nat: VRF routing & FIB improvements
[vpp.git] / src / plugins / nat / nat44-ed / nat44_ed.c
index 7907d8f..3b1c9a2 100644 (file)
@@ -1,6 +1,4 @@
 /*
- * snat.c - simple nat plugin
- *
  * Copyright (c) 2016 Cisco and/or its affiliates.
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -38,7 +36,7 @@
 #include <nat/nat44-ed/nat44_ed_affinity.h>
 #include <nat/nat44-ed/nat44_ed_inlines.h>
 
-#include <vpp/stats/stat_segment.h>
+#include <vlib/stats/stats.h>
 
 snat_main_t snat_main;
 
@@ -78,7 +76,6 @@ static_always_inline void nat_validate_interface_counters (snat_main_t *sm,
     }                                                                         \
   while (0)
 
-/* Hook up input features */
 VNET_FEATURE_INIT (nat_pre_in2out, static) = {
   .arc_name = "ip4-unicast",
   .node_name = "nat-pre-in2out",
@@ -92,6 +89,18 @@ VNET_FEATURE_INIT (nat_pre_out2in, static) = {
                                "ip4-dhcp-client-detect",
                               "ip4-sv-reassembly-feature"),
 };
+VNET_FEATURE_INIT (ip4_nat44_ed_classify, static) = {
+  .arc_name = "ip4-unicast",
+  .node_name = "nat44-ed-classify",
+  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa",
+                              "ip4-sv-reassembly-feature"),
+};
+VNET_FEATURE_INIT (ip4_nat_handoff_classify, static) = {
+  .arc_name = "ip4-unicast",
+  .node_name = "nat44-handoff-classify",
+  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa",
+                              "ip4-sv-reassembly-feature"),
+};
 VNET_FEATURE_INIT (snat_in2out_worker_handoff, static) = {
   .arc_name = "ip4-unicast",
   .node_name = "nat44-in2out-worker-handoff",
@@ -103,17 +112,6 @@ VNET_FEATURE_INIT (snat_out2in_worker_handoff, static) = {
   .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa",
                                "ip4-dhcp-client-detect"),
 };
-VNET_FEATURE_INIT (ip4_snat_in2out, static) = {
-  .arc_name = "ip4-unicast",
-  .node_name = "nat44-in2out",
-  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa","ip4-sv-reassembly-feature"),
-};
-VNET_FEATURE_INIT (ip4_snat_out2in, static) = {
-  .arc_name = "ip4-unicast",
-  .node_name = "nat44-out2in",
-  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa","ip4-sv-reassembly-feature",
-                               "ip4-dhcp-client-detect"),
-};
 VNET_FEATURE_INIT (ip4_nat44_ed_in2out, static) = {
   .arc_name = "ip4-unicast",
   .node_name = "nat44-ed-in2out",
@@ -125,32 +123,9 @@ VNET_FEATURE_INIT (ip4_nat44_ed_out2in, static) = {
   .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa","ip4-sv-reassembly-feature",
                                "ip4-dhcp-client-detect"),
 };
-VNET_FEATURE_INIT (ip4_nat44_ed_classify, static) = {
-  .arc_name = "ip4-unicast",
-  .node_name = "nat44-ed-classify",
-  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa","ip4-sv-reassembly-feature"),
-};
-VNET_FEATURE_INIT (ip4_nat_handoff_classify, static) = {
-  .arc_name = "ip4-unicast",
-  .node_name = "nat44-handoff-classify",
-  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa","ip4-sv-reassembly-feature"),
-};
-VNET_FEATURE_INIT (ip4_snat_in2out_fast, static) = {
-  .arc_name = "ip4-unicast",
-  .node_name = "nat44-in2out-fast",
-  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa","ip4-sv-reassembly-feature"),
-};
-VNET_FEATURE_INIT (ip4_snat_out2in_fast, static) = {
-  .arc_name = "ip4-unicast",
-  .node_name = "nat44-out2in-fast",
-  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa","ip4-sv-reassembly-feature",
-                               "ip4-dhcp-client-detect"),
-};
-
-/* Hook up output features */
-VNET_FEATURE_INIT (ip4_snat_in2out_output, static) = {
+VNET_FEATURE_INIT (nat_pre_in2out_output, static) = {
   .arc_name = "ip4-output",
-  .node_name = "nat44-in2out-output",
+  .node_name = "nat-pre-in2out-output",
   .runs_after = VNET_FEATURES ("ip4-sv-reassembly-output-feature"),
   .runs_before = VNET_FEATURES ("acl-plugin-out-ip4-fa"),
 };
@@ -160,12 +135,6 @@ VNET_FEATURE_INIT (ip4_snat_in2out_output_worker_handoff, static) = {
   .runs_after = VNET_FEATURES ("ip4-sv-reassembly-output-feature"),
   .runs_before = VNET_FEATURES ("acl-plugin-out-ip4-fa"),
 };
-VNET_FEATURE_INIT (nat_pre_in2out_output, static) = {
-  .arc_name = "ip4-output",
-  .node_name = "nat-pre-in2out-output",
-  .runs_after = VNET_FEATURES ("ip4-sv-reassembly-output-feature"),
-  .runs_before = VNET_FEATURES ("acl-plugin-out-ip4-fa"),
-};
 VNET_FEATURE_INIT (ip4_nat44_ed_in2out_output, static) = {
   .arc_name = "ip4-output",
   .node_name = "nat44-ed-in2out-output",
@@ -185,34 +154,14 @@ static int nat44_ed_add_static_mapping_internal (
   ip4_address_t l_addr, ip4_address_t e_addr, u16 l_port, u16 e_port,
   ip_protocol_t proto, u32 vrf_id, u32 sw_if_index, u32 flags,
   ip4_address_t pool_addr, u8 *tag);
-static int nat44_ed_del_static_mapping_internal (
-  ip4_address_t l_addr, ip4_address_t e_addr, u16 l_port, u16 e_port,
-  ip_protocol_t proto, u32 vrf_id, u32 sw_if_index, u32 flags);
+static int nat44_ed_del_static_mapping_internal (ip4_address_t l_addr,
+                                                ip4_address_t e_addr,
+                                                u16 l_port, u16 e_port,
+                                                ip_protocol_t proto,
+                                                u32 vrf_id, u32 flags);
 
 u32 nat_calc_bihash_buckets (u32 n_elts);
 
-u8 *
-format_ed_session_kvp (u8 * s, va_list * args)
-{
-  clib_bihash_kv_16_8_t *v = va_arg (*args, clib_bihash_kv_16_8_t *);
-
-  u8 proto;
-  u16 r_port, l_port;
-  ip4_address_t l_addr, r_addr;
-  u32 fib_index;
-
-  split_ed_kv (v, &l_addr, &r_addr, &proto, &fib_index, &l_port, &r_port);
-  s = format (s,
-             "local %U:%d remote %U:%d proto %U fib %d thread-index %u "
-             "session-index %u",
-             format_ip4_address, &l_addr, clib_net_to_host_u16 (l_port),
-             format_ip4_address, &r_addr, clib_net_to_host_u16 (r_port),
-             format_ip_protocol, proto, fib_index,
-             ed_value_get_thread_index (v), ed_value_get_session_index (v));
-
-  return s;
-}
-
 static_always_inline int
 nat44_ed_sm_i2o_add (snat_main_t *sm, snat_static_mapping_t *m,
                     ip4_address_t addr, u16 port, u32 fib_index, u8 proto)
@@ -290,25 +239,6 @@ nat44_ed_free_session_data (snat_main_t *sm, snat_session_t *s,
     }
 }
 
-static int
-is_snat_address_used_in_static_mapping (snat_main_t *sm, ip4_address_t addr)
-{
-  snat_static_mapping_t *m;
-  pool_foreach (m, sm->static_mappings)
-    {
-      if (is_sm_addr_only (m->flags) || is_sm_out2in_only (m->flags) ||
-         is_sm_identity_nat (m->flags))
-       {
-         continue;
-       }
-      if (m->external_addr.as_u32 == addr.as_u32)
-       {
-         return 1;
-       }
-    }
-  return 0;
-}
-
 static ip_interface_address_t *
 nat44_ed_get_ip_interface_address (u32 sw_if_index, ip4_address_t addr)
 {
@@ -415,41 +345,91 @@ nat44_ed_bind_if_addr_to_nat_addr (u32 sw_if_index)
     }
 }
 
+static_always_inline snat_fib_entry_reg_t *
+nat44_ed_get_fib_entry_reg (ip4_address_t addr, u32 sw_if_index, int *out_idx)
+{
+  snat_main_t *sm = &snat_main;
+  snat_fib_entry_reg_t *fe;
+  int i;
+
+  for (i = 0; i < vec_len (sm->fib_entry_reg); i++)
+    {
+      fe = sm->fib_entry_reg + i;
+      if ((addr.as_u32 == fe->addr.as_u32) && (sw_if_index == fe->sw_if_index))
+       {
+         if (out_idx)
+           {
+             *out_idx = i;
+           }
+         return fe;
+       }
+    }
+  return NULL;
+}
+
 static void
-nat44_ed_add_del_addr_to_fib (ip4_address_t *addr, u8 p_len, u32 sw_if_index,
-                             int is_add)
+nat44_ed_add_fib_entry_reg (ip4_address_t addr, u32 sw_if_index)
 {
   // Add the external NAT address to the FIB as receive entries. This ensures
   // that VPP will reply to ARP for this address and we don't need to enable
   // proxy ARP on the outside interface.
-
   snat_main_t *sm = &snat_main;
-  fib_prefix_t prefix = {
-    .fp_len = p_len,
-    .fp_proto = FIB_PROTOCOL_IP4,
-    .fp_addr = {
-               .ip4.as_u32 = addr->as_u32,
-               },
-  };
-  u32 fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
+  snat_fib_entry_reg_t *fe;
 
