_static_mapping_match(sm, key0, &sm0, 1, 0))
+                {
+                  b0->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION];
+                  /*
+                   * Send DHCP packets to the ipv4 stack, or we won't
+                   * be able to use dhcp client on the outside interface
+                   */
+                  if (proto0 != SNAT_PROTOCOL_UDP
+                      || (udp0->dst_port
+                          != clib_host_to_net_u16(UDP_DST_PORT_dhcp_to_client)))
+                    next0 = SNAT_OUT2IN_NEXT_DROP;
+                  goto trace0;
+                }
+
+              /* Create session initiated by host from external network */
+              s0 = create_session_for_static_mapping(sm, b0, sm0, key0, node,
+                                                     thread_index);
+              if (!s0)
+                {
+                  b0->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION];
+                  next0 = SNAT_OUT2IN_NEXT_DROP;
+                  goto trace0;
+                }
+            }
+          else
+            s0 = pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
+                                    value0.value);
+
+          old_addr0 = ip0->dst_address.as_u32;
+          ip0->dst_address = s0->in2out.addr;
+          new_addr0 = ip0->dst_address.as_u32;
+          vnet_buffer(b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
+
+          sum0 = ip0->checksum;
+          sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
+                                 ip4_header_t,
+                                 dst_address /* changed member */);
+          ip0->checksum = ip_csum_fold (sum0);
+
+          if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
+            {
+              old_port0 = tcp0->dst_port;
+              tcp0->dst_port = s0->in2out.port;
+              new_port0 = tcp0->dst_port;
+
+              sum0 = tcp0->checksum;
+              sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
+                                     ip4_header_t,
+                                     dst_address /* changed member */);
+
+              sum0 = ip_csum_update (sum0, old_port0, new_port0,
+                                     ip4_header_t /* cheat */,
+                                     length /* changed member */);
+              tcp0->checksum = ip_csum_fold(sum0);
+            }
+          else
+            {
+              old_port0 = udp0->dst_port;
+              udp0->dst_port = s0->in2out.port;
+              udp0->checksum = 0;
+            }
+
+          /* Accounting */
+          s0->last_heard = now;
+          s0->total_pkts++;
+          s0->total_bytes += vlib_buffer_length_in_chain (vm, b0);
+          /* Per-user LRU list maintenance for dynamic translation */
+          if (!snat_is_session_static (s0))
+            {
+              clib_dlist_remove (sm->per_thread_data[thread_index].list_pool,
+                                 s0->per_user_index);
+              clib_dlist_addtail (sm->per_thread_data[thread_index].list_pool,
+                                  s0->per_user_list_head_index,
+                                  s0->per_user_index);
+            }
+        trace0:
+
+          if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
+                            && (b0->flags & VLIB_BUFFER_IS_TRACED)))
+            {
+              snat_out2in_trace_t *t =
+                 vlib_add_trace (vm, node, b0, sizeof (*t));
+              t->sw_if_index = sw_if_index0;
+              t->next_index = next0;
+              t->session_index = ~0;
+              if (s0)
+                t->session_index = s0 - sm->per_thread_data[thread_index].sessions;
+            }
+
+          pkts_processed += next0 != SNAT_OUT2IN_NEXT_DROP;
+
+
+          ip1 = vlib_buffer_get_current (b1);
+          udp1 = ip4_next_header (ip1);
+          tcp1 = (tcp_header_t *) udp1;
+          icmp1 = (icmp46_header_t *) udp1;
+
+          sw_if_index1 = vnet_buffer(b1)->sw_if_index[VLIB_RX];
+	  rx_fib_index1 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index,
+                                   sw_if_index1);
+
+          if (PREDICT_FALSE(ip1->ttl == 1))
+            {
+              vnet_buffer (b1)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+              icmp4_error_set_vnet_buffer (b1, ICMP4_time_exceeded,
+                                           ICMP4_time_exceeded_ttl_exceeded_in_transit,
+                                           0);
+              next1 = SNAT_OUT2IN_NEXT_ICMP_ERROR;
+              goto trace1;
+            }
+
+          proto1 = ip_proto_to_snat_proto (ip1->protocol);
+
+          if (PREDICT_FALSE (proto1 == ~0))
+            {
+              snat_out2in_unknown_proto(sm, b1, ip1, rx_fib_index1,
+                                        thread_index, now, vm);
+              goto trace1;
+            }
+
+          if (PREDICT_FALSE (proto1 == SNAT_PROTOCOL_ICMP))
+            {
+              next1 = icmp_out2in_slow_path
+                (sm, b1, ip1, icmp1, sw_if_index1, rx_fib_index1, node,
+                 next1, now, thread_index, &s1);
+              goto trace1;
+            }
+
+          key1.addr = ip1->dst_address;
+          key1.port = udp1->dst_port;
+          key1.protocol = proto1;
+          key1.fib_index = rx_fib_index1;
+
+          kv1.key = key1.as_u64;
+
+          if (clib_bihash_search_8_8 (&sm->out2in, &kv1, &value1))
+            {
+              /* Try to match static mapping by external address and port,
+                 destination address and port in packet */
+              if (snat_static_mapping_match(sm, key1, &sm1, 1, 0))
+                {
+                  b1->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION];
+                  /*
+                   * Send DHCP packets to the ipv4 stack, or we won't
+                   * be able to use dhcp client on the outside interface
+                   */
+                  if (proto1 != SNAT_PROTOCOL_UDP
+                      || (udp1->dst_port
+                          != clib_host_to_net_u16(UDP_DST_PORT_dhcp_to_client)))
+                    next1 = SNAT_OUT2IN_NEXT_DROP;
+                  goto trace1;
+                }
+
+              /* Create session initiated by host from external network */
+              s1 = create_session_for_static_mapping(sm, b1, sm1, key1, node,
