Typos. A bunch of typos I've been collecting.
[vpp.git] / src / vnet / ethernet / arp.c
index 711b786..12c3fa4 100644 (file)
  */
 
 #include <vnet/ip/ip.h>
+#include <vnet/ip/ip_neighbor.h>
 #include <vnet/ip/ip6.h>
 #include <vnet/ethernet/ethernet.h>
-#include <vnet/ethernet/arp_packet.h>
+#include <vnet/ethernet/arp.h>
 #include <vnet/l2/l2_input.h>
 #include <vppinfra/mhash.h>
 #include <vnet/fib/ip4_fib.h>
+#include <vnet/fib/fib_entry_src.h>
 #include <vnet/adj/adj_nbr.h>
 #include <vnet/adj/adj_mcast.h>
 #include <vnet/mpls/mpls.h>
+#include <vnet/l2/feat_bitmap.h>
 
 /**
  * @file
@@ -51,8 +54,8 @@ typedef struct ethernet_arp_interface_t_
 
 typedef struct
 {
-  u32 lo_addr;
-  u32 hi_addr;
+  ip4_address_t lo_addr;
+  ip4_address_t hi_addr;
   u32 fib_index;
 } ethernet_proxy_arp_t;
 
@@ -63,7 +66,7 @@ typedef struct
   uword type_opaque;
   uword data;
   /* Used for arp event notification only */
-  void *data_callback;
+  arp_change_event_cb_t data_callback;
   u32 pid;
 } pending_resolution_t;
 
@@ -91,6 +94,9 @@ typedef struct
 
   /* Proxy arp vector */
   ethernet_proxy_arp_t *proxy_arps;
+
+  uword wc_ip4_arp_publisher_node;
+  uword wc_ip4_arp_publisher_et;
 } ethernet_arp_main_t;
 
 static ethernet_arp_main_t ethernet_arp_main;
@@ -98,15 +104,21 @@ static ethernet_arp_main_t ethernet_arp_main;
 typedef struct
 {
   u32 sw_if_index;
-  ethernet_arp_ip4_over_ethernet_address_t a;
-  int is_static;
-  int is_no_fib_entry;
-  int flags;
+  ip4_address_t ip4;
+  mac_address_t mac;
+  ip_neighbor_flags_t nbr_flags;
+  u32 flags;
 #define ETHERNET_ARP_ARGS_REMOVE (1<<0)
 #define ETHERNET_ARP_ARGS_FLUSH  (1<<1)
 #define ETHERNET_ARP_ARGS_POPULATE  (1<<2)
+#define ETHERNET_ARP_ARGS_WC_PUB  (1<<3)
 } vnet_arp_set_ip4_over_ethernet_rpc_args_t;
 
+static const u8 vrrp_prefix[] = { 0x00, 0x00, 0x5E, 0x00, 0x01 };
+
+/* Node index for send_garp_na_process */
+u32 send_garp_na_process_node_index;
+
 static void
 set_ip4_over_ethernet_rpc_callback (vnet_arp_set_ip4_over_ethernet_rpc_args_t
                                    * a);
@@ -193,7 +205,7 @@ format_ethernet_arp_header (u8 * s, va_list * va)
 {
   ethernet_arp_header_t *a = va_arg (*va, ethernet_arp_header_t *);
   u32 max_header_bytes = va_arg (*va, u32);
-  uword indent;
+  u32 indent;
   u16 l2_type, l3_type;
 
   if (max_header_bytes != 0 && sizeof (a[0]) > max_header_bytes)
@@ -215,9 +227,9 @@ format_ethernet_arp_header (u8 * s, va_list * va)
     {
       s = format (s, "\n%U%U/%U -> %U/%U",
                  format_white_space, indent,
-                 format_ethernet_address, a->ip4_over_ethernet[0].ethernet,
+                 format_mac_address_t, &a->ip4_over_ethernet[0].mac,
                  format_ip4_address, &a->ip4_over_ethernet[0].ip4,
-                 format_ethernet_address, a->ip4_over_ethernet[1].ethernet,
+                 format_mac_address_t, &a->ip4_over_ethernet[1].mac,
                  format_ip4_address, &a->ip4_over_ethernet[1].ip4);
     }
   else
@@ -249,20 +261,20 @@ format_ethernet_arp_ip4_entry (u8 * s, va_list * va)
 
   si = vnet_get_sw_interface (vnm, e->sw_if_index);
 
-  if (e->flags & ETHERNET_ARP_IP4_ENTRY_FLAG_STATIC)
+  if (e->flags & IP_NEIGHBOR_FLAG_STATIC)
     flags = format (flags, "S");
 
-  if (e->flags & ETHERNET_ARP_IP4_ENTRY_FLAG_DYNAMIC)
+  if (e->flags & IP_NEIGHBOR_FLAG_DYNAMIC)
     flags = format (flags, "D");
 
-  if (e->flags & ETHERNET_ARP_IP4_ENTRY_FLAG_NO_FIB_ENTRY)
+  if (e->flags & IP_NEIGHBOR_FLAG_NO_FIB_ENTRY)
     flags = format (flags, "N");
 
-  s = format (s, "%=12U%=16U%=6s%=20U%=24U",
-             format_vlib_cpu_time, vnm->vlib_main, e->cpu_time_last_updated,
+  s = format (s, "%=12U%=16U%=6s%=20U%U",
+             format_vlib_time, vnm->vlib_main, e->time_last_updated,
              format_ip4_address, &e->ip4_address,
              flags ? (char *) flags : "",
-             format_ethernet_address, e->ethernet_address,
+             format_mac_address_t, &e->mac,
              format_vnet_sw_interface_name, vnm, si);
 
   vec_free (flags);
@@ -342,11 +354,12 @@ arp_nbr_probe (ip_adjacency_t * adj)
   h =
     vlib_packet_template_get_packet (vm, &im->ip4_arp_request_packet_template,
                                     &bi);
+  if (!h)
+    return;
 
   hi = vnet_get_sup_hw_interface (vnm, adj->rewrite_header.sw_if_index);
 
-  clib_memcpy (h->ip4_over_ethernet[0].ethernet,
-              hi->hw_address, sizeof (h->ip4_over_ethernet[0].ethernet));
+  mac_address_from_bytes (&h->ip4_over_ethernet[0].mac, hi->hw_address);
 
   h->ip4_over_ethernet[0].ip4 = src[0];
   h->ip4_over_ethernet[1].ip4 = adj->sub_type.nbr.next_hop.ip4;
@@ -375,7 +388,7 @@ arp_mk_complete (adj_index_t ai, ethernet_arp_ip4_entry_t * e)
     (ai, ADJ_NBR_REWRITE_FLAG_COMPLETE,
      ethernet_build_rewrite (vnet_get_main (),
                             e->sw_if_index,
-                            adj_get_link_type (ai), e->ethernet_address));
+                            adj_get_link_type (ai), &e->mac));
 }
 
 static void
@@ -445,8 +458,10 @@ arp_update_adjacency (vnet_main_t * vnm, u32 sw_if_index, u32 ai)
 
   switch (adj->lookup_next_index)
     {
-    case IP_LOOKUP_NEXT_ARP:
     case IP_LOOKUP_NEXT_GLEAN:
+      adj_glean_update_rewrite (ai);
+      break;
+    case IP_LOOKUP_NEXT_ARP:
       if (NULL != e)
        {
          adj_nbr_walk_nh4 (sw_if_index,
@@ -478,6 +493,15 @@ arp_update_adjacency (vnet_main_t * vnm, u32 sw_if_index, u32 ai)
          arp_nbr_probe (adj);
        }
       break;
+    case IP_LOOKUP_NEXT_BCAST:
+      adj_nbr_update_rewrite (ai,
+                             ADJ_NBR_REWRITE_FLAG_COMPLETE,
+                             ethernet_build_rewrite
+                             (vnm,
+                              sw_if_index,
+                              VNET_LINK_IP4,
+                              VNET_REWRITE_FOR_SW_INTERFACE_ADDRESS_BROADCAST));
+      break;
     case IP_LOOKUP_NEXT_MCAST:
       {
        /*
@@ -496,10 +520,9 @@ arp_update_adjacency (vnet_main_t * vnm, u32 sw_if_index, u32 ai)
         * Complete the remaining fields of the adj's rewrite to direct the
         * complete of the rewrite at switch time by copying in the IP
         * dst address's bytes.
-        * Ofset is 2 bytes into the MAC desintation address. And we copy 23 bits
-        * from the address.
+        * Offset is 2 bytes into the MAC destination address.
         */
-       adj_mcast_update_rewrite (ai, rewrite, offset, 0x007fffff);
+       adj_mcast_update_rewrite (ai, rewrite, offset);
 
        break;
       }
@@ -507,7 +530,7 @@ arp_update_adjacency (vnet_main_t * vnm, u32 sw_if_index, u32 ai)
     case IP_LOOKUP_NEXT_PUNT:
     case IP_LOOKUP_NEXT_LOCAL:
     case IP_LOOKUP_NEXT_REWRITE:
-    case IP_LOOKUP_NEXT_LOAD_BALANCE:
+    case IP_LOOKUP_NEXT_MCAST_MIDCHAIN:
     case IP_LOOKUP_NEXT_MIDCHAIN:
     case IP_LOOKUP_NEXT_ICMP_ERROR:
     case IP_LOOKUP_N_NEXT:
@@ -516,22 +539,93 @@ arp_update_adjacency (vnet_main_t * vnm, u32 sw_if_index, u32 ai)
     }
 }
 
