nat: nat44-ed cleanup & fixes
[vpp.git] / src / plugins / nat / nat44-ed / nat44_ed.c
index a110436..bf802f5 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.
 #include <vppinfra/bihash_16_8.h>
 
 #include <nat/lib/log.h>
-#include <nat/lib/nat_syslog.h>
 #include <nat/lib/nat_inlines.h>
 #include <nat/lib/ipfix_logging.h>
+#include <vnet/syslog/syslog.h>
+#include <nat/lib/nat_syslog_constants.h>
+#include <nat/lib/nat_syslog.h>
 
 #include <nat/nat44-ed/nat44_ed.h>
 #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;
 
@@ -76,7 +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",
@@ -90,6 +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",
@@ -101,17 +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",
@@ -123,32 +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"),
 };
@@ -158,12 +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",
@@ -177,165 +148,288 @@ VLIB_PLUGIN_REGISTER () = {
 };
 
 static void nat44_ed_db_init (u32 translations, u32 translation_buckets);
-
-static void nat44_ed_db_free ();
+static void nat44_ed_worker_db_free (snat_main_per_thread_data_t *tsm);
+
+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 flags);
 
 u32 nat_calc_bihash_buckets (u32 n_elts);
 
-u8 *
-format_session_kvp (u8 * s, va_list * args)
+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)
 {
-  clib_bihash_kv_8_8_t *v = va_arg (*args, clib_bihash_kv_8_8_t *);
-
-  s = format (s, "%U thread-index %llu session-index %llu", format_snat_key,
-             v->key, nat_value_get_thread_index (v),
-             nat_value_get_session_index (v));
-
-  return s;
+  ASSERT (!pool_is_free (sm->static_mappings, m));
+  clib_bihash_kv_16_8_t kv;
+  nat44_ed_sm_init_i2o_kv (&kv, addr.as_u32, port, fib_index, proto,
+                          m - sm->static_mappings);
+  return clib_bihash_add_del_16_8 (&sm->flow_hash, &kv, 1 /*is_add*/);
 }
 
-u8 *
-format_static_mapping_kvp (u8 * s, va_list * args)
+static_always_inline int
+nat44_ed_sm_i2o_del (snat_main_t *sm, ip4_address_t addr, u16 port,
+                    u32 fib_index, u8 proto)
 {
-  clib_bihash_kv_8_8_t *v = va_arg (*args, clib_bihash_kv_8_8_t *);
+  clib_bihash_kv_16_8_t kv;
+  nat44_ed_sm_init_i2o_k (&kv, addr.as_u32, port, fib_index, proto);
+  return clib_bihash_add_del_16_8 (&sm->flow_hash, &kv, 0 /*is_add*/);
+}
 
-  s = format (s, "%U static-mapping-index %llu",
-             format_snat_key, v->key, v->value);
+static_always_inline int
+nat44_ed_sm_o2i_add (snat_main_t *sm, snat_static_mapping_t *m,
+                    ip4_address_t addr, u16 port, u32 fib_index, u8 proto)
+{
+  ASSERT (!pool_is_free (sm->static_mappings, m));
+  clib_bihash_kv_16_8_t kv;
+  nat44_ed_sm_init_o2i_kv (&kv, addr.as_u32, port, fib_index, proto,
+                          m - sm->static_mappings);
+  return clib_bihash_add_del_16_8 (&sm->flow_hash, &kv, 1 /*is_add*/);
+}
 
-  return s;
+static_always_inline int
+nat44_ed_sm_o2i_del (snat_main_t *sm, ip4_address_t addr, u16 port,
+                    u32 fib_index, u8 proto)
+{
+  clib_bihash_kv_16_8_t kv;
+  nat44_ed_sm_init_o2i_k (&kv, addr.as_u32, port, fib_index, proto);
+  return clib_bihash_add_del_16_8 (&sm->flow_hash, &kv, 0 /*is_add*/);
 }
 
-u8 *
-format_ed_session_kvp (u8 * s, va_list * args)
+void
+nat44_ed_free_session_data (snat_main_t *sm, snat_session_t *s,
+                           u32 thread_index, u8 is_ha)
 {
-  clib_bihash_kv_16_8_t *v = va_arg (*args, clib_bihash_kv_16_8_t *);
+  per_vrf_sessions_unregister_session (s, thread_index);
 
-  u8 proto;
-  u16 r_port, l_port;
-  ip4_address_t l_addr, r_addr;
-  u32 fib_index;
+  if (nat_ed_ses_i2o_flow_hash_add_del (sm, thread_index, s, 0))
+    nat_elog_warn (sm, "flow hash del failed");
+
+  if (nat_ed_ses_o2i_flow_hash_add_del (sm, thread_index, s, 0))
+    nat_elog_warn (sm, "flow hash del failed");
+
+  if (na44_ed_is_fwd_bypass_session (s))
+    {
+      return;
+    }
+
+  if (nat44_ed_is_affinity_session (s))
+    nat_affinity_unlock (s->ext_host_addr, s->out2in.addr, s->proto,
+                        s->out2in.port);
 
-  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));
+  if (!is_ha)
+    nat_syslog_nat44_sdel (0, s->in2out.fib_index, &s->in2out.addr,
+                          s->in2out.port, &s->ext_host_nat_addr,
+                          s->ext_host_nat_port, &s->out2in.addr,
+                          s->out2in.port, &s->ext_host_addr, s->ext_host_port,
+                          s->proto, nat44_ed_is_twice_nat_session (s));
 
-  return s;
+  if (!is_ha)
+    {
+      /* log NAT event */
+      nat_ipfix_logging_nat44_ses_delete (
+       thread_index, s->in2out.addr.as_u32, s->out2in.addr.as_u32, s->proto,
+       s->in2out.port, s->out2in.port, s->in2out.fib_index);
+    }
 }
 
-void
-nat_free_session_data (snat_main_t * sm, snat_session_t * s, u32 thread_index,
-                      u8 is_ha)
+static ip_interface_address_t *
+nat44_ed_get_ip_interface_address (u32 sw_if_index, ip4_address_t addr)
 {
-      per_vrf_sessions_unregister_session (s, thread_index);
-
-      if (nat_ed_ses_i2o_flow_hash_add_del (sm, thread_index, s, 0))
-       nat_elog_warn (sm, "flow hash del failed");
+  snat_main_t *sm = &snat_main;
 
-      if (nat_ed_ses_o2i_flow_hash_add_del (sm, thread_index, s, 0))
-       nat_elog_warn (sm, "flow hash del failed");
+  ip_lookup_main_t *lm = &sm->ip4_main->lookup_main;
+  ip_interface_address_t *ia;
+  ip4_address_t *ip4a;
 
-      if (na44_ed_is_fwd_bypass_session (s))
+  foreach_ip_interface_address (
+    lm, ia, sw_if_index, 1, ({
+      ip4a = ip_interface_address_get_address (lm, ia);
+      nat_log_debug ("sw_if_idx: %u addr: %U ? %U", sw_if_index,
+                    format_ip4_address, ip4a, format_ip4_address, &addr);
+      if (ip4a->as_u32 == addr.as_u32)
        {
-         return;
+         return ia;
        }
+    }));
+  return NULL;
+}
 