-  if (is_add)
+  if (!(fe = nat44_ed_get_fib_entry_reg (addr, sw_if_index, 0)))
     {
+      fib_prefix_t prefix = {
+        .fp_len = 32,
+        .fp_proto = FIB_PROTOCOL_IP4,
+        .fp_addr = {
+                 .ip4.as_u32 = addr.as_u32,
+               },
+      };
+      u32 fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
       fib_table_entry_update_one_path (fib_index, &prefix, sm->fib_src_low,
                                       (FIB_ENTRY_FLAG_CONNECTED |
                                        FIB_ENTRY_FLAG_LOCAL |
                                        FIB_ENTRY_FLAG_EXCLUSIVE),
                                       DPO_PROTO_IP4, NULL, sw_if_index, ~0, 1,
                                       NULL, FIB_ROUTE_PATH_FLAG_NONE);
+
+      vec_add2 (sm->fib_entry_reg, fe, 1);
+      clib_memset (fe, 0, sizeof (*fe));
+      fe->addr.as_u32 = addr.as_u32;
+      fe->sw_if_index = sw_if_index;
     }
-  else
+  fe->count++;
+}
+
+static void
+nat44_ed_del_fib_entry_reg (ip4_address_t addr, u32 sw_if_index)
+{
+  snat_main_t *sm = &snat_main;
+  snat_fib_entry_reg_t *fe;
+  int i;
+
+  if ((fe = nat44_ed_get_fib_entry_reg (addr, sw_if_index, &i)))
     {
-      fib_table_entry_delete (fib_index, &prefix, sm->fib_src_low);
+      fe->count--;
+      if (0 == fe->count)
+       {
+         fib_prefix_t prefix = {
+            .fp_len = 32,
+            .fp_proto = FIB_PROTOCOL_IP4,
+            .fp_addr = {
+              .ip4.as_u32 = addr.as_u32,
+                   },
+          };
+         u32 fib_index =
+           ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
+         fib_table_entry_delete (fib_index, &prefix, sm->fib_src_low);
+         vec_del1 (sm->fib_entry_reg, i);
+       }
     }
 }
 
 static void
-nat44_ed_add_del_addr_to_fib_foreach_out_if (ip4_address_t *addr, u8 is_add)
+nat44_ed_add_del_interface_fib_reg_entries (ip4_address_t addr, u8 is_add)
 {
   snat_main_t *sm = &snat_main;
   snat_interface_t *i;
@@ -458,42 +438,66 @@ nat44_ed_add_del_addr_to_fib_foreach_out_if (ip4_address_t *addr, u8 is_add)
     {
       if (nat44_ed_is_interface_outside (i))
        {
-         nat44_ed_add_del_addr_to_fib (addr, 32, i->sw_if_index, is_add);
+         if (is_add)
+           {
+             nat44_ed_add_fib_entry_reg (addr, i->sw_if_index);
+           }
+         else
+           {
+             nat44_ed_del_fib_entry_reg (addr, i->sw_if_index);
+           }
        }
     }
   pool_foreach (i, sm->output_feature_interfaces)
     {
       if (nat44_ed_is_interface_outside (i))
        {
-         nat44_ed_add_del_addr_to_fib (addr, 32, i->sw_if_index, is_add);
+         if (is_add)
+           {
+             nat44_ed_add_fib_entry_reg (addr, i->sw_if_index);
+           }
+         else
+           {
+             nat44_ed_del_fib_entry_reg (addr, i->sw_if_index);
+           }
        }
     }
 }
 
 static_always_inline void
-nat44_ed_add_del_addr_to_fib_foreach_addr (u32 sw_if_index, u8 is_add)
+nat44_ed_add_del_nat_addr_fib_reg_entries (u32 sw_if_index, u8 is_add)
 {
   snat_main_t *sm = &snat_main;
   snat_address_t *ap;
 
   vec_foreach (ap, sm->addresses)
     {
-      nat44_ed_add_del_addr_to_fib (&ap->addr, 32, sw_if_index, is_add);
+      if (is_add)
+       {
+         nat44_ed_add_fib_entry_reg (ap->addr, sw_if_index);
+       }
+      else
+       {
+         nat44_ed_del_fib_entry_reg (ap->addr, sw_if_index);
+       }
     }
 }
 
 static_always_inline void
-nat44_ed_add_del_addr_to_fib_foreach_addr_only_sm (u32 sw_if_index, u8 is_add)
+nat44_ed_add_del_sm_fib_reg_entries (u32 sw_if_index, u8 is_add)
 {
   snat_main_t *sm = &snat_main;
   snat_static_mapping_t *m;
 
   pool_foreach (m, sm->static_mappings)
     {
-      if (is_sm_addr_only (m->flags) && !is_sm_identity_nat (m->flags))
+      if (is_add)
        {
-         nat44_ed_add_del_addr_to_fib (&m->external_addr, 32, sw_if_index,
-                                       is_add);
+         nat44_ed_add_fib_entry_reg (m->external_addr, sw_if_index);
+       }
+      else
+       {
+         nat44_ed_del_fib_entry_reg (m->external_addr, sw_if_index);
        }
     }
 }
@@ -544,21 +548,20 @@ nat44_ed_add_address (ip4_address_t *addr, u32 vrf_id, u8 twice_nat)
     {
       // if we don't have enabled interface we don't add address
       // to fib
-      nat44_ed_add_del_addr_to_fib_foreach_out_if (addr, 1);
+      nat44_ed_add_del_interface_fib_reg_entries (*addr, 1);
       nat44_ed_update_outside_if_addresses (ap);
     }
   return 0;
 }
 
 int
-nat44_ed_del_address (ip4_address_t addr, u8 delete_sm, u8 twice_nat)
+nat44_ed_del_address (ip4_address_t addr, u8 twice_nat)
 {
   snat_main_t *sm = &snat_main;
   snat_address_t *a = 0, *addresses;
   snat_session_t *ses;
   u32 *ses_to_be_removed = 0, *ses_index;
   snat_main_per_thread_data_t *tsm;
-  snat_static_mapping_t *m;
   int j;
 
   addresses = twice_nat ? sm->twice_nat_addresses : sm->addresses;
@@ -577,33 +580,15 @@ nat44_ed_del_address (ip4_address_t addr, u8 delete_sm, u8 twice_nat)
       return VNET_API_ERROR_NO_SUCH_ENTRY;
     }
 
-  if (delete_sm)
-    {
-      pool_foreach (m, sm->static_mappings)
-       {
-         if (m->external_addr.as_u32 == addr.as_u32)
-           {
-             nat44_ed_del_static_mapping_internal (
-               m->local_addr, m->external_addr, m->local_port,
-               m->external_port, ip_proto_to_nat_proto (m->proto), m->vrf_id,
-               ~0, m->flags);
-           }
-       }
-    }
-  else
-    {
-      if (is_snat_address_used_in_static_mapping (sm, addr))
-       {
-         nat_log_err ("address used in static mapping");
-         return VNET_API_ERROR_UNSPECIFIED;
-       }
-    }
-
-  // delete sessions using address
+  // delete dynamic sessions only
   vec_foreach (tsm, sm->per_thread_data)
     {
       pool_foreach (ses, tsm->sessions)
        {
+         if (ses->flags & SNAT_SESSION_FLAG_STATIC_MAPPING)
+           {
+             continue;
+           }
          if (ses->out2in.addr.as_u32 == addr.as_u32)
            {
              nat44_ed_free_session_data (sm, ses, tsm - sm->per_thread_data,
@@ -621,7 +606,7 @@ nat44_ed_del_address (ip4_address_t addr, u8 delete_sm, u8 twice_nat)
 
   if (!twice_nat)
     {
-      nat44_ed_add_del_addr_to_fib_foreach_out_if (&addr, 0);
+      nat44_ed_add_del_interface_fib_reg_entries (addr, 0);
     }
 
   if (a->fib_index != ~0)
@@ -641,6 +626,134 @@ nat44_ed_del_address (ip4_address_t addr, u8 delete_sm, u8 twice_nat)
   return 0;
 }
 
+vrf_table_t *
+nat44_ed_get_vrf_table (u32 table_vrf_id)
+{
+  snat_main_t *sm = &snat_main;
+  vrf_table_t *t;
+
+  pool_foreach (t, sm->vrf_tables)
+    {
+      if (table_vrf_id == t->table_vrf_id)
+       {
+         return t;
+       }
+    }
+  return NULL;
+}
+
+vrf_route_t *
+nat44_ed_get_vrf_route (vrf_table_t *t, u32 vrf_id)
+{
+  vrf_route_t *r;
+
+  pool_foreach (r, t->routes)
+    {
+      if (vrf_id == r->vrf_id)
+       {
+         return r;
+       }
+    }
+  return NULL;
+}
+
+int
+nat44_ed_add_del_vrf_table (u32 table_vrf_id, bool is_add)
+{
+  snat_main_t *sm = &snat_main;
+  vrf_table_t *t;
+  vrf_route_t *r;
+
+  t = nat44_ed_get_vrf_table (table_vrf_id);
+  if (t)
+    {
+      if (is_add)
+       {
+         return VNET_API_ERROR_VALUE_EXIST;
+       }
+      pool_foreach (r, t->routes)
+       {
+         fib_table_unlock (r->fib_index, FIB_PROTOCOL_IP4, sm->fib_src_low);
+       }
+      fib_table_unlock (t->table_fib_index, FIB_PROTOCOL_IP4, sm->fib_src_low);
+
+      pool_free (t->routes);
+      pool_put (sm->vrf_tables, t);
+    }
+  else
+    {
+      if (!is_add)
+       {
+         return VNET_API_ERROR_NO_SUCH_ENTRY;
+       }
+      pool_get (sm->vrf_tables, t);
+      clib_memset (t, 0, sizeof (*t));
+      t->table_vrf_id = table_vrf_id;
+      t->table_fib_index = fib_table_find_or_create_and_lock (
+       FIB_PROTOCOL_IP4, table_vrf_id, sm->fib_src_low);
+    }
+
+  return 0;
+}
+
+void
+nat44_ed_del_vrf_tables ()
+{
+  snat_main_t *sm = &snat_main;
+  vrf_table_t *t;
+  vrf_route_t *r;
+
+  pool_foreach (t, sm->vrf_tables)
+    {
+      pool_foreach (r, t->routes)
+       {
+         fib_table_unlock (r->fib_index, FIB_PROTOCOL_IP4, sm->fib_src_low);
+       }
+      fib_table_unlock (t->table_fib_index, FIB_PROTOCOL_IP4, sm->fib_src_low);
+      pool_free (t->routes);
+    }
+  pool_free (sm->vrf_tables);
+}
+
+int
+nat44_ed_add_del_vrf_route (u32 table_vrf_id, u32 vrf_id, bool is_add)
+{
+  snat_main_t *sm = &snat_main;
+  vrf_table_t *t;
+  vrf_route_t *r;
+
+  t = nat44_ed_get_vrf_table (table_vrf_id);
+  if (!t)
+    {
+      return VNET_API_ERROR_NO_SUCH_ENTRY;
+    }
+
+  r = nat44_ed_get_vrf_route (t, vrf_id);
+  if (r)
+    {
+      if (is_add)
+       {
+         return VNET_API_ERROR_VALUE_EXIST;
+       }
+      fib_table_unlock (r->fib_index, FIB_PROTOCOL_IP4, sm->fib_src_low);
+      pool_put (t->routes, r);
+    }
+  else
+    {
+      if (!is_add)
+       {
+         return VNET_API_ERROR_NO_SUCH_ENTRY;
+       }
+      pool_get (t->routes, r);
+      clib_memset (r, 0, sizeof (*r));
+      r->vrf_id = vrf_id;
+      r->fib_index = fib_table_find_or_create_and_lock (
+       FIB_PROTOCOL_IP4, vrf_id, sm->fib_src_low);
+    }
+
+  return 0;
+}
+
 u32
 get_thread_idx_by_port (u16 e_port)
 {
@@ -730,38 +843,18 @@ nat44_ed_sm_i2o_lookup (snat_main_t *sm, ip4_address_t addr, u16 port,
   return nat44_ed_sm_lookup (sm, &kv);
 }
 
