L2 BD: introduce a BD interface on which to send UU packets

Change-Id: I21ad6b04c19c8735d057174b1f260a59f2812241
Signed-off-by: Neale Ranns <nranns@cisco.com>

10 files changed, 451 insertions, 61 deletions

diff --git a/src/vnet/l2/l2.api b/src/vnet/l2/l2.api
index fdb7db7551d..2164ca74406 100644
--- a/src/vnet/l2/l2.api
+++ b/src/vnet/l2/l2.api
@@ -309,17 +309,27 @@ manual_print manual_endian define bridge_domain_details
   u8 mac_age;
   u8 bd_tag[64];
   u32 bvi_sw_if_index;
+  u32 uu_fwd_sw_if_index;
   u32 n_sw_ifs;
   vl_api_bridge_domain_sw_if_t sw_if_details[n_sw_ifs];
 };
 
-/** \brief Set bridge flags (such as L2_LEARN, L2_FWD, L2_FLOOD, 
-    L2_UU_FLOOD, or L2_ARP_TERM bits) request
+/** \brief Flags that can be changed on a bridge domain */
+enum bd_flags
+{
+  BRIDGE_API_FLAG_LEARN = 0x1,
+  BRIDGE_API_FLAG_FWD = 0x2,
+  BRIDGE_API_FLAG_FLOOD = 0x4,
+  BRIDGE_API_FLAG_UU_FLOOD = 0x8,
+  BRIDGE_API_FLAG_ARP_TERM = 0x10,
+};
+
+/** \brief Set bridge flags request
     @param client_index - opaque cookie to identify the sender
     @param context - sender context, to match reply w/ request
     @param bd_id - the bridge domain to set the flags for
     @param is_set - if non-zero, set the flags, else clear them
-    @param feature_bitmap - bits (as above) that are non-zero to set or clear
+    @param flags - flags that are non-zero to set or clear
 */
 define bridge_flags
 {
@@ -327,7 +337,7 @@ define bridge_flags
   u32 context;
   u32 bd_id;
   u8 is_set;
-  u32 feature_bitmap;
+  vl_api_bd_flags_t flags;
 };
 
 /** \brief Set bridge flags response
@@ -419,6 +429,21 @@ autoreply define sw_interface_set_l2_xconnect
   u8 enable;
 };
 
+/**
+ * @brief An enumeration of the type of ports that can be added
+ *        to a bridge domain
+ */
+enum l2_port_type
+{
+  /* a 'normal' interface, i.e. not BVI or UU-Flood */
+  L2_API_PORT_TYPE_NORMAL = 0,
+  /* a BVI interface in the BD */
+  L2_API_PORT_TYPE_BVI = 1,
+  /* The interface on which to forward unknown unicast packets
+   * If this is not set for a BD then UU is flooded */
+  L2_API_PORT_TYPE_UU_FWD = 2,
+};
+
 /** \brief Interface bridge mode request
     @param client_index - opaque cookie to identify the sender
     @param context - sender context, to match reply w/ request
@@ -428,14 +453,15 @@ autoreply define sw_interface_set_l2_xconnect
     @param shg - Split horizon group, for bridge mode only
     @param enable - Enable beige mode if not 0, else set to L3 mode
 */
+
 autoreply define sw_interface_set_l2_bridge
 {
   u32 client_index;
   u32 context;
   u32 rx_sw_if_index;
   u32 bd_id;
+  vl_api_l2_port_type_t port_type;
   u8 shg;
-  u8 bvi;
   u8 enable;
 };
 
diff --git a/src/vnet/l2/l2_api.c b/src/vnet/l2/l2_api.c
index ab3a7c6fd64..3f27feb638a 100644
--- a/src/vnet/l2/l2_api.c
+++ b/src/vnet/l2/l2_api.c
@@ -26,6 +26,7 @@
 #include <vnet/l2/l2_fib.h>
 #include <vnet/l2/l2_vtr.h>
 #include <vnet/l2/l2_learn.h>
+#include <vnet/l2/l2_bd.h>
 
 #include <vnet/vnet_msg_enum.h>
 
@@ -464,6 +465,7 @@ send_bridge_domain_details (l2input_main_t * l2im,
   mp->learn = bd_feature_learn (bd_config);
   mp->arp_term = bd_feature_arp_term (bd_config);
   mp->bvi_sw_if_index = ntohl (bd_config->bvi_sw_if_index);
+  mp->uu_fwd_sw_if_index = ntohl (bd_config->uu_fwd_sw_if_index);
   mp->mac_age = bd_config->mac_age;
   if (bd_config->bd_tag)
     {
@@ -527,6 +529,27 @@ vl_api_bridge_domain_dump_t_handler (vl_api_bridge_domain_dump_t * mp)
     }
 }
 