-      if (nat44_ed_is_affinity_session (s))
-       nat_affinity_unlock (s->ext_host_addr, s->out2in.addr, s->nat_proto,
-                            s->out2in.port);
-
-      if (!is_ha)
-       nat_syslog_nat44_sdel (
-         0, s->in2out.fib_index, &s->in2out.addr, s->in2out.port,
-         &s->ext_host_nat_addr, s->ext_host_nat_port, &s->out2in.addr,
-         s->out2in.port, &s->ext_host_addr, s->ext_host_port, s->nat_proto,
-         nat44_ed_is_twice_nat_session (s));
+static int
+nat44_ed_resolve_nat_addr_len (snat_address_t *ap,
+                              snat_interface_t *interfaces)
+{
+  ip_interface_address_t *ia;
+  snat_interface_t *i;
+  u32 fib_index;
 
-      if (snat_is_unk_proto_session (s))
-       return;
+  pool_foreach (i, interfaces)
+    {
+      if (!nat44_ed_is_interface_outside (i))
+       {
+         continue;
+       }
 
-      if (!is_ha)
+      fib_index = ip4_fib_table_get_index_for_sw_if_index (i->sw_if_index);
+      if (fib_index != ap->fib_index)
        {
-         /* log NAT event */
-         nat_ipfix_logging_nat44_ses_delete (
-           thread_index, s->in2out.addr.as_u32, s->out2in.addr.as_u32,
-           s->nat_proto, s->in2out.port, s->out2in.port, s->in2out.fib_index);
+         continue;
        }
 
-  /* Twice NAT address and port for external host */
-      if (nat44_ed_is_twice_nat_session (s))
+      if ((ia = nat44_ed_get_ip_interface_address (i->sw_if_index, ap->addr)))
        {
-         snat_free_outside_address_and_port (
-           sm->twice_nat_addresses, thread_index, &s->ext_host_nat_addr,
-           s->ext_host_nat_port, s->nat_proto);
+         ap->addr_len = ia->address_length;
+         ap->sw_if_index = i->sw_if_index;
+         ap->net.as_u32 = (ap->addr.as_u32 >> (32 - ap->addr_len))
+                          << (32 - ap->addr_len);
+
+         nat_log_debug ("pool addr %U binds to -> sw_if_idx: %u net: %U/%u",
+                        format_ip4_address, &ap->addr, ap->sw_if_index,
+                        format_ip4_address, &ap->net, ap->addr_len);
+         return 0;
        }
+    }
+  return 1;
+}
+
+static void
+nat44_ed_update_outside_if_addresses (snat_address_t *ap)
+{
+  snat_main_t *sm = &snat_main;
 
-      if (nat44_ed_is_session_static (s))
-       return;
+  if (!nat44_ed_resolve_nat_addr_len (ap, sm->interfaces))
+    {
+      return;
+    }
 
-      snat_free_outside_address_and_port (sm->addresses, thread_index,
-                                         &s->out2in.addr, s->out2in.port,
-                                         s->nat_proto);
+  if (!nat44_ed_resolve_nat_addr_len (ap, sm->output_feature_interfaces))
+    {
+      return;
+    }
 }
 
-static int
-is_snat_address_used_in_static_mapping (snat_main_t *sm, ip4_address_t addr)
+static void
+nat44_ed_bind_if_addr_to_nat_addr (u32 sw_if_index)
 {
-  snat_static_mapping_t *m;
-  pool_foreach (m, sm->static_mappings)
+  snat_main_t *sm = &snat_main;
+  ip_interface_address_t *ia;
+  snat_address_t *ap;
+
+  u32 fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
+
+  vec_foreach (ap, sm->addresses)
     {
-      if (is_sm_addr_only (m->flags) || is_sm_out2in_only (m->flags) ||
-         is_sm_identity_nat (m->flags))
+      if (fib_index != ap->fib_index)
        {
          continue;
        }
-      if (m->external_addr.as_u32 == addr.as_u32)
+
+      if ((ia = nat44_ed_get_ip_interface_address (sw_if_index, ap->addr)))
        {
-         return 1;
+         ap->addr_len = ia->address_length;
+         ap->sw_if_index = sw_if_index;
+         ap->net.as_u32 = (ap->addr.as_u32 >> (32 - ap->addr_len))
+                          << (32 - ap->addr_len);
+
+         nat_log_debug ("pool addr %U binds to -> sw_if_idx: %u net: %U/%u",
+                        format_ip4_address, &ap->addr, ap->sw_if_index,
+                        format_ip4_address, &ap->net, ap->addr_len);
+         return;
        }
     }
-  return 0;
+}
+
+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;
@@ -344,42 +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_fib_entry_reg (m->external_addr, sw_if_index);
+       }
+      else
        {
-         nat44_ed_add_del_addr_to_fib (&m->external_addr, 32, sw_if_index,
-                                       is_add);
+         nat44_ed_del_fib_entry_reg (m->external_addr, sw_if_index);
        }
     }
 }
@@ -388,7 +506,6 @@ int
 nat44_ed_add_address (ip4_address_t *addr, u32 vrf_id, u8 twice_nat)
 {
   snat_main_t *sm = &snat_main;
-  vlib_thread_main_t *tm = vlib_get_thread_main ();
   snat_address_t *ap, *addresses;
 
   addresses = twice_nat ? sm->twice_nat_addresses : sm->addresses;
@@ -417,6 +534,7 @@ nat44_ed_add_address (ip4_address_t *addr, u32 vrf_id, u8 twice_nat)
       vec_add2 (sm->addresses, ap, 1);
     }
 
+  ap->addr_len = ~0;
   ap->fib_index = ~0;
   ap->addr = *addr;
 
@@ -426,34 +544,24 @@ nat44_ed_add_address (ip4_address_t *addr, u32 vrf_id, u8 twice_nat)
        FIB_PROTOCOL_IP4, vrf_id, sm->fib_src_low);
     }
 
-#define _(N, i, n, s)                                                         \
-  clib_memset (ap->busy_##n##_port_refcounts, 0,                              \
-              sizeof (ap->busy_##n##_port_refcounts));                       \
-  ap->busy_##n##_ports = 0;                                                   \
-  ap->busy_##n##_ports_per_thread = 0;                                        \
-  vec_validate_init_empty (ap->busy_##n##_ports_per_thread,                   \
-                          tm->n_vlib_mains - 1, 0);
-  foreach_nat_protocol
-#undef _
-
-    if (!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);
-  }
+  if (!twice_nat)
+    {
+      // if we don't have enabled interface we don't add address
+      // to fib
+      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;
@@ -472,27 +580,33 @@ nat44_ed_del_address (ip4_address_t addr, u8 delete_sm, u8 twice_nat)
       return VNET_API_ERROR_NO_SUCH_ENTRY;
     }
 