+                                                     thread_index);
+              if (!s1)
+                {
+                  b1->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION];
+                  next1 = SNAT_OUT2IN_NEXT_DROP;
+                  goto trace1;
+                }
+            }
+          else
+            s1 = pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
+                                    value1.value);
+
+          old_addr1 = ip1->dst_address.as_u32;
+          ip1->dst_address = s1->in2out.addr;
+          new_addr1 = ip1->dst_address.as_u32;
+          vnet_buffer(b1)->sw_if_index[VLIB_TX] = s1->in2out.fib_index;
+
+          sum1 = ip1->checksum;
+          sum1 = ip_csum_update (sum1, old_addr1, new_addr1,
+                                 ip4_header_t,
+                                 dst_address /* changed member */);
+          ip1->checksum = ip_csum_fold (sum1);
+
+          if (PREDICT_TRUE(proto1 == SNAT_PROTOCOL_TCP))
+            {
+              old_port1 = tcp1->dst_port;
+              tcp1->dst_port = s1->in2out.port;
+              new_port1 = tcp1->dst_port;
+
+              sum1 = tcp1->checksum;
+              sum1 = ip_csum_update (sum1, old_addr1, new_addr1,
+                                     ip4_header_t,
+                                     dst_address /* changed member */);
+
+              sum1 = ip_csum_update (sum1, old_port1, new_port1,
+                                     ip4_header_t /* cheat */,
+                                     length /* changed member */);
+              tcp1->checksum = ip_csum_fold(sum1);
+            }
+          else
+            {
+              old_port1 = udp1->dst_port;
+              udp1->dst_port = s1->in2out.port;
+              udp1->checksum = 0;
+            }
+
+          /* Accounting */
+          s1->last_heard = now;
+          s1->total_pkts++;
+          s1->total_bytes += vlib_buffer_length_in_chain (vm, b1);
+          /* Per-user LRU list maintenance for dynamic translation */
+          if (!snat_is_session_static (s1))
+            {
+              clib_dlist_remove (sm->per_thread_data[thread_index].list_pool,
+                                 s1->per_user_index);
+              clib_dlist_addtail (sm->per_thread_data[thread_index].list_pool,
+                                  s1->per_user_list_head_index,
+                                  s1->per_user_index);
+            }
+        trace1:
+
+          if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
+                            && (b1->flags & VLIB_BUFFER_IS_TRACED)))
+            {
+              snat_out2in_trace_t *t =
+                 vlib_add_trace (vm, node, b1, sizeof (*t));
+              t->sw_if_index = sw_if_index1;
+              t->next_index = next1;
+              t->session_index = ~0;
+              if (s1)
+                t->session_index = s1 - sm->per_thread_data[thread_index].sessions;
+            }
+
+          pkts_processed += next1 != SNAT_OUT2IN_NEXT_DROP;
+
+          /* verify speculative enqueues, maybe switch current next frame */
+          vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
+                                           to_next, n_left_to_next,
+                                           bi0, bi1, next0, next1);
+        }
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+          u32 bi0;
+	  vlib_buffer_t * b0;
+          u32 next0 = SNAT_OUT2IN_NEXT_LOOKUP;
+          u32 sw_if_index0;
+          ip4_header_t * ip0;
+          ip_csum_t sum0;
+          u32 new_addr0, old_addr0;
+          u16 new_port0, old_port0;
+          udp_header_t * udp0;
+          tcp_header_t * tcp0;
+          icmp46_header_t * icmp0;
+          snat_session_key_t key0, sm0;
+          u32 rx_fib_index0;
+          u32 proto0;
+          snat_session_t * s0 = 0;
+          clib_bihash_kv_8_8_t kv0, value0;
+
+          /* speculatively enqueue b0 to the current next frame */
+	  bi0 = from[0];
+	  to_next[0] = bi0;
+	  from += 1;
+	  to_next += 1;
+	  n_left_from -= 1;
+	  n_left_to_next -= 1;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+
+          vnet_buffer (b0)->snat.flags = 0;
+
+          ip0 = vlib_buffer_get_current (b0);
+          udp0 = ip4_next_header (ip0);
+          tcp0 = (tcp_header_t *) udp0;
+          icmp0 = (icmp46_header_t *) udp0;
+
+          sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
+	  rx_fib_index0 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index,
+                                   sw_if_index0);
+
+          proto0 = ip_proto_to_snat_proto (ip0->protocol);
+
+          if (PREDICT_FALSE (proto0 == ~0))
+            {
+              snat_out2in_unknown_proto(sm, b0, ip0, rx_fib_index0,
+                                        thread_index, now, vm);
+              goto trace00;
+            }
+
+          if (PREDICT_FALSE(ip0->ttl == 1))
+            {
+              vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+              icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
+                                           ICMP4_time_exceeded_ttl_exceeded_in_transit,
+                                           0);
+              next0 = SNAT_OUT2IN_NEXT_ICMP_ERROR;
+              goto trace00;
+            }
+
+          if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
+            {
+              next0 = icmp_out2in_slow_path
+                (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
+                 next0, now, thread_index, &s0);
+              goto trace00;
+            }
+
+          key0.addr = ip0->dst_address;
+          key0.port = udp0->dst_port;
+          key0.protocol = proto0;
+          key0.fib_index = rx_fib_index0;
+
+          kv0.key = key0.as_u64;
+
+          if (clib_bihash_search_8_8 (&sm->out2in, &kv0, &value0))
+            {
+              /* Try to match static mapping by external address and port,
+                 destination address and port in packet */
+              if (snat_static_mapping_match(sm, key0, &sm0, 1, 0))
+                {
+                  b0->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION];
+                  /*
+                   * Send DHCP packets to the ipv4 stack, or we won't
+                   * be able to use dhcp client on the outside interface
+                   */
+                  if (proto0 != SNAT_PROTOCOL_UDP