+static bd_flags_t
+bd_flags_decode (vl_api_bd_flags_t v)
+{
+  bd_flags_t f = L2_NONE;
+
+  v = ntohl (v);
+
+  if (v & BRIDGE_API_FLAG_LEARN)
+    f |= L2_LEARN;
+  if (v & BRIDGE_API_FLAG_FWD)
+    f |= L2_FWD;
+  if (v & BRIDGE_API_FLAG_FLOOD)
+    f |= L2_FLOOD;
+  if (v & BRIDGE_API_FLAG_UU_FLOOD)
+    f |= L2_UU_FLOOD;
+  if (v & BRIDGE_API_FLAG_ARP_TERM)
+    f |= L2_ARP_TERM;
+
+  return (f);
+}
+
 static void
 vl_api_bridge_flags_t_handler (vl_api_bridge_flags_t * mp)
 {
@@ -535,7 +558,7 @@ vl_api_bridge_flags_t_handler (vl_api_bridge_flags_t * mp)
   vl_api_bridge_flags_reply_t *rmp;
   int rv = 0;
 
-  u32 flags = ntohl (mp->feature_bitmap);
+  bd_flags_t flags = bd_flags_decode (mp->flags);
   u32 bd_id = ntohl (mp->bd_id);
   if (bd_id == 0)
     {
@@ -656,11 +679,13 @@ static void
     {
       VALIDATE_TX_SW_IF_INDEX (mp);
       rv = set_int_l2_mode (vm, vnm, MODE_L2_XC,
-			    rx_sw_if_index, 0, 0, 0, tx_sw_if_index);
+			    rx_sw_if_index, 0,
+			    L2_BD_PORT_TYPE_NORMAL, 0, tx_sw_if_index);
     }
   else
     {
-      rv = set_int_l2_mode (vm, vnm, MODE_L3, rx_sw_if_index, 0, 0, 0, 0);
+      rv = set_int_l2_mode (vm, vnm, MODE_L3, rx_sw_if_index, 0,
+			    L2_BD_PORT_TYPE_NORMAL, 0, 0);
     }
 
   BAD_RX_SW_IF_INDEX_LABEL;
@@ -669,6 +694,27 @@ static void
   REPLY_MACRO (VL_API_SW_INTERFACE_SET_L2_XCONNECT_REPLY);
 }
 
+static int
+l2_bd_port_type_decode (vl_api_l2_port_type_t v, l2_bd_port_type_t * l)
+{
+  v = clib_net_to_host_u32 (v);
+
+  switch (v)
+    {
+    case L2_API_PORT_TYPE_NORMAL:
+      *l = L2_BD_PORT_TYPE_NORMAL;
+      return 0;
+    case L2_API_PORT_TYPE_BVI:
+      *l = L2_BD_PORT_TYPE_BVI;
+      return 0;
+    case L2_API_PORT_TYPE_UU_FWD:
+      *l = L2_BD_PORT_TYPE_UU_FWD;
+      return 0;
+    }
+
+  return (VNET_API_ERROR_INVALID_VALUE);
+}
+
 static void
   vl_api_sw_interface_set_l2_bridge_t_handler
   (vl_api_sw_interface_set_l2_bridge_t * mp)
@@ -678,29 +724,31 @@ static void
   int rv = 0;
   vlib_main_t *vm = vlib_get_main ();
   vnet_main_t *vnm = vnet_get_main ();
+  l2_bd_port_type_t pt;
 
   VALIDATE_RX_SW_IF_INDEX (mp);
   u32 rx_sw_if_index = ntohl (mp->rx_sw_if_index);
+  rv = l2_bd_port_type_decode (mp->port_type, &pt);
 
-
+  if (0 != rv)
+    goto out;
   if (mp->enable)
     {
       VALIDATE_BD_ID (mp);
       u32 bd_id = ntohl (mp->bd_id);
       u32 bd_index = bd_find_or_add_bd_index (bdm, bd_id);
-      u32 bvi = mp->bvi;
-      u8 shg = mp->shg;
+
       rv = set_int_l2_mode (vm, vnm, MODE_L2_BRIDGE,
-			    rx_sw_if_index, bd_index, bvi, shg, 0);
+			    rx_sw_if_index, bd_index, pt, mp->shg, 0);
     }
   else
     {
-      rv = set_int_l2_mode (vm, vnm, MODE_L3, rx_sw_if_index, 0, 0, 0, 0);
+      rv = set_int_l2_mode (vm, vnm, MODE_L3, rx_sw_if_index, 0, pt, 0, 0);
     }
 