-  if (delete_sm)
+  // delete dynamic sessions only
+  vec_foreach (tsm, sm->per_thread_data)
     {
-      pool_foreach (m, sm->static_mappings)
+      pool_foreach (ses, tsm->sessions)
        {
-         if (m->external_addr.as_u32 == addr.as_u32)
+         if (ses->flags & SNAT_SESSION_FLAG_STATIC_MAPPING)
            {
-             nat44_ed_del_static_mapping (m->local_addr, m->external_addr,
-                                          m->local_port, m->external_port,
-                                          m->proto, m->vrf_id, ~0, m->flags);
+             continue;
+           }
+         if (ses->out2in.addr.as_u32 == addr.as_u32)
+           {
+             nat44_ed_free_session_data (sm, ses, tsm - sm->per_thread_data,
+                                         0);
+             vec_add1 (ses_to_be_removed, ses - tsm->sessions);
            }
        }
-    }
-  else
-    {
-      // TODO: why ?
-      // check if address is used in some static mapping
-      if (is_snat_address_used_in_static_mapping (sm, addr))
+      vec_foreach (ses_index, ses_to_be_removed)
        {
-         nat_log_err ("address used in static mapping");
-         return VNET_API_ERROR_UNSPECIFIED;
+         ses = pool_elt_at_index (tsm->sessions, ses_index[0]);
+         nat_ed_session_delete (sm, ses, tsm - sm->per_thread_data, 1);
        }
+      vec_free (ses_to_be_removed);
+    }
+
+  if (!twice_nat)
+    {
+      nat44_ed_add_del_interface_fib_reg_entries (addr, 0);
     }
 
   if (a->fib_index != ~0)
@@ -500,39 +614,15 @@ nat44_ed_del_address (ip4_address_t addr, u8 delete_sm, u8 twice_nat)
       fib_table_unlock (a->fib_index, FIB_PROTOCOL_IP4, sm->fib_src_low);
     }
 
-  // delete sessions using address
-  if (a->busy_tcp_ports || a->busy_udp_ports || a->busy_icmp_ports)
+  if (!twice_nat)
     {
-      vec_foreach (tsm, sm->per_thread_data)
-       {
-         pool_foreach (ses, tsm->sessions)
-           {
-             if (ses->out2in.addr.as_u32 == addr.as_u32)
-               {
-                 nat_free_session_data (sm, ses, tsm - sm->per_thread_data,
-                                        0);
-                 vec_add1 (ses_to_be_removed, ses - tsm->sessions);
-               }
-           }
-         vec_foreach (ses_index, ses_to_be_removed)
-           {
-             ses = pool_elt_at_index (tsm->sessions, ses_index[0]);
-             nat_ed_session_delete (sm, ses, tsm - sm->per_thread_data, 1);
-           }
-         vec_free (ses_to_be_removed);
-       }
+      vec_del1 (sm->addresses, j);
+    }
+  else
+    {
+      vec_del1 (sm->twice_nat_addresses, j);
     }
 
-#define _(N, i, n, s) vec_free (a->busy_##n##_ports_per_thread);
-  foreach_nat_protocol
-#undef _
-
-    if (!twice_nat)
-  {
-    vec_del1 (sm->addresses, j);
-    nat44_ed_add_del_addr_to_fib_foreach_out_if (&addr, 0);
-  }
-  else { vec_del1 (sm->twice_nat_addresses, j); }
   return 0;
 }
 
@@ -569,18 +659,17 @@ nat_ed_static_mapping_del_sessions (snat_main_t * sm,
       }
     if (!addr_only)
       {
-        if ((s->out2in.addr.as_u32 != e_addr.as_u32) ||
-            s->out2in.port != e_port ||
-            s->in2out.port != l_port ||
-            s->nat_proto != protocol)
-          continue;
+       if ((s->out2in.addr.as_u32 != e_addr.as_u32) ||
+           s->out2in.port != e_port || s->in2out.port != l_port ||
+           s->proto != protocol)
+         continue;
       }
 
     if (nat44_ed_is_lb_session (s))
       continue;
     if (!nat44_ed_is_session_static (s))
       continue;
-    nat_free_session_data (sm, s, tsm - sm->per_thread_data, 0);
+    nat44_ed_free_session_data (sm, s, tsm - sm->per_thread_data, 0);
     vec_add1 (indexes_to_free, s - tsm->sessions);
     if (!addr_only)
       break;
@@ -594,118 +683,50 @@ nat_ed_static_mapping_del_sessions (snat_main_t * sm,
   vec_free (indexes_to_free);
 }
 
-int
-nat44_ed_reserve_port (ip4_address_t addr, u16 port, nat_protocol_t proto)
+static_always_inline snat_static_mapping_t *
+nat44_ed_sm_lookup (snat_main_t *sm, clib_bihash_kv_16_8_t *kv)
 {
-  u32 ti = get_thread_idx_by_port (port);
-  snat_main_t *sm = &snat_main;
-  snat_address_t *a = 0;
-  int i;
-
-  for (i = 0; i < vec_len (sm->addresses); i++)
+  clib_bihash_kv_16_8_t v;
+  int rc = clib_bihash_search_16_8 (&sm->flow_hash, kv, &v);
+  if (!rc)
     {
-      a = sm->addresses + i;
-
-      if (a->addr.as_u32 != addr.as_u32)
-       continue;
-
-      switch (proto)
-       {
-#define _(N, j, n, s)                                                         \
-  case NAT_PROTOCOL_##N:                                                      \
-    if (a->busy_##n##_port_refcounts[port])                                   \
-      goto done;                                                              \
-    ++a->busy_##n##_port_refcounts[port];                                     \
-    if (port > 1024)                                                          \
-      {                                                                       \
-       a->busy_##n##_ports++;                                                \
-       a->busy_##n##_ports_per_thread[ti]++;                                 \
-      }                                                                       \
-    break;
-         foreach_nat_protocol
-#undef _
-           default : nat_elog_info (sm, "unknown protocol");
-         goto done;
-       }
-
-      return 0;
+      ASSERT (0 == ed_value_get_thread_index (&v));
+      return pool_elt_at_index (sm->static_mappings,
+                               ed_value_get_session_index (&v));
     }
-
-done:
-  return 1;
+  return NULL;
 }
 
-int
-nat44_ed_free_port (ip4_address_t addr, u16 port, nat_protocol_t proto)
+snat_static_mapping_t *
+nat44_ed_sm_o2i_lookup (snat_main_t *sm, ip4_address_t addr, u16 port,
+                       u32 fib_index, u8 proto)
 {
-  u32 ti = get_thread_idx_by_port (port);
-  snat_main_t *sm = &snat_main;
-  snat_address_t *a = 0;
-  int i;
-
-  for (i = 0; i < vec_len (sm->addresses); i++)
-    {
-      a = sm->addresses + i;
-
-      if (a->addr.as_u32 != addr.as_u32)
-       continue;
-
-      switch (proto)
-       {
-#define _(N, j, n, s)                                                         \
-  case NAT_PROTOCOL_##N:                                                      \
-    --a->busy_##n##_port_refcounts[port];                                     \
-    if (port > 1024)                                                          \
-      {                                                                       \
-       a->busy_##n##_ports--;                                                \
-       a->busy_##n##_ports_per_thread[ti]--;                                 \
-      }                                                                       \
-    break;
-         foreach_nat_protocol
-#undef _
-           default : nat_elog_info (sm, "unknown protocol");
-         goto done;
-       }
-
-      return 0;
-    }
-
-done:
-  return 1;
+  clib_bihash_kv_16_8_t kv;
+  nat44_ed_sm_init_o2i_k (&kv, addr.as_u32, port, fib_index, proto);
+  return nat44_ed_sm_lookup (sm, &kv);
 }
 
-void
-nat44_ed_add_resolve_record (ip4_address_t l_addr, u16 l_port, u16 e_port,
-                            nat_protocol_t proto, u32 vrf_id, u32 sw_if_index,
-                            u32 flags, ip4_address_t pool_addr, u8 *tag)
+snat_static_mapping_t *
+nat44_ed_sm_i2o_lookup (snat_main_t *sm, ip4_address_t addr, u16 port,
+                       u32 fib_index, u8 proto)
 {
-  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);
+  clib_bihash_kv_16_8_t kv;
+  nat44_ed_sm_init_i2o_k (&kv, addr.as_u32, port, fib_index, proto);
+  return nat44_ed_sm_lookup (sm, &kv);
 }
 