-int
+static void
+arp_adj_fib_add (ethernet_arp_ip4_entry_t * e, u32 fib_index)
+{
+  fib_prefix_t pfx = {
+    .fp_len = 32,
+    .fp_proto = FIB_PROTOCOL_IP4,
+    .fp_addr.ip4 = e->ip4_address,
+  };
+
+  e->fib_entry_index =
+    fib_table_entry_path_add (fib_index, &pfx, FIB_SOURCE_ADJ,
+                             FIB_ENTRY_FLAG_ATTACHED,
+                             DPO_PROTO_IP4, &pfx.fp_addr,
+                             e->sw_if_index, ~0, 1, NULL,
+                             FIB_ROUTE_PATH_FLAG_NONE);
+  fib_table_lock (fib_index, FIB_PROTOCOL_IP4, FIB_SOURCE_ADJ);
+}
+
+static void
+arp_adj_fib_remove (ethernet_arp_ip4_entry_t * e, u32 fib_index)
+{
+  if (FIB_NODE_INDEX_INVALID != e->fib_entry_index)
+    {
+      fib_prefix_t pfx = {
+       .fp_len = 32,
+       .fp_proto = FIB_PROTOCOL_IP4,
+       .fp_addr.ip4 = e->ip4_address,
+      };
+      u32 fib_index;
+
+      fib_index = ip4_fib_table_get_index_for_sw_if_index (e->sw_if_index);
+
+      fib_table_entry_path_remove (fib_index, &pfx,
+                                  FIB_SOURCE_ADJ,
+                                  DPO_PROTO_IP4,
+                                  &pfx.fp_addr,
+                                  e->sw_if_index, ~0, 1,
+                                  FIB_ROUTE_PATH_FLAG_NONE);
+      fib_table_unlock (fib_index, FIB_PROTOCOL_IP4, FIB_SOURCE_ADJ);
+    }
+}
+
+static ethernet_arp_ip4_entry_t *
+force_reuse_arp_entry (void)
+{
+  ethernet_arp_ip4_entry_t *e;
+  ethernet_arp_main_t *am = &ethernet_arp_main;
+  u32 count = 0;
+  u32 index = pool_next_index (am->ip4_entry_pool, am->arp_delete_rotor);
+  if (index == ~0)             /* Try again from elt 0 */
+    index = pool_next_index (am->ip4_entry_pool, index);
+
+  /* Find a non-static random entry to free up for reuse */
+  do
+    {
+      if ((count++ == 100) || (index == ~0))
+       return NULL;            /* give up after 100 entries */
+      e = pool_elt_at_index (am->ip4_entry_pool, index);
+      am->arp_delete_rotor = index;
+      index = pool_next_index (am->ip4_entry_pool, index);
+    }
+  while (e->flags & IP_NEIGHBOR_FLAG_STATIC);
+
+  /* Remove ARP entry from its interface and update fib */
+  hash_unset
+    (am->ethernet_arp_by_sw_if_index[e->sw_if_index].arp_entries,
+     e->ip4_address.as_u32);
+  arp_adj_fib_remove
+    (e, ip4_fib_table_get_index_for_sw_if_index (e->sw_if_index));
+  adj_nbr_walk_nh4 (e->sw_if_index,
+                   &e->ip4_address, arp_mk_incomplete_walk, e);
+  return e;
+}
+
+static int
 vnet_arp_set_ip4_over_ethernet_internal (vnet_main_t * vnm,
                                         vnet_arp_set_ip4_over_ethernet_rpc_args_t
                                         * args)
 {
   ethernet_arp_ip4_entry_t *e = 0;
   ethernet_arp_main_t *am = &ethernet_arp_main;
-  ethernet_arp_ip4_over_ethernet_address_t *a = &args->a;
   vlib_main_t *vm = vlib_get_main ();
   int make_new_arp_cache_entry = 1;
   uword *p;
   pending_resolution_t *pr, *mc;
   ethernet_arp_interface_t *arp_int;
-  int is_static = args->is_static;
   u32 sw_if_index = args->sw_if_index;
-  int is_no_fib_entry = args->is_no_fib_entry;
 
   vec_validate (am->ethernet_arp_by_sw_if_index, sw_if_index);
 
@@ -539,52 +633,56 @@ vnet_arp_set_ip4_over_ethernet_internal (vnet_main_t * vnm,
 
   if (NULL != arp_int->arp_entries)
     {
-      p = hash_get (arp_int->arp_entries, a->ip4.as_u32);
+      p = hash_get (arp_int->arp_entries, args->ip4.as_u32);
       if (p)
        {
          e = pool_elt_at_index (am->ip4_entry_pool, p[0]);
 
          /* Refuse to over-write static arp. */
-         if (!is_static && (e->flags & ETHERNET_ARP_IP4_ENTRY_FLAG_STATIC))
-           return -2;
+         if (!(args->nbr_flags & IP_NEIGHBOR_FLAG_STATIC) &&
+             (e->flags & IP_NEIGHBOR_FLAG_STATIC))
+           {
+             /* if MAC address match, still check to send event */
+             if (mac_address_equal (&e->mac, &args->mac))
+               goto check_customers;
+             return -2;
+           }
          make_new_arp_cache_entry = 0;
        }
     }
 
   if (make_new_arp_cache_entry)
     {
-      pool_get (am->ip4_entry_pool, e);
-
-      if (NULL == arp_int->arp_entries)
+      if (am->limit_arp_cache_size &&
+         pool_elts (am->ip4_entry_pool) >= am->limit_arp_cache_size)
        {
-         arp_int->arp_entries = hash_create (0, sizeof (u32));
+         e = force_reuse_arp_entry ();
+         if (NULL == e)
+           return -2;
        }
+      else
+       pool_get (am->ip4_entry_pool, e);
+
+      if (NULL == arp_int->arp_entries)
+       arp_int->arp_entries = hash_create (0, sizeof (u32));
 
-      hash_set (arp_int->arp_entries, a->ip4.as_u32, e - am->ip4_entry_pool);
+      hash_set (arp_int->arp_entries, args->ip4.as_u32,
+               e - am->ip4_entry_pool);
 
       e->sw_if_index = sw_if_index;
-      e->ip4_address = a->ip4;
-      clib_memcpy (e->ethernet_address,
-                  a->ethernet, sizeof (e->ethernet_address));
+      e->ip4_address = args->ip4;
+      e->fib_entry_index = FIB_NODE_INDEX_INVALID;
+      mac_address_copy (&e->mac, &args->mac);
 
-      if (!is_no_fib_entry)
+      if (!(args->nbr_flags & IP_NEIGHBOR_FLAG_NO_FIB_ENTRY))
        {
-         fib_prefix_t pfx = {
-           .fp_len = 32,
-           .fp_proto = FIB_PROTOCOL_IP4,
-           .fp_addr.ip4 = a->ip4,
-         };
-         u32 fib_index;
-
-         fib_index =
-           ip4_fib_table_get_index_for_sw_if_index (e->sw_if_index);
-         e->fib_entry_index =
-           fib_table_entry_update_one_path (fib_index, &pfx, FIB_SOURCE_ADJ,
-                                            FIB_ENTRY_FLAG_ATTACHED,
-                                            FIB_PROTOCOL_IP4, &pfx.fp_addr,
-                                            e->sw_if_index, ~0, 1, NULL,
-                                            FIB_ROUTE_PATH_FLAG_NONE);
-         e->flags |= ETHERNET_ARP_IP4_ENTRY_FLAG_NO_FIB_ENTRY;
+         arp_adj_fib_add (e,
+                          ip4_fib_table_get_index_for_sw_if_index
+                          (e->sw_if_index));
+       }
+      else
+       {
+         e->flags |= IP_NEIGHBOR_FLAG_NO_FIB_ENTRY;
        }
     }
   else
@@ -593,25 +691,34 @@ vnet_arp_set_ip4_over_ethernet_internal (vnet_main_t * vnm,
        * prevent a DoS attack from the data-plane that
        * spams us with no-op updates to the MAC address
        */
-      if (0 == memcmp (e->ethernet_address,
-                      a->ethernet, sizeof (e->ethernet_address)))
-       return -1;
+      if (mac_address_equal (&e->mac, &args->mac))
+       {
+         e->time_last_updated = vlib_time_now (vm);
+         goto check_customers;
+       }
 
-      /* Update time stamp and ethernet address. */
-      clib_memcpy (e->ethernet_address, a->ethernet,
-                  sizeof (e->ethernet_address));
+      /* Update ethernet address. */
+      mac_address_copy (&e->mac, &args->mac);
     }
 
-  e->cpu_time_last_updated = clib_cpu_time_now ();
-  if (is_static)
-    e->flags |= ETHERNET_ARP_IP4_ENTRY_FLAG_STATIC;
+  /* Update time stamp and flags. */
+  e->time_last_updated = vlib_time_now (vm);
+  if (args->nbr_flags & IP_NEIGHBOR_FLAG_STATIC)
+    {
+      e->flags &= ~IP_NEIGHBOR_FLAG_DYNAMIC;
+      e->flags |= IP_NEIGHBOR_FLAG_STATIC;
+    }
   else
-    e->flags |= ETHERNET_ARP_IP4_ENTRY_FLAG_DYNAMIC;
+    {
+      e->flags &= ~IP_NEIGHBOR_FLAG_STATIC;
+      e->flags |= IP_NEIGHBOR_FLAG_DYNAMIC;
+    }
 
   adj_nbr_walk_nh4 (sw_if_index, &e->ip4_address, arp_mk_complete_walk, e);
 
+check_customers:
   /* Customer(s) waiting for this address to be resolved? */
-  p = hash_get (am->pending_resolutions_by_address, a->ip4.as_u32);
+  p = hash_get (am->pending_resolutions_by_address, args->ip4.as_u32);
   if (p)
     {
       u32 next_index;
@@ -626,11 +733,11 @@ vnet_arp_set_ip4_over_ethernet_internal (vnet_main_t * vnm,
          pool_put (am->pending_resolutions, pr);
        }
 
-      hash_unset (am->pending_resolutions_by_address, a->ip4.as_u32);
+      hash_unset (am->pending_resolutions_by_address, args->ip4.as_u32);
     }
 
   /* Customer(s) requesting ARP event for this address? */
-  p = hash_get (am->mac_changes_by_address, a->ip4.as_u32);
+  p = hash_get (am->mac_changes_by_address, args->ip4.as_u32);
   if (p)
     {
       u32 next_index;
@@ -638,14 +745,12 @@ vnet_arp_set_ip4_over_ethernet_internal (vnet_main_t * vnm,
 
       while (next_index != (u32) ~ 0)
        {
-         int (*fp) (u32, u8 *, u32, u32);
          int rv = 1;
          mc = pool_elt_at_index (am->mac_changes, next_index);
-         fp = mc->data_callback;
 
          /* Call the user's data callback, return 1 to suppress dup events */
-         if (fp)
-           rv = (*fp) (mc->data, a->ethernet, sw_if_index, 0);
+         if (mc->data_callback)
+           rv = (mc->data_callback) (mc->data, &args->mac, sw_if_index, 0);
 
          /*
           * Signal the resolver process, as long as the user
@@ -694,7 +799,7 @@ vnet_register_ip4_arp_resolution_event (vnet_main_t * vnm,
 
 int
 vnet_add_del_ip4_arp_change_event (vnet_main_t * vnm,
-                                  void *data_callback,
+                                  arp_change_event_cb_t data_callback,
                                   u32 pid,
                                   void *address_arg,
                                   uword node_index,
@@ -702,76 +807,65 @@ vnet_add_del_ip4_arp_change_event (vnet_main_t * vnm,
 {
   ethernet_arp_main_t *am = &ethernet_arp_main;
   ip4_address_t *address = address_arg;
-  uword *p;
+
+  /* Try to find an existing entry */
+  u32 *first = (u32 *) hash_get (am->mac_changes_by_address, address->as_u32);
+  u32 *p = first;
   pending_resolution_t *mc;
-  void (*fp) (u32, u8 *) = data_callback;
+  while (p && *p != ~0)
+    {
+      mc = pool_elt_at_index (am->mac_changes, *p);
+      if (mc->node_index == node_index && mc->type_opaque == type_opaque
+         && mc->pid == pid)
+       break;
+      p = &mc->next_index;
+    }
 
+  int found = p && *p != ~0;
   if (is_add)
     {
-      pool_get (am->mac_changes, mc);
+      if (found)
+       return VNET_API_ERROR_ENTRY_ALREADY_EXISTS;
 