   BAD_RX_SW_IF_INDEX_LABEL;
   BAD_BD_ID_LABEL;
-
+out:
   REPLY_MACRO (VL_API_SW_INTERFACE_SET_L2_BRIDGE_REPLY);
 }
 
diff --git a/src/vnet/l2/l2_bd.c b/src/vnet/l2/l2_bd.c
index 973beb71cd0..47bdce6af68 100644
--- a/src/vnet/l2/l2_bd.c
+++ b/src/vnet/l2/l2_bd.c
@@ -52,8 +52,9 @@ bd_validate (l2_bridge_domain_t * bd_config)
 {
   if (bd_is_valid (bd_config))
     return;
-  bd_config->feature_bitmap = ~L2INPUT_FEAT_ARP_TERM;
+  bd_config->feature_bitmap = ~(L2INPUT_FEAT_ARP_TERM | L2INPUT_FEAT_UU_FWD);
   bd_config->bvi_sw_if_index = ~0;
+  bd_config->uu_fwd_sw_if_index = ~0;
   bd_config->members = 0;
   bd_config->flood_count = 0;
   bd_config->tun_master_count = 0;
@@ -240,7 +241,7 @@ VLIB_INIT_FUNCTION (l2bd_init);
     Return 0 if ok, non-zero if for an error.
 */
 u32
-bd_set_flags (vlib_main_t * vm, u32 bd_index, u32 flags, u32 enable)
+bd_set_flags (vlib_main_t * vm, u32 bd_index, bd_flags_t flags, u32 enable)
 {
 
   l2_bridge_domain_t *bd_config = l2input_bd_config (bd_index);
@@ -894,7 +895,7 @@ VLIB_CLI_COMMAND (bd_arp_entry_cli, static) = {
 };
 /* *INDENT-ON* */
 
-u8 *
+static u8 *
 format_vtr (u8 * s, va_list * args)
 {
   u32 vtr_op = va_arg (*args, u32);
@@ -929,6 +930,20 @@ format_vtr (u8 * s, va_list * args)
     }
 }
 
+static u8 *
+format_uu_cfg (u8 * s, va_list * args)
+{
+  l2_bridge_domain_t *bd_config = va_arg (*args, l2_bridge_domain_t *);
+
+  if (bd_config->feature_bitmap & L2INPUT_FEAT_UU_FWD)
+    return (format (s, "%U", format_vnet_sw_if_index_name_with_NA,
+		    vnet_get_main (), bd_config->uu_fwd_sw_if_index));
+  else if (bd_config->feature_bitmap & L2INPUT_FEAT_UU_FLOOD)
+    return (format (s, "flood"));
+  else
+    return (format (s, "drop"));
+}
+
 /**
    Show bridge-domain state.
    The CLI format is:
@@ -1002,10 +1017,10 @@ bd_show (vlib_main_t * vm, unformat_input_t * input, vlib_cli_command_t * cmd)
 	    {
 	      printed = 1;
 	      vlib_cli_output (vm,
-			       "%=8s %=7s %=4s %=9s %=9s %=9s %=9s %=9s %=9s %=9s",
+			       "%=8s %=7s %=4s %=9s %=9s %=9s %=11s %=9s %=9s %=11s",
 			       "BD-ID", "Index", "BSN", "Age(min)",
-			       "Learning", "U-Forwrd", "UU-Flood", "Flooding",
-			       "ARP-Term", "BVI-Intf");
+			       "Learning", "U-Forwrd", "UU-Flood",
+			       "Flooding", "ARP-Term", "BVI-Intf");
 	    }
 
 	  if (bd_config->mac_age)
@@ -1013,14 +1028,13 @@ bd_show (vlib_main_t * vm, unformat_input_t * input, vlib_cli_command_t * cmd)
 	  else
 	    as = format (as, "off");
 	  vlib_cli_output (vm,
-			   "%=8d %=7d %=4d %=9v %=9s %=9s %=9s %=9s %=9s %=9U",
+			   "%=8d %=7d %=4d %=9v %=9s %=9s %=11U %=9s %=9s %=11U",
 			   bd_config->bd_id, bd_index, bd_config->seq_num, as,
 			   bd_config->feature_bitmap & L2INPUT_FEAT_LEARN ?
 			   "on" : "off",
 			   bd_config->feature_bitmap & L2INPUT_FEAT_FWD ?
 			   "on" : "off",
-			   bd_config->feature_bitmap & L2INPUT_FEAT_UU_FLOOD ?
-			   "on" : "off",
+			   format_uu_cfg, bd_config,
 			   bd_config->feature_bitmap & L2INPUT_FEAT_FLOOD ?
 			   "on" : "off",
 			   bd_config->feature_bitmap & L2INPUT_FEAT_ARP_TERM ?
@@ -1055,6 +1069,13 @@ bd_show (vlib_main_t * vm, unformat_input_t * input, vlib_cli_command_t * cmd)
 				 "-", i < bd_config->flood_count ? "*" : "-",
 				 format_vtr, vtr_opr, dot1q, tag1, tag2);
 	      }
+	      if (~0 != bd_config->uu_fwd_sw_if_index)
+		vlib_cli_output (vm, "%=30U%=7d%=5d%=5d%=5s%=9s%=30s",
+				 format_vnet_sw_if_index_name, vnm,
+				 bd_config->uu_fwd_sw_if_index,
+				 bd_config->uu_fwd_sw_if_index,
+				 0, 0, "uu", "-", "None");
+
 	    }
 
 	  if ((detail || arp) &&
@@ -1150,7 +1171,7 @@ bd_add_del (l2_bridge_domain_add_del_args_t * a)
 	return VNET_API_ERROR_BD_ID_EXCEED_MAX;
       bd_index = bd_add_bd_index (bdm, a->bd_id);
 