-int
+static snat_static_mapping_resolve_t *
 nat44_ed_get_resolve_record (ip4_address_t l_addr, u16 l_port, u16 e_port,
-                            nat_protocol_t proto, u32 vrf_id, u32 sw_if_index,
-                            u32 flags, int *out)
+                            ip_protocol_t proto, u32 vrf_id, u32 sw_if_index,
+                            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)
        {
@@ -734,27 +755,27 @@ 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,
-                            nat_protocol_t proto, u32 vrf_id, u32 sw_if_index,
+                            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;
@@ -781,15 +802,75 @@ nat44_ed_validate_sm_input (u32 flags)
 
 int
 nat44_ed_add_static_mapping (ip4_address_t l_addr, ip4_address_t e_addr,
-                            u16 l_port, u16 e_port, nat_protocol_t proto,
+                            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))
+       {
+         return VNET_API_ERROR_VALUE_EXIST;
+       }
+
+      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)
+       {
+         return 0;
+       }
+
+      e_addr.as_u32 = first_int_addr->as_u32;
+      rp->is_resolved = 1;
+    }
+
+  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
+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;
-  clib_bihash_kv_8_8_t kv, value;
-  nat44_lb_addr_port_t *local;
-  snat_static_mapping_t *m;
-  u32 fib_index = ~0;
   int rv;
 
   if (!sm->enabled)
@@ -803,27 +884,16 @@ nat44_ed_add_static_mapping (ip4_address_t l_addr, ip4_address_t e_addr,
       return rv;
     }
 
-  if (is_sm_addr_only (flags))
-    {
-      e_port = l_port = proto = 0;
-    }
-
+  // interface bound mapping
   if (is_sm_switch_address (flags))
     {
-      // this mapping is interface bound
-      ip4_address_t *first_int_addr;
-
-      // check if this record isn't registered for resolve
-      if (!nat44_ed_get_resolve_record (l_addr, l_port, e_port, proto, vrf_id,
-                                       sw_if_index, flags, 0))
+      if (nat44_ed_del_resolve_record (l_addr, l_port, e_port, proto, vrf_id,
+                                      sw_if_index, flags))
        {
-         return VNET_API_ERROR_VALUE_EXIST;
+         return VNET_API_ERROR_NO_SUCH_ENTRY;
        }
-      // register record for resolve
-      nat44_ed_add_resolve_record (l_addr, l_port, e_port, proto, vrf_id,
-                                  sw_if_index, flags, pool_addr, tag);
 
-      first_int_addr =
+      ip4_address_t *first_int_addr =
        ip4_interface_first_address (sm->ip4_main, sw_if_index, 0);
       if (!first_int_addr)
        {
@@ -834,25 +904,44 @@ nat44_ed_add_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, flags);
+}
+
+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)
+{
+  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))
+    {
+      e_port = l_port = proto = 0;
+    }
+
   if (is_sm_identity_nat (flags))
     {
       l_port = e_port;
       l_addr.as_u32 = e_addr.as_u32;
     }
 
-  // fib index 0
-  init_nat_k (&kv, e_addr, e_port, 0, proto);
-
-  if (!clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv, &value))
+  m = nat44_ed_sm_o2i_lookup (sm, e_addr, e_port, 0, proto);
+  if (m)
     {
-      m = pool_elt_at_index (sm->static_mappings, value.value);
+      // 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)
@@ -867,9 +956,8 @@ nat44_ed_add_static_mapping (ip4_address_t l_addr, ip4_address_t e_addr,
       local->fib_index = fib_table_find_or_create_and_lock (
        FIB_PROTOCOL_IP4, vrf_id, sm->fib_src_low);
 
-      init_nat_kv (&kv, m->local_addr, m->local_port, local->fib_index,
-                  m->proto, 0, m - sm->static_mappings);
-      clib_bihash_add_del_8_8 (&sm->static_mapping_by_local, &kv, 1);
+      nat44_ed_sm_i2o_add (sm, m, m->local_addr, m->local_port,
+                          local->fib_index, m->proto);
 
       return 0;
     }
@@ -891,28 +979,12 @@ nat44_ed_add_static_mapping (ip4_address_t l_addr, ip4_address_t e_addr,
   // identity nat supports multiple records in local mapping
   if (!(is_sm_out2in_only (flags) || is_sm_identity_nat (flags)))
     {
-      init_nat_k (&kv, l_addr, l_port, fib_index, proto);
-      if (!clib_bihash_search_8_8 (&sm->static_mapping_by_local, &kv, &value))
+      if (nat44_ed_sm_i2o_lookup (sm, l_addr, l_port, fib_index, proto))
        {
          return VNET_API_ERROR_VALUE_EXIST;
        }
     }
 
-  if (!(is_sm_out2in_only (flags) || is_sm_addr_only (flags) ||
-       sm->static_mapping_only))
-    {
-      if (nat44_ed_reserve_port (e_addr, e_port, proto))
-       {
-         // 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));
 
@@ -920,13 +992,9 @@ nat44_ed_add_static_mapping (ip4_address_t l_addr, ip4_address_t e_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;
@@ -945,24 +1013,15 @@ nat44_ed_add_static_mapping (ip4_address_t l_addr, ip4_address_t e_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))
     {
-      init_nat_kv (&kv, m->local_addr, m->local_port, fib_index, m->proto, 0,
-                  m - sm->static_mappings);
-      clib_bihash_add_del_8_8 (&sm->static_mapping_by_local, &kv, 1);
+      nat44_ed_sm_i2o_add (sm, m, m->local_addr, m->local_port, fib_index,
+                          m->proto);
     }
 
-  init_nat_kv (&kv, m->external_addr, m->external_port, 0, m->proto, 0,
-              m - sm->static_mappings);
-  clib_bihash_add_del_8_8 (&sm->static_mapping_by_external, &kv, 1);
+  nat44_ed_sm_o2i_add (sm, m, m->external_addr, m->external_port, 0, m->proto);
 
   if (sm->num_workers > 1)
     {
@@ -976,62 +1035,29 @@ nat44_ed_add_static_mapping (ip4_address_t l_addr, ip4_address_t e_addr,
       vec_add1 (m->workers, worker_index);
     }
 
+  nat44_ed_add_del_interface_fib_reg_entries (e_addr, 1);
+
   return 0;
 }
 
-int
-nat44_ed_del_static_mapping (ip4_address_t l_addr, ip4_address_t e_addr,
-                            u16 l_port, u16 e_port, nat_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)
 {
   snat_main_per_thread_data_t *tsm;
   snat_main_t *sm = &snat_main;
 
-  clib_bihash_kv_8_8_t kv, value;
   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))
     {
       e_port = l_port = proto = 0;
     }
 
-  if (is_sm_switch_address (flags))
-    {
-      // this mapping is interface bound
-      ip4_address_t *first_int_addr;
-
-      // delete record registered for resolve
-      if (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;
-       }
-
-      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;
-    }
-
   if (is_sm_identity_nat (flags))
     {
       l_port = e_port;
@@ -1039,24 +1065,17 @@ nat44_ed_del_static_mapping (ip4_address_t l_addr, ip4_address_t e_addr,
     }
 
   // fib index 0
-  init_nat_k (&kv, e_addr, e_port, 0, proto);
-
-  if (clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv, &value))
+  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;
     }
 