-void
-nat44_ed_add_resolve_record (ip4_address_t l_addr, u16 l_port, u16 e_port,
-                            ip_protocol_t proto, u32 vrf_id, u32 sw_if_index,
-                            u32 flags, ip4_address_t pool_addr, u8 *tag)
-{
-  snat_static_map_resolve_t *rp;
-  snat_main_t *sm = &snat_main;
-
-  vec_add2 (sm->to_resolve, rp, 1);
-  rp->l_addr.as_u32 = l_addr.as_u32;
-  rp->l_port = l_port;
-  rp->e_port = e_port;
-  rp->sw_if_index = sw_if_index;
-  rp->vrf_id = vrf_id;
-  rp->proto = proto;
-  rp->flags = flags;
-  rp->pool_addr = pool_addr;
-  rp->tag = vec_dup (tag);
-}
-
-int
+static snat_static_mapping_resolve_t *
 nat44_ed_get_resolve_record (ip4_address_t l_addr, u16 l_port, u16 e_port,
                             ip_protocol_t proto, u32 vrf_id, u32 sw_if_index,
-                            u32 flags, int *out)
+                            u32 flags, int *out_idx)
 {
-  snat_static_map_resolve_t *rp;
+  snat_static_mapping_resolve_t *rp;
   snat_main_t *sm = &snat_main;
   int i;
 
-  for (i = 0; i < vec_len (sm->to_resolve); i++)
+  for (i = 0; i < vec_len (sm->sm_to_resolve); i++)
     {
-      rp = sm->to_resolve + i;
+      rp = sm->sm_to_resolve + i;
 
       if (rp->sw_if_index == sw_if_index && rp->vrf_id == vrf_id)
        {
@@ -790,27 +883,27 @@ nat44_ed_get_resolve_record (ip4_address_t l_addr, u16 l_port, u16 e_port,
            {
              continue;
            }
-         if (out)
+         if (out_idx)
            {
-             *out = i;
+             *out_idx = i;
            }
-         return 0;
+         return rp;
        }
     }
-  return 1;
+  return NULL;
 }
 
-int
+static int
 nat44_ed_del_resolve_record (ip4_address_t l_addr, u16 l_port, u16 e_port,
                             ip_protocol_t proto, u32 vrf_id, u32 sw_if_index,
                             u32 flags)
 {
   snat_main_t *sm = &snat_main;
   int i;
-  if (!nat44_ed_get_resolve_record (l_addr, l_port, e_port, proto, vrf_id,
-                                   sw_if_index, flags, &i))
+  if (nat44_ed_get_resolve_record (l_addr, l_port, e_port, proto, vrf_id,
+                                  sw_if_index, flags, &i))
     {
-      vec_del1 (sm->to_resolve, i);
+      vec_del1 (sm->sm_to_resolve, i);
       return 0;
     }
   return 1;
@@ -835,50 +928,69 @@ nat44_ed_validate_sm_input (u32 flags)
   return 0;
 }
 
-snat_address_t *
-nat44_ed_addr_lookup (snat_main_t *sm, u32 addr)
-{
-  for (int i = 0; i < vec_len (sm->addresses); ++i)
-    {
-      if (sm->addresses[i].addr.as_u32 == addr)
-       return &sm->addresses[i];
-    }
-  return NULL;
-}
-
 int
 nat44_ed_add_static_mapping (ip4_address_t l_addr, ip4_address_t e_addr,
                             u16 l_port, u16 e_port, ip_protocol_t proto,
                             u32 vrf_id, u32 sw_if_index, u32 flags,
                             ip4_address_t pool_addr, u8 *tag)
 {
+  snat_static_mapping_resolve_t *rp;
   snat_main_t *sm = &snat_main;
+  int rv;
+
+  if (!sm->enabled)
+    {
+      return VNET_API_ERROR_UNSUPPORTED;
+    }
+
+  rv = nat44_ed_validate_sm_input (flags);
+  if (rv != 0)
+    {
+      return rv;
+    }
 
   // interface bound mapping
   if (is_sm_switch_address (flags))
     {
-      if (!nat44_ed_get_resolve_record (l_addr, l_port, e_port, proto, vrf_id,
-                                       sw_if_index, flags, 0))
+      if (nat44_ed_get_resolve_record (l_addr, l_port, e_port, proto, vrf_id,
+                                      sw_if_index, flags, 0))
        {
          return VNET_API_ERROR_VALUE_EXIST;
        }
 
-      nat44_ed_add_resolve_record (l_addr, l_port, e_port, proto, vrf_id,
-                                  sw_if_index, flags, pool_addr, tag);
+      vec_add2 (sm->sm_to_resolve, rp, 1);
+      rp->l_addr.as_u32 = l_addr.as_u32;
+      rp->l_port = l_port;
+      rp->e_port = e_port;
+      rp->sw_if_index = sw_if_index;
+      rp->vrf_id = vrf_id;
+      rp->proto = proto;
+      rp->flags = flags;
+      rp->pool_addr = pool_addr;
+      rp->tag = vec_dup (tag);
+      rp->is_resolved = 0;
+
       ip4_address_t *first_int_addr =
        ip4_interface_first_address (sm->ip4_main, sw_if_index, 0);
       if (!first_int_addr)
        {
-         // dhcp resolution required
          return 0;
        }
 
       e_addr.as_u32 = first_int_addr->as_u32;
+      rp->is_resolved = 1;
     }
 
-  return nat44_ed_add_static_mapping_internal (l_addr, e_addr, l_port, e_port,
-                                              proto, vrf_id, sw_if_index,
-                                              flags, pool_addr, tag);
+  rv = nat44_ed_add_static_mapping_internal (l_addr, e_addr, l_port, e_port,
+                                            proto, vrf_id, sw_if_index, flags,
+                                            pool_addr, tag);
+  if ((0 != rv) && is_sm_switch_address (flags))
+    {
+      nat44_ed_del_resolve_record (l_addr, l_port, e_port, proto, vrf_id,
+                                  sw_if_index, flags);
+    }
+
+  return rv;
 }
 
 int
@@ -886,8 +998,19 @@ nat44_ed_del_static_mapping (ip4_address_t l_addr, ip4_address_t e_addr,
                             u16 l_port, u16 e_port, ip_protocol_t proto,
                             u32 vrf_id, u32 sw_if_index, u32 flags)
 {
-
   snat_main_t *sm = &snat_main;
+  int rv;
+
+  if (!sm->enabled)
+    {
+      return VNET_API_ERROR_UNSUPPORTED;
+    }
+
+  rv = nat44_ed_validate_sm_input (flags);
+  if (rv != 0)
+    {
+      return rv;
+    }
 
   // interface bound mapping
   if (is_sm_switch_address (flags))
@@ -909,8 +1032,8 @@ nat44_ed_del_static_mapping (ip4_address_t l_addr, ip4_address_t e_addr,
       e_addr.as_u32 = first_int_addr->as_u32;
     }
 
-  return nat44_ed_del_static_mapping_internal (
-    l_addr, e_addr, l_port, e_port, proto, vrf_id, sw_if_index, flags);
+  return nat44_ed_del_static_mapping_internal (l_addr, e_addr, l_port, e_port,
+                                              proto, vrf_id, flags);
 }
 
 static int
@@ -924,18 +1047,6 @@ nat44_ed_add_static_mapping_internal (ip4_address_t l_addr,
   nat44_lb_addr_port_t *local;
   snat_static_mapping_t *m;
   u32 fib_index = ~0;
-  int rv;
-
-  if (!sm->enabled)
-    {
-      return VNET_API_ERROR_UNSUPPORTED;
-    }
-
-  rv = nat44_ed_validate_sm_input (flags);
-  if (rv != 0)
-    {
-      return rv;
-    }
 
   if (is_sm_addr_only (flags))
     {
@@ -951,13 +1062,14 @@ nat44_ed_add_static_mapping_internal (ip4_address_t l_addr,
   m = nat44_ed_sm_o2i_lookup (sm, e_addr, e_port, 0, proto);
   if (m)
     {
+      // case:
+      // adding local identity nat record for different vrf table
+
       if (!is_sm_identity_nat (m->flags))
        {
          return VNET_API_ERROR_VALUE_EXIST;
        }
 
-      // case:
-      // adding local identity nat record for different vrf table
       pool_foreach (local, m->locals)
        {
          if (local->vrf_id == vrf_id)
@@ -1001,21 +1113,6 @@ nat44_ed_add_static_mapping_internal (ip4_address_t l_addr,
        }
     }
 
-  if (!(is_sm_out2in_only (flags) || is_sm_addr_only (flags) ||
-       sm->static_mapping_only))
-    {
-      if (!nat44_ed_addr_lookup (sm, e_addr.as_u32))
-       {
-         // remove resolve record
-         if (is_sm_switch_address (flags) && !is_sm_identity_nat (flags))
-           {
-             nat44_ed_del_resolve_record (l_addr, l_port, e_port, proto,
-                                          vrf_id, sw_if_index, flags);
-           }
-         return VNET_API_ERROR_NO_SUCH_ENTRY;
-       }
-    }
-
   pool_get (sm->static_mappings, m);
   clib_memset (m, 0, sizeof (*m));
 
@@ -1023,13 +1120,9 @@ nat44_ed_add_static_mapping_internal (ip4_address_t l_addr,
   m->local_addr = l_addr;
   m->external_addr = e_addr;
 
+  m->pool_addr = pool_addr;
   m->tag = vec_dup (tag);
 