-      u32 enable_flags = 0, disable_flags = 0;
+      bd_flags_t enable_flags = 0, disable_flags = 0;
       if (a->flood)
 	enable_flags |= L2_FLOOD;
       else
diff --git a/src/vnet/l2/l2_bd.h b/src/vnet/l2/l2_bd.h
index ffc75339e97..226e30ecfd4 100644
--- a/src/vnet/l2/l2_bd.h
+++ b/src/vnet/l2/l2_bd.h
@@ -21,6 +21,13 @@
 #include <vlib/vlib.h>
 #include <vnet/vnet.h>
 
+typedef enum l2_bd_port_type_t_
+{
+  L2_BD_PORT_TYPE_NORMAL = 0,
+  L2_BD_PORT_TYPE_BVI = 1,
+  L2_BD_PORT_TYPE_UU_FWD = 2,
+} l2_bd_port_type_t;
+
 typedef struct
 {
   /* hash bd_id -> bd_index */
@@ -53,16 +60,23 @@ typedef struct
 
 typedef struct
 {
-  u32 feature_bitmap;
   /*
    * Contains bit enables for flooding, learning, and forwarding.
    * All other feature bits should always be set.
-   *
+   */
+  u32 feature_bitmap;
+  /*
    * identity of the bridge-domain's BVI interface
    * set to ~0 if there is no BVI
    */
   u32 bvi_sw_if_index;
 
+  /*
+   * identity of the bridge-domain's UU flood interface
+   * set to ~0 if there is no such configuration
+   */
+  u32 uu_fwd_sw_if_index;
+
   /* bridge domain id, not to be confused with bd_index */
   u32 bd_id;
 
@@ -128,14 +142,18 @@ bd_add_member (l2_bridge_domain_t * bd_config, l2_flood_member_t * member);
 
 u32 bd_remove_member (l2_bridge_domain_t * bd_config, u32 sw_if_index);
 
-
-#define L2_LEARN   (1<<0)
-#define L2_FWD     (1<<1)
-#define L2_FLOOD   (1<<2)
-#define L2_UU_FLOOD (1<<3)
-#define L2_ARP_TERM (1<<4)
-
-u32 bd_set_flags (vlib_main_t * vm, u32 bd_index, u32 flags, u32 enable);
+typedef enum bd_flags_t_
+{
+  L2_NONE = 0,
+  L2_LEARN = (1 << 0),
+  L2_FWD = (1 << 1),
+  L2_FLOOD = (1 << 2),
+  L2_UU_FLOOD = (1 << 3),
+  L2_ARP_TERM = (1 << 4),
+} bd_flags_t;
+
+u32 bd_set_flags (vlib_main_t * vm, u32 bd_index, bd_flags_t flags,
+		  u32 enable);
 void bd_set_mac_age (vlib_main_t * vm, u32 bd_index, u8 age);
 int bd_add_del (l2_bridge_domain_add_del_args_t * args);
 
diff --git a/src/vnet/l2/l2_flood.c b/src/vnet/l2/l2_flood.c
index ee3d6d4621f..97a4ff59da7 100644
--- a/src/vnet/l2/l2_flood.c
+++ b/src/vnet/l2/l2_flood.c
@@ -372,10 +372,12 @@ VLIB_REGISTER_NODE (l2flood_node,static) = {
         [L2FLOOD_NEXT_DROP] = "error-drop",
   },
 };
-/* *INDENT-ON* */
 
 VLIB_NODE_FUNCTION_MULTIARCH (l2flood_node, l2flood_node_fn)
-     clib_error_t *l2flood_init (vlib_main_t * vm)
+/* *INDENT-ON* */
+
+clib_error_t *
+l2flood_init (vlib_main_t * vm)
 {
   l2flood_main_t *mp = &l2flood_main;
 
diff --git a/src/vnet/l2/l2_fwd.c b/src/vnet/l2/l2_fwd.c
index 0fad124b89f..c647e3dbd06 100644
--- a/src/vnet/l2/l2_fwd.c
+++ b/src/vnet/l2/l2_fwd.c
@@ -211,7 +211,8 @@ l2fwd_process (vlib_main_t * vm,
        * lookup miss, so flood which is typically the next feature
        * unless some other feature is inserted before uu_flood
        */
-      if (vnet_buffer (b0)->l2.feature_bitmap & L2INPUT_FEAT_UU_FLOOD)
+      if (vnet_buffer (b0)->l2.feature_bitmap &
+	  (L2INPUT_FEAT_UU_FLOOD | L2INPUT_FEAT_UU_FWD))
 	{
 	  *next0 = vnet_l2_feature_next (b0, msm->feat_next_node_index,
 					 L2INPUT_FEAT_FWD);
@@ -223,7 +224,6 @@ l2fwd_process (vlib_main_t * vm,
 	  *next0 = L2FWD_NEXT_DROP;
 	}
     }
-
 }
 