-  m = pool_elt_at_index (sm->static_mappings, value.value);
-
   if (is_sm_identity_nat (flags))
     {
-      u8 failure = 1;
+      u8 found = 0;
 
-      if (!is_sm_switch_address (flags))
+      if (vrf_id == ~0)
        {
          vrf_id = sm->inside_vrf_id;
        }
@@ -1068,11 +1087,11 @@ nat44_ed_del_static_mapping (ip4_address_t l_addr, ip4_address_t e_addr,
              local = pool_elt_at_index (m->locals, local - m->locals);
              fib_index = local->fib_index;
              pool_put (m->locals, local);
-             failure = 0;
+             found = 1;
            }
        }
 
-      if (failure)
+      if (!found)
        {
          return VNET_API_ERROR_NO_SUCH_ENTRY;
        }
@@ -1082,51 +1101,38 @@ nat44_ed_del_static_mapping (ip4_address_t l_addr, ip4_address_t e_addr,
       fib_index = m->fib_index;
     }
 
-  if (!(is_sm_out2in_only (flags) || is_sm_addr_only (flags) ||
-       sm->static_mapping_only))
+  if (!is_sm_out2in_only (flags))
     {
-      if (nat44_ed_free_port (e_addr, e_port, proto))
-       {
-         return VNET_API_ERROR_INVALID_VALUE;
-       }
+      nat44_ed_sm_i2o_del (sm, l_addr, l_port, fib_index, proto);
     }
 
-  if (!is_sm_out2in_only (flags))
+  // delete sessions for static mapping
+  if (sm->num_workers > 1)
     {
-      init_nat_k (&kv, l_addr, l_port, fib_index, proto);
-      clib_bihash_add_del_8_8 (&sm->static_mapping_by_local, &kv, 0);
+      tsm = vec_elt_at_index (sm->per_thread_data, m->workers[0]);
     }
-
-  if (!sm->static_mapping_only || sm->static_mapping_connection_tracking)
+  else
     {
-      // 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, 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);
 
   if (!pool_elts (m->locals))
     {
       // this is last record remove all required stuff
       // fib_index 0
-      init_nat_k (&kv, e_addr, e_port, 0, proto);
-      clib_bihash_add_del_8_8 (&sm->static_mapping_by_external, &kv, 0);
+      nat44_ed_sm_o2i_del (sm, e_addr, e_port, 0, proto);
 
       vec_free (m->tag);
       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;
@@ -1134,17 +1140,17 @@ nat44_ed_del_static_mapping (ip4_address_t l_addr, ip4_address_t e_addr,
 
 int
 nat44_ed_add_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
-                               nat_protocol_t proto,
+                               ip_protocol_t proto,
                                nat44_lb_addr_port_t *locals, u32 flags,
                                u8 *tag, u32 affinity)
 {
   snat_main_t *sm = &snat_main;
   snat_static_mapping_t *m;
-  clib_bihash_kv_8_8_t kv, value;
   snat_address_t *a = 0;
 
   nat44_lb_addr_port_t *local;
   uword *bitmap = 0;
+  int rc = 0;
 
   int i;
 
@@ -1153,15 +1159,7 @@ nat44_ed_add_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
       return VNET_API_ERROR_UNSUPPORTED;
     }
 
-  init_nat_k (&kv, e_addr, e_port, 0, proto);
-  if (clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv, &value))
-    {
-      m = 0;
-    }
-  else
-    {
-      m = pool_elt_at_index (sm->static_mappings, value.value);
-    }
+  m = nat44_ed_sm_o2i_lookup (sm, e_addr, e_port, 0, proto);
 
   if (m)
     {
@@ -1173,7 +1171,7 @@ 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 */
@@ -1181,25 +1179,11 @@ nat44_ed_add_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
        {
          if (sm->addresses[i].addr.as_u32 == e_addr.as_u32)
            {
-             a = sm->addresses + i;
              /* External port must be unused */
-             switch (proto)
+             a = sm->addresses + i;
+             if (nat44_ed_sm_o2i_lookup (sm, a->addr, e_port, 0, proto))
                {
-#define _(N, j, n, s)                                                         \
-  case NAT_PROTOCOL_##N:                                                      \
-    if (a->busy_##n##_port_refcounts[e_port])                                 \
-      return VNET_API_ERROR_INVALID_VALUE;                                    \
-    ++a->busy_##n##_port_refcounts[e_port];                                   \
-    if (e_port > 1024)                                                        \
-      {                                                                       \
-       a->busy_##n##_ports++;                                                \
-       a->busy_##n##_ports_per_thread[get_thread_idx_by_port (e_port)]++;    \
-      }                                                                       \
-    break;
-                 foreach_nat_protocol
-#undef _
-                   default : nat_elog_info (sm, "unknown protocol");
-                 return VNET_API_ERROR_INVALID_VALUE_2;
+                 return VNET_API_ERROR_VALUE_EXIST;
                }
              break;
            }
@@ -1228,11 +1212,10 @@ nat44_ed_add_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
   else
     m->affinity_per_service_list_head_index = ~0;
 
-  init_nat_kv (&kv, m->external_addr, m->external_port, 0, m->proto, 0,
-              m - sm->static_mappings);
-  if (clib_bihash_add_del_8_8 (&sm->static_mapping_by_external, &kv, 1))
+  if (nat44_ed_sm_o2i_add (sm, m, m->external_addr, m->external_port, 0,
+                          m->proto))
     {
-      nat_elog_err (sm, "static_mapping_by_external key add failed");
+      nat_log_err ("sm o2i key add failed");
       return VNET_API_ERROR_UNSPECIFIED;
     }
 
@@ -1242,10 +1225,16 @@ nat44_ed_add_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
        FIB_PROTOCOL_IP4, locals[i].vrf_id, sm->fib_src_low);
       if (!is_sm_out2in_only (flags))
        {
-         init_nat_kv (&kv, locals[i].addr, locals[i].port,
-                      locals[i].fib_index, m->proto, 0,
-                      m - sm->static_mappings);
-         clib_bihash_add_del_8_8 (&sm->static_mapping_by_local, &kv, 1);
+         if (nat44_ed_sm_o2i_add (sm, m, e_addr, e_port, 0, proto))
+           {
+             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
+             // we've done and deal with partial cleanups and since bihash
+             // adds are (extremely improbable) the only points of failure,
+             // it's easier to just do it this way
+           }
        }
       locals[i].prefix = (i == 0) ?
                           locals[i].probability :
@@ -1272,72 +1261,36 @@ nat44_ed_add_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
        }
     }
 
-  return 0;
+  return rc;
 }
 
 int
 nat44_ed_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
-                               nat_protocol_t proto, u32 flags)
+                               ip_protocol_t proto, u32 flags)
 {
   snat_main_t *sm = &snat_main;
   snat_static_mapping_t *m;
-  clib_bihash_kv_8_8_t kv, value;
-  snat_address_t *a = 0;
 
   nat44_lb_addr_port_t *local;
   snat_main_per_thread_data_t *tsm;
   snat_session_t *s;
-  int i;
 
   if (!sm->enabled)
     {
       return VNET_API_ERROR_UNSUPPORTED;
     }
 
-  init_nat_k (&kv, e_addr, e_port, 0, proto);
-  if (clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv, &value))
-    m = 0;
-  else
-    m = pool_elt_at_index (sm->static_mappings, value.value);
-
+  m = nat44_ed_sm_o2i_lookup (sm, e_addr, e_port, 0, proto);
   if (!m)
     return VNET_API_ERROR_NO_SUCH_ENTRY;
 
   if (!is_sm_lb (m->flags))
     return VNET_API_ERROR_INVALID_VALUE;
 