-  if (is_sm_exact_address (flags) && is_sm_twice_nat (flags))
-    {
-      m->pool_addr = pool_addr;
-    }
-
   if (!is_sm_addr_only (flags))
     {
       m->local_port = l_port;
@@ -1048,12 +1141,6 @@ nat44_ed_add_static_mapping_internal (ip4_address_t l_addr,
     {
       m->vrf_id = vrf_id;
       m->fib_index = fib_index;
-
-      // not identity && addr only
-      if (is_sm_addr_only (flags))
-       {
-         nat44_ed_add_del_addr_to_fib_foreach_out_if (&e_addr, 1);
-       }
     }
 
   if (!is_sm_out2in_only (flags))
@@ -1076,6 +1163,8 @@ nat44_ed_add_static_mapping_internal (ip4_address_t l_addr,
       vec_add1 (m->workers, worker_index);
     }
 
+  nat44_ed_add_del_interface_fib_reg_entries (e_addr, 1);
+
   return 0;
 }
 
@@ -1083,26 +1172,14 @@ static int
 nat44_ed_del_static_mapping_internal (ip4_address_t l_addr,
                                      ip4_address_t e_addr, u16 l_port,
                                      u16 e_port, ip_protocol_t proto,
-                                     u32 vrf_id, u32 sw_if_index, u32 flags)
+                                     u32 vrf_id, u32 flags)
 {
-  snat_main_per_thread_data_t *tsm;
-  snat_main_t *sm = &snat_main;
-
-  nat44_lb_addr_port_t *local;
-  snat_static_mapping_t *m;
-  u32 fib_index = ~0;
-  int rv;
-
-  if (!sm->enabled)
-    {
-      return VNET_API_ERROR_UNSUPPORTED;
-    }
-
-  rv = nat44_ed_validate_sm_input (flags);
-  if (rv != 0)
-    {
-      return rv;
-    }
+  snat_main_per_thread_data_t *tsm;
+  snat_main_t *sm = &snat_main;
+
+  nat44_lb_addr_port_t *local;
+  snat_static_mapping_t *m;
+  u32 fib_index = ~0;
 
   if (is_sm_addr_only (flags))
     {
@@ -1117,13 +1194,8 @@ nat44_ed_del_static_mapping_internal (ip4_address_t l_addr,
 
   // fib index 0
   m = nat44_ed_sm_o2i_lookup (sm, e_addr, e_port, 0, proto);
-
   if (!m)
     {
-      if (is_sm_switch_address (flags))
-       {
-         return 0;
-       }
       return VNET_API_ERROR_NO_SUCH_ENTRY;
     }
 
@@ -1157,32 +1229,24 @@ nat44_ed_del_static_mapping_internal (ip4_address_t l_addr,
       fib_index = m->fib_index;
     }
 
-  if (!(is_sm_out2in_only (flags) || is_sm_addr_only (flags) ||
-       sm->static_mapping_only))
-    {
-      if (!nat44_ed_addr_lookup (sm, e_addr.as_u32))
-       {
-         return VNET_API_ERROR_INVALID_VALUE;
-       }
-    }
-
   if (!is_sm_out2in_only (flags))
     {
       nat44_ed_sm_i2o_del (sm, l_addr, l_port, fib_index, proto);
     }
 
-  if (!sm->static_mapping_only || sm->static_mapping_connection_tracking)
+  // delete sessions for static mapping
+  if (sm->num_workers > 1)
     {
-      // delete sessions for static mapping
-      if (sm->num_workers > 1)
-       tsm = vec_elt_at_index (sm->per_thread_data, m->workers[0]);
-      else
-       tsm = vec_elt_at_index (sm->per_thread_data, sm->num_workers);
-
-      nat_ed_static_mapping_del_sessions (
-       sm, tsm, m->local_addr, m->local_port, m->proto, fib_index,
-       is_sm_addr_only (flags), e_addr, e_port);
+      tsm = vec_elt_at_index (sm->per_thread_data, m->workers[0]);
     }
+  else
+    {
+      tsm = vec_elt_at_index (sm->per_thread_data, sm->num_workers);
+    }
+
+  nat_ed_static_mapping_del_sessions (sm, tsm, m->local_addr, m->local_port,
+                                     m->proto, fib_index,
+                                     is_sm_addr_only (flags), e_addr, e_port);
 
   fib_table_unlock (fib_index, FIB_PROTOCOL_IP4, sm->fib_src_low);
 
@@ -1196,10 +1260,7 @@ nat44_ed_del_static_mapping_internal (ip4_address_t l_addr,
       vec_free (m->workers);
       pool_put (sm->static_mappings, m);
 
-      if (is_sm_addr_only (flags) && !is_sm_identity_nat (flags))
-       {
-         nat44_ed_add_del_addr_to_fib_foreach_out_if (&e_addr, 0);
-       }
+      nat44_ed_add_del_interface_fib_reg_entries (e_addr, 0);
     }
 
   return 0;
@@ -1238,7 +1299,7 @@ nat44_ed_add_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
       return VNET_API_ERROR_INVALID_VALUE;
     }
 
-  if (!(sm->static_mapping_only || is_sm_out2in_only (flags)))
+  if (!is_sm_out2in_only (flags))
     {
       /* Find external address in allocated addresses and reserve port for
         address and port pair mapping when dynamic translations enabled */
@@ -1282,7 +1343,7 @@ nat44_ed_add_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
   if (nat44_ed_sm_o2i_add (sm, m, m->external_addr, m->external_port, 0,
                           m->proto))
     {
-      nat_elog_err (sm, "sm o2i key add failed");
+      nat_log_err ("sm o2i key add failed");
       return VNET_API_ERROR_UNSPECIFIED;
     }
 
@@ -1294,7 +1355,7 @@ nat44_ed_add_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
        {
          if (nat44_ed_sm_o2i_add (sm, m, e_addr, e_port, 0, proto))
            {
-             nat_elog_err (sm, "sm o2i key add failed");
+             nat_log_err ("sm o2i key add failed");
              rc = VNET_API_ERROR_UNSPECIFIED;
              // here we continue with add operation so that it can be safely
              // reversed in delete path - otherwise we'd have to track what
@@ -1357,7 +1418,7 @@ nat44_ed_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
   if (nat44_ed_sm_o2i_del (sm, m->external_addr, m->external_port, 0,
                           m->proto))
     {
-      nat_elog_err (sm, "sm o2i key del failed");
+      nat_log_err ("sm o2i key del failed");
       return VNET_API_ERROR_UNSPECIFIED;
     }
 
@@ -1369,7 +1430,7 @@ nat44_ed_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
          if (nat44_ed_sm_i2o_del (sm, local->addr, local->port,
                                   local->fib_index, m->proto))
            {
-             nat_elog_err (sm, "sm i2o key del failed");
+             nat_log_err ("sm i2o key del failed");
              return VNET_API_ERROR_UNSPECIFIED;
            }
        }
@@ -1478,7 +1539,7 @@ nat44_ed_add_del_lb_static_mapping_local (ip4_address_t e_addr, u16 e_port,
          if (nat44_ed_sm_i2o_add (sm, m, l_addr, l_port, local->fib_index,
                                   proto))
            {
-             nat_elog_err (sm, "sm i2o key add failed");
+             nat_log_err ("sm i2o key add failed");
              pool_put (m->locals, local);
              return VNET_API_ERROR_UNSPECIFIED;
            }
@@ -1499,7 +1560,7 @@ nat44_ed_add_del_lb_static_mapping_local (ip4_address_t e_addr, u16 e_port,
        {
          if (nat44_ed_sm_i2o_del (sm, l_addr, l_port, match_local->fib_index,
                                   proto))
-           nat_elog_err (sm, "sm i2o key del failed");
+           nat_log_err ("sm i2o key del failed");
        }
 
       if (sm->num_workers > 1)
@@ -1622,10 +1683,10 @@ update_per_vrf_sessions_vec (u32 fib_index, int is_del)
     }
 }
 
-static_always_inline nat_outside_fib_t *
-nat44_ed_get_outside_fib (nat_outside_fib_t *outside_fibs, u32 fib_index)
+static_always_inline nat_fib_t *
+nat44_ed_get_outside_fib (nat_fib_t *outside_fibs, u32 fib_index)
 {
-  nat_outside_fib_t *f;
+  nat_fib_t *f;
   vec_foreach (f, outside_fibs)
     {
       if (f->fib_index == fib_index)
@@ -1656,7 +1717,7 @@ nat44_ed_add_interface (u32 sw_if_index, u8 is_inside)
   const char *del_feature_name, *feature_name;
   snat_main_t *sm = &snat_main;
 
-  nat_outside_fib_t *outside_fib;
+  nat_fib_t *outside_fib;
   snat_interface_t *i;
   u32 fib_index;
   int rv;
@@ -1738,17 +1799,17 @@ nat44_ed_add_interface (u32 sw_if_index, u8 is_inside)
       outside_fib = nat44_ed_get_outside_fib (sm->outside_fibs, fib_index);
       if (outside_fib)
        {
-         outside_fib->refcount++;
+         outside_fib->ref_count++;
        }
       else
        {
          vec_add2 (sm->outside_fibs, outside_fib, 1);
          outside_fib->fib_index = fib_index;
-         outside_fib->refcount = 1;
+         outside_fib->ref_count = 1;
        }
 
-      nat44_ed_add_del_addr_to_fib_foreach_addr (sw_if_index, 1);
-      nat44_ed_add_del_addr_to_fib_foreach_addr_only_sm (sw_if_index, 1);
+      nat44_ed_add_del_nat_addr_fib_reg_entries (sw_if_index, 1);
+      nat44_ed_add_del_sm_fib_reg_entries (sw_if_index, 1);
 
       nat44_ed_bind_if_addr_to_nat_addr (sw_if_index);
     }
@@ -1766,7 +1827,7 @@ nat44_ed_del_interface (u32 sw_if_index, u8 is_inside)
   const char *del_feature_name, *feature_name;
   snat_main_t *sm = &snat_main;
 
-  nat_outside_fib_t *outside_fib;
+  nat_fib_t *outside_fib;
   snat_interface_t *i;
   u32 fib_index;
   int rv;
@@ -1851,15 +1912,15 @@ nat44_ed_del_interface (u32 sw_if_index, u8 is_inside)
       outside_fib = nat44_ed_get_outside_fib (sm->outside_fibs, fib_index);
       if (outside_fib)
        {
-         outside_fib->refcount--;
-         if (!outside_fib->refcount)
+         outside_fib->ref_count--;
+         if (!outside_fib->ref_count)
            {
              vec_del1 (sm->outside_fibs, outside_fib - sm->outside_fibs);
            }
        }
 