 
diff --git a/src/vnet/l2/l2_input.c b/src/vnet/l2/l2_input.c
index 1c9ddaac04a..f94ef668c41 100644
--- a/src/vnet/l2/l2_input.c
+++ b/src/vnet/l2/l2_input.c
@@ -573,7 +573,7 @@ set_int_l2_mode (vlib_main_t * vm, vnet_main_t * vnet_main,	/*           */
 		 u32 mode,	/* One of L2 modes or back to L3 mode        */
 		 u32 sw_if_index,	/* sw interface index                */
 		 u32 bd_index,	/* for bridged interface                     */
-		 u32 bvi,	/* the bridged interface is the BVI          */
+		 l2_bd_port_type_t port_type,	/* port_type */
 		 u32 shg,	/* the bridged interface split horizon group */
 		 u32 xc_sw_if_index)	/* peer interface for xconnect       */
 {
@@ -613,6 +613,11 @@ set_int_l2_mode (vlib_main_t * vm, vnet_main_t * vnet_main,	/*           */
 	  si = vnet_get_sw_interface (vnm, sw_if_index);
 	  si->flood_class = VNET_FLOOD_CLASS_NO_FLOOD;
 	}
+      if (bd_config->uu_fwd_sw_if_index == sw_if_index)
+	{
+	  bd_config->uu_fwd_sw_if_index = ~0;
+	  bd_config->feature_bitmap &= ~L2INPUT_FEAT_UU_FWD;
+	}
 
       /* Clear MACs learned on the interface */
       if ((config->feature_bitmap & L2INPUT_FEAT_LEARN) ||
@@ -657,6 +662,8 @@ set_int_l2_mode (vlib_main_t * vm, vnet_main_t * vnet_main,	/*           */
 
       if (mode == MODE_L2_BRIDGE)
 	{
+	  u8 member_flags;
+
 	  /*
 	   * Remove a check that the interface must be an Ethernet.
 	   * Specifically so we can bridge to L3 tunnel interfaces.
@@ -676,8 +683,12 @@ set_int_l2_mode (vlib_main_t * vm, vnet_main_t * vnet_main,	/*           */
 	   * Enable forwarding, flooding, learning and ARP termination by default
 	   * (note that ARP term is disabled on BD feature bitmap by default)
 	   */
-	  config->feature_bitmap |= L2INPUT_FEAT_FWD | L2INPUT_FEAT_UU_FLOOD |
-	    L2INPUT_FEAT_FLOOD | L2INPUT_FEAT_LEARN | L2INPUT_FEAT_ARP_TERM;
+	  config->feature_bitmap |= (L2INPUT_FEAT_FWD |
+				     L2INPUT_FEAT_UU_FLOOD |
+				     L2INPUT_FEAT_UU_FWD |
+				     L2INPUT_FEAT_FLOOD |
+				     L2INPUT_FEAT_LEARN |
+				     L2INPUT_FEAT_ARP_TERM);
 
 	  /* Make sure last-chance drop is configured */
 	  config->feature_bitmap |= L2INPUT_FEAT_DROP;
@@ -692,7 +703,7 @@ set_int_l2_mode (vlib_main_t * vm, vnet_main_t * vnet_main,	/*           */
 	  /* TODO: think: add l2fib entry even for non-bvi interface? */
 
 	  /* Do BVI interface initializations */
-	  if (bvi)
+	  if (L2_BD_PORT_TYPE_BVI == port_type)
 	    {
 	      vnet_sw_interface_t *si;
 
@@ -715,16 +726,29 @@ set_int_l2_mode (vlib_main_t * vm, vnet_main_t * vnet_main,	/*           */
 	      /* since this is a BVI interface we want to flood to it */
 	      si = vnet_get_sw_interface (vnm, sw_if_index);
 	      si->flood_class = VNET_FLOOD_CLASS_BVI;
+	      member_flags = L2_FLOOD_MEMBER_BVI;
+	    }
+	  else if (L2_BD_PORT_TYPE_UU_FWD == port_type)
+	    {
+	      bd_config->uu_fwd_sw_if_index = sw_if_index;
+	      bd_config->feature_bitmap |= L2INPUT_FEAT_UU_FWD;
+	    }
+	  else
+	    {
+	      member_flags = L2_FLOOD_MEMBER_NORMAL;
 	    }
 
-	  /* Add interface to bridge-domain flood vector */
-	  l2_flood_member_t member = {
-	    .sw_if_index = sw_if_index,
-	    .flags = bvi ? L2_FLOOD_MEMBER_BVI : L2_FLOOD_MEMBER_NORMAL,
-	    .shg = shg,
-	  };
-	  bd_add_member (bd_config, &member);
-
+	  if (L2_BD_PORT_TYPE_NORMAL == port_type ||
+	      L2_BD_PORT_TYPE_BVI == port_type)
+	    {
+	      /* Add interface to bridge-domain flood vector */
+	      l2_flood_member_t member = {
+		.sw_if_index = sw_if_index,
+		.flags = member_flags,
+		.shg = shg,
+	      };
+	      bd_add_member (bd_config, &member);
+	    }
 	}
       else if (mode == MODE_L2_XC)
 	{
@@ -827,10 +851,10 @@ int_l2_bridge (vlib_main_t * vm,
 	       unformat_input_t * input, vlib_cli_command_t * cmd)
 {
   vnet_main_t *vnm = vnet_get_main ();
+  l2_bd_port_type_t port_type;
   clib_error_t *error = 0;
   u32 bd_index, bd_id;
   u32 sw_if_index;
-  u32 bvi;
   u32 rc;
   u32 shg;
 