-      mc->next_index = ~0;
-      mc->node_index = node_index;
-      mc->type_opaque = type_opaque;
-      mc->data = data;
-      mc->data_callback = data_callback;
-      mc->pid = pid;
+      pool_get (am->mac_changes, mc);
+      /* *INDENT-OFF* */
+      *mc = (pending_resolution_t)
+      {
+        .next_index = ~0,
+        .node_index = node_index,
+        .type_opaque = type_opaque,
+        .data = data,
+        .data_callback = data_callback,
+        .pid = pid,
+      };
+      /* *INDENT-ON* */
 
-      p = hash_get (am->mac_changes_by_address, address->as_u32);
+      /* Insert new resolution at the end of the list */
+      u32 new_idx = mc - am->mac_changes;
       if (p)
-       {
-         /* Insert new resolution at the head of the list */
-         mc->next_index = p[0];
-         hash_unset (am->mac_changes_by_address, address->as_u32);
-       }
-
-      hash_set (am->mac_changes_by_address, address->as_u32,
-               mc - am->mac_changes);
-      return 0;
+       p[0] = new_idx;
+      else
+       hash_set (am->mac_changes_by_address, address->as_u32, new_idx);
     }
   else
     {
-      u32 index;
-      pending_resolution_t *mc_last = 0;
-
-      p = hash_get (am->mac_changes_by_address, address->as_u32);
-      if (p == 0)
+      if (!found)
        return VNET_API_ERROR_NO_SUCH_ENTRY;
 
-      index = p[0];
+      /* Clients may need to clean up pool entries, too */
+      if (data_callback)
+       /* no new mac addrs */
+       (data_callback) (mc->data, NULL, ~0, NULL);
 
-      while (index != (u32) ~ 0)
-       {
-         mc = pool_elt_at_index (am->mac_changes, index);
-         if (mc->node_index == node_index &&
-             mc->type_opaque == type_opaque && mc->pid == pid)
-           {
-             /* Clients may need to clean up pool entries, too */
-             if (fp)
-               (*fp) (mc->data, 0 /* no new mac addrs */ );
-             if (index == p[0])
-               {
-                 hash_unset (am->mac_changes_by_address, address->as_u32);
-                 if (mc->next_index != ~0)
-                   hash_set (am->mac_changes_by_address, address->as_u32,
-                             mc->next_index);
-                 pool_put (am->mac_changes, mc);
-                 return 0;
-               }
-             else
-               {
-                 ASSERT (mc_last);
-                 mc_last->next_index = mc->next_index;
-                 pool_put (am->mac_changes, mc);
-                 return 0;
-               }
-           }
-         mc_last = mc;
-         index = mc->next_index;
-       }
+      /* Remove the entry from the list and delete the entry */
+      *p = mc->next_index;
+      pool_put (am->mac_changes, mc);
 
-      return VNET_API_ERROR_NO_SUCH_ENTRY;
+      /* Remove from hash if we deleted the last entry */
+      if (*p == ~0 && p == first)
+       hash_unset (am->mac_changes_by_address, address->as_u32);
     }
+  return 0;
 }
 
 /* Either we drop the packet or we send a reply to the sender. */
@@ -788,16 +882,17 @@ typedef enum
   _ (l3_type_not_ip4, "L3 type not IP4")                               \
   _ (l3_src_address_not_local, "IP4 source address not local to subnet") \
   _ (l3_dst_address_not_local, "IP4 destination address not local to subnet") \
+  _ (l3_dst_address_unset, "IP4 destination address is unset")          \
   _ (l3_src_address_is_local, "IP4 source address matches local interface") \
   _ (l3_src_address_learned, "ARP request IP4 source address learned")  \
   _ (replies_received, "ARP replies received")                         \
   _ (opcode_not_request, "ARP opcode not request")                      \
   _ (proxy_arp_replies_sent, "Proxy ARP replies sent")                 \
   _ (l2_address_mismatch, "ARP hw addr does not match L2 frame src addr") \
-  _ (missing_interface_address, "ARP missing interface address") \
   _ (gratuitous_arp, "ARP probe or announcement dropped") \
   _ (interface_no_table, "Interface is not mapped to an IP table") \
   _ (interface_not_ip_enabled, "Interface is not IP enabled") \
+  _ (unnumbered_mismatch, "RX interface is unnumbered to different subnet") \
 
 typedef enum
 {
@@ -807,187 +902,40 @@ typedef enum
     ETHERNET_ARP_N_ERROR,
 } ethernet_arp_input_error_t;
 
-
-static void
-unset_random_arp_entry (void)
-{
-  ethernet_arp_main_t *am = &ethernet_arp_main;
-  ethernet_arp_ip4_entry_t *e;
-  vnet_main_t *vnm = vnet_get_main ();
-  ethernet_arp_ip4_over_ethernet_address_t delme;
-  u32 index;
-
-  index = pool_next_index (am->ip4_entry_pool, am->arp_delete_rotor);
-  am->arp_delete_rotor = index;
-
-  /* Try again from elt 0, could happen if an intfc goes down */
-  if (index == ~0)
-    {
-      index = pool_next_index (am->ip4_entry_pool, am->arp_delete_rotor);
-      am->arp_delete_rotor = index;
-    }
-
-  /* Nothing left in the pool */
-  if (index == ~0)
-    return;
-
-  e = pool_elt_at_index (am->ip4_entry_pool, index);
-
-  clib_memcpy (&delme.ethernet, e->ethernet_address, 6);
-  delme.ip4.as_u32 = e->ip4_address.as_u32;
-
-  vnet_arp_unset_ip4_over_ethernet (vnm, e->sw_if_index, &delme);
-}
-
 static int
 arp_unnumbered (vlib_buffer_t * p0,
-               u32 pi0, ethernet_header_t * eth0, u32 sw_if_index)
+               u32 input_sw_if_index, u32 conn_sw_if_index)
 {
-  vlib_main_t *vm = vlib_get_main ();
   vnet_main_t *vnm = vnet_get_main ();
   vnet_interface_main_t *vim = &vnm->interface_main;
   vnet_sw_interface_t *si;
-  vnet_hw_interface_t *hi;
-  u32 unnum_src_sw_if_index;
-  u32 *broadcast_swifs = 0;
-  u32 *buffers = 0;
-  u32 n_alloc = 0;
-  vlib_buffer_t *b0;
-  int i;
-  u8 dst_mac_address[6];
-  i16 header_size;
-  ethernet_arp_header_t *arp0;
-
-  /* Save the dst mac address */
-  clib_memcpy (dst_mac_address, eth0->dst_address, sizeof (dst_mac_address));
 
-  /* Figure out which sw_if_index supplied the address */
-  unnum_src_sw_if_index = sw_if_index;
+  /* verify that the input interface is unnumbered to the connected.
+   * the connected interface is the interface on which the subnet is
+   * configured */
+  si = &vim->sw_interfaces[input_sw_if_index];
 
-  /* Track down all users of the unnumbered source */
-  /* *INDENT-OFF* */
-  pool_foreach (si, vim->sw_interfaces,
-  ({
-    if (si->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED &&
-       (si->unnumbered_sw_if_index == unnum_src_sw_if_index))
-      {
-       vec_add1 (broadcast_swifs, si->sw_if_index);
-      }
-  }));
-  /* *INDENT-ON* */
-
-  /* If there are no interfaces un-unmbered to this interface,
-     we are done  here. */
-  if (0 == vec_len (broadcast_swifs))
-    return 0;
-
-  /* Allocate buffering if we need it */
-  if (vec_len (broadcast_swifs) > 1)
+  if (!(si->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED &&
+       (si->unnumbered_sw_if_index == conn_sw_if_index)))
     {
-      vec_validate (buffers, vec_len (broadcast_swifs) - 2);
-      n_alloc = vlib_buffer_alloc (vm, buffers, vec_len (buffers));
-      _vec_len (buffers) = n_alloc;
-      for (i = 0; i < n_alloc; i++)
-       {
-         b0 = vlib_get_buffer (vm, buffers[i]);
-
-         /* xerox (partially built) ARP pkt */
-         clib_memcpy (b0->data, p0->data,
-                      p0->current_length + p0->current_data);
-         b0->current_data = p0->current_data;
-         b0->current_length = p0->current_length;
-         vnet_buffer (b0)->sw_if_index[VLIB_RX] =
-           vnet_buffer (p0)->sw_if_index[VLIB_RX];
-       }
-    }
-
-  vec_insert (buffers, 1, 0);
-  buffers[0] = pi0;
-
-  for (i = 0; i < vec_len (buffers); i++)
-    {
-      b0 = vlib_get_buffer (vm, buffers[i]);
-      arp0 = vlib_buffer_get_current (b0);
-
-      hi = vnet_get_sup_hw_interface (vnm, broadcast_swifs[i]);
-      si = vnet_get_sw_interface (vnm, broadcast_swifs[i]);
-
-      /* For decoration, most likely */
-      vnet_buffer (b0)->sw_if_index[VLIB_TX] = hi->sw_if_index;
-
-      /* Fix ARP pkt src address */
-      clib_memcpy (arp0->ip4_over_ethernet[0].ethernet, hi->hw_address, 6);
-
-      /* Build L2 encaps for this swif */
-      header_size = sizeof (ethernet_header_t);
-      if (si->sub.eth.flags.one_tag)
-       header_size += 4;
-      else if (si->sub.eth.flags.two_tags)
-       header_size += 8;
-
-      vlib_buffer_advance (b0, -header_size);
-      eth0 = vlib_buffer_get_current (b0);
-
-      if (si->sub.eth.flags.one_tag)
-       {
-         ethernet_vlan_header_t *outer = (void *) (eth0 + 1);
-
-         eth0->type = si->sub.eth.flags.dot1ad ?
-           clib_host_to_net_u16 (ETHERNET_TYPE_DOT1AD) :
-           clib_host_to_net_u16 (ETHERNET_TYPE_VLAN);
-         outer->priority_cfi_and_id =
-           clib_host_to_net_u16 (si->sub.eth.outer_vlan_id);
-         outer->type = clib_host_to_net_u16 (ETHERNET_TYPE_ARP);
-
-       }
-      else if (si->sub.eth.flags.two_tags)
-       {
-         ethernet_vlan_header_t *outer = (void *) (eth0 + 1);
-         ethernet_vlan_header_t *inner = (void *) (outer + 1);
-
-         eth0->type = si->sub.eth.flags.dot1ad ?
-           clib_host_to_net_u16 (ETHERNET_TYPE_DOT1AD) :
-           clib_host_to_net_u16 (ETHERNET_TYPE_VLAN);
-         outer->priority_cfi_and_id =
-           clib_host_to_net_u16 (si->sub.eth.outer_vlan_id);
-         outer->type = clib_host_to_net_u16 (ETHERNET_TYPE_VLAN);
-         inner->priority_cfi_and_id =
-           clib_host_to_net_u16 (si->sub.eth.inner_vlan_id);
-         inner->type = clib_host_to_net_u16 (ETHERNET_TYPE_ARP);
-
-       }
-      else
-       {
-         eth0->type = clib_host_to_net_u16 (ETHERNET_TYPE_ARP);
-       }
-
-      /* Restore the original dst address, set src address */
-      clib_memcpy (eth0->dst_address, dst_mac_address,
-                  sizeof (eth0->dst_address));
-      clib_memcpy (eth0->src_address, hi->hw_address,
-                  sizeof (eth0->src_address));
-
-      /* Transmit replicas */
-      if (i > 0)
-       {
-         vlib_frame_t *f =
-           vlib_get_frame_to_node (vm, hi->output_node_index);
-         u32 *to_next = vlib_frame_vector_args (f);
-         to_next[0] = buffers[i];
-         f->n_vectors = 1;
-         vlib_put_frame_to_node (vm, hi->output_node_index, f);
-       }
+      /* the input interface is not unnumbered to the interface on which
+       * the sub-net is configured that covers the ARP request.
+       * So this is not the case for unnumbered.. */
+      return 0;
     }
 