-      nat44_ed_add_del_addr_to_fib_foreach_addr (sw_if_index, 0);
-      nat44_ed_add_del_addr_to_fib_foreach_addr_only_sm (sw_if_index, 0);
+      nat44_ed_add_del_nat_addr_fib_reg_entries (sw_if_index, 0);
+      nat44_ed_add_del_sm_fib_reg_entries (sw_if_index, 0);
     }
 
   return 0;
@@ -1870,7 +1931,7 @@ nat44_ed_add_output_interface (u32 sw_if_index)
 {
   snat_main_t *sm = &snat_main;
 
-  nat_outside_fib_t *outside_fib;
+  nat_fib_t *outside_fib;
   snat_interface_t *i;
   u32 fib_index;
   int rv;
@@ -1948,17 +2009,17 @@ nat44_ed_add_output_interface (u32 sw_if_index)
   outside_fib = nat44_ed_get_outside_fib (sm->outside_fibs, fib_index);
   if (outside_fib)
     {
-      outside_fib->refcount++;
+      outside_fib->ref_count++;
     }
   else
     {
       vec_add2 (sm->outside_fibs, outside_fib, 1);
       outside_fib->fib_index = fib_index;
-      outside_fib->refcount = 1;
+      outside_fib->ref_count = 1;
     }
 
-  nat44_ed_add_del_addr_to_fib_foreach_addr (sw_if_index, 1);
-  nat44_ed_add_del_addr_to_fib_foreach_addr_only_sm (sw_if_index, 1);
+  nat44_ed_add_del_nat_addr_fib_reg_entries (sw_if_index, 1);
+  nat44_ed_add_del_sm_fib_reg_entries (sw_if_index, 1);
 
   nat44_ed_bind_if_addr_to_nat_addr (sw_if_index);
 
@@ -1970,7 +2031,7 @@ nat44_ed_del_output_interface (u32 sw_if_index)
 {
   snat_main_t *sm = &snat_main;
 
-  nat_outside_fib_t *outside_fib;
+  nat_fib_t *outside_fib;
   snat_interface_t *i;
   u32 fib_index;
   int rv;
@@ -2038,15 +2099,15 @@ nat44_ed_del_output_interface (u32 sw_if_index)
   outside_fib = nat44_ed_get_outside_fib (sm->outside_fibs, fib_index);
   if (outside_fib)
     {
-      outside_fib->refcount--;
-      if (!outside_fib->refcount)
+      outside_fib->ref_count--;
+      if (!outside_fib->ref_count)
        {
          vec_del1 (sm->outside_fibs, outside_fib - sm->outside_fibs);
        }
     }
 
-  nat44_ed_add_del_addr_to_fib_foreach_addr (sw_if_index, 0);
-  nat44_ed_add_del_addr_to_fib_foreach_addr_only_sm (sw_if_index, 0);
+  nat44_ed_add_del_nat_addr_fib_reg_entries (sw_if_index, 0);
+  nat44_ed_add_del_sm_fib_reg_entries (sw_if_index, 0);
 
   return 0;
 }
@@ -2082,6 +2143,18 @@ nat44_ed_set_frame_queue_nelts (u32 frame_queue_nelts)
 {
   fail_if_enabled ();
   snat_main_t *sm = &snat_main;
+
+  if ((sm->fq_in2out_index != ~0) || (sm->fq_out2in_index != ~0) ||
+      (sm->fq_in2out_output_index != ~0))
+    {
+      // frame queu nelts can be set only before first
+      // call to nat44_plugin_enable after that it
+      // doesn't make sense
+      nat_log_err ("Frame queue was already initialized. "
+                  "Change is not possible");
+      return 1;
+    }
+
   sm->frame_queue_nelts = frame_queue_nelts;
   return 0;
 }
@@ -2091,7 +2164,7 @@ nat44_ed_update_outside_fib_cb (ip4_main_t *im, uword opaque, u32 sw_if_index,
                                u32 new_fib_index, u32 old_fib_index)
 {
   snat_main_t *sm = &snat_main;
-  nat_outside_fib_t *outside_fib;
+  nat_fib_t *outside_fib;
   snat_interface_t *i;
   u8 is_add = 1;
   u8 match = 0;
@@ -2103,7 +2176,7 @@ nat44_ed_update_outside_fib_cb (ip4_main_t *im, uword opaque, u32 sw_if_index,
     }
 
   pool_foreach (i, sm->interfaces)
-     {
+    {
       if (i->sw_if_index == sw_if_index)
         {
          if (!(nat44_ed_is_interface_outside (i)))
@@ -2113,7 +2186,7 @@ nat44_ed_update_outside_fib_cb (ip4_main_t *im, uword opaque, u32 sw_if_index,
     }
 
   pool_foreach (i, sm->output_feature_interfaces)
-     {
+    {
       if (i->sw_if_index == sw_if_index)
         {
          if (!(nat44_ed_is_interface_outside (i)))
@@ -2126,30 +2199,30 @@ nat44_ed_update_outside_fib_cb (ip4_main_t *im, uword opaque, u32 sw_if_index,
     return;
 
   vec_foreach (outside_fib, sm->outside_fibs)
-  {
-    if (outside_fib->fib_index == old_fib_index)
-      {
-       outside_fib->refcount--;
-       if (!outside_fib->refcount)
-         vec_del1 (sm->outside_fibs, outside_fib - sm->outside_fibs);
-       break;
-      }
-  }
+    {
+      if (outside_fib->fib_index == old_fib_index)
+       {
+         outside_fib->ref_count--;
+         if (!outside_fib->ref_count)
+           vec_del1 (sm->outside_fibs, outside_fib - sm->outside_fibs);
+         break;
+       }
+    }
 
   vec_foreach (outside_fib, sm->outside_fibs)
-  {
-    if (outside_fib->fib_index == new_fib_index)
-      {
-       outside_fib->refcount++;
-       is_add = 0;
-       break;
-      }
-  }
+    {
+      if (outside_fib->fib_index == new_fib_index)
+       {
+         outside_fib->ref_count++;
+         is_add = 0;
+         break;
+       }
+    }
 
   if (is_add)
     {
       vec_add2 (sm->outside_fibs, outside_fib, 1);
-      outside_fib->refcount = 1;
+      outside_fib->ref_count = 1;
       outside_fib->fib_index = new_fib_index;
     }
 }
@@ -2162,7 +2235,7 @@ static void nat44_ed_add_del_interface_address_cb (
   ip4_main_t *im, uword opaque, u32 sw_if_index, ip4_address_t *address,
   u32 address_length, u32 if_address_index, u32 is_delete);
 
-static void nat44_ed_add_del_static_mapping_addr_only_cb (
+static void nat44_ed_add_del_static_mapping_cb (
   ip4_main_t *im, uword opaque, u32 sw_if_index, ip4_address_t *address,
   u32 address_length, u32 if_address_index, u32 is_delete);
 
@@ -2225,21 +2298,6 @@ nat_ip_table_add_del (vnet_main_t * vnm, u32 table_id, u32 is_add)
 
 VNET_IP_TABLE_ADD_DEL_FUNCTION (nat_ip_table_add_del);
 
-void
-nat44_set_node_indexes (snat_main_t * sm, vlib_main_t * vm)
-{
-  vlib_node_t *node;
-
-  node = vlib_get_node_by_name (vm, (u8 *) "nat44-ed-out2in");
-  sm->out2in_node_index = node->index;
-
-  node = vlib_get_node_by_name (vm, (u8 *) "nat44-ed-in2out");
-  sm->in2out_node_index = node->index;
-
-  node = vlib_get_node_by_name (vm, (u8 *) "nat44-ed-in2out-output");
-  sm->in2out_output_node_index = node->index;
-}
-
 #define nat_validate_simple_counter(c, i)                                     \
   do                                                                          \
     {                                                                         \
@@ -2287,8 +2345,6 @@ nat_init (vlib_main_t * vm)
   sm->vnet_main = vnet_get_main ();
   // convenience
   sm->ip4_main = &ip4_main;
-  sm->api_main = vlibapi_get_main ();
-  sm->ip4_lookup_main = &ip4_main.lookup_main;
 
   // frame queue indices used for handoff
   sm->fq_out2in_index = ~0;
@@ -2297,15 +2353,13 @@ nat_init (vlib_main_t * vm)
 
   sm->log_level = NAT_LOG_ERROR;
 
-  nat44_set_node_indexes (sm, vm);
-
   sm->log_class = vlib_log_register_class ("nat", 0);
   nat_ipfix_logging_init (vm);
 
   nat_init_simple_counter (sm->total_sessions, "total-sessions",
                           "/nat44-ed/total-sessions");
-  sm->max_cfg_sessions_gauge = stat_segment_new_entry (
-    (u8 *) "/nat44-ed/max-cfg-sessions", STAT_DIR_TYPE_SCALAR_INDEX);
+  sm->max_cfg_sessions_gauge =
+    vlib_stats_add_gauge ("/nat44-ed/max-cfg-sessions");
 
 #define _(x)                                                                  \
   nat_init_simple_counter (sm->counters.fastpath.in2out.x, #x,                \
@@ -2351,7 +2405,7 @@ nat_init (vlib_main_t * vm)
   /* callbacks to call when interface address changes. */
   cbi.function = nat44_ed_add_del_interface_address_cb;
   vec_add1 (sm->ip4_main->add_del_interface_address_callbacks, cbi);
-  cbi.function = nat44_ed_add_del_static_mapping_addr_only_cb;
+  cbi.function = nat44_ed_add_del_static_mapping_cb;
   vec_add1 (sm->ip4_main->add_del_interface_address_callbacks, cbi);
 
   /* callbacks to call when interface to table biding changes */
@@ -2380,26 +2434,15 @@ nat44_plugin_enable (nat44_config_t c)
 
   fail_if_enabled ();
 
-  if (c.static_mapping_only && !c.connection_tracking)
-    {
-      nat_log_err ("unsupported combination of configuration");
-      return 1;
-    }
-
-  sm->static_mapping_only = c.static_mapping_only;
-  sm->static_mapping_connection_tracking = c.connection_tracking;
-
   sm->forwarding_enabled = 0;
   sm->mss_clamping = 0;
-  sm->pat = (!c.static_mapping_only ||
-            (c.static_mapping_only && c.connection_tracking));
 
   if (!c.sessions)
     c.sessions = 63 * 1024;
 
   sm->max_translations_per_thread = c.sessions;
-  stat_segment_set_state_counter (sm->max_cfg_sessions_gauge,
-                                 sm->max_translations_per_thread);
+  vlib_stats_set_gauge (sm->max_cfg_sessions_gauge,
+                       sm->max_translations_per_thread);
   sm->translation_buckets = nat_calc_bihash_buckets (c.sessions);
 
   vec_add1 (sm->max_translations_per_fib, sm->max_translations_per_thread);
@@ -2415,6 +2458,8 @@ nat44_plugin_enable (nat44_config_t c)
 
   nat44_ed_db_init (sm->max_translations_per_thread, sm->translation_buckets);
 