@@ -857,7 +881,11 @@ int_l2_bridge (vlib_main_t * vm,
   bd_index = bd_find_or_add_bd_index (&bd_main, bd_id);
 
   /* optional bvi  */
-  bvi = unformat (input, "bvi");
+  port_type = L2_BD_PORT_TYPE_NORMAL;
+  if (unformat (input, "bvi"))
+    port_type = L2_BD_PORT_TYPE_BVI;
+  if (unformat (input, "uu-fwd"))
+    port_type = L2_BD_PORT_TYPE_UU_FWD;
 
   /* optional split horizon group */
   shg = 0;
@@ -865,8 +893,8 @@ int_l2_bridge (vlib_main_t * vm,
 
   /* set the interface mode */
   if ((rc =
-       set_int_l2_mode (vm, vnm, MODE_L2_BRIDGE, sw_if_index, bd_index, bvi,
-			shg, 0)))
+       set_int_l2_mode (vm, vnm, MODE_L2_BRIDGE, sw_if_index, bd_index,
+			port_type, shg, 0)))
     {
       if (rc == MODE_ERROR_ETH)
 	{
@@ -920,7 +948,7 @@ done:
 /* *INDENT-OFF* */
 VLIB_CLI_COMMAND (int_l2_bridge_cli, static) = {
   .path = "set interface l2 bridge",
-  .short_help = "set interface l2 bridge <interface> <bridge-domain-id> [bvi] [shg]",
+  .short_help = "set interface l2 bridge <interface> <bridge-domain-id> [bvi|uu-fwd] [shg]",
   .function = int_l2_bridge,
 };
 /* *INDENT-ON* */
@@ -956,7 +984,8 @@ int_l2_xc (vlib_main_t * vm,
 
   /* set the interface mode */
   if (set_int_l2_mode
-      (vm, vnm, MODE_L2_XC, sw_if_index, 0, 0, 0, xc_sw_if_index))
+      (vm, vnm, MODE_L2_XC, sw_if_index, 0, L2_BD_PORT_TYPE_NORMAL,
+       0, xc_sw_if_index))
     {
       error = clib_error_return (0, "invalid configuration for interface",
 				 format_unformat_error, input);
@@ -1010,7 +1039,8 @@ int_l3 (vlib_main_t * vm, unformat_input_t * input, vlib_cli_command_t * cmd)
     }
 
   /* set the interface mode */
-  if (set_int_l2_mode (vm, vnm, MODE_L3, sw_if_index, 0, 0, 0, 0))
+  if (set_int_l2_mode (vm, vnm, MODE_L3, sw_if_index, 0,
+		       L2_BD_PORT_TYPE_NORMAL, 0, 0))
     {
       error = clib_error_return (0, "invalid configuration for interface",
 				 format_unformat_error, input);
diff --git a/src/vnet/l2/l2_input.h b/src/vnet/l2/l2_input.h
index fb601334f37..4d6f1a32177 100644
--- a/src/vnet/l2/l2_input.h
+++ b/src/vnet/l2/l2_input.h
@@ -104,6 +104,7 @@ l2input_bd_config (u32 bd_index)
  _(FLOOD,         "l2-flood")                   \
  _(ARP_TERM,      "arp-term-l2bd")              \
  _(UU_FLOOD,      "l2-flood")                   \
+ _(UU_FWD,        "l2-uu-fwd")                  \
  _(GBP_FWD,       "gbp-fwd")                    \
  _(FWD,           "l2-fwd")                     \
  _(RW,            "l2-rw")                      \
@@ -213,7 +214,8 @@ u32 set_int_l2_mode (vlib_main_t * vm,
 		     vnet_main_t * vnet_main,
 		     u32 mode,
 		     u32 sw_if_index,
-		     u32 bd_index, u32 bvi, u32 shg, u32 xc_sw_if_index);
+		     u32 bd_index, l2_bd_port_type_t port_type,
+		     u32 shg, u32 xc_sw_if_index);
 