-  /* The regular path outputs the original pkt.. */
-  vnet_buffer (p0)->sw_if_index[VLIB_TX] = broadcast_swifs[0];
-
-  vec_free (broadcast_swifs);
-  vec_free (buffers);
-
   return !0;
 }
 
+static u32
+arp_learn (vnet_main_t * vnm,
+          ethernet_arp_main_t * am, u32 sw_if_index,
+          const ethernet_arp_ip4_over_ethernet_address_t * addr)
+{
+  vnet_arp_set_ip4_over_ethernet (vnm, sw_if_index, addr, 0);
+  return (ETHERNET_ARP_ERROR_l3_src_address_learned);
+}
+
 static uword
 arp_input (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
 {
@@ -1017,14 +965,16 @@ arp_input (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
          vlib_buffer_t *p0;
          vnet_hw_interface_t *hw_if0;
          ethernet_arp_header_t *arp0;
-         ethernet_header_t *eth0;
-         ip4_address_t *if_addr0, proxy_src;
+         ethernet_header_t *eth_rx, *eth_tx;
+         const ip4_address_t *if_addr0;
+         ip4_address_t proxy_src;
          u32 pi0, error0, next0, sw_if_index0, conn_sw_if_index0, fib_index0;
-         u8 is_request0, dst_is_local0, is_unnum0;
+         u8 is_request0, dst_is_local0, is_unnum0, is_vrrp_reply0;
          ethernet_proxy_arp_t *pa;
          fib_node_index_t dst_fei, src_fei;
-         fib_prefix_t pfx0;
+         const fib_prefix_t *pfx0;
          fib_entry_flag_t src_flags, dst_flags;
+         u8 *rewrite0, rewrite0_len;
 
          pi0 = from[0];
          to_next[0] = pi0;
@@ -1036,6 +986,8 @@ arp_input (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
 
          p0 = vlib_get_buffer (vm, pi0);
          arp0 = vlib_buffer_get_current (p0);
+         /* Fill in ethernet header. */
+         eth_rx = ethernet_buffer_get_header (p0);
 
          is_request0 = arp0->opcode
            == clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_request);
@@ -1050,6 +1002,9 @@ arp_input (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
            (arp0->l3_type !=
             clib_net_to_host_u16 (ETHERNET_TYPE_IP4) ?
             ETHERNET_ARP_ERROR_l3_type_not_ip4 : error0);
+         error0 =
+           (0 == arp0->ip4_over_ethernet[0].ip4.as_u32 ?
+            ETHERNET_ARP_ERROR_l3_dst_address_unset : error0);
 
          sw_if_index0 = vnet_buffer (p0)->sw_if_index[VLIB_RX];
 
@@ -1074,94 +1029,204 @@ arp_input (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
                                          32);
          dst_flags = fib_entry_get_flags (dst_fei);
 
-         src_fei = ip4_fib_table_lookup (ip4_fib_get (fib_index0),
-                                         &arp0->ip4_over_ethernet[0].ip4,
-                                         32);
-         src_flags = fib_entry_get_flags (src_fei);
-
          conn_sw_if_index0 = fib_entry_get_resolving_interface (dst_fei);
 
-         if (!(FIB_ENTRY_FLAG_CONNECTED & dst_flags))
-           {
-             error0 = ETHERNET_ARP_ERROR_l3_dst_address_not_local;
-             goto drop1;
-           }
-
          /* Honor unnumbered interface, if any */
          is_unnum0 = sw_if_index0 != conn_sw_if_index0;
 
-         /* Source must also be local to subnet of matching interface address. */
-         if (!((FIB_ENTRY_FLAG_ATTACHED & src_flags) ||
-               (FIB_ENTRY_FLAG_CONNECTED & src_flags)))
+         {
+           /*
+            * we're looking for FIB entries that indicate the source
+            * is attached. There may be more specific non-attached
+            * routes that match the source, but these do not influence
+            * whether we respond to an ARP request, i.e. they do not
+            * influence whether we are the correct way for the sender
+            * to reach us, they only affect how we reach the sender.
+            */
+           fib_entry_t *src_fib_entry;
+           const fib_prefix_t *pfx;
+           fib_entry_src_t *src;
+           fib_source_t source;
+           int attached;
+           int mask;
+
+           mask = 32;
+           attached = 0;
+
+           do
+             {
+               src_fei = ip4_fib_table_lookup (ip4_fib_get (fib_index0),
+                                               &arp0->
+                                               ip4_over_ethernet[0].ip4,
+                                               mask);
+               src_fib_entry = fib_entry_get (src_fei);
+
+               /*
+                * It's possible that the source that provides the
+                * flags we need, or the flags we must not have,
+                * is not the best source, so check then all.
+                */
+                /* *INDENT-OFF* */
+                FOR_EACH_SRC_ADDED(src_fib_entry, src, source,
+                ({
+                  src_flags = fib_entry_get_flags_for_source (src_fei, source);
+
+                  /* Reject requests/replies with our local interface
+                     address. */
+                  if (FIB_ENTRY_FLAG_LOCAL & src_flags)
+                    {
+                      error0 = ETHERNET_ARP_ERROR_l3_src_address_is_local;
+                      /*
+                       * When VPP has an interface whose address is also
+                       * applied to a TAP interface on the host, then VPP's
+                       * TAP interface will be unnumbered  to the 'real'
+                       * interface and do proxy ARP from the host.
+                       * The curious aspect of this setup is that ARP requests
+                       * from the host will come from the VPP's own address.
+                       * So don't drop immediately here, instead go see if this
+                       * is a proxy ARP case.
+                       */
+                      goto drop1;
+                    }
+                  /* A Source must also be local to subnet of matching
+                   * interface address. */
+                  if ((FIB_ENTRY_FLAG_ATTACHED & src_flags) ||
+                      (FIB_ENTRY_FLAG_CONNECTED & src_flags))
+                    {
+                      attached = 1;
+                      break;
+                    }
+                  /*
+                   * else
+                   *  The packet was sent from an address that is not
+                   *  connected nor attached i.e. it is not from an
+                   *  address that is covered by a link's sub-net,
+                   *  nor is it a already learned host resp.
+                   */
+                }));
+                /* *INDENT-ON* */
+
+               /*
+                * shorter mask lookup for the next iteration.
+                */
+               pfx = fib_entry_get_prefix (src_fei);
+               mask = pfx->fp_len - 1;
+
+               /*
+                * continue until we hit the default route or we find
+                * the attached we are looking for. The most likely
+                * outcome is we find the attached with the first source
+                * on the first lookup.
+                */
+             }
+           while (!attached &&
+                  !fib_entry_is_sourced (src_fei, FIB_SOURCE_DEFAULT_ROUTE));
+
+           if (!attached)
+             {
+               /*
+                * the matching route is a not attached, i.e. it was
+                * added as a result of routing, rather than interface/ARP
+                * configuration. If the matching route is not a host route
+                * (i.e. a /32)
+                */
+               error0 = ETHERNET_ARP_ERROR_l3_src_address_not_local;
+               goto drop2;
+             }
+         }
+
+         if (fib_entry_is_sourced (dst_fei, FIB_SOURCE_ADJ))
            {
              /*
-              * The packet was sent from an address that is not connected nor attached
-              * i.e. it is not from an address that is covered by a link's sub-net,
-              * nor is it a already learned host resp.
+              * We matched an adj-fib on ths source subnet (a /32 previously
+              * added as a result of ARP). If this request is a gratuitous
+              * ARP, then learn from it.
+              * The check for matching an adj-fib, is to prevent hosts
+              * from spamming us with gratuitous ARPS that might otherwise
+              * blow our ARP cache
               */
-             error0 = ETHERNET_ARP_ERROR_l3_src_address_not_local;
+             if (arp0->ip4_over_ethernet[0].ip4.as_u32 ==
+                 arp0->ip4_over_ethernet[1].ip4.as_u32)
+               error0 = arp_learn (vnm, am, sw_if_index0,
+                                   &arp0->ip4_over_ethernet[0]);
              goto drop2;
            }
+         else if (!(FIB_ENTRY_FLAG_CONNECTED & dst_flags))
+           {
+             error0 = ETHERNET_ARP_ERROR_l3_dst_address_not_local;
+             goto drop1;
+           }
+
          if (sw_if_index0 != fib_entry_get_resolving_interface (src_fei))
            {
              /*
               * The interface the ARP was received on is not the interface
-              * on which the covering prefix is configured. Maybe this is a case
-              * for unnumbered.
+              * on which the covering prefix is configured. Maybe this is a
+              * case for unnumbered.
               */
              is_unnum0 = 1;
            }
 
-         /* Reject requests/replies with our local interface address. */
-         if (FIB_ENTRY_FLAG_LOCAL & src_flags)
-           {
-             error0 = ETHERNET_ARP_ERROR_l3_src_address_is_local;
-             goto drop2;
-           }
-
          dst_is_local0 = (FIB_ENTRY_FLAG_LOCAL & dst_flags);
-         fib_entry_get_prefix (dst_fei, &pfx0);
-         if_addr0 = &pfx0.fp_addr.ip4;
+         pfx0 = fib_entry_get_prefix (dst_fei);
+         if_addr0 = &pfx0->fp_addr.ip4;
 
-         /* Fill in ethernet header. */
-         eth0 = ethernet_buffer_get_header (p0);
+         is_vrrp_reply0 =
+           ((arp0->opcode ==
+             clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_reply))
+            &&
+            (!memcmp
+             (arp0->ip4_over_ethernet[0].mac.bytes, vrrp_prefix,
+              sizeof (vrrp_prefix))));
 
          /* Trash ARP packets whose ARP-level source addresses do not
-            match their L2-frame-level source addresses */
-         if (memcmp (eth0->src_address, arp0->ip4_over_ethernet[0].ethernet,
-                     sizeof (eth0->src_address)))
+            match their L2-frame-level source addresses, unless it's
+            a reply from a VRRP virtual router */
+         if (!ethernet_mac_address_equal
+             (eth_rx->src_address,
+              arp0->ip4_over_ethernet[0].mac.bytes) && !is_vrrp_reply0)
            {
              error0 = ETHERNET_ARP_ERROR_l2_address_mismatch;
              goto drop2;
            }
 