+  nat44_ed_init_tcp_state_stable (sm);
+
   nat_affinity_enable ();
 
   nat_reset_timeouts (&sm->timeouts);
@@ -2428,20 +2473,26 @@ nat44_plugin_enable (nat44_config_t c)
 
   if (sm->num_workers > 1)
     {
+      vlib_main_t *vm = vlib_get_main ();
+      vlib_node_t *node;
+
       if (sm->fq_in2out_index == ~0)
        {
-         sm->fq_in2out_index = vlib_frame_queue_main_init (
-           sm->in2out_node_index, sm->frame_queue_nelts);
+         node = vlib_get_node_by_name (vm, (u8 *) "nat44-ed-in2out");
+         sm->fq_in2out_index =
+           vlib_frame_queue_main_init (node->index, sm->frame_queue_nelts);
        }
       if (sm->fq_out2in_index == ~0)
        {
-         sm->fq_out2in_index = vlib_frame_queue_main_init (
-           sm->out2in_node_index, sm->frame_queue_nelts);
+         node = vlib_get_node_by_name (vm, (u8 *) "nat44-ed-out2in");
+         sm->fq_out2in_index =
+           vlib_frame_queue_main_init (node->index, sm->frame_queue_nelts);
        }
       if (sm->fq_in2out_output_index == ~0)
        {
-         sm->fq_in2out_output_index = vlib_frame_queue_main_init (
-           sm->in2out_output_node_index, sm->frame_queue_nelts);
+         node = vlib_get_node_by_name (vm, (u8 *) "nat44-ed-in2out-output");
+         sm->fq_in2out_output_index =
+           vlib_frame_queue_main_init (node->index, sm->frame_queue_nelts);
        }
     }
 
@@ -2461,7 +2512,7 @@ nat44_ed_del_addresses ()
   vec = vec_dup (sm->addresses);
   vec_foreach (a, vec)
     {
-      error = nat44_ed_del_address (a->addr, 0, 0);
+      error = nat44_ed_del_address (a->addr, 0);
       if (error)
        {
          nat_log_err ("error occurred while removing adderess");
@@ -2474,7 +2525,7 @@ nat44_ed_del_addresses ()
   vec = vec_dup (sm->twice_nat_addresses);
   vec_foreach (a, vec)
     {
-      error = nat44_ed_del_address (a->addr, 0, 1);
+      error = nat44_ed_del_address (a->addr, 1);
       if (error)
        {
          nat_log_err ("error occurred while removing adderess");
@@ -2484,11 +2535,8 @@ nat44_ed_del_addresses ()
   vec_free (sm->twice_nat_addresses);
   sm->twice_nat_addresses = 0;
 
-  vec_free (sm->auto_add_sw_if_indices_twice_nat);
-  sm->auto_add_sw_if_indices_twice_nat = 0;
-
-  vec_free (sm->auto_add_sw_if_indices);
-  sm->auto_add_sw_if_indices = 0;
+  vec_free (sm->addr_to_resolve);
+  sm->addr_to_resolve = 0;
 
   return error;
 }
@@ -2557,7 +2605,7 @@ nat44_ed_del_static_mappings ()
     {
       error = nat44_ed_del_static_mapping_internal (
        m->local_addr, m->external_addr, m->local_port, m->external_port,
-       m->proto, m->vrf_id, ~0, m->flags);
+       m->proto, m->vrf_id, m->flags);
       if (error)
        {
          nat_log_err ("error occurred while removing mapping");
@@ -2567,8 +2615,8 @@ nat44_ed_del_static_mappings ()
   pool_free (sm->static_mappings);
   sm->static_mappings = 0;
 
-  vec_free (sm->to_resolve);
-  sm->to_resolve = 0;
+  vec_free (sm->sm_to_resolve);
+  sm->sm_to_resolve = 0;
 
   return error;
 }
@@ -2598,21 +2646,22 @@ nat44_plugin_disable ()
   if (rc)
     error = 1;
 
+  nat44_ed_del_vrf_tables ();
+
   vec_free (sm->max_translations_per_fib);
   sm->max_translations_per_fib = 0;
 
   clib_bihash_free_16_8 (&sm->flow_hash);
 
-  if (sm->pat)
+  vec_foreach (tsm, sm->per_thread_data)
     {
-      vec_foreach (tsm, sm->per_thread_data)
-       {
-         nat44_ed_worker_db_free (tsm);
-       }
+      nat44_ed_worker_db_free (tsm);
     }
 
   clib_memset (&sm->rconfig, 0, sizeof (sm->rconfig));
 
+  nat_affinity_disable ();
+
   sm->forwarding_enabled = 0;
   sm->enabled = 0;
 
@@ -2668,11 +2717,12 @@ nat44_ed_sm_match (snat_main_t *sm, ip4_address_t match_addr, u16 match_port,
       if (m)
        return m;
 
-      /* Try address only mapping */
+      // try address only mapping
       m = nat44_ed_sm_i2o_lookup (sm, match_addr, 0, match_fib_index, 0);
       if (m)
        return m;
 
+      // default static mapping fib index (based on configuration)
       if (sm->inside_fib_index != match_fib_index)
        {
          m = nat44_ed_sm_i2o_lookup (sm, match_addr, match_port,
@@ -2680,12 +2730,13 @@ nat44_ed_sm_match (snat_main_t *sm, ip4_address_t match_addr, u16 match_port,
          if (m)
            return m;
 
-         /* Try address only mapping */
+         // try address only mapping
          m = nat44_ed_sm_i2o_lookup (sm, match_addr, 0, sm->inside_fib_index,
                                      0);
          if (m)
            return m;
        }
+      // TODO: this specific use case may be deprecated (needs testing)
       if (sm->outside_fib_index != match_fib_index)
        {
          m = nat44_ed_sm_i2o_lookup (sm, match_addr, match_port,
@@ -2693,7 +2744,7 @@ nat44_ed_sm_match (snat_main_t *sm, ip4_address_t match_addr, u16 match_port,
          if (m)
            return m;
 
-         /* Try address only mapping */
+         // try address only mapping
          m = nat44_ed_sm_i2o_lookup (sm, match_addr, 0, sm->outside_fib_index,
                                      0);
          if (m)
@@ -2707,7 +2758,7 @@ nat44_ed_sm_match (snat_main_t *sm, ip4_address_t match_addr, u16 match_port,
       if (m)
        return m;
 
-      /* Try address only mapping */
+      // try address only mapping
       m = nat44_ed_sm_o2i_lookup (sm, match_addr, 0, 0, 0);
       if (m)
        return m;
@@ -2716,15 +2767,16 @@ nat44_ed_sm_match (snat_main_t *sm, ip4_address_t match_addr, u16 match_port,
 }
 
 int
-snat_static_mapping_match (vlib_main_t *vm, snat_main_t *sm,
-                          ip4_address_t match_addr, u16 match_port,
-                          u32 match_fib_index, ip_protocol_t match_protocol,
+snat_static_mapping_match (vlib_main_t *vm, ip4_address_t match_addr,
+                          u16 match_port, u32 match_fib_index,
+                          ip_protocol_t match_protocol,
                           ip4_address_t *mapping_addr, u16 *mapping_port,
                           u32 *mapping_fib_index, int by_external,
                           u8 *is_addr_only, twice_nat_type_t *twice_nat,
                           lb_nat_type_t *lb, ip4_address_t *ext_host_addr,
                           u8 *is_identity_nat, snat_static_mapping_t **out)
 {
+  snat_main_t *sm = &snat_main;
   snat_static_mapping_t *m;
   u32 rand, lo = 0, hi, mid, *tmp = 0, i;
   nat44_lb_addr_port_t *local;
@@ -2868,7 +2920,7 @@ nat44_ed_get_in2out_worker_index (vlib_buffer_t *b, ip4_header_t *ip,
       if (PREDICT_FALSE (is_output))
        {
          fib_index = sm->outside_fib_index;
-         nat_outside_fib_t *outside_fib;
+         nat_fib_t *outside_fib;
          fib_node_index_t fei = FIB_NODE_INDEX_INVALID;
          fib_prefix_t pfx = {
                  .fp_proto = FIB_PROTOCOL_IP4,
@@ -3064,7 +3116,7 @@ nat44_ed_get_out2in_worker_index (vlib_buffer_t *b, ip4_header_t *ip,
     {
       udp_header_t *udp = ip4_next_header (ip);
       icmp46_header_t *icmp = (icmp46_header_t *) udp;
-      icmp_echo_header_t *echo = (icmp_echo_header_t *) (icmp + 1);
+      nat_icmp_echo_header_t *echo = (nat_icmp_echo_header_t *) (icmp + 1);
       if (!icmp_type_is_error_message
          (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags))
        port = vnet_buffer (b)->ip.reass.l4_src_port;
@@ -3078,13 +3130,13 @@ nat44_ed_get_out2in_worker_index (vlib_buffer_t *b, ip4_header_t *ip,
            {
            case IP_PROTOCOL_ICMP:
              icmp = (icmp46_header_t *) l4_header;
-             echo = (icmp_echo_header_t *) (icmp + 1);
+             echo = (nat_icmp_echo_header_t *) (icmp + 1);
              port = echo->identifier;
              break;
            case IP_PROTOCOL_UDP:
              /* breakthrough */
            case IP_PROTOCOL_TCP:
-             port = ((tcp_udp_header_t *) l4_header)->src_port;
+             port = ((nat_tcp_udp_header_t *) l4_header)->src_port;
              break;
            default:
              next_worker_index = vlib_get_thread_index ();
@@ -3172,8 +3224,8 @@ nat44_update_session_limit (u32 session_limit, u32 vrf_id)
     return 1;
   sm->max_translations_per_thread = nat44_get_max_session_limit ();
 
-  stat_segment_set_state_counter (sm->max_cfg_sessions_gauge,
-                                 sm->max_translations_per_thread);
+  vlib_stats_set_gauge (sm->max_cfg_sessions_gauge,
+                       sm->max_translations_per_thread);
 
   sm->translation_buckets =
     nat_calc_bihash_buckets (sm->max_translations_per_thread);
@@ -3231,13 +3283,10 @@ nat44_ed_db_init (u32 translations, u32 translation_buckets)
 
   reinit_ed_flow_hash ();
 