+                      || (udp0->dst_port
+                          != clib_host_to_net_u16(UDP_DST_PORT_dhcp_to_client)))
+
+                    next0 = SNAT_OUT2IN_NEXT_DROP;
+                  goto trace00;
+                }
+
+              /* Create session initiated by host from external network */
+              s0 = create_session_for_static_mapping(sm, b0, sm0, key0, node,
+                                                     thread_index);
+              if (!s0)
+                {
+                  b0->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION];
+                    next0 = SNAT_OUT2IN_NEXT_DROP;
+                  goto trace00;
+                }
+            }
+          else
+            s0 = pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
+                                    value0.value);
+
+          old_addr0 = ip0->dst_address.as_u32;
+          ip0->dst_address = s0->in2out.addr;
+          new_addr0 = ip0->dst_address.as_u32;
+          vnet_buffer(b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
+
+          sum0 = ip0->checksum;
+          sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
+                                 ip4_header_t,
+                                 dst_address /* changed member */);
+          ip0->checksum = ip_csum_fold (sum0);
+
+          if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
+            {
+              old_port0 = tcp0->dst_port;
+              tcp0->dst_port = s0->in2out.port;
+              new_port0 = tcp0->dst_port;
+
+              sum0 = tcp0->checksum;
+              sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
+                                     ip4_header_t,
+                                     dst_address /* changed member */);
+
+              sum0 = ip_csum_update (sum0, old_port0, new_port0,
+                                     ip4_header_t /* cheat */,
+                                     length /* changed member */);
+              tcp0->checksum = ip_csum_fold(sum0);
+            }
+          else
+            {
+              old_port0 = udp0->dst_port;
+              udp0->dst_port = s0->in2out.port;
+              udp0->checksum = 0;
+            }
+
+          /* Accounting */
+          s0->last_heard = now;
+          s0->total_pkts++;
+          s0->total_bytes += vlib_buffer_length_in_chain (vm, b0);
+          /* Per-user LRU list maintenance for dynamic translation */
+          if (!snat_is_session_static (s0))
+            {
+              clib_dlist_remove (sm->per_thread_data[thread_index].list_pool,
+                                 s0->per_user_index);
+              clib_dlist_addtail (sm->per_thread_data[thread_index].list_pool,
+                                  s0->per_user_list_head_index,
+                                  s0->per_user_index);
+            }
+        trace00:
+
+          if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
+                            && (b0->flags & VLIB_BUFFER_IS_TRACED)))
+            {
+              snat_out2in_trace_t *t =
+                 vlib_add_trace (vm, node, b0, sizeof (*t));
+              t->sw_if_index = sw_if_index0;
+              t->next_index = next0;
+              t->session_index = ~0;
+              if (s0)
+                t->session_index = s0 - sm->per_thread_data[thread_index].sessions;
+            }
+
+          pkts_processed += next0 != SNAT_OUT2IN_NEXT_DROP;
+
+          /* verify speculative enqueue, maybe switch current next frame */
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
+					   to_next, n_left_to_next,
+					   bi0, next0);
+	}
+
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+
+  vlib_node_increment_counter (vm, snat_out2in_node.index,
+                               SNAT_OUT2IN_ERROR_OUT2IN_PACKETS,
+                               pkts_processed);
+  return frame->n_vectors;
+}
+
+VLIB_REGISTER_NODE (snat_out2in_node) = {
+  .function = snat_out2in_node_fn,
+  .name = "nat44-out2in",
+  .vector_size = sizeof (u32),
+  .format_trace = format_snat_out2in_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+
+  .n_errors = ARRAY_LEN(snat_out2in_error_strings),
+  .error_strings = snat_out2in_error_strings,
+
+  .runtime_data_bytes = sizeof (snat_runtime_t),
+
+  .n_next_nodes = SNAT_OUT2IN_N_NEXT,
+
+  /* edit / add dispositions here */
+  .next_nodes = {
+    [SNAT_OUT2IN_NEXT_DROP] = "error-drop",
+    [SNAT_OUT2IN_NEXT_LOOKUP] = "ip4-lookup",
+    [SNAT_OUT2IN_NEXT_ICMP_ERROR] = "ip4-icmp-error",
+  },
+};
+VLIB_NODE_FUNCTION_MULTIARCH (snat_out2in_node, snat_out2in_node_fn);
+
+/**************************/
+/*** deterministic mode ***/
+/**************************/
+static uword
+snat_det_out2in_node_fn (vlib_main_t * vm,
+                         vlib_node_runtime_t * node,
+                         vlib_frame_t * frame)
+{
+  u32 n_left_from, * from, * to_next;
+  snat_out2in_next_t next_index;
+  u32 pkts_processed = 0;
+  snat_main_t * sm = &snat_main;
+  u32 thread_index = vlib_get_thread_index ();
+
+  from = vlib_frame_vector_args (frame);
+  n_left_from = frame->n_vectors;
+  next_index = node->cached_next_index;
+
+  while (n_left_from > 0)
+    {
+      u32 n_left_to_next;
+
+      vlib_get_next_frame (vm, node, next_index,
+			   to_next, n_left_to_next);
+
+      while (n_left_from >= 4 && n_left_to_next >= 2)
+        {
+          u32 bi0, bi1;
+	  vlib_buffer_t * b0, * b1;
+          u32 next0 = SNAT_OUT2IN_NEXT_LOOKUP;
+          u32 next1 = SNAT_OUT2IN_NEXT_LOOKUP;
+          u32 sw_if_index0, sw_if_index1;
+          ip4_header_t * ip0, * ip1;
+          ip_csum_t sum0, sum1;
+          ip4_address_t new_addr0, old_addr0, new_addr1, old_addr1;
+          u16 new_port0, old_port0, old_port1, new_port1;
+          udp_header_t * udp0, * udp1;
+          tcp_header_t * tcp0, * tcp1;
+          u32 proto0, proto1;
+          snat_det_out_key_t key0, key1;
+          snat_det_map_t * dm0, * dm1;
+          snat_det_session_t * ses0 = 0, * ses1 = 0;
+          u32 rx_fib_index0, rx_fib_index1;
+          icmp46_header_t * icmp0, * icmp1;
+
+	  /* Prefetch next iteration. */
+	  {
+	    vlib_buffer_t * p2, * p3;
+
+	    p2 = vlib_get_buffer (vm, from[2]);
+	    p3 = vlib_get_buffer (vm, from[3]);
+
+	    vlib_prefetch_buffer_header (p2, LOAD);
+	    vlib_prefetch_buffer_header (p3, LOAD);
+
+	    CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, STORE);