-  if (!(sm->static_mapping_only || is_sm_out2in_only (flags)))
-    {
-      for (i = 0; i < vec_len (sm->addresses); i++)
-       {
-         if (sm->addresses[i].addr.as_u32 == e_addr.as_u32)
-           {
-             a = sm->addresses + i;
-             switch (proto)
-               {
-#define _(N, j, n, s)                                                         \
-  case NAT_PROTOCOL_##N:                                                      \
-    --a->busy_##n##_port_refcounts[e_port];                                   \
-    if (e_port > 1024)                                                        \
-      {                                                                       \
-       a->busy_##n##_ports--;                                                \
-       a->busy_##n##_ports_per_thread[get_thread_idx_by_port (e_port)]--;    \
-      }                                                                       \
-    break;
-                 foreach_nat_protocol
-#undef _
-                   default : nat_elog_info (sm, "unknown protocol");
-                 return VNET_API_ERROR_INVALID_VALUE_2;
-               }
-             break;
-           }
-       }
-    }
-
-  init_nat_k (&kv, m->external_addr, m->external_port, 0, m->proto);
-  if (clib_bihash_add_del_8_8 (&sm->static_mapping_by_external, &kv, 0))
+  if (nat44_ed_sm_o2i_del (sm, m->external_addr, m->external_port, 0,
+                          m->proto))
     {
-      nat_elog_err (sm, "static_mapping_by_external key del failed");
+      nat_log_err ("sm o2i key del failed");
       return VNET_API_ERROR_UNSPECIFIED;
     }
 
@@ -1346,11 +1299,10 @@ nat44_ed_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
       fib_table_unlock (local->fib_index, FIB_PROTOCOL_IP4, sm->fib_src_low);
       if (!is_sm_out2in_only (flags))
        {
-         init_nat_k (&kv, local->addr, local->port, local->fib_index,
-                     m->proto);
-         if (clib_bihash_add_del_8_8 (&sm->static_mapping_by_local, &kv, 0))
+         if (nat44_ed_sm_i2o_del (sm, local->addr, local->port,
+                                  local->fib_index, m->proto))
            {
-             nat_elog_err (sm, "static_mapping_by_local key del failed");
+             nat_log_err ("sm i2o key del failed");
              return VNET_API_ERROR_UNSPECIFIED;
            }
        }
@@ -1377,7 +1329,7 @@ nat44_ed_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
              s->in2out.port != local->port)
            continue;
 
-         nat_free_session_data (sm, s, tsm - sm->per_thread_data, 0);
+         nat44_ed_free_session_data (sm, s, tsm - sm->per_thread_data, 0);
          nat_ed_session_delete (sm, s, tsm - sm->per_thread_data, 1);
        }
     }
@@ -1398,12 +1350,11 @@ nat44_ed_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
 int
 nat44_ed_add_del_lb_static_mapping_local (ip4_address_t e_addr, u16 e_port,
                                          ip4_address_t l_addr, u16 l_port,
-                                         nat_protocol_t proto, u32 vrf_id,
+                                         ip_protocol_t proto, u32 vrf_id,
                                          u8 probability, u8 is_add)
 {
   snat_main_t *sm = &snat_main;
   snat_static_mapping_t *m = 0;
-  clib_bihash_kv_8_8_t kv, value;
   nat44_lb_addr_port_t *local, *prev_local, *match_local = 0;
   snat_main_per_thread_data_t *tsm;
   snat_session_t *s;
@@ -1416,9 +1367,7 @@ nat44_ed_add_del_lb_static_mapping_local (ip4_address_t e_addr, u16 e_port,
       return VNET_API_ERROR_UNSUPPORTED;
     }
 
-  init_nat_k (&kv, e_addr, e_port, 0, proto);
-  if (!clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv, &value))
-    m = pool_elt_at_index (sm->static_mappings, value.value);
+  m = nat44_ed_sm_o2i_lookup (sm, e_addr, e_port, 0, proto);
 
   if (!m)
     {
@@ -1459,10 +1408,13 @@ nat44_ed_add_del_lb_static_mapping_local (ip4_address_t e_addr, u16 e_port,
 
       if (!is_sm_out2in_only (m->flags))
        {
-         init_nat_kv (&kv, l_addr, l_port, local->fib_index, proto, 0,
-                      m - sm->static_mappings);
-         if (clib_bihash_add_del_8_8 (&sm->static_mapping_by_local, &kv, 1))
-           nat_elog_err (sm, "static_mapping_by_local key add failed");
+         if (nat44_ed_sm_i2o_add (sm, m, l_addr, l_port, local->fib_index,
+                                  proto))
+           {
+             nat_log_err ("sm i2o key add failed");
+             pool_put (m->locals, local);
+             return VNET_API_ERROR_UNSPECIFIED;
+           }
        }
     }
   else
@@ -1478,9 +1430,9 @@ nat44_ed_add_del_lb_static_mapping_local (ip4_address_t e_addr, u16 e_port,
 
       if (!is_sm_out2in_only (m->flags))
        {
-         init_nat_k (&kv, l_addr, l_port, match_local->fib_index, proto);
-         if (clib_bihash_add_del_8_8 (&sm->static_mapping_by_local, &kv, 0))
-           nat_elog_err (sm, "static_mapping_by_local key del failed");
+         if (nat44_ed_sm_i2o_del (sm, l_addr, l_port, match_local->fib_index,
+                                  proto))
+           nat_log_err ("sm i2o key del failed");
        }
 
       if (sm->num_workers > 1)
@@ -1504,7 +1456,7 @@ nat44_ed_add_del_lb_static_mapping_local (ip4_address_t e_addr, u16 e_port,
              s->in2out.port != match_local->port)
            continue;
 
-         nat_free_session_data (sm, s, tsm - sm->per_thread_data, 0);
+         nat44_ed_free_session_data (sm, s, tsm - sm->per_thread_data, 0);
          nat_ed_session_delete (sm, s, tsm - sm->per_thread_data, 1);
       }
 
@@ -1728,8 +1680,10 @@ nat44_ed_add_interface (u32 sw_if_index, u8 is_inside)
          outside_fib->refcount = 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);
     }
   else
     {
@@ -1837,8 +1791,8 @@ nat44_ed_del_interface (u32 sw_if_index, u8 is_inside)
            }
        }
 
-      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;
@@ -1936,8 +1890,10 @@ nat44_ed_add_output_interface (u32 sw_if_index)
       outside_fib->refcount = 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);
 
   return 0;
 }
@@ -2022,8 +1978,8 @@ nat44_ed_del_output_interface (u32 sw_if_index)
        }
     }
 
-  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;
 }
@@ -2059,6 +2015,18 @@ 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;
 }
@@ -2080,7 +2048,7 @@ 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)))
@@ -2090,7 +2058,7 @@ 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)))
@@ -2103,25 +2071,25 @@ 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->refcount--;
+         if (!outside_fib->refcount)
+           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->refcount++;
+         is_add = 0;
+         break;
+       }
+    }
 
   if (is_add)
     {
@@ -2139,7 +2107,7 @@ 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);
 