-         /* Learn or update sender's mapping only for requests or unicasts
-            that don't match local interface address. */
-         if (ethernet_address_cast (eth0->dst_address) ==
-             ETHERNET_ADDRESS_UNICAST || is_request0)
+         /* Learn or update sender's mapping only for replies to addresses
+          * that are local to the subnet */
+         if (arp0->opcode ==
+             clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_reply))
            {
-             if (am->limit_arp_cache_size &&
-                 pool_elts (am->ip4_entry_pool) >= am->limit_arp_cache_size)
-               unset_random_arp_entry ();
-
-             vnet_arp_set_ip4_over_ethernet (vnm, sw_if_index0,
-                                             &arp0->ip4_over_ethernet[0],
-                                             0 /* is_static */ , 0);
-             error0 = ETHERNET_ARP_ERROR_l3_src_address_learned;
-           }
+             if (dst_is_local0)
+               error0 = arp_learn (vnm, am, sw_if_index0,
+                                   &arp0->ip4_over_ethernet[0]);
+             else
+               /* a reply for a non-local destination could be a GARP.
+                * GARPs for hosts we know were handled above, so this one
+                * we drop */
+               error0 = ETHERNET_ARP_ERROR_l3_dst_address_not_local;
 
-         /* Only send a reply for requests sent which match a local interface. */
-         if (!(is_request0 && dst_is_local0))
+             goto drop1;
+           }
+         else if (arp0->opcode ==
+                  clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_request) &&
+                  (dst_is_local0 == 0))
            {
-             error0 =
-               (arp0->opcode ==
-                clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_reply) ?
-                ETHERNET_ARP_ERROR_replies_received : error0);
              goto drop1;
            }
 
-         /* Send a reply. */
        send_reply:
+         /* Send a reply.
+            An adjacency to the sender is not always present,
+            so we use the interface to build us a rewrite string
+            which will contain all the necessary tags. */
+         rewrite0 = ethernet_build_rewrite (vnm, sw_if_index0,
+                                            VNET_LINK_ARP,
+                                            eth_rx->src_address);
+         rewrite0_len = vec_len (rewrite0);
+
+         /* Figure out how much to rewind current data from adjacency. */
+         vlib_buffer_advance (p0, -rewrite0_len);
+         eth_tx = vlib_buffer_get_current (p0);
+
          vnet_buffer (p0)->sw_if_index[VLIB_TX] = sw_if_index0;
          hw_if0 = vnet_get_sup_hw_interface (vnm, sw_if_index0);
 
@@ -1173,77 +1238,38 @@ arp_input (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
 
          arp0->ip4_over_ethernet[1] = arp0->ip4_over_ethernet[0];
 
-         clib_memcpy (arp0->ip4_over_ethernet[0].ethernet,
-                      hw_if0->hw_address, 6);
+         mac_address_from_bytes (&arp0->ip4_over_ethernet[0].mac,
+                                 hw_if0->hw_address);
          clib_mem_unaligned (&arp0->ip4_over_ethernet[0].ip4.data_u32, u32) =
            if_addr0->data_u32;
 
          /* Hardware must be ethernet-like. */
          ASSERT (vec_len (hw_if0->hw_address) == 6);
 
-         clib_memcpy (eth0->dst_address, eth0->src_address, 6);
-         clib_memcpy (eth0->src_address, hw_if0->hw_address, 6);
+         /* the rx nd tx ethernet headers wil overlap in the case
+          * when we received a tagged VLAN=0 packet, but we are sending
+          * back untagged */
+         clib_memcpy_fast (eth_tx, rewrite0, vec_len (rewrite0));
+         vec_free (rewrite0);
 
-         /* Figure out how much to rewind current data from adjacency. */
-         /* get the adj from the destination's covering connected */
          if (NULL == pa)
            {
              if (is_unnum0)
                {
-                 if (!arp_unnumbered (p0, pi0, eth0, conn_sw_if_index0))
-                   goto drop2;
-               }
-             else
-               {
-                 ip_adjacency_t *adj0 = NULL;
-                 adj_index_t ai;
-
-                 if (FIB_ENTRY_FLAG_ATTACHED & src_flags)
-                   {
-                     /*
-                      * If the source is attached use the adj from that source.
-                      */
-                     ai = fib_entry_get_adj (src_fei);
-                     if (ADJ_INDEX_INVALID != ai)
-                       {
-                         adj0 = adj_get (ai);
-                       }
-                   }
-                 else
+                 if (!arp_unnumbered (p0, sw_if_index0, conn_sw_if_index0))
                    {
-                     /*
-                      * Get the glean adj from the cover. This is presumably interface
-                      * sourced, and therefre needs to be a glean adj.
-                      */
-                     ai = fib_entry_get_adj_for_source
-                       (ip4_fib_table_lookup
-                        (ip4_fib_get (fib_index0),
-                         &arp0->ip4_over_ethernet[1].ip4, 31),
-                        FIB_SOURCE_INTERFACE);
-
-                     if (ADJ_INDEX_INVALID != ai)
-                       {
-                         adj0 = adj_get (ai);
-
-                         if (adj0->lookup_next_index == IP_LOOKUP_NEXT_GLEAN)
-                           {
-                             adj0 = NULL;
-                           }
-                       }
-                   }
-                 if (NULL != adj0)
-                   {
-                     vlib_buffer_advance (p0,
-                                          -adj0->rewrite_header.data_bytes);
-                   }
-                 else
-                   {
-                     error0 = ETHERNET_ARP_ERROR_missing_interface_address;
+                     error0 = ETHERNET_ARP_ERROR_unnumbered_mismatch;
                      goto drop2;
                    }
                }
            }
 
+         /* We are going to reply to this request, so, in the absence of
+            errors, learn the sender */
+         if (!error0)
+           error0 = arp_learn (vnm, am, sw_if_index0,
+                               &arp0->ip4_over_ethernet[1]);
+
          vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
                                           n_left_to_next, pi0, next0);
 
@@ -1251,9 +1277,8 @@ arp_input (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
          continue;
 
        drop1:
-         if (0 == arp0->ip4_over_ethernet[0].ip4.as_u32 ||
-             (arp0->ip4_over_ethernet[0].ip4.as_u32 ==
-              arp0->ip4_over_ethernet[1].ip4.as_u32))
+         if (arp0->ip4_over_ethernet[0].ip4.as_u32 ==
+             arp0->ip4_over_ethernet[1].ip4.as_u32)
            {
              error0 = ETHERNET_ARP_ERROR_gratuitous_arp;
              goto drop2;
@@ -1276,27 +1301,21 @@ arp_input (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
 
              vec_foreach (pa, am->proxy_arps)
              {
-               u32 lo_addr = clib_net_to_host_u32 (pa->lo_addr);
-               u32 hi_addr = clib_net_to_host_u32 (pa->hi_addr);
+               u32 lo_addr = clib_net_to_host_u32 (pa->lo_addr.as_u32);
+               u32 hi_addr = clib_net_to_host_u32 (pa->hi_addr.as_u32);
 
                /* an ARP request hit in the proxy-arp table? */
                if ((this_addr >= lo_addr && this_addr <= hi_addr) &&
                    (fib_index0 == pa->fib_index))
                  {
-                   eth0 = ethernet_buffer_get_header (p0);
                    proxy_src.as_u32 =
                      arp0->ip4_over_ethernet[1].ip4.data_u32;
 
                    /*
-                    * Rewind buffer, direct code above not to
-                    * think too hard about it.
+                    * change the interface address to the proxied
                     */
                    if_addr0 = &proxy_src;
                    is_unnum0 = 0;
-                   i32 ethernet_start =
-                     vnet_buffer (p0)->ethernet.start_of_ethernet_header;
-                   i32 rewind = p0->current_data - ethernet_start;
-                   vlib_buffer_advance (p0, -rewind);
                    n_proxy_arp_replies_sent++;
                    goto send_reply;
                  }
@@ -1364,6 +1383,13 @@ ip4_arp_entry_sort (void *a1, void *a2)
   return cmp;
 }
 
+ethernet_arp_ip4_entry_t *
+ip4_neighbors_pool (void)
+{
+  ethernet_arp_main_t *am = &ethernet_arp_main;
+  return am->ip4_entry_pool;
+}
+
 ethernet_arp_ip4_entry_t *
 ip4_neighbor_entries (u32 sw_if_index)
 {
@@ -1453,7 +1479,7 @@ typedef struct
   pg_edit_t opcode;
   struct
   {
-    pg_edit_t ethernet;
+    pg_edit_t mac;
     pg_edit_t ip4;
   } ip4_over_ethernet[2];
 } pg_ethernet_arp_header_t;
@@ -1468,9 +1494,9 @@ pg_ethernet_arp_header_init (pg_ethernet_arp_header_t * p)
   _(n_l2_address_bytes);
   _(n_l3_address_bytes);
   _(opcode);
-  _(ip4_over_ethernet[0].ethernet);
+  _(ip4_over_ethernet[0].mac);
   _(ip4_over_ethernet[0].ip4);
-  _(ip4_over_ethernet[1].ethernet);
+  _(ip4_over_ethernet[1].mac);
   _(ip4_over_ethernet[1].ip4);
 #undef _
 }
@@ -1496,11 +1522,11 @@ unformat_pg_arp_header (unformat_input_t * input, va_list * args)
                 unformat_pg_edit,
                 unformat_ethernet_arp_opcode_net_byte_order, &p->opcode,
                 unformat_pg_edit,
-                unformat_ethernet_address, &p->ip4_over_ethernet[0].ethernet,
+                unformat_mac_address_t, &p->ip4_over_ethernet[0].mac,
                 unformat_pg_edit,
                 unformat_ip4_address, &p->ip4_over_ethernet[0].ip4,
                 unformat_pg_edit,
-                unformat_ethernet_address, &p->ip4_over_ethernet[1].ethernet,
+                unformat_mac_address_t, &p->ip4_over_ethernet[1].mac,
                 unformat_pg_edit,
                 unformat_ip4_address, &p->ip4_over_ethernet[1].ip4))
     {
@@ -1525,14 +1551,17 @@ ip4_set_arp_limit (u32 arp_limit)
  */
 int
 vnet_arp_unset_ip4_over_ethernet (vnet_main_t * vnm,
-                                 u32 sw_if_index, void *a_arg)
+                                 u32 sw_if_index,
+                                 const
+                                 ethernet_arp_ip4_over_ethernet_address_t *
+                                 a)
 {
-  ethernet_arp_ip4_over_ethernet_address_t *a = a_arg;
-  vnet_arp_set_ip4_over_ethernet_rpc_args_t args;
-
-  args.sw_if_index = sw_if_index;
-  args.flags = ETHERNET_ARP_ARGS_REMOVE;
-  clib_memcpy (&args.a, a, sizeof (*a));
+  vnet_arp_set_ip4_over_ethernet_rpc_args_t args = {
+    .sw_if_index = sw_if_index,
+    .flags = ETHERNET_ARP_ARGS_REMOVE,
+    .ip4 = a->ip4,
+    .mac = a->mac,
+  };
 
   vl_api_rpc_call_main_thread (set_ip4_over_ethernet_rpc_callback,
                               (u8 *) & args, sizeof (args));
@@ -1540,48 +1569,93 @@ vnet_arp_unset_ip4_over_ethernet (vnet_main_t * vnm,
 }
 