+	    CLIB_PREFETCH (p3->data, CLIB_CACHE_LINE_BYTES, STORE);
+	  }
+
+          /* speculatively enqueue b0 and b1 to the current next frame */
+	  to_next[0] = bi0 = from[0];
+	  to_next[1] = bi1 = from[1];
+	  from += 2;
+	  to_next += 2;
+	  n_left_from -= 2;
+	  n_left_to_next -= 2;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+	  b1 = vlib_get_buffer (vm, bi1);
+
+          ip0 = vlib_buffer_get_current (b0);
+          udp0 = ip4_next_header (ip0);
+          tcp0 = (tcp_header_t *) udp0;
+
+          sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
+
+          if (PREDICT_FALSE(ip0->ttl == 1))
+            {
+              vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+              icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
+                                           ICMP4_time_exceeded_ttl_exceeded_in_transit,
+                                           0);
+              next0 = SNAT_OUT2IN_NEXT_ICMP_ERROR;
+              goto trace0;
+            }
+
+          proto0 = ip_proto_to_snat_proto (ip0->protocol);
+
+          if (PREDICT_FALSE(proto0 == SNAT_PROTOCOL_ICMP))
+            {
+              rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index(sw_if_index0);
+              icmp0 = (icmp46_header_t *) udp0;
+
+              next0 = icmp_out2in(sm, b0, ip0, icmp0, sw_if_index0,
+                                  rx_fib_index0, node, next0, thread_index,
+                                  &ses0, &dm0);
+              goto trace0;
+            }
+
+          key0.ext_host_addr = ip0->src_address;
+          key0.ext_host_port = tcp0->src;
+          key0.out_port = tcp0->dst;
+
+          dm0 = snat_det_map_by_out(sm, &ip0->dst_address);
+          if (PREDICT_FALSE(!dm0))
+            {
+              clib_warning("unknown dst address:  %U",
+                           format_ip4_address, &ip0->dst_address);
+              next0 = SNAT_OUT2IN_NEXT_DROP;
+              b0->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION];
+              goto trace0;
+            }
+
+          snat_det_reverse(dm0, &ip0->dst_address,
+                           clib_net_to_host_u16(tcp0->dst), &new_addr0);
+
+          ses0 = snat_det_get_ses_by_out (dm0, &new_addr0, key0.as_u64);
+          if (PREDICT_FALSE(!ses0))
+            {
+              clib_warning("no match src %U:%d dst %U:%d for user %U",
+                           format_ip4_address, &ip0->src_address,
+                           clib_net_to_host_u16 (tcp0->src),
+                           format_ip4_address, &ip0->dst_address,
+                           clib_net_to_host_u16 (tcp0->dst),
+                           format_ip4_address, &new_addr0);
+              next0 = SNAT_OUT2IN_NEXT_DROP;
+              b0->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION];
+              goto trace0;
+            }
+          new_port0 = ses0->in_port;
+
+          old_addr0 = ip0->dst_address;
+          ip0->dst_address = new_addr0;
+          vnet_buffer(b0)->sw_if_index[VLIB_TX] = sm->inside_fib_index;
+
+          sum0 = ip0->checksum;
+          sum0 = ip_csum_update (sum0, old_addr0.as_u32, new_addr0.as_u32,
+                                 ip4_header_t,
+                                 dst_address /* changed member */);
+          ip0->checksum = ip_csum_fold (sum0);
+
+          if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
+            {
+              if (tcp0->flags & TCP_FLAG_FIN && ses0->state == SNAT_SESSION_TCP_ESTABLISHED)
+                ses0->state = SNAT_SESSION_TCP_CLOSE_WAIT;
+              else if (tcp0->flags & TCP_FLAG_ACK && ses0->state == SNAT_SESSION_TCP_LAST_ACK)
+                snat_det_ses_close(dm0, ses0);
+
+              old_port0 = tcp0->dst;
+              tcp0->dst = new_port0;
+
+              sum0 = tcp0->checksum;
+              sum0 = ip_csum_update (sum0, old_addr0.as_u32, new_addr0.as_u32,
+                                     ip4_header_t,
+                                     dst_address /* changed member */);
+
+              sum0 = ip_csum_update (sum0, old_port0, new_port0,
+                                     ip4_header_t /* cheat */,
+                                     length /* changed member */);
+              tcp0->checksum = ip_csum_fold(sum0);
+            }
+          else
+            {
+              old_port0 = udp0->dst_port;
+              udp0->dst_port = new_port0;
+              udp0->checksum = 0;
+            }
+
+        trace0:
+
+          if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
+                            && (b0->flags & VLIB_BUFFER_IS_TRACED)))
+            {
+              snat_out2in_trace_t *t =
+                 vlib_add_trace (vm, node, b0, sizeof (*t));
+              t->sw_if_index = sw_if_index0;
+              t->next_index = next0;
+              t->session_index = ~0;
+              if (ses0)
+                t->session_index = ses0 - dm0->sessions;
+            }
+
+          pkts_processed += next0 != SNAT_OUT2IN_NEXT_DROP;
+
+	  b1 = vlib_get_buffer (vm, bi1);
+
+          ip1 = vlib_buffer_get_current (b1);
+          udp1 = ip4_next_header (ip1);
+          tcp1 = (tcp_header_t *) udp1;
+
+          sw_if_index1 = vnet_buffer(b1)->sw_if_index[VLIB_RX];
+
+          if (PREDICT_FALSE(ip1->ttl == 1))
+            {
+              vnet_buffer (b1)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+              icmp4_error_set_vnet_buffer (b1, ICMP4_time_exceeded,
+                                           ICMP4_time_exceeded_ttl_exceeded_in_transit,
+                                           0);
+              next1 = SNAT_OUT2IN_NEXT_ICMP_ERROR;
+              goto trace1;
+            }
+
+          proto1 = ip_proto_to_snat_proto (ip1->protocol);
+
+          if (PREDICT_FALSE(proto1 == SNAT_PROTOCOL_ICMP))
+            {
+              rx_fib_index1 = ip4_fib_table_get_index_for_sw_if_index(sw_if_index1);
+              icmp1 = (icmp46_header_t *) udp1;
+
+              next1 = icmp_out2in(sm, b1, ip1, icmp1, sw_if_index1,
+                                  rx_fib_index1, node, next1, thread_index,
+                                  &ses1, &dm1);
+              goto trace1;
+            }
+
+          key1.ext_host_addr = ip1->src_address;
+          key1.ext_host_port = tcp1->src;
+          key1.out_port = tcp1->dst;
+