 static inline void
 vnet_update_l2_len (vlib_buffer_t * b)
diff --git a/src/vnet/l2/l2_uu_fwd.c b/src/vnet/l2/l2_uu_fwd.c
new file mode 100644
index 00000000000..fd79387bbe0
--- /dev/null
+++ b/src/vnet/l2/l2_uu_fwd.c
@@ -0,0 +1,242 @@
+/*
+ * l2_uu_fwd.c : Foward unknown unicast packets to BD's configured interface
+ *
+ * Copyright (c) 2018 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/l2/l2_bd.h>
+#include <vnet/l2/l2_input.h>
+
+#define foreach_l2_uu_fwd_error					\
+_(L2_UU_FWD,           "L2 UU fwd")
+
+typedef enum
+{
+#define _(sym,str) L2_UU_FWD_ERROR_##sym,
+  foreach_l2_uu_fwd_error
+#undef _
+    L2_UU_FWD_N_ERROR,
+} l2_uu_fwd_error_t;
+
+static char *l2_uu_fwd_error_strings[] = {
+#define _(sym,string) string,
+  foreach_l2_uu_fwd_error
+#undef _
+};
+
+typedef enum
+{
+  L2_UU_FWD_NEXT_DROP,
+  L2_UU_FWD_NEXT_L2_OUTPUT,
+  L2_UU_FWD_N_NEXT,
+} l2_uu_fwd_next_t;
+
+typedef struct
+{
+  u32 sw_if_index;
+} l2_uu_fwd_trace_t;
+
+/* packet trace format function */
+static u8 *
+format_l2_uu_fwd_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 *);
+  l2_uu_fwd_trace_t *t = va_arg (*args, l2_uu_fwd_trace_t *);
+
+  s = format (s, "l2-uu-fwd: sw_if_index %d", t->sw_if_index);
+  return s;
+}
+
+static uword
+l2_uu_fwd_node_fn (vlib_main_t * vm,
+		   vlib_node_runtime_t * node, vlib_frame_t * frame)
+{
+  u32 n_left_from, *from, *to_next;
+  l2_uu_fwd_next_t next_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 >= 8 && n_left_to_next >= 4)
+	{
+	  const l2_bridge_domain_t *bdc0, *bdc1, *bdc2, *bdc3;
+	  l2_uu_fwd_next_t next0, next1, next2, next3;
+	  vlib_buffer_t *b0, *b1, *b2, *b3;
+	  u32 bi0, bi1, bi2, bi3;
+
+	  {
+	    vlib_buffer_t *b4, *b5, *b6, *b7;
+
+	    b4 = vlib_get_buffer (vm, from[4]);
+	    b5 = vlib_get_buffer (vm, from[5]);
+	    b6 = vlib_get_buffer (vm, from[6]);
+	    b7 = vlib_get_buffer (vm, from[7]);
+
+	    vlib_prefetch_buffer_header (b4, STORE);
+	    vlib_prefetch_buffer_header (b5, STORE);
+	    vlib_prefetch_buffer_header (b6, STORE);
+	    vlib_prefetch_buffer_header (b7, STORE);
+	  }
+	  bi0 = to_next[0] = from[0];
+	  bi1 = to_next[1] = from[1];
+	  bi2 = to_next[2] = from[2];
+	  bi3 = to_next[3] = from[3];
+
+	  from += 4;
+	  to_next += 4;
+	  n_left_from -= 4;
+	  n_left_to_next -= 4;
+
+	  next3 = next2 = next1 = next0 = L2_UU_FWD_NEXT_L2_OUTPUT;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+	  b1 = vlib_get_buffer (vm, bi1);
+	  b2 = vlib_get_buffer (vm, bi2);
+	  b3 = vlib_get_buffer (vm, bi3);
+
+	  bdc0 = vec_elt_at_index (l2input_main.bd_configs,
+				   vnet_buffer (b0)->l2.bd_index);
+	  bdc1 = vec_elt_at_index (l2input_main.bd_configs,
+				   vnet_buffer (b1)->l2.bd_index);
+	  bdc2 = vec_elt_at_index (l2input_main.bd_configs,
+				   vnet_buffer (b2)->l2.bd_index);
+	  bdc3 = vec_elt_at_index (l2input_main.bd_configs,
+				   vnet_buffer (b3)->l2.bd_index);
+
+	  ASSERT (~0 != bdc0->uu_fwd_sw_if_index);
+
+	  vnet_buffer (b0)->sw_if_index[VLIB_TX] = bdc0->uu_fwd_sw_if_index;
+	  vnet_buffer (b1)->sw_if_index[VLIB_TX] = bdc1->uu_fwd_sw_if_index;
+	  vnet_buffer (b2)->sw_if_index[VLIB_TX] = bdc2->uu_fwd_sw_if_index;
+	  vnet_buffer (b3)->sw_if_index[VLIB_TX] = bdc3->uu_fwd_sw_if_index;
+
+	  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE) &&
+			     (b0->flags & VLIB_BUFFER_IS_TRACED)))
+	    {
+	      l2_uu_fwd_trace_t *t;
+
+	      t = vlib_add_trace (vm, node, b0, sizeof (*t));
+	      t->sw_if_index = bdc0->uu_fwd_sw_if_index;
+	    }
+	  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE) &&
+			     (b1->flags & VLIB_BUFFER_IS_TRACED)))