-  if (sm->pat)
+  vec_foreach (tsm, sm->per_thread_data)
     {
-      vec_foreach (tsm, sm->per_thread_data)
-       {
-         nat44_ed_worker_db_init (tsm, sm->max_translations_per_thread,
-                                  sm->translation_buckets);
-       }
+      nat44_ed_worker_db_init (tsm, sm->max_translations_per_thread,
+                              sm->translation_buckets);
     }
 }
 
@@ -3257,95 +3306,105 @@ nat44_ed_sessions_clear ()
 
   reinit_ed_flow_hash ();
 
-  if (sm->pat)
+  vec_foreach (tsm, sm->per_thread_data)
     {
-      vec_foreach (tsm, sm->per_thread_data)
-       {
-
-         nat44_ed_worker_db_free (tsm);
-         nat44_ed_worker_db_init (tsm, sm->max_translations_per_thread,
-                                  sm->translation_buckets);
-       }
+      nat44_ed_worker_db_free (tsm);
+      nat44_ed_worker_db_init (tsm, sm->max_translations_per_thread,
+                              sm->translation_buckets);
     }
   vlib_zero_simple_counter (&sm->total_sessions, 0);
 }
 
 static void
-nat44_ed_add_del_static_mapping_addr_only_cb (
-  ip4_main_t *im, uword opaque, u32 sw_if_index, ip4_address_t *address,
-  u32 address_length, u32 if_address_index, u32 is_delete)
+nat44_ed_add_del_static_mapping_cb (ip4_main_t *im, uword opaque,
+                                   u32 sw_if_index, ip4_address_t *address,
+                                   u32 address_length, u32 if_address_index,
+                                   u32 is_delete)
 {
-  snat_static_map_resolve_t *rp;
+  snat_static_mapping_resolve_t *rp;
   snat_main_t *sm = &snat_main;
-  snat_static_mapping_t *m;
-  int i, rv = 0, match = 0;
+  int rv = 0;
 
   if (!sm->enabled)
     {
       return;
     }
 
-  // find first addr_only resolve record by sw_if_index
-  for (i = 0; i < vec_len (sm->to_resolve); i++)
+  vec_foreach (rp, sm->sm_to_resolve)
     {
-      rp = sm->to_resolve + i;
-      if (is_sm_addr_only (rp->flags) && rp->sw_if_index == sw_if_index)
+      if (sw_if_index == rp->sw_if_index)
        {
-         match = 1;
-         break;
+         if (is_delete)
+           {
+             if (rp->is_resolved)
+               {
+                 rv = nat44_ed_del_static_mapping_internal (
+                   rp->l_addr, address[0], rp->l_port, rp->e_port, rp->proto,
+                   rp->vrf_id, rp->flags);
+                 if (rv)
+                   {
+                     nat_log_err ("ed del static mapping failed");
+                   }
+                 else
+                   {
+                     rp->is_resolved = 0;
+                   }
+               }
+           }
+         else
+           {
+             if (!rp->is_resolved)
+               {
+                 rv = nat44_ed_add_static_mapping_internal (
+                   rp->l_addr, address[0], rp->l_port, rp->e_port, rp->proto,
+                   rp->vrf_id, ~0, rp->flags, rp->pool_addr, rp->tag);
+                 if (rv)
+                   {
+                     nat_log_err ("ed add static mapping failed");
+                   }
+                 else
+                   {
+                     rp->is_resolved = 1;
+                   }
+               }
+           }
        }
     }
-  if (!match)
-    {
-      return;
-    }
+}
 
-  m = nat44_ed_sm_o2i_lookup (
-    sm, *address, is_sm_addr_only (rp->flags) ? 0 : rp->e_port, 0, rp->proto);
+static int
+nat44_ed_get_addr_resolve_record (u32 sw_if_index, u8 twice_nat, int *out)
+{
+  snat_main_t *sm = &snat_main;
+  snat_address_resolve_t *rp;
+  int i;
 
-  if (is_delete)
-    {
-      if (m)
-       {
-         rv = nat44_ed_del_static_mapping_internal (
-           rp->l_addr, address[0], rp->l_port, rp->e_port, rp->proto,
-           rp->vrf_id, ~0, rp->flags);
-       }
-      if (rv)
-       {
-         nat_elog_notice_X1 (sm, "nat44_ed_del_static_mapping returned %d",
-                             "i4", rv);
-       }
-    }
-  else
+  for (i = 0; i < vec_len (sm->addr_to_resolve); i++)
     {
-      if (!m)
-       {
-         rv = nat44_ed_add_static_mapping_internal (
-           rp->l_addr, address[0], rp->l_port, rp->e_port, rp->proto,
-           rp->vrf_id, ~0, rp->flags, rp->pool_addr, rp->tag);
-       }
-      // else: don't trip over lease renewal, static config
-      if (rv)
+      rp = sm->addr_to_resolve + i;
+
+      if ((rp->sw_if_index == sw_if_index) && (rp->is_twice_nat == twice_nat))
        {
-         nat_elog_notice_X1 (sm, "nat44_ed_add_static_mapping returned %d",
-                             "i4", rv);
+         if (out)
+           {
+             *out = i;
+           }
+         return 0;
        }
     }
+  return 1;
 }
-
-static_always_inline int
-is_sw_if_index_reg_for_auto_resolve (u32 *sw_if_indices, u32 sw_if_index)
+static int
+nat44_ed_del_addr_resolve_record (u32 sw_if_index, u8 twice_nat)
 {
-  u32 *i;
-  vec_foreach (i, sw_if_indices)
+  snat_main_t *sm = &snat_main;
+  int i;
+  if (!nat44_ed_get_addr_resolve_record (sw_if_index, twice_nat, &i))
     {
-      if (*i == sw_if_index)
-       {
-         return 1;
-       }
+      vec_del1 (sm->addr_to_resolve, i);
+      return 0;
     }
-  return 0;
+  return 1;
 }
 
 static void
@@ -3355,23 +3414,21 @@ nat44_ed_add_del_interface_address_cb (ip4_main_t *im, uword opaque,
                                       u32 if_address_index, u32 is_delete)
 {
   snat_main_t *sm = &snat_main;
-  snat_static_map_resolve_t *rp;
-  snat_address_t *ap, *addresses = sm->addresses;
+  snat_address_resolve_t *arp;
+  snat_address_t *ap;
   u8 twice_nat = 0;
-  int rv, i;
+  int i, rv;
 
   if (!sm->enabled)
     {
       return;
     }
 
-  if (!is_sw_if_index_reg_for_auto_resolve (sm->auto_add_sw_if_indices,
-                                           sw_if_index))
+  if (nat44_ed_get_addr_resolve_record (sw_if_index, twice_nat, &i))
     {
-      if (!is_sw_if_index_reg_for_auto_resolve (
-           sm->auto_add_sw_if_indices_twice_nat, sw_if_index))
+      twice_nat = 1;
+      if (nat44_ed_get_addr_resolve_record (sw_if_index, twice_nat, &i))
        {
-         // interface resolve
          u32 fib_index =
            ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
          vec_foreach (ap, sm->addresses)
@@ -3400,51 +3457,35 @@ nat44_ed_add_del_interface_address_cb (ip4_main_t *im, uword opaque,
            }
          return;
        }
-      else
-       {
-         addresses = sm->twice_nat_addresses;
-         twice_nat = 1;
-       }
     }
 
+  arp = sm->addr_to_resolve + i;
+
   if (!is_delete)
     {
-      // don't trip over lease renewal, static config
-      for (i = 0; i < vec_len (addresses); i++)
+      if (arp->is_resolved)
        {
-         if (addresses[i].addr.as_u32 == address->as_u32)
-           {
-             return;
-           }
+         return;
        }
 
-      (void) nat44_ed_add_address (address, ~0, twice_nat);
-
-      // scan static mapping switch address resolution record vector
-      for (i = 0; i < vec_len (sm->to_resolve); i++)
+      rv = nat44_ed_add_address (address, ~0, arp->is_twice_nat);
+      if (0 == rv)
        {
-         rp = sm->to_resolve + i;
-         if (is_sm_addr_only (rp->flags))
-           {
-             continue;
-           }
-         if (rp->sw_if_index == sw_if_index)
-           {
-             rv = nat44_ed_add_static_mapping_internal (
-               rp->l_addr, address[0], rp->l_port, rp->e_port, rp->proto,
-               rp->vrf_id, sw_if_index, rp->flags, rp->pool_addr, rp->tag);
-             if (rv)
-               {
-                 nat_elog_notice_X1 (
-                   sm, "add_static_mapping_internal returned %d", "i4", rv);
-               }
-           }
+         arp->is_resolved = 1;
        }
     }
   else
     {
-      // remove all static mapping records
-      (void) nat44_ed_del_address (address[0], 1, twice_nat);
+      if (!arp->is_resolved)
+       {
+         return;
+       }
+
+      rv = nat44_ed_del_address (address[0], arp->is_twice_nat);
+      if (0 == rv)
+       {
+         arp->is_resolved = 0;
+       }
     }
 }
 
@@ -3454,34 +3495,34 @@ nat44_ed_add_interface_address (u32 sw_if_index, u8 twice_nat)
   snat_main_t *sm = &snat_main;
   ip4_main_t *ip4_main = sm->ip4_main;
   ip4_address_t *first_int_addr;
-  u32 *auto_add_sw_if_indices = twice_nat ?
-                                 sm->auto_add_sw_if_indices_twice_nat :
-                                 sm->auto_add_sw_if_indices;
-  int i;
+  snat_address_resolve_t *ap;
+  int rv;
 
-  for (i = 0; i < vec_len (auto_add_sw_if_indices); i++)
+  if (!sm->enabled)
     {
-      if (auto_add_sw_if_indices[i] == sw_if_index)
-       {
-         return VNET_API_ERROR_VALUE_EXIST;
-       }
+      return VNET_API_ERROR_UNSUPPORTED;
     }
 
-  // add to the auto-address list
-  if (twice_nat)
+  if (!nat44_ed_get_addr_resolve_record (sw_if_index, twice_nat, 0))
     {
-      vec_add1 (sm->auto_add_sw_if_indices_twice_nat, sw_if_index);
-    }
-  else
-    {
-      vec_add1 (sm->auto_add_sw_if_indices, sw_if_index);
+      return VNET_API_ERROR_VALUE_EXIST;
     }
 