+          dm1 = snat_det_map_by_out(sm, &ip1->dst_address);
+          if (PREDICT_FALSE(!dm1))
+            {
+              clib_warning("unknown dst address:  %U",
+                           format_ip4_address, &ip1->dst_address);
+              next1 = SNAT_OUT2IN_NEXT_DROP;
+              b1->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION];
+              goto trace1;
+            }
+
+          snat_det_reverse(dm1, &ip1->dst_address,
+                           clib_net_to_host_u16(tcp1->dst), &new_addr1);
+
+          ses1 = snat_det_get_ses_by_out (dm1, &new_addr1, key1.as_u64);
+          if (PREDICT_FALSE(!ses1))
+            {
+              clib_warning("no match src %U:%d dst %U:%d for user %U",
+                           format_ip4_address, &ip1->src_address,
+                           clib_net_to_host_u16 (tcp1->src),
+                           format_ip4_address, &ip1->dst_address,
+                           clib_net_to_host_u16 (tcp1->dst),
+                           format_ip4_address, &new_addr1);
+              next1 = SNAT_OUT2IN_NEXT_DROP;
+              b1->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION];
+              goto trace1;
+            }
+          new_port1 = ses1->in_port;
+
+          old_addr1 = ip1->dst_address;
+          ip1->dst_address = new_addr1;
+          vnet_buffer(b1)->sw_if_index[VLIB_TX] = sm->inside_fib_index;
+
+          sum1 = ip1->checksum;
+          sum1 = ip_csum_update (sum1, old_addr1.as_u32, new_addr1.as_u32,
+                                 ip4_header_t,
+                                 dst_address /* changed member */);
+          ip1->checksum = ip_csum_fold (sum1);
+
+          if (PREDICT_TRUE(proto1 == SNAT_PROTOCOL_TCP))
+            {
+              if (tcp1->flags & TCP_FLAG_FIN && ses1->state == SNAT_SESSION_TCP_ESTABLISHED)
+                ses1->state = SNAT_SESSION_TCP_CLOSE_WAIT;
+              else if (tcp1->flags & TCP_FLAG_ACK && ses1->state == SNAT_SESSION_TCP_LAST_ACK)
+                snat_det_ses_close(dm1, ses1);
+
+              old_port1 = tcp1->dst;
+              tcp1->dst = new_port1;
+
+              sum1 = tcp1->checksum;
+              sum1 = ip_csum_update (sum1, old_addr1.as_u32, new_addr1.as_u32,
+                                     ip4_header_t,
+                                     dst_address /* changed member */);
+
+              sum1 = ip_csum_update (sum1, old_port1, new_port1,
+                                     ip4_header_t /* cheat */,
+                                     length /* changed member */);
+              tcp1->checksum = ip_csum_fold(sum1);
+            }
+          else
+            {
+              old_port1 = udp1->dst_port;
+              udp1->dst_port = new_port1;
+              udp1->checksum = 0;
+            }
+
+        trace1:
+
+          if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
+                            && (b1->flags & VLIB_BUFFER_IS_TRACED)))
+            {
+              snat_out2in_trace_t *t =
+                 vlib_add_trace (vm, node, b1, sizeof (*t));
+              t->sw_if_index = sw_if_index1;
+              t->next_index = next1;
+              t->session_index = ~0;
+              if (ses1)
+                t->session_index = ses1 - dm1->sessions;
+            }
+
+          pkts_processed += next1 != SNAT_OUT2IN_NEXT_DROP;
+
+          /* verify speculative enqueues, maybe switch current next frame */
+          vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
+                                           to_next, n_left_to_next,
+                                           bi0, bi1, next0, next1);
+         }
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+          u32 bi0;
+	  vlib_buffer_t * b0;
+          u32 next0 = SNAT_OUT2IN_NEXT_LOOKUP;
+          u32 sw_if_index0;
+          ip4_header_t * ip0;
+          ip_csum_t sum0;
+          ip4_address_t new_addr0, old_addr0;
+          u16 new_port0, old_port0;
+          udp_header_t * udp0;
+          tcp_header_t * tcp0;
+          u32 proto0;
+          snat_det_out_key_t key0;
+          snat_det_map_t * dm0;
+          snat_det_session_t * ses0 = 0;
+          u32 rx_fib_index0;
+          icmp46_header_t * icmp0;
+
+          /* speculatively enqueue b0 to the current next frame */
+	  bi0 = from[0];
+	  to_next[0] = bi0;
+	  from += 1;
+	  to_next += 1;
+	  n_left_from -= 1;
+	  n_left_to_next -= 1;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+
+          ip0 = vlib_buffer_get_current (b0);
+          udp0 = ip4_next_header (ip0);
+          tcp0 = (tcp_header_t *) udp0;
+
+          sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
+
+          if (PREDICT_FALSE(ip0->ttl == 1))
+            {
+              vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+              icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
+                                           ICMP4_time_exceeded_ttl_exceeded_in_transit,
+                                           0);
+              next0 = SNAT_OUT2IN_NEXT_ICMP_ERROR;
+              goto trace00;
+            }
+
+          proto0 = ip_proto_to_snat_proto (ip0->protocol);
+
+          if (PREDICT_FALSE(proto0 == SNAT_PROTOCOL_ICMP))
+            {
+              rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index(sw_if_index0);
+              icmp0 = (icmp46_header_t *) udp0;
+
+              next0 = icmp_out2in(sm, b0, ip0, icmp0, sw_if_index0,
+                                  rx_fib_index0, node, next0, thread_index,
+                                  &ses0, &dm0);
+              goto trace00;
+            }
+
+          key0.ext_host_addr = ip0->src_address;
+          key0.ext_host_port = tcp0->src;
+          key0.out_port = tcp0->dst;
+
+          dm0 = snat_det_map_by_out(sm, &ip0->dst_address);
+          if (PREDICT_FALSE(!dm0))
+            {
+              clib_warning("unknown dst address:  %U",
+                           format_ip4_address, &ip0->dst_address);
+              next0 = SNAT_OUT2IN_NEXT_DROP;
+              b0->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION];
+              goto trace00;
+            }
+
+          snat_det_reverse(dm0, &ip0->dst_address,
+                           clib_net_to_host_u16(tcp0->dst), &new_addr0);
+
+          ses0 = snat_det_get_ses_by_out (dm0, &new_addr0, key0.as_u64);
+          if (PREDICT_FALSE(!ses0))
+            {