+	    {
+	      l2_uu_fwd_trace_t *t;
+
+	      t = vlib_add_trace (vm, node, b1, sizeof (*t));
+	      t->sw_if_index = bdc1->uu_fwd_sw_if_index;
+	    }
+	  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE) &&
+			     (b1->flags & VLIB_BUFFER_IS_TRACED)))
+	    {
+	      l2_uu_fwd_trace_t *t;
+
+	      t = vlib_add_trace (vm, node, b2, sizeof (*t));
+	      t->sw_if_index = bdc2->uu_fwd_sw_if_index;
+	    }
+	  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE) &&
+			     (b1->flags & VLIB_BUFFER_IS_TRACED)))
+	    {
+	      l2_uu_fwd_trace_t *t;
+
+	      t = vlib_add_trace (vm, node, b3, sizeof (*t));
+	      t->sw_if_index = bdc3->uu_fwd_sw_if_index;
+	    }
+	  vlib_validate_buffer_enqueue_x4 (vm, node, next_index,
+					   to_next, n_left_to_next,
+					   bi0, bi1, bi2, bi3,
+					   next0, next1, next2, next3);
+	}
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+	  const l2_bridge_domain_t *bdc0;
+	  l2_uu_fwd_next_t next0;
+	  vlib_buffer_t *b0;
+	  u32 bi0;
+
+	  bi0 = from[0];
+	  to_next[0] = bi0;
+	  from += 1;
+	  to_next += 1;
+	  n_left_from -= 1;
+	  n_left_to_next -= 1;
+	  next0 = L2_UU_FWD_NEXT_L2_OUTPUT;
+	  b0 = vlib_get_buffer (vm, bi0);
+
+	  bdc0 = vec_elt_at_index (l2input_main.bd_configs,
+				   vnet_buffer (b0)->l2.bd_index);
+	  ASSERT (~0 != bdc0->uu_fwd_sw_if_index);
+
+	  vnet_buffer (b0)->sw_if_index[VLIB_TX] = bdc0->uu_fwd_sw_if_index;
+
+	  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE) &&
+			     (b0->flags & VLIB_BUFFER_IS_TRACED)))
+	    {
+	      l2_uu_fwd_trace_t *t;
+
+	      t = vlib_add_trace (vm, node, b0, sizeof (*t));
+	      t->sw_if_index = bdc0->uu_fwd_sw_if_index;
+	    }
+	  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, node->node_index,
+			       L2_UU_FWD_ERROR_L2_UU_FWD, frame->n_vectors);
+
+  return frame->n_vectors;
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (l2_uu_fwd_node,static) = {
+  .function = l2_uu_fwd_node_fn,
+  .name = "l2-uu-fwd",
+  .vector_size = sizeof (u32),
+  .format_trace = format_l2_uu_fwd_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+
+  .n_errors = ARRAY_LEN(l2_uu_fwd_error_strings),
+  .error_strings = l2_uu_fwd_error_strings,
+
+  .n_next_nodes = L2_UU_FWD_N_NEXT,
+
+  .next_nodes = {
+        [L2_UU_FWD_NEXT_DROP] = "error-drop",
+        [L2_UU_FWD_NEXT_L2_OUTPUT] = "l2-output",
+  },
+};
+
+VLIB_NODE_FUNCTION_MULTIARCH (l2_uu_fwd_node, l2_uu_fwd_node_fn)
+/* *INDENT-ON* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/vnet/l2/l2_xcrw.c b/src/vnet/l2/l2_xcrw.c
index d08a5d8f8e8..334e8641455 100644
--- a/src/vnet/l2/l2_xcrw.c
+++ b/src/vnet/l2/l2_xcrw.c
@@ -366,8 +366,8 @@ vnet_configure_l2_xcrw (vlib_main_t * vm, vnet_main_t * vnm,
       if (vec_len (rewrite))
 	vnet_rewrite_set_data (a[0], rewrite, vec_len (rewrite));
 
-      set_int_l2_mode (vm, vnm, MODE_L2_XC, t->l2_sw_if_index, 0, 0, 0,
-		       t->tunnel_sw_if_index);
+      set_int_l2_mode (vm, vnm, MODE_L2_XC, t->l2_sw_if_index, 0,
+		       L2_BD_PORT_TYPE_NORMAL, 0, t->tunnel_sw_if_index);
       hash_set (xcm->tunnel_index_by_l2_sw_if_index,
 		t->l2_sw_if_index, t - xcm->tunnels);
       return 0;
@@ -384,7 +384,8 @@ vnet_configure_l2_xcrw (vlib_main_t * vm, vnet_main_t * vnm,
       /* Reset adj to drop traffic */
       memset (a, 0, sizeof (*a));
 
-      set_int_l2_mode (vm, vnm, MODE_L3, t->l2_sw_if_index, 0, 0, 0, 0);
+      set_int_l2_mode (vm, vnm, MODE_L3, t->l2_sw_if_index, 0,
+		       L2_BD_PORT_TYPE_NORMAL, 0, 0);
 
       vnet_sw_interface_set_flags (vnm, t->tunnel_sw_if_index, 0 /* down */ );