-  // if the address is already bound - or static - add it now
+  vec_add2 (sm->addr_to_resolve, ap, 1);
+  ap->sw_if_index = sw_if_index;
+  ap->is_twice_nat = twice_nat;
+  ap->is_resolved = 0;
+
   first_int_addr = ip4_interface_first_address (ip4_main, sw_if_index, 0);
   if (first_int_addr)
     {
-      (void) nat44_ed_add_address (first_int_addr, ~0, twice_nat);
+      rv = nat44_ed_add_address (first_int_addr, ~0, twice_nat);
+      if (0 != rv)
+       {
+         nat44_ed_del_addr_resolve_record (sw_if_index, twice_nat);
+         return rv;
+       }
+      ap->is_resolved = 1;
     }
 
   return 0;
@@ -3493,62 +3534,24 @@ nat44_ed_del_interface_address (u32 sw_if_index, u8 twice_nat)
   snat_main_t *sm = &snat_main;
   ip4_main_t *ip4_main = sm->ip4_main;
   ip4_address_t *first_int_addr;
-  snat_static_map_resolve_t *rp;
-  u32 *indices_to_delete = 0;
-  int i, j;
-  u32 *auto_add_sw_if_indices;
 
   if (!sm->enabled)
     {
       return VNET_API_ERROR_UNSUPPORTED;
     }
 
-  auto_add_sw_if_indices = twice_nat ? sm->auto_add_sw_if_indices_twice_nat :
-                                      sm->auto_add_sw_if_indices;
-
-  for (i = 0; i < vec_len (auto_add_sw_if_indices); i++)
+  if (nat44_ed_del_addr_resolve_record (sw_if_index, twice_nat))
     {
-      if (auto_add_sw_if_indices[i] == sw_if_index)
-       {
-         first_int_addr =
-           ip4_interface_first_address (ip4_main, sw_if_index, 0);
-         if (first_int_addr)
-           {
-             // remove all static mapping records
-             (void) nat44_ed_del_address (first_int_addr[0], 1, twice_nat);
-           }
-         else
-           {
-             for (j = 0; j < vec_len (sm->to_resolve); j++)
-               {
-                 rp = sm->to_resolve + j;
-                 if (rp->sw_if_index == sw_if_index)
-                   {
-                     vec_add1 (indices_to_delete, j);
-                   }
-               }
-             if (vec_len (indices_to_delete))
-               {
-                 for (j = vec_len (indices_to_delete) - 1; j >= 0; j--)
-                   {
-                     vec_del1 (sm->to_resolve, j);
-                   }
-                 vec_free (indices_to_delete);
-               }
-           }
+      return VNET_API_ERROR_NO_SUCH_ENTRY;
+    }
 
-         if (twice_nat)
-           {
-             vec_del1 (sm->auto_add_sw_if_indices_twice_nat, i);
-           }
-         else
-           {
-             vec_del1 (sm->auto_add_sw_if_indices, i);
-           }
-         return 0;
-       }
+  first_int_addr = ip4_interface_first_address (ip4_main, sw_if_index, 0);
+  if (first_int_addr)
+    {
+      return nat44_ed_del_address (first_int_addr[0], twice_nat);
     }
-  return VNET_API_ERROR_NO_SUCH_ENTRY;
+
+  return 0;
 }
 
 int
@@ -3781,7 +3784,7 @@ nat_6t_flow_icmp_translate (vlib_main_t *vm, snat_main_t *sm, vlib_buffer_t *b,
     return NAT_ED_TRNSL_ERR_TRANSLATION_FAILED;
 
   icmp46_header_t *icmp = ip4_next_header (ip);
-  icmp_echo_header_t *echo = (icmp_echo_header_t *) (icmp + 1);
+  nat_icmp_echo_header_t *echo = (nat_icmp_echo_header_t *) (icmp + 1);
 
   if ((!vnet_buffer (b)->ip.reass.is_non_first_fragment))
     {
@@ -3797,7 +3800,7 @@ nat_6t_flow_icmp_translate (vlib_main_t *vm, snat_main_t *sm, vlib_buffer_t *b,
            {
              ip_csum_t sum = icmp->checksum;
              sum = ip_csum_update (sum, echo->identifier, f->rewrite.icmp_id,
-                                   icmp_echo_header_t,
+                                   nat_icmp_echo_header_t,
                                    identifier /* changed member */);
              echo->identifier = f->rewrite.icmp_id;
              icmp->checksum = ip_csum_fold (sum);
@@ -3877,6 +3880,9 @@ nat_6t_flow_icmp_translate (vlib_main_t *vm, snat_main_t *sm, vlib_buffer_t *b,
              icmp->checksum = new_icmp_sum;
              break;
            case IP_PROTOCOL_ICMP:
+             nat_6t_flow_ip4_translate (sm, b, inner_ip, f, inner_proto,
+                                        1 /* is_icmp_inner_ip4 */,
+                                        0 /* skip_saddr_rewrite */);
              if (f->ops & NAT_FLOW_OP_ICMP_ID_REWRITE)
                {
                  icmp46_header_t *inner_icmp = ip4_next_header (inner_ip);
@@ -3884,19 +3890,21 @@ nat_6t_flow_icmp_translate (vlib_main_t *vm, snat_main_t *sm, vlib_buffer_t *b,
                    {
                      return NAT_ED_TRNSL_ERR_PACKET_TRUNCATED;
                    }
-                 icmp_echo_header_t *inner_echo =
-                   (icmp_echo_header_t *) (inner_icmp + 1);
+                 nat_icmp_echo_header_t *inner_echo =
+                   (nat_icmp_echo_header_t *) (inner_icmp + 1);
                  if (f->rewrite.icmp_id != inner_echo->identifier)
                    {
                      ip_csum_t sum = icmp->checksum;
-                     sum = ip_csum_update (
-                       sum, inner_echo->identifier, f->rewrite.icmp_id,
-                       icmp_echo_header_t, identifier /* changed member */);
+                     sum = ip_csum_update (sum, inner_echo->identifier,
+                                           f->rewrite.icmp_id,
+                                           nat_icmp_echo_header_t,
+                                           identifier /* changed member */);
                      icmp->checksum = ip_csum_fold (sum);
                      ip_csum_t inner_sum = inner_icmp->checksum;
                      inner_sum = ip_csum_update (
                        sum, inner_echo->identifier, f->rewrite.icmp_id,
-                       icmp_echo_header_t, identifier /* changed member */);
+                       nat_icmp_echo_header_t,
+                       identifier /* changed member */);
                      inner_icmp->checksum = ip_csum_fold (inner_sum);
                      inner_echo->identifier = f->rewrite.icmp_id;
                    }
@@ -3968,110 +3976,7 @@ nat_6t_flow_buf_translate_o2i (vlib_main_t *vm, snat_main_t *sm,
                                    0 /* is_i2o */);
 }
 
-u8 *
-format_nat_6t (u8 *s, va_list *args)
-{
-  nat_6t_t *t = va_arg (*args, nat_6t_t *);
-
-  s = format (s, "saddr %U sport %u daddr %U dport %u proto %U fib_idx %u",
-             format_ip4_address, t->saddr.as_u8,
-             clib_net_to_host_u16 (t->sport), format_ip4_address,
-             t->daddr.as_u8, clib_net_to_host_u16 (t->dport),
-             format_ip_protocol, t->proto, t->fib_index);
-  return s;
-}
-
-u8 *
-format_nat_ed_translation_error (u8 *s, va_list *args)
-{
-  nat_translation_error_e e = va_arg (*args, nat_translation_error_e);
-
-  switch (e)
-    {
-    case NAT_ED_TRNSL_ERR_SUCCESS:
-      s = format (s, "success");
-      break;
-    case NAT_ED_TRNSL_ERR_TRANSLATION_FAILED:
-      s = format (s, "translation-failed");
-      break;
-    case NAT_ED_TRNSL_ERR_FLOW_MISMATCH:
-      s = format (s, "flow-mismatch");
-      break;
-    case NAT_ED_TRNSL_ERR_PACKET_TRUNCATED:
-      s = format (s, "packet-truncated");
-      break;
-    case NAT_ED_TRNSL_ERR_INNER_IP_CORRUPT:
-      s = format (s, "inner-ip-corrupted");
-      break;
-    case NAT_ED_TRNSL_ERR_INVALID_CSUM:
-      s = format (s, "invalid-checksum");
-      break;
-    }
-  return s;
-}
-
-u8 *
-format_nat_6t_flow (u8 *s, va_list *args)
-{
-  nat_6t_flow_t *f = va_arg (*args, nat_6t_flow_t *);
-
-  s = format (s, "match: %U ", format_nat_6t, &f->match);
-  int r = 0;
-  if (f->ops & NAT_FLOW_OP_SADDR_REWRITE)
-    {
-      s = format (s, "rewrite: saddr %U ", format_ip4_address,
-                 f->rewrite.saddr.as_u8);
-      r = 1;
-    }
-  if (f->ops & NAT_FLOW_OP_SPORT_REWRITE)
-    {
-      if (!r)
-       {
-         s = format (s, "rewrite: ");
-         r = 1;
-       }
-      s = format (s, "sport %u ", clib_net_to_host_u16 (f->rewrite.sport));
-    }
-  if (f->ops & NAT_FLOW_OP_DADDR_REWRITE)
-    {
-      if (!r)
-       {
-         s = format (s, "rewrite: ");
-         r = 1;
-       }
-      s = format (s, "daddr %U ", format_ip4_address, f->rewrite.daddr.as_u8);
-    }
-  if (f->ops & NAT_FLOW_OP_DPORT_REWRITE)
-    {
-      if (!r)
-       {
-         s = format (s, "rewrite: ");
-         r = 1;
-       }
-      s = format (s, "dport %u ", clib_net_to_host_u16 (f->rewrite.dport));
-    }
-  if (f->ops & NAT_FLOW_OP_ICMP_ID_REWRITE)
-    {
-      if (!r)
-       {
-         s = format (s, "rewrite: ");
-         r = 1;
-       }
-      s = format (s, "icmp-id %u ", clib_net_to_host_u16 (f->rewrite.icmp_id));
-    }
-  if (f->ops & NAT_FLOW_OP_TXFIB_REWRITE)
-    {
-      if (!r)
-       {
-         s = format (s, "rewrite: ");
-         r = 1;
-       }
-      s = format (s, "txfib %u ", f->rewrite.fib_index);
-    }
-  return s;
-}
-
-static inline void
+static_always_inline void
 nat_syslog_nat44_sess (u32 ssubix, u32 sfibix, ip4_address_t *isaddr,
                       u16 isport, ip4_address_t *xsaddr, u16 xsport,
                       ip4_address_t *idaddr, u16 idport,