 /**
- * @brief Internally generated event to flush the ARP cache on an
- * interface state change event.
- * A flush will remove dynamic ARP entries, and for statics remove the MAC
- * address from the corresponding adjacencies.
+ * @brief publish wildcard arp event
+ * @param sw_if_index The interface on which the ARP entries are acted
  */
 static int
-vnet_arp_flush_ip4_over_ethernet (vnet_main_t * vnm,
-                                 u32 sw_if_index, void *a_arg)
+vnet_arp_wc_publish (u32 sw_if_index,
+                    const ethernet_arp_ip4_over_ethernet_address_t * a)
 {
-  ethernet_arp_ip4_over_ethernet_address_t *a = a_arg;
-  vnet_arp_set_ip4_over_ethernet_rpc_args_t args;
-
-  args.sw_if_index = sw_if_index;
-  args.flags = ETHERNET_ARP_ARGS_FLUSH;
-  clib_memcpy (&args.a, a, sizeof (*a));
+  vnet_arp_set_ip4_over_ethernet_rpc_args_t args = {
+    .flags = ETHERNET_ARP_ARGS_WC_PUB,
+    .sw_if_index = sw_if_index,
+    .ip4 = a->ip4,
+    .mac = a->mac,
+  };
 
   vl_api_rpc_call_main_thread (set_ip4_over_ethernet_rpc_callback,
                               (u8 *) & args, sizeof (args));
   return 0;
 }
 
-/**
- * @brief Internally generated event to populate the ARP cache on an
- * interface state change event.
- * For static entries this will re-source the adjacencies.
- *
- * @param sw_if_index The interface on which the ARP entires are acted
- */
+static void
+vnet_arp_wc_publish_internal (vnet_main_t * vnm,
+                             vnet_arp_set_ip4_over_ethernet_rpc_args_t *
+                             args)
+{
+  vlib_main_t *vm = vlib_get_main ();
+  ethernet_arp_main_t *am = &ethernet_arp_main;
+  uword ni = am->wc_ip4_arp_publisher_node;
+  uword et = am->wc_ip4_arp_publisher_et;
+
+  if (ni == (uword) ~ 0)
+    return;
+  wc_arp_report_t *r =
+    vlib_process_signal_event_data (vm, ni, et, 1, sizeof *r);
+  r->ip.as_u32 = args->ip4.as_u32;
+  r->sw_if_index = args->sw_if_index;
+  mac_address_copy (&r->mac, &args->mac);
+}
+
+void
+wc_arp_set_publisher_node (uword node_index, uword event_type)
+{
+  ethernet_arp_main_t *am = &ethernet_arp_main;
+  am->wc_ip4_arp_publisher_node = node_index;
+  am->wc_ip4_arp_publisher_et = event_type;
+}
+
+static void
+arp_entry_free (ethernet_arp_interface_t * eai, ethernet_arp_ip4_entry_t * e);
+
 static int
-vnet_arp_populate_ip4_over_ethernet (vnet_main_t * vnm,
-                                    u32 sw_if_index, void *a_arg)
+vnet_arp_flush_ip4_over_ethernet_internal (vnet_main_t * vnm,
+                                          vnet_arp_set_ip4_over_ethernet_rpc_args_t
+                                          * args)
 {
-  ethernet_arp_ip4_over_ethernet_address_t *a = a_arg;
-  vnet_arp_set_ip4_over_ethernet_rpc_args_t args;
+  ethernet_arp_main_t *am = &ethernet_arp_main;
+  ethernet_arp_ip4_entry_t *e;
+  ethernet_arp_interface_t *eai;
 
-  args.sw_if_index = sw_if_index;
-  args.flags = ETHERNET_ARP_ARGS_POPULATE;
-  clib_memcpy (&args.a, a, sizeof (*a));
+  if (vec_len (am->ethernet_arp_by_sw_if_index) <= args->sw_if_index)
+    return 0;
 
-  vl_api_rpc_call_main_thread (set_ip4_over_ethernet_rpc_callback,
-                              (u8 *) & args, sizeof (args));
-  return 0;
+  eai = &am->ethernet_arp_by_sw_if_index[args->sw_if_index];
+
+  e = arp_entry_find (eai, &args->ip4);
+
+  if (NULL != e)
+    {
+      adj_nbr_walk_nh4 (e->sw_if_index,
+                       &e->ip4_address, arp_mk_incomplete_walk, e);
+
+      /*
+       * The difference between flush and unset, is that an unset
+       * means delete for static and dynamic entries. A flush
+       * means delete only for dynamic. Flushing is what the DP
+       * does in response to interface events. unset is only done
+       * by the control plane.
+       */
+      if (e->flags & IP_NEIGHBOR_FLAG_STATIC)
+       {
+         e->flags &= ~IP_NEIGHBOR_FLAG_DYNAMIC;
+       }
+      else if (e->flags & IP_NEIGHBOR_FLAG_DYNAMIC)
+       {
+         arp_entry_free (eai, e);
+       }
+    }
+  return (0);
 }
 
 /*
@@ -1630,20 +1704,58 @@ arp_add_del_interface_address (ip4_main_t * im,
 
       for (i = 0; i < vec_len (to_delete); i++)
        {
-         ethernet_arp_ip4_over_ethernet_address_t delme;
          e = pool_elt_at_index (am->ip4_entry_pool, to_delete[i]);
 
-         clib_memcpy (&delme.ethernet, e->ethernet_address, 6);
-         delme.ip4.as_u32 = e->ip4_address.as_u32;
+         vnet_arp_set_ip4_over_ethernet_rpc_args_t delme = {
+           .ip4.as_u32 = e->ip4_address.as_u32,
+           .sw_if_index = e->sw_if_index,
+           .flags = ETHERNET_ARP_ARGS_FLUSH,
+         };
+         mac_address_copy (&delme.mac, &e->mac);
 
-         vnet_arp_flush_ip4_over_ethernet (vnet_get_main (),
-                                           e->sw_if_index, &delme);
+         vnet_arp_flush_ip4_over_ethernet_internal (vnet_get_main (),
+                                                    &delme);
        }
 
       vec_free (to_delete);
     }
 }
 
+static void
+arp_table_bind (ip4_main_t * im,
+               uword opaque,
+               u32 sw_if_index, u32 new_fib_index, u32 old_fib_index)
+{
+  ethernet_arp_main_t *am = &ethernet_arp_main;
+  ethernet_arp_interface_t *eai;
+  ethernet_arp_ip4_entry_t *e;
+  hash_pair_t *pair;
+
+  /*
+   * the IP table that the interface is bound to has changed.
+   * reinstall all the adj fibs.
+   */
+
+  if (vec_len (am->ethernet_arp_by_sw_if_index) <= sw_if_index)
+    return;
+
+  eai = &am->ethernet_arp_by_sw_if_index[sw_if_index];
+
+  /* *INDENT-OFF* */
+  hash_foreach_pair (pair, eai->arp_entries,
+  ({
+    e = pool_elt_at_index(am->ip4_entry_pool,
+                          pair->value[0]);
+    /*
+     * remove the adj-fib from the old table and add to the new
+     */
+    arp_adj_fib_remove(e, old_fib_index);
+    arp_adj_fib_add(e, new_fib_index);
+  }));
+  /* *INDENT-ON* */
+
+}
+
 static clib_error_t *
 ethernet_arp_init (vlib_main_t * vm)
 {
@@ -1670,6 +1782,7 @@ ethernet_arp_init (vlib_main_t * vm)
 
   am->pending_resolutions_by_address = hash_create (0, sizeof (uword));
   am->mac_changes_by_address = hash_create (0, sizeof (uword));
+  am->wc_ip4_arp_publisher_node = (uword) ~ 0;
 
   /* don't trace ARP error packets */
   {
@@ -1689,6 +1802,11 @@ ethernet_arp_init (vlib_main_t * vm)
   cb.function_opaque = 0;
   vec_add1 (im->add_del_interface_address_callbacks, cb);
 
+  ip4_table_bind_callback_t cbt;
+  cbt.function = arp_table_bind;
+  cbt.function_opaque = 0;
+  vec_add1 (im->table_bind_callbacks, cbt);
+
   return 0;
 }
 
@@ -1699,9 +1817,8 @@ arp_entry_free (ethernet_arp_interface_t * eai, ethernet_arp_ip4_entry_t * e)
 {
   ethernet_arp_main_t *am = &ethernet_arp_main;
 
-  /* it's safe to delete the ADJ source on the FIB entry, even if it
-   * was added */
-  fib_table_entry_delete_index (e->fib_entry_index, FIB_SOURCE_ADJ);
+  arp_adj_fib_remove
+    (e, ip4_fib_table_get_index_for_sw_if_index (e->sw_if_index));
   hash_unset (eai->arp_entries, e->ip4_address.as_u32);
   pool_put (am->ip4_entry_pool, e);
 }
@@ -1715,53 +1832,23 @@ vnet_arp_unset_ip4_over_ethernet_internal (vnet_main_t * vnm,
   ethernet_arp_ip4_entry_t *e;
   ethernet_arp_interface_t *eai;
 
+  if (vec_len (am->ethernet_arp_by_sw_if_index) <= args->sw_if_index)
+    return 0;
+
   eai = &am->ethernet_arp_by_sw_if_index[args->sw_if_index];
 
-  e = arp_entry_find (eai, &args->a.ip4);
+  e = arp_entry_find (eai, &args->ip4);
 
   if (NULL != e)
     {
-      arp_entry_free (eai, e);
-
       adj_nbr_walk_nh4 (e->sw_if_index,
-                       &e->ip4_address, arp_mk_incomplete_walk, NULL);
+                       &e->ip4_address, arp_mk_incomplete_walk, e);
+      arp_entry_free (eai, e);
     }
 
   return 0;
 }
 
-static int
-vnet_arp_flush_ip4_over_ethernet_internal (vnet_main_t * vnm,
-                                          vnet_arp_set_ip4_over_ethernet_rpc_args_t
-                                          * args)
-{
-  ethernet_arp_main_t *am = &ethernet_arp_main;
-  ethernet_arp_ip4_entry_t *e;
-  ethernet_arp_interface_t *eai;
-
-  eai = &am->ethernet_arp_by_sw_if_index[args->sw_if_index];
-
-  e = arp_entry_find (eai, &args->a.ip4);
-
-  if (NULL != e)
-    {
-      adj_nbr_walk_nh4 (e->sw_if_index,
-                       &e->ip4_address, arp_mk_incomplete_walk, e);
-
-      /*
-       * The difference between flush and unset, is that an unset
-       * means delete for static and dynamic entries. A flush
-       * means delete only for dynamic. Flushing is what the DP
-       * does in response to interface events. unset is only done
-       * by the control plane.
-       */
-      if (e->flags & ETHERNET_ARP_IP4_ENTRY_FLAG_DYNAMIC)
-       {
-         arp_entry_free (eai, e);
-       }
-    }
-  return (0);
-}
 
 static int
 vnet_arp_populate_ip4_over_ethernet_internal (vnet_main_t * vnm,
@@ -1772,9 +1859,10 @@ vnet_arp_populate_ip4_over_ethernet_internal (vnet_main_t * vnm,
   ethernet_arp_ip4_entry_t *e;
   ethernet_arp_interface_t *eai;
 