+              clib_warning("no match src %U:%d dst %U:%d for user %U",
+                           format_ip4_address, &ip0->src_address,
+                           clib_net_to_host_u16 (tcp0->src),
+                           format_ip4_address, &ip0->dst_address,
+                           clib_net_to_host_u16 (tcp0->dst),
+                           format_ip4_address, &new_addr0);
+              next0 = SNAT_OUT2IN_NEXT_DROP;
+              b0->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION];
+              goto trace00;
+            }
+          new_port0 = ses0->in_port;
+
+          old_addr0 = ip0->dst_address;
+          ip0->dst_address = new_addr0;
+          vnet_buffer(b0)->sw_if_index[VLIB_TX] = sm->inside_fib_index;
+
+          sum0 = ip0->checksum;
+          sum0 = ip_csum_update (sum0, old_addr0.as_u32, new_addr0.as_u32,
+                                 ip4_header_t,
+                                 dst_address /* changed member */);
+          ip0->checksum = ip_csum_fold (sum0);
+
+          if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
+            {
+              if (tcp0->flags & TCP_FLAG_FIN && ses0->state == SNAT_SESSION_TCP_ESTABLISHED)
+                ses0->state = SNAT_SESSION_TCP_CLOSE_WAIT;
+              else if (tcp0->flags & TCP_FLAG_ACK && ses0->state == SNAT_SESSION_TCP_LAST_ACK)
+                snat_det_ses_close(dm0, ses0);
+
+              old_port0 = tcp0->dst;
+              tcp0->dst = new_port0;
+
+              sum0 = tcp0->checksum;
+              sum0 = ip_csum_update (sum0, old_addr0.as_u32, new_addr0.as_u32,
+                                     ip4_header_t,
+                                     dst_address /* changed member */);
+
+              sum0 = ip_csum_update (sum0, old_port0, new_port0,
+                                     ip4_header_t /* cheat */,
+                                     length /* changed member */);
+              tcp0->checksum = ip_csum_fold(sum0);
+            }
+          else
+            {
+              old_port0 = udp0->dst_port;
+              udp0->dst_port = new_port0;
+              udp0->checksum = 0;
+            }
+
+        trace00:
+
+          if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
+                            && (b0->flags & VLIB_BUFFER_IS_TRACED)))
+            {
+              snat_out2in_trace_t *t =
+                 vlib_add_trace (vm, node, b0, sizeof (*t));
+              t->sw_if_index = sw_if_index0;
+              t->next_index = next0;
+              t->session_index = ~0;
+              if (ses0)
+                t->session_index = ses0 - dm0->sessions;
+            }
+
+          pkts_processed += next0 != SNAT_OUT2IN_NEXT_DROP;
+
+          /* verify speculative enqueue, maybe switch current next frame */
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
+					   to_next, n_left_to_next,
+					   bi0, next0);
+	}
+
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+
+  vlib_node_increment_counter (vm, snat_det_out2in_node.index,
+                               SNAT_OUT2IN_ERROR_OUT2IN_PACKETS,
+                               pkts_processed);
+  return frame->n_vectors;
+}
+
+VLIB_REGISTER_NODE (snat_det_out2in_node) = {
+  .function = snat_det_out2in_node_fn,
+  .name = "nat44-det-out2in",
+  .vector_size = sizeof (u32),
+  .format_trace = format_snat_out2in_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+
+  .n_errors = ARRAY_LEN(snat_out2in_error_strings),
+  .error_strings = snat_out2in_error_strings,
+
+  .runtime_data_bytes = sizeof (snat_runtime_t),
+
+  .n_next_nodes = SNAT_OUT2IN_N_NEXT,
+
+  /* edit / add dispositions here */
+  .next_nodes = {
+    [SNAT_OUT2IN_NEXT_DROP] = "error-drop",
+    [SNAT_OUT2IN_NEXT_LOOKUP] = "ip4-lookup",
+    [SNAT_OUT2IN_NEXT_ICMP_ERROR] = "ip4-icmp-error",
+  },
+};
+VLIB_NODE_FUNCTION_MULTIARCH (snat_det_out2in_node, snat_det_out2in_node_fn);
+
+/**
+ * Get address and port values to be used for ICMP packet translation
+ * and create session if needed
+ *
+ * @param[in,out] sm             NAT main
+ * @param[in,out] node           NAT node runtime
+ * @param[in] thread_index       thread index
+ * @param[in,out] b0             buffer containing packet to be translated
+ * @param[out] p_proto           protocol used for matching
+ * @param[out] p_value           address and port after NAT translation
+ * @param[out] p_dont_translate  if packet should not be translated
+ * @param d                      optional parameter
+ * @param e                      optional parameter
+ */
+u32 icmp_match_out2in_det(snat_main_t *sm, vlib_node_runtime_t *node,
+                          u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
+                          snat_session_key_t *p_value,
+                          u8 *p_dont_translate, void *d, void *e)
+{
+  ip4_header_t *ip0;
+  icmp46_header_t *icmp0;
+  u32 sw_if_index0;
+  u8 protocol;
+  snat_det_out_key_t key0;
+  u8 dont_translate = 0;
+  u32 next0 = ~0;
+  icmp_echo_header_t *echo0, *inner_echo0 = 0;
+  ip4_header_t *inner_ip0;
+  void *l4_header = 0;
+  icmp46_header_t *inner_icmp0;
+  snat_det_map_t * dm0 = 0;
+  ip4_address_t new_addr0 = {{0}};
+  snat_det_session_t * ses0 = 0;
+  ip4_address_t out_addr;
+
+  ip0 = vlib_buffer_get_current (b0);
+  icmp0 = (icmp46_header_t *) ip4_next_header (ip0);
+  echo0 = (icmp_echo_header_t *)(icmp0+1);
+  sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
+
+  if (!icmp_is_error_message (icmp0))
+    {
+      protocol = SNAT_PROTOCOL_ICMP;
+      key0.ext_host_addr = ip0->src_address;
+      key0.ext_host_port = 0;
+      key0.out_port = echo0->identifier;
+      out_addr = ip0->dst_address;
+    }
+  else
+    {
+      inner_ip0 = (ip4_header_t *)(echo0+1);
+      l4_header = ip4_next_header (inner_ip0);
+      protocol = ip_proto_to_snat_proto (inner_ip0->protocol);
+      key0.ext_host_addr = inner_ip0->dst_address;
+      out_addr = inner_ip0->src_address;
+      switch (protocol)
+        {
+        case SNAT_PROTOCOL_ICMP:
+          inner_icmp0 = (icmp46_header_t*)l4_header;
+          inner_echo0 = (icmp_echo_header_t *)(inner_icmp0+1);
+          key0.ext_host_port = 0;
+          key0.out_port = inner_echo0->identifier;
+          break;
+        case SNAT_PROTOCOL_UDP:
+        case SNAT_PROTOCOL_TCP:
+          key0.ext_host_port = ((tcp_udp_header_t*)l4_header)->dst_port;