@@ -2163,8 +2131,8 @@ test_key_calc_split ()
   u32 thread_index = 3000000001;
   u32 session_index = 3000000221;
   clib_bihash_kv_16_8_t kv;
-  init_ed_kv (&kv, l_addr, l_port, r_addr, r_port, fib_index, proto,
-             thread_index, session_index);
+  init_ed_kv (&kv, l_addr.as_u32, l_port, r_addr.as_u32, r_port, fib_index,
+             proto, thread_index, session_index);
   ip4_address_t l_addr2;
   ip4_address_t r_addr2;
   clib_memset (&l_addr2, 0, sizeof (l_addr2));
@@ -2183,16 +2151,6 @@ test_key_calc_split ()
   ASSERT (fib_index == fib_index2);
   ASSERT (thread_index == ed_value_get_thread_index (&kv));
   ASSERT (session_index == ed_value_get_session_index (&kv));
-
-  fib_index = 7001;
-  proto = 5;
-  nat_protocol_t proto3 = ~0;
-  u64 key = calc_nat_key (l_addr, l_port, fib_index, proto);
-  split_nat_key (key, &l_addr2, &l_port2, &fib_index2, &proto3);
-  ASSERT (l_addr.as_u32 == l_addr2.as_u32);
-  ASSERT (l_port == l_port2);
-  ASSERT (proto == proto3);
-  ASSERT (fib_index == fib_index2);
 }
 
 static clib_error_t *
@@ -2212,21 +2170,6 @@ 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                                                                          \
     {                                                                         \
@@ -2274,8 +2217,6 @@ 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;
@@ -2284,15 +2225,13 @@ 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,                \
@@ -2338,7 +2277,7 @@ 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 */
@@ -2367,26 +2306,15 @@ 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);
@@ -2402,6 +2330,8 @@ 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);
@@ -2415,20 +2345,26 @@ 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);
        }
     }
 
@@ -2438,30 +2374,52 @@ nat44_plugin_enable (nat44_config_t c)
   return 0;
 }
 
-void
-nat44_addresses_free (snat_address_t ** addresses)
+int
+nat44_ed_del_addresses ()
 {
-  snat_address_t *ap;
-  vec_foreach (ap, *addresses)
+  snat_main_t *sm = &snat_main;
+  snat_address_t *a, *vec;
+  int error = 0;
+
+  vec = vec_dup (sm->addresses);
+  vec_foreach (a, vec)
+    {
+      error = nat44_ed_del_address (a->addr, 0);
+      if (error)
+       {
+         nat_log_err ("error occurred while removing adderess");
+       }
+    }
+  vec_free (vec);
+  vec_free (sm->addresses);
+  sm->addresses = 0;
+
+  vec = vec_dup (sm->twice_nat_addresses);
+  vec_foreach (a, vec)
     {
-    #define _(N, i, n, s) \
-      vec_free (ap->busy_##n##_ports_per_thread);
-      foreach_nat_protocol
-    #undef _
+      error = nat44_ed_del_address (a->addr, 1);
+      if (error)
+       {
+         nat_log_err ("error occurred while removing adderess");
+       }
     }
-  vec_free (*addresses);
-  *addresses = 0;
+  vec_free (vec);
+  vec_free (sm->twice_nat_addresses);
+  sm->twice_nat_addresses = 0;
+
+  vec_free (sm->addr_to_resolve);
+  sm->addr_to_resolve = 0;
+
+  return error;
 }
 
 int
-nat44_plugin_disable ()
+nat44_ed_del_interfaces ()
 {
   snat_main_t *sm = &snat_main;
   snat_interface_t *i, *pool;
   int error = 0;
 
-  fail_if_disabled ();
-
   pool = pool_dup (sm->interfaces);
   pool_foreach (i, pool)
     {
@@ -2473,51 +2431,111 @@ nat44_plugin_disable ()
        {
          error = nat44_ed_del_interface (i->sw_if_index, 0);
        }
+
       if (error)
-        {
-          nat_log_err ("error occurred while removing interface %u",
-                       i->sw_if_index);
-        }
+       {
+         nat_log_err ("error occurred while removing interface");
+       }
     }
-  pool_free (sm->interfaces);
   pool_free (pool);
+  pool_free (sm->interfaces);
   sm->interfaces = 0;
+  return error;
+}
+
+int
+nat44_ed_del_output_interfaces ()
+{
+  snat_main_t *sm = &snat_main;
+  snat_interface_t *i, *pool;
+  int error = 0;
 
   pool = pool_dup (sm->output_feature_interfaces);
   pool_foreach (i, pool)
     {
       error = nat44_ed_del_output_interface (i->sw_if_index);
       if (error)
-        {
-          nat_log_err ("error occurred while removing interface %u",
-                       i->sw_if_index);
-        }
+       {
+         nat_log_err ("error occurred while removing output interface");
+       }
     }
-  pool_free (sm->output_feature_interfaces);
   pool_free (pool);
+  pool_free (sm->output_feature_interfaces);
   sm->output_feature_interfaces = 0;
+  return error;
+}
+
+int
+nat44_ed_del_static_mappings ()
+{
+  snat_main_t *sm = &snat_main;
+  snat_static_mapping_t *m, *pool;
+  int error = 0;
+
+  pool = pool_dup (sm->static_mappings);
+  pool_foreach (m, pool)
+    {
+      error = nat44_ed_del_static_mapping_internal (
+       m->local_addr, m->external_addr, m->local_port, m->external_port,
+       m->proto, m->vrf_id, m->flags);
+      if (error)
+       {
+         nat_log_err ("error occurred while removing mapping");
+       }
+    }
+  pool_free (pool);
+  pool_free (sm->static_mappings);
+  sm->static_mappings = 0;
+
+  vec_free (sm->sm_to_resolve);
+  sm->sm_to_resolve = 0;
+
+  return error;
+}
+
+int
+nat44_plugin_disable ()
+{
+  snat_main_per_thread_data_t *tsm;
+  snat_main_t *sm = &snat_main;
+  int rc, error = 0;
+
+  fail_if_disabled ();
+
+  rc = nat44_ed_del_static_mappings ();
+  if (rc)
+    error = 1;
+
+  rc = nat44_ed_del_addresses ();
+  if (rc)
+    error = 1;
+
+  rc = nat44_ed_del_interfaces ();
+  if (rc)
+    error = 1;
+
+  rc = nat44_ed_del_output_interfaces ();
+  if (rc)
+    error = 1;
 
   vec_free (sm->max_translations_per_fib);
+  sm->max_translations_per_fib = 0;
 
-  nat44_ed_db_free ();
+  clib_bihash_free_16_8 (&sm->flow_hash);
 
-  nat44_addresses_free (&sm->addresses);
-  nat44_addresses_free (&sm->twice_nat_addresses);
+  vec_foreach (tsm, sm->per_thread_data)
+    {
+      nat44_ed_worker_db_free (tsm);
+    }
 
-  vec_free (sm->to_resolve);
-  vec_free (sm->auto_add_sw_if_indices);
-  vec_free (sm->auto_add_sw_if_indices_twice_nat);
+  clib_memset (&sm->rconfig, 0, sizeof (sm->rconfig));
 
-  sm->to_resolve = 0;
-  sm->auto_add_sw_if_indices = 0;
-  sm->auto_add_sw_if_indices_twice_nat = 0;
+  nat_affinity_disable ();
 
   sm->forwarding_enabled = 0;
-
   sm->enabled = 0;
-  clib_memset (&sm->rconfig, 0, sizeof (sm->rconfig));
 