+  vec_validate (am->ethernet_arp_by_sw_if_index, args->sw_if_index);
   eai = &am->ethernet_arp_by_sw_if_index[args->sw_if_index];
 
-  e = arp_entry_find (eai, &args->a.ip4);
+  e = arp_entry_find (eai, &args->ip4);
 
   if (NULL != e)
     {
@@ -1789,7 +1877,7 @@ set_ip4_over_ethernet_rpc_callback (vnet_arp_set_ip4_over_ethernet_rpc_args_t
                                    * a)
 {
   vnet_main_t *vm = vnet_get_main ();
-  ASSERT (os_get_cpu_number () == 0);
+  ASSERT (vlib_get_thread_index () == 0);
 
   if (a->flags & ETHERNET_ARP_ARGS_REMOVE)
     vnet_arp_unset_ip4_over_ethernet_internal (vm, a);
@@ -1797,6 +1885,8 @@ set_ip4_over_ethernet_rpc_callback (vnet_arp_set_ip4_over_ethernet_rpc_args_t
     vnet_arp_flush_ip4_over_ethernet_internal (vm, a);
   else if (a->flags & ETHERNET_ARP_ARGS_POPULATE)
     vnet_arp_populate_ip4_over_ethernet_internal (vm, a);
+  else if (a->flags & ETHERNET_ARP_ARGS_WC_PUB)
+    vnet_arp_wc_publish_internal (vm, a);
   else
     vnet_arp_set_ip4_over_ethernet_internal (vm, a);
 }
@@ -1810,36 +1900,39 @@ ethernet_arp_sw_interface_up_down (vnet_main_t * vnm,
 {
   ethernet_arp_main_t *am = &ethernet_arp_main;
   ethernet_arp_ip4_entry_t *e;
-  u32 i, *to_delete = 0;
+  u32 i, *to_update = 0;
 
   /* *INDENT-OFF* */
   pool_foreach (e, am->ip4_entry_pool,
   ({
     if (e->sw_if_index == sw_if_index)
-      vec_add1 (to_delete,
+      vec_add1 (to_update,
                e - am->ip4_entry_pool);
   }));
   /* *INDENT-ON* */
 
-  for (i = 0; i < vec_len (to_delete); i++)
+  for (i = 0; i < vec_len (to_update); i++)
     {
-      ethernet_arp_ip4_over_ethernet_address_t delme;
-      e = pool_elt_at_index (am->ip4_entry_pool, to_delete[i]);
+      e = pool_elt_at_index (am->ip4_entry_pool, to_update[i]);
 
-      clib_memcpy (&delme.ethernet, e->ethernet_address, 6);
-      delme.ip4.as_u32 = e->ip4_address.as_u32;
+      vnet_arp_set_ip4_over_ethernet_rpc_args_t update_me = {
+       .ip4.as_u32 = e->ip4_address.as_u32,
+       .sw_if_index = e->sw_if_index,
+      };
+      mac_address_copy (&update_me.mac, &e->mac);
 
       if (flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP)
        {
-         vnet_arp_populate_ip4_over_ethernet (vnm, e->sw_if_index, &delme);
+         update_me.flags = ETHERNET_ARP_ARGS_POPULATE;
+         vnet_arp_populate_ip4_over_ethernet_internal (vnm, &update_me);
        }
       else
        {
-         vnet_arp_flush_ip4_over_ethernet (vnm, e->sw_if_index, &delme);
+         update_me.flags = ETHERNET_ARP_ARGS_FLUSH;
+         vnet_arp_flush_ip4_over_ethernet_internal (vnm, &update_me);
        }
-
     }
-  vec_free (to_delete);
+  vec_free (to_update);
 
   return 0;
 }
@@ -1862,32 +1955,45 @@ increment_ip4_and_mac_address (ethernet_arp_ip4_over_ethernet_address_t * a)
 
   for (i = 5; i >= 0; i--)
     {
-      old = a->ethernet[i];
-      a->ethernet[i] += 1;
-      if (old < a->ethernet[i])
+      old = a->mac.bytes[i];
+      a->mac.bytes[i] += 1;
+      if (old < a->mac.bytes[i])
        break;
     }
 }
 
 int
 vnet_arp_set_ip4_over_ethernet (vnet_main_t * vnm,
-                               u32 sw_if_index, void *a_arg,
-                               int is_static, int is_no_fib_entry)
+                               u32 sw_if_index,
+                               const ethernet_arp_ip4_over_ethernet_address_t
+                               * a, ip_neighbor_flags_t flags)
 {
-  ethernet_arp_ip4_over_ethernet_address_t *a = a_arg;
-  vnet_arp_set_ip4_over_ethernet_rpc_args_t args;
-
-  args.sw_if_index = sw_if_index;
-  args.is_static = is_static;
-  args.is_no_fib_entry = is_no_fib_entry;
-  args.flags = 0;
-  clib_memcpy (&args.a, a, sizeof (*a));
+  vnet_arp_set_ip4_over_ethernet_rpc_args_t args = {
+    .sw_if_index = sw_if_index,
+    .nbr_flags = flags,
+    .flags = 0,
+    .ip4.as_u32 = a->ip4.as_u32,
+    .mac = a->mac,
+  };
 
   vl_api_rpc_call_main_thread (set_ip4_over_ethernet_rpc_callback,
                               (u8 *) & args, sizeof (args));
   return 0;
 }
 
+void
+proxy_arp_walk (proxy_arp_walk_t cb, void *data)
+{
+  ethernet_arp_main_t *am = &ethernet_arp_main;
+  ethernet_proxy_arp_t *pa;
+
+  vec_foreach (pa, am->proxy_arps)
+  {
+    if (!cb (&pa->lo_addr, &pa->hi_addr, pa->fib_index, data))
+      break;
+  }
+}
+
 int
 vnet_proxy_arp_add_del (ip4_address_t * lo_addr,
                        ip4_address_t * hi_addr, u32 fib_index, int is_del)
@@ -1898,8 +2004,8 @@ vnet_proxy_arp_add_del (ip4_address_t * lo_addr,
 
   vec_foreach (pa, am->proxy_arps)
   {
-    if (pa->lo_addr == lo_addr->as_u32
-       && pa->hi_addr == hi_addr->as_u32 && pa->fib_index == fib_index)
+    if (pa->lo_addr.as_u32 == lo_addr->as_u32 &&
+       pa->hi_addr.as_u32 == hi_addr->as_u32 && pa->fib_index == fib_index)
       {
        found_at_index = pa - am->proxy_arps;
        break;
@@ -1919,31 +2025,28 @@ vnet_proxy_arp_add_del (ip4_address_t * lo_addr,
 
   /* add, not in table */
   vec_add2 (am->proxy_arps, pa, 1);
-  pa->lo_addr = lo_addr->as_u32;
-  pa->hi_addr = hi_addr->as_u32;
+  pa->lo_addr.as_u32 = lo_addr->as_u32;
+  pa->hi_addr.as_u32 = hi_addr->as_u32;
   pa->fib_index = fib_index;
   return 0;
 }
 
 /*
- * Remove any proxy arp entries asdociated with the
- * specificed fib.
+ * Remove any proxy arp entries associated with the
+ * specified fib.
  */
 int
 vnet_proxy_arp_fib_reset (u32 fib_id)
 {
-  ip4_main_t *im = &ip4_main;
   ethernet_arp_main_t *am = &ethernet_arp_main;
   ethernet_proxy_arp_t *pa;
   u32 *entries_to_delete = 0;
   u32 fib_index;
-  uword *p;
   int i;
 
-  p = hash_get (im->fib_index_by_table_id, fib_id);
-  if (!p)
+  fib_index = fib_table_find (FIB_PROTOCOL_IP4, fib_id);
+  if (~0 == fib_index)
     return VNET_API_ERROR_NO_SUCH_ENTRY;
-  fib_index = p[0];
 
   vec_foreach (pa, am->proxy_arps)
   {
@@ -1975,9 +2078,10 @@ ip_arp_add_del_command_fn (vlib_main_t * vm,
   int count = 1;
   u32 fib_index = 0;
   u32 fib_id;
-  int is_static = 0;
-  int is_no_fib_entry = 0;
   int is_proxy = 0;
+  ip_neighbor_flags_t flags;
+
+  flags = IP_NEIGHBOR_FLAG_NONE;
 
   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
     {
@@ -1985,28 +2089,27 @@ ip_arp_add_del_command_fn (vlib_main_t * vm,
       if (unformat (input, "%U %U %U",
                    unformat_vnet_sw_interface, vnm, &sw_if_index,
                    unformat_ip4_address, &addr.ip4,
-                   unformat_ethernet_address, &addr.ethernet))
+                   unformat_mac_address_t, &addr.mac))
        addr_valid = 1;
 
       else if (unformat (input, "delete") || unformat (input, "del"))
        is_del = 1;
 
       else if (unformat (input, "static"))
-       is_static = 1;
+       flags |= IP_NEIGHBOR_FLAG_STATIC;
 
       else if (unformat (input, "no-fib-entry"))
-       is_no_fib_entry = 1;
+       flags |= IP_NEIGHBOR_FLAG_NO_FIB_ENTRY;
 
       else if (unformat (input, "count %d", &count))
        ;
 
       else if (unformat (input, "fib-id %d", &fib_id))
        {
-         ip4_main_t *im = &ip4_main;
-         uword *p = hash_get (im->fib_index_by_table_id, fib_id);
-         if (!p)
+         fib_index = fib_table_find (FIB_PROTOCOL_IP4, fib_id);
+
+         if (~0 == fib_index)
            return clib_error_return (0, "fib ID %d doesn't exist\n", fib_id);
-         fib_index = p[0];
        }
 
       else if (unformat (input, "proxy %U - %U",
@@ -2039,8 +2142,7 @@ ip_arp_add_del_command_fn (vlib_main_t * vm,
                (vnm, &addr.ip4, vlib_current_process (vm),
                 1 /* type */ , 0 /* data */ );
 
-             vnet_arp_set_ip4_over_ethernet
-               (vnm, sw_if_index, &addr, is_static, is_no_fib_entry);
+             vnet_arp_set_ip4_over_ethernet (vnm, sw_if_index, &addr, flags);
 
              vlib_process_wait_for_event (vm);
              event_type = vlib_process_get_events (vm, &event_data);
@@ -2231,22 +2333,26 @@ arp_term_l2bd (vlib_main_t * vm,
          ethertype0 = clib_net_to_host_u16 (*(u16 *) (l3h0 - 2));
          arp0 = (ethernet_arp_header_t *) l3h0;
 