+          key0.out_port = ((tcp_udp_header_t*)l4_header)->src_port;
+          break;
+        default:
+          b0->error = node->errors[SNAT_OUT2IN_ERROR_UNSUPPORTED_PROTOCOL];
+          next0 = SNAT_OUT2IN_NEXT_DROP;
+          goto out;
+        }
+    }
+
+  dm0 = snat_det_map_by_out(sm, &out_addr);
+  if (PREDICT_FALSE(!dm0))
+    {
+      /* Don't NAT packet aimed at the intfc address */
+      if (PREDICT_FALSE(is_interface_addr(sm, node, sw_if_index0,
+                                          ip0->dst_address.as_u32)))
+        {
+          dont_translate = 1;
+          goto out;
+        }
+      clib_warning("unknown dst address:  %U",
+                   format_ip4_address, &ip0->dst_address);
+      goto out;
+    }
+
+  snat_det_reverse(dm0, &ip0->dst_address,
+                   clib_net_to_host_u16(key0.out_port), &new_addr0);
+
+  ses0 = snat_det_get_ses_by_out (dm0, &new_addr0, key0.as_u64);
+  if (PREDICT_FALSE(!ses0))
+    {
+      /* Don't NAT packet aimed at the intfc address */
+      if (PREDICT_FALSE(is_interface_addr(sm, node, sw_if_index0,
+                                          ip0->dst_address.as_u32)))
+        {
+          dont_translate = 1;
+          goto out;
+        }
+      clib_warning("no match src %U:%d dst %U:%d for user %U",
+                   format_ip4_address, &key0.ext_host_addr,
+                   clib_net_to_host_u16 (key0.ext_host_port),
+                   format_ip4_address, &out_addr,
+                   clib_net_to_host_u16 (key0.out_port),
+                   format_ip4_address, &new_addr0);
+      b0->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION];
+      next0 = SNAT_OUT2IN_NEXT_DROP;
+      goto out;
+    }
+
+  if (PREDICT_FALSE(icmp0->type != ICMP4_echo_reply &&
+                    !icmp_is_error_message (icmp0)))
+    {
+      b0->error = node->errors[SNAT_OUT2IN_ERROR_BAD_ICMP_TYPE];
+      next0 = SNAT_OUT2IN_NEXT_DROP;
+      goto out;
+    }
+
+  goto out;
+
+out:
+  *p_proto = protocol;
+  if (ses0)
+    {
+      p_value->addr = new_addr0;
+      p_value->fib_index = sm->inside_fib_index;
+      p_value->port = ses0->in_port;
+    }
+  *p_dont_translate = dont_translate;
+  if (d)
+    *(snat_det_session_t**)d = ses0;
+  if (e)
+    *(snat_det_map_t**)e = dm0;
+  return next0;
+}
+
+/**********************/
+/*** worker handoff ***/
+/**********************/
+static uword
+snat_out2in_worker_handoff_fn (vlib_main_t * vm,
+                               vlib_node_runtime_t * node,
+                               vlib_frame_t * frame)
+{
+  snat_main_t *sm = &snat_main;
+  vlib_thread_main_t *tm = vlib_get_thread_main ();
+  u32 n_left_from, *from, *to_next = 0;
+  static __thread vlib_frame_queue_elt_t **handoff_queue_elt_by_worker_index;
+  static __thread vlib_frame_queue_t **congested_handoff_queue_by_worker_index
+    = 0;
+  vlib_frame_queue_elt_t *hf = 0;
+  vlib_frame_t *f = 0;
+  int i;
+  u32 n_left_to_next_worker = 0, *to_next_worker = 0;
+  u32 next_worker_index = 0;
+  u32 current_worker_index = ~0;
+  u32 thread_index = vlib_get_thread_index ();
+
+  ASSERT (vec_len (sm->workers));
+
+  if (PREDICT_FALSE (handoff_queue_elt_by_worker_index == 0))
+    {
+      vec_validate (handoff_queue_elt_by_worker_index, tm->n_vlib_mains - 1);
+
+      vec_validate_init_empty (congested_handoff_queue_by_worker_index,
+			       sm->first_worker_index + sm->num_workers - 1,
+			       (vlib_frame_queue_t *) (~0));
+    }
+
+  from = vlib_frame_vector_args (frame);
+  n_left_from = frame->n_vectors;
+
+  while (n_left_from > 0)
+    {
+      u32 bi0;
+      vlib_buffer_t *b0;
+      u32 sw_if_index0;
+      u32 rx_fib_index0;
+      ip4_header_t * ip0;
+      u8 do_handoff;
+
+      bi0 = from[0];
+      from += 1;
+      n_left_from -= 1;
+
+      b0 = vlib_get_buffer (vm, bi0);
+
+      sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
+      rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index(sw_if_index0);
+
+      ip0 = vlib_buffer_get_current (b0);
+
+      next_worker_index = sm->worker_out2in_cb(ip0, rx_fib_index0);
+
+      if (PREDICT_FALSE (next_worker_index != thread_index))
+        {
+          do_handoff = 1;
+
+          if (next_worker_index != current_worker_index)
+            {
+              if (hf)
+                hf->n_vectors = VLIB_FRAME_SIZE - n_left_to_next_worker;
+
+              hf = vlib_get_worker_handoff_queue_elt (sm->fq_out2in_index,
+                                                      next_worker_index,
+                                                      handoff_queue_elt_by_worker_index);
+
+              n_left_to_next_worker = VLIB_FRAME_SIZE - hf->n_vectors;
+              to_next_worker = &hf->buffer_index[hf->n_vectors];
+              current_worker_index = next_worker_index;
+            }
+
+          /* enqueue to correct worker thread */
+          to_next_worker[0] = bi0;
+          to_next_worker++;
+          n_left_to_next_worker--;
+
+          if (n_left_to_next_worker == 0)
+            {
+              hf->n_vectors = VLIB_FRAME_SIZE;
+              vlib_put_frame_queue_elt (hf);
+              current_worker_index = ~0;
+              handoff_queue_elt_by_worker_index[next_worker_index] = 0;
+              hf = 0;
+            }
+        }
+      else
+        {
+          do_handoff = 0;
+          /* if this is 1st frame */
+          if (!f)
+            {
+              f = vlib_get_frame_to_node (vm, sm->out2in_node_index);
+              to_next = vlib_frame_vector_args (f);
+            }
+
+          to_next[0] = bi0;
+          to_next += 1;
+          f->n_vectors++;
+        }
+
+      if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
+			 && (b0->flags & VLIB_BUFFER_IS_TRACED)))
+	{
+          snat_out2in_worker_handoff_trace_t *t =
+            vlib_add_trace (vm, node, b0, sizeof (*t));
+          t->next_worker_index = next_worker_index;
+          t->do_handoff = do_handoff;
+        }
+    }
+
+  if (f)
+    vlib_put_frame_to_node (vm, sm->out2in_node_index, f);
+
+  if (hf)
+    hf->n_vectors = VLIB_FRAME_SIZE - n_left_to_next_worker;
+
+  /* Ship frames to the worker nodes */
+  for (i = 0; i < vec_len (handoff_queue_elt_by_worker_index); i++)
+    {
+      if (handoff_queue_elt_by_worker_index[i])
+	{
+	  hf = handoff_queue_elt_by_worker_index[i];
+	  /*
+	   * It works better to let the handoff node
+	   * rate-adapt, always ship the handoff queue element.