-  return 0;
+  return error;
 }
 
 void
@@ -2548,7 +2566,7 @@ nat44_ed_forwarding_enable_disable (u8 is_enable)
       vec_foreach (ses_index, ses_to_be_removed)
        {
          s = pool_elt_at_index (tsm->sessions, ses_index[0]);
-         nat_free_session_data (sm, s, tsm - sm->per_thread_data, 0);
+         nat44_ed_free_session_data (sm, s, tsm - sm->per_thread_data, 0);
          nat_ed_session_delete (sm, s, tsm - sm->per_thread_data, 1);
        }
 
@@ -2556,88 +2574,88 @@ nat44_ed_forwarding_enable_disable (u8 is_enable)
     }
 }
 
-void
-snat_free_outside_address_and_port (snat_address_t *addresses,
-                                   u32 thread_index, ip4_address_t *addr,
-                                   u16 port, nat_protocol_t protocol)
+static_always_inline snat_static_mapping_t *
+nat44_ed_sm_match (snat_main_t *sm, ip4_address_t match_addr, u16 match_port,
+                  u32 match_fib_index, ip_protocol_t match_protocol,
+                  int by_external)
 {
-  snat_main_t *sm = &snat_main;
-  snat_address_t *a;
-  u32 address_index;
-  u16 port_host_byte_order = clib_net_to_host_u16 (port);
-
-  for (address_index = 0; address_index < vec_len (addresses);
-       address_index++)
+  snat_static_mapping_t *m;
+  if (!by_external)
     {
-      if (addresses[address_index].addr.as_u32 == addr->as_u32)
-       break;
-    }
+      m = nat44_ed_sm_i2o_lookup (sm, match_addr, match_port, match_fib_index,
+                                 match_protocol);
+      if (m)
+       return m;
 
-  ASSERT (address_index < vec_len (addresses));
+      /* Try address only mapping */
+      m = nat44_ed_sm_i2o_lookup (sm, match_addr, 0, match_fib_index, 0);
+      if (m)
+       return m;
+
+      if (sm->inside_fib_index != match_fib_index)
+       {
+         m = nat44_ed_sm_i2o_lookup (sm, match_addr, match_port,
+                                     sm->inside_fib_index, match_protocol);
+         if (m)
+           return m;
 
-  a = addresses + address_index;
+         /* Try address only mapping */
+         m = nat44_ed_sm_i2o_lookup (sm, match_addr, 0, sm->inside_fib_index,
+                                     0);
+         if (m)
+           return m;
+       }
+      if (sm->outside_fib_index != match_fib_index)
+       {
+         m = nat44_ed_sm_i2o_lookup (sm, match_addr, match_port,
+                                     sm->outside_fib_index, match_protocol);
+         if (m)
+           return m;
 
-  switch (protocol)
+         /* Try address only mapping */
+         m = nat44_ed_sm_i2o_lookup (sm, match_addr, 0, sm->outside_fib_index,
+                                     0);
+         if (m)
+           return m;
+       }
+    }
+  else
     {
-#define _(N, i, n, s) \
-    case NAT_PROTOCOL_##N: \
-      ASSERT (a->busy_##n##_port_refcounts[port_host_byte_order] >= 1); \
-      --a->busy_##n##_port_refcounts[port_host_byte_order]; \
-      a->busy_##n##_ports--; \
-      a->busy_##n##_ports_per_thread[thread_index]--; \
-      break;
-      foreach_nat_protocol
-#undef _
-       default : nat_elog_info (sm, "unknown protocol");
-      return;
+      m =
+       nat44_ed_sm_o2i_lookup (sm, match_addr, match_port, 0, match_protocol);
+      if (m)
+       return m;
+
+      /* Try address only mapping */
+      m = nat44_ed_sm_o2i_lookup (sm, match_addr, 0, 0, 0);
+      if (m)
+       return m;
     }
+  return 0;
 }
 
 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, nat_protocol_t match_protocol,
+                          u32 match_fib_index, ip_protocol_t match_protocol,
                           ip4_address_t *mapping_addr, u16 *mapping_port,
-                          u32 *mapping_fib_index, u8 by_external,
+                          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)
 {
-  clib_bihash_kv_8_8_t kv, value;
-  clib_bihash_8_8_t *mapping_hash;
   snat_static_mapping_t *m;
   u32 rand, lo = 0, hi, mid, *tmp = 0, i;
   nat44_lb_addr_port_t *local;
   u8 backend_index;
 
-  if (!by_external)
-    {
-      mapping_hash = &sm->static_mapping_by_local;
-      init_nat_k (&kv, match_addr, match_port, match_fib_index,
-                 match_protocol);
-      if (clib_bihash_search_8_8 (mapping_hash, &kv, &value))
-       {
-         /* Try address only mapping */
-         init_nat_k (&kv, match_addr, 0, match_fib_index, 0);
-         if (clib_bihash_search_8_8 (mapping_hash, &kv, &value))
-           return 1;
-       }
-    }
-  else
+  m = nat44_ed_sm_match (sm, match_addr, match_port, match_fib_index,
+                        match_protocol, by_external);
+  if (!m)
     {
-      mapping_hash = &sm->static_mapping_by_external;
-      init_nat_k (&kv, match_addr, match_port, 0, match_protocol);
-      if (clib_bihash_search_8_8 (mapping_hash, &kv, &value))
-       {
-         /* Try address only mapping */
-         init_nat_k (&kv, match_addr, 0, 0, 0);
-         if (clib_bihash_search_8_8 (mapping_hash, &kv, &value))
-           return 1;
-       }
+      return 1;
     }
 
-  m = pool_elt_at_index (sm->static_mappings, value.value);
-
   if (by_external)
     {
       if (is_sm_lb (m->flags))
@@ -2814,8 +2832,9 @@ nat44_ed_get_in2out_worker_index (vlib_buffer_t *b, ip4_header_t *ip,
                b, ip, &lookup_saddr, &lookup_sport, &lookup_daddr,
                &lookup_dport, &lookup_protocol))
            {
-             init_ed_k (&kv16, lookup_saddr, lookup_sport, lookup_daddr,
-                        lookup_dport, rx_fib_index, lookup_protocol);
+             init_ed_k (&kv16, lookup_saddr.as_u32, lookup_sport,
+                        lookup_daddr.as_u32, lookup_dport, rx_fib_index,
+                        lookup_protocol);
              if (!clib_bihash_search_16_8 (&sm->flow_hash, &kv16, &value16))
                {
                  next_worker_index = ed_value_get_thread_index (&value16);
@@ -2826,9 +2845,10 @@ nat44_ed_get_in2out_worker_index (vlib_buffer_t *b, ip4_header_t *ip,
            }
        }
 
-      init_ed_k (&kv16, ip->src_address, vnet_buffer (b)->ip.reass.l4_src_port,
-                ip->dst_address, vnet_buffer (b)->ip.reass.l4_dst_port,
-                fib_index, ip->protocol);
+      init_ed_k (&kv16, ip->src_address.as_u32,
+                vnet_buffer (b)->ip.reass.l4_src_port, ip->dst_address.as_u32,
+                vnet_buffer (b)->ip.reass.l4_dst_port, fib_index,
+                ip->protocol);
 
       if (!clib_bihash_search_16_8 (&sm->flow_hash, &kv16, &value16))
        {
@@ -2839,9 +2859,10 @@ nat44_ed_get_in2out_worker_index (vlib_buffer_t *b, ip4_header_t *ip,
        