-         if (PREDICT_FALSE ((ethertype0 != ETHERNET_TYPE_ARP) ||
-                            (arp0->opcode !=
-                             clib_host_to_net_u16
-                             (ETHERNET_ARP_OPCODE_request))))
+         if (ethertype0 != ETHERNET_TYPE_ARP)
            goto check_ip6_nd;
 
-         /* Must be ARP request packet here */
+         if ((arp0->opcode !=
+              clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_request)) &&
+             (arp0->opcode !=
+              clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_reply)))
+           goto check_ip6_nd;
+
+         /* Must be ARP request/reply packet here */
          if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE) &&
                             (p0->flags & VLIB_BUFFER_IS_TRACED)))
            {
              u8 *t0 = vlib_add_trace (vm, node, p0,
                                       sizeof (ethernet_arp_input_trace_t));
-             clib_memcpy (t0, l3h0, sizeof (ethernet_arp_input_trace_t));
+             clib_memcpy_fast (t0, l3h0,
+                               sizeof (ethernet_arp_input_trace_t));
            }
 
-         error0 = ETHERNET_ARP_ERROR_replies_sent;
+         error0 = 0;
          error0 =
            (arp0->l2_type !=
             clib_net_to_host_u16 (ETHERNET_ARP_HARDWARE_TYPE_ethernet)
@@ -2262,43 +2368,33 @@ arp_term_l2bd (vlib_main_t * vm,
            goto drop;
 
          /* Trash ARP packets whose ARP-level source addresses do not
-            match their L2-frame-level source addresses  */
+            match, or if requester address is mcast */
          if (PREDICT_FALSE
-             (memcmp
-              (eth0->src_address, arp0->ip4_over_ethernet[0].ethernet,
-               sizeof (eth0->src_address))))
+             (!ethernet_mac_address_equal (eth0->src_address,
+                                           arp0->ip4_over_ethernet[0].
+                                           mac.bytes))
+             || ethernet_address_cast (arp0->ip4_over_ethernet[0].mac.bytes))
            {
-             error0 = ETHERNET_ARP_ERROR_l2_address_mismatch;
+             /* VRRP virtual MAC may be different to SMAC in ARP reply */
+             if (!ethernet_mac_address_equal
+                 (arp0->ip4_over_ethernet[0].mac.bytes, vrrp_prefix))
+               {
+                 error0 = ETHERNET_ARP_ERROR_l2_address_mismatch;
+                 goto drop;
+               }
+           }
+         if (PREDICT_FALSE
+             (ip4_address_is_multicast (&arp0->ip4_over_ethernet[0].ip4)))
+           {
+             error0 = ETHERNET_ARP_ERROR_l3_src_address_not_local;
              goto drop;
            }
 
          /* Check if anyone want ARP request events for L2 BDs */
          {
-           pending_resolution_t *mc;
            ethernet_arp_main_t *am = &ethernet_arp_main;
-           uword *p = hash_get (am->mac_changes_by_address, 0);
-           if (p)
-             {
-               u32 next_index = p[0];
-               while (next_index != (u32) ~ 0)
-                 {
-                   int (*fp) (u32, u8 *, u32, u32);
-                   int rv = 1;
-                   mc = pool_elt_at_index (am->mac_changes, next_index);
-                   fp = mc->data_callback;
-                   /* Call the callback, return 1 to suppress dup events */
-                   if (fp)
-                     rv = (*fp) (mc->data,
-                                 arp0->ip4_over_ethernet[0].ethernet,
-                                 sw_if_index0,
-                                 arp0->ip4_over_ethernet[0].ip4.as_u32);
-                   /* Signal the resolver process */
-                   if (rv == 0)
-                     vlib_process_signal_event (vm, mc->node_index,
-                                                mc->type_opaque, mc->data);
-                   next_index = mc->next_index;
-                 }
-             }
+           if (am->wc_ip4_arp_publisher_node != (uword) ~ 0)
+             vnet_arp_wc_publish (sw_if_index0, &arp0->ip4_over_ethernet[0]);
          }
 
          /* lookup BD mac_by_ip4 hash table for MAC entry */
@@ -2314,15 +2410,18 @@ arp_term_l2bd (vlib_main_t * vm,
 
          if (PREDICT_FALSE (!macp0))
            goto next_l2_feature;       /* MAC not found */
+         if (PREDICT_FALSE (arp0->ip4_over_ethernet[0].ip4.as_u32 ==
+                            arp0->ip4_over_ethernet[1].ip4.as_u32))
+           goto next_l2_feature;       /* GARP */
 
          /* MAC found, send ARP reply -
             Convert ARP request packet to ARP reply */
          arp0->opcode = clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_reply);
          arp0->ip4_over_ethernet[1] = arp0->ip4_over_ethernet[0];
          arp0->ip4_over_ethernet[0].ip4.as_u32 = ip0;
-         clib_memcpy (arp0->ip4_over_ethernet[0].ethernet, macp0, 6);
-         clib_memcpy (eth0->dst_address, eth0->src_address, 6);
-         clib_memcpy (eth0->src_address, macp0, 6);
+         mac_address_from_bytes (&arp0->ip4_over_ethernet[0].mac, macp0);
+         clib_memcpy_fast (eth0->dst_address, eth0->src_address, 6);
+         clib_memcpy_fast (eth0->src_address, macp0, 6);
          n_replies_sent += 1;
 
        output_response:
@@ -2362,12 +2461,8 @@ arp_term_l2bd (vlib_main_t * vm,
 
        next_l2_feature:
          {
-           u32 feature_bitmap0 =
-             vnet_buffer (p0)->l2.feature_bitmap & ~L2INPUT_FEAT_ARP_TERM;
-           vnet_buffer (p0)->l2.feature_bitmap = feature_bitmap0;
-           next0 =
-             feat_bitmap_get_next_node_index (arp_term_next_node_index,
-                                              feature_bitmap0);
+           next0 = vnet_l2_feature_next (p0, arp_term_next_node_index,
+                                         L2INPUT_FEAT_ARP_TERM);
            vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
                                             to_next, n_left_to_next,
                                             pi0, next0);
@@ -2443,6 +2538,7 @@ ethernet_arp_change_mac (u32 sw_if_index)
 {
   ethernet_arp_main_t *am = &ethernet_arp_main;
   ethernet_arp_ip4_entry_t *e;
+  adj_index_t ai;
 
   /* *INDENT-OFF* */
   pool_foreach (e, am->ip4_entry_pool,
@@ -2450,8 +2546,101 @@ ethernet_arp_change_mac (u32 sw_if_index)
     change_arp_mac (sw_if_index, e);
   }));
   /* *INDENT-ON* */
+
+  ai = adj_glean_get (FIB_PROTOCOL_IP4, sw_if_index);
+
+  if (ADJ_INDEX_INVALID != ai)
+    adj_glean_update_rewrite (ai);
 }
 
+void
+send_ip4_garp (vlib_main_t * vm, u32 sw_if_index)
+{
+  ip4_main_t *i4m = &ip4_main;
+  ip4_address_t *ip4_addr = ip4_interface_first_address (i4m, sw_if_index, 0);
+
+  send_ip4_garp_w_addr (vm, ip4_addr, sw_if_index);
+}
+
+void
+send_ip4_garp_w_addr (vlib_main_t * vm,
+                     const ip4_address_t * ip4_addr, u32 sw_if_index)
+{
+  ip4_main_t *i4m = &ip4_main;
+  vnet_main_t *vnm = vnet_get_main ();
+  u8 *rewrite, rewrite_len;
+  vnet_hw_interface_t *hi = vnet_get_sup_hw_interface (vnm, sw_if_index);
+
+  if (ip4_addr)
+    {
+      clib_warning ("Sending GARP for IP4 address %U on sw_if_idex %d",
+                   format_ip4_address, ip4_addr, sw_if_index);
+
+      /* Form GARP packet for output - Gratuitous ARP is an ARP request packet
+         where the interface IP/MAC pair is used for both source and request
+         MAC/IP pairs in the request */
+      u32 bi = 0;
+      ethernet_arp_header_t *h = vlib_packet_template_get_packet
+       (vm, &i4m->ip4_arp_request_packet_template, &bi);
+
+      if (!h)
+       return;
+
+      mac_address_from_bytes (&h->ip4_over_ethernet[0].mac, hi->hw_address);
+      mac_address_from_bytes (&h->ip4_over_ethernet[1].mac, hi->hw_address);
+      h->ip4_over_ethernet[0].ip4 = ip4_addr[0];
+      h->ip4_over_ethernet[1].ip4 = ip4_addr[0];
+
+      /* Setup MAC header with ARP Etype and broadcast DMAC */
+      vlib_buffer_t *b = vlib_get_buffer (vm, bi);
+      rewrite =
+       ethernet_build_rewrite (vnm, sw_if_index, VNET_LINK_ARP,
+                               VNET_REWRITE_FOR_SW_INTERFACE_ADDRESS_BROADCAST);
+      rewrite_len = vec_len (rewrite);
+      vlib_buffer_advance (b, -rewrite_len);
+      ethernet_header_t *e = vlib_buffer_get_current (b);
+      clib_memcpy_fast (e->dst_address, rewrite, rewrite_len);
+      vec_free (rewrite);
+
+      /* Send GARP packet out the specified interface */
+      vnet_buffer (b)->sw_if_index[VLIB_RX] =
+       vnet_buffer (b)->sw_if_index[VLIB_TX] = sw_if_index;
+      vlib_frame_t *f = vlib_get_frame_to_node (vm, hi->output_node_index);
+      u32 *to_next = vlib_frame_vector_args (f);
+      to_next[0] = bi;
+      f->n_vectors = 1;
+      vlib_put_frame_to_node (vm, hi->output_node_index, f);
+    }
+}
+
+/*
+ * Remove any arp entries associated with the specified interface
+ */
+static clib_error_t *
+vnet_arp_delete_sw_interface (vnet_main_t * vnm, u32 sw_if_index, u32 is_add)
+{
+  if (!is_add && sw_if_index != ~0)
+    {
+      ethernet_arp_main_t *am = &ethernet_arp_main;
+      ethernet_arp_ip4_entry_t *e;
+      /* *INDENT-OFF* */
+      pool_foreach (e, am->ip4_entry_pool, ({
+        if (e->sw_if_index != sw_if_index)
+          continue;
+        vnet_arp_set_ip4_over_ethernet_rpc_args_t args = {
+          .sw_if_index = sw_if_index,
+          .ip4 = e->ip4_address,
+        };
+        vnet_arp_unset_ip4_over_ethernet_internal (vnm, &args);
+      }));
+      /* *INDENT-ON* */
+    }
+
+  return (NULL);
+}
+
+VNET_SW_INTERFACE_ADD_DEL_FUNCTION (vnet_arp_delete_sw_interface);
+
 /*
  * fd.io coding-style-patch-verification: ON
  *