+	   */
+	  if (1 || hf->n_vectors == hf->last_n_vectors)
+	    {
+	      vlib_put_frame_queue_elt (hf);
+	      handoff_queue_elt_by_worker_index[i] = 0;
+	    }
+	  else
+	    hf->last_n_vectors = hf->n_vectors;
+	}
+      congested_handoff_queue_by_worker_index[i] =
+	(vlib_frame_queue_t *) (~0);
+    }
+  hf = 0;
+  current_worker_index = ~0;
+  return frame->n_vectors;
+}
+
+VLIB_REGISTER_NODE (snat_out2in_worker_handoff_node) = {
+  .function = snat_out2in_worker_handoff_fn,
+  .name = "nat44-out2in-worker-handoff",
+  .vector_size = sizeof (u32),
+  .format_trace = format_snat_out2in_worker_handoff_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+
+  .n_next_nodes = 1,
+
+  .next_nodes = {
+    [0] = "error-drop",
+  },
+};
+
+VLIB_NODE_FUNCTION_MULTIARCH (snat_out2in_worker_handoff_node, snat_out2in_worker_handoff_fn);
+
+static uword
+snat_out2in_fast_node_fn (vlib_main_t * vm,
+                          vlib_node_runtime_t * node,
+		          vlib_frame_t * frame)
+{
+  u32 n_left_from, * from, * to_next;
+  snat_out2in_next_t next_index;
+  u32 pkts_processed = 0;
+  snat_main_t * sm = &snat_main;
+
+  from = vlib_frame_vector_args (frame);
+  n_left_from = frame->n_vectors;
+  next_index = node->cached_next_index;
+
+  while (n_left_from > 0)
+    {
+      u32 n_left_to_next;
+
+      vlib_get_next_frame (vm, node, next_index,
+			   to_next, n_left_to_next);
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+          u32 bi0;
+	  vlib_buffer_t * b0;
+          u32 next0 = SNAT_OUT2IN_NEXT_DROP;
+          u32 sw_if_index0;
+          ip4_header_t * ip0;
+          ip_csum_t sum0;
+          u32 new_addr0, old_addr0;
+          u16 new_port0, old_port0;
+          udp_header_t * udp0;
+          tcp_header_t * tcp0;
+          icmp46_header_t * icmp0;
+          snat_session_key_t key0, sm0;
+          u32 proto0;
+          u32 rx_fib_index0;
+
+          /* speculatively enqueue b0 to the current next frame */
+	  bi0 = from[0];
+	  to_next[0] = bi0;
+	  from += 1;
+	  to_next += 1;
+	  n_left_from -= 1;
+	  n_left_to_next -= 1;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+
+          ip0 = vlib_buffer_get_current (b0);
+          udp0 = ip4_next_header (ip0);
+          tcp0 = (tcp_header_t *) udp0;
+          icmp0 = (icmp46_header_t *) udp0;
+
+          sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
+	  rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index(sw_if_index0);
+
+	  vnet_feature_next (sw_if_index0, &next0, b0);
+
+          if (PREDICT_FALSE(ip0->ttl == 1))
+            {
+              vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+              icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
+                                           ICMP4_time_exceeded_ttl_exceeded_in_transit,
+                                           0);
+              next0 = SNAT_OUT2IN_NEXT_ICMP_ERROR;
+              goto trace00;
+            }
+
+          proto0 = ip_proto_to_snat_proto (ip0->protocol);
+
+          if (PREDICT_FALSE (proto0 == ~0))
+              goto trace00;
+
+          if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
+            {
+              next0 = icmp_out2in(sm, b0, ip0, icmp0, sw_if_index0,
+                                  rx_fib_index0, node, next0, ~0, 0, 0);
+              goto trace00;
+            }
+
+          key0.addr = ip0->dst_address;
+          key0.port = udp0->dst_port;
+          key0.fib_index = rx_fib_index0;
+
+          if (snat_static_mapping_match(sm, key0, &sm0, 1, 0))
+            {
+              b0->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION];
+              goto trace00;
+            }
+
+          new_addr0 = sm0.addr.as_u32;
+          new_port0 = sm0.port;
+          vnet_buffer(b0)->sw_if_index[VLIB_TX] = sm0.fib_index;
+          old_addr0 = ip0->dst_address.as_u32;
+          ip0->dst_address.as_u32 = new_addr0;
+
+          sum0 = ip0->checksum;
+          sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
+                                 ip4_header_t,
+                                 dst_address /* changed member */);
+          ip0->checksum = ip_csum_fold (sum0);
+
+          if (PREDICT_FALSE(new_port0 != udp0->dst_port))
+            {
+               if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
+                {
+                  old_port0 = tcp0->dst_port;
+                  tcp0->dst_port = new_port0;
+
+                  sum0 = tcp0->checksum;
+                  sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
+                                         ip4_header_t,
+                                         dst_address /* changed member */);
+
+                  sum0 = ip_csum_update (sum0, old_port0, new_port0,
+                                         ip4_header_t /* cheat */,
+                                         length /* changed member */);
+                  tcp0->checksum = ip_csum_fold(sum0);
+                }
+              else
+                {
+                  old_port0 = udp0->dst_port;
+                  udp0->dst_port = new_port0;
+                  udp0->checksum = 0;
+                }
+            }
+          else
+            {
+              if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
+                {
+                  sum0 = tcp0->checksum;
+                  sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
+                                         ip4_header_t,
+                                         dst_address /* changed member */);
+
+                  tcp0->checksum = ip_csum_fold(sum0);
+                }
+            }
+
+        trace00:
+
+          if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
+                            && (b0->flags & VLIB_BUFFER_IS_TRACED)))
+            {
+              snat_out2in_trace_t *t =
+                 vlib_add_trace (vm, node, b0, sizeof (*t));
+              t->sw_if_index = sw_if_index0;
+              t->next_index = next0;
+            }
+
+          pkts_processed += next0 != SNAT_OUT2IN_NEXT_DROP;
+
+          /* verify speculative enqueue, maybe switch current next frame */
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
+					   to_next, n_left_to_next,
+					   bi0, next0);
+	}
+
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+
+  vlib_node_increment_counter (vm, snat_out2in_fast_node.index,
+                               SNAT_OUT2IN_ERROR_OUT2IN_PACKETS,
+                               pkts_processed);
+  return frame->n_vectors;
+}
+
+VLIB_REGISTER_NODE (snat_out2in_fast_node) = {
+  .function = snat_out2in_fast_node_fn,
+  .name = "nat44-out2in-fast",
+  .vector_size = sizeof (u32),
+  .format_trace = format_snat_out2in_fast_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+
+  .n_errors = ARRAY_LEN(snat_out2in_error_strings),
+  .error_strings = snat_out2in_error_strings,
+
+  .runtime_data_bytes = sizeof (snat_runtime_t),
+
+  .n_next_nodes = SNAT_OUT2IN_N_NEXT,
+
+  /* edit / add dispositions here */
+  .next_nodes = {
+    [SNAT_OUT2IN_NEXT_LOOKUP] = "ip4-lookup",
+    [SNAT_OUT2IN_NEXT_DROP] = "error-drop",
+    [SNAT_OUT2IN_NEXT_ICMP_ERROR] = "ip4-icmp-error",
+  },
+};
+VLIB_NODE_FUNCTION_MULTIARCH (snat_out2in_fast_node, snat_out2in_fast_node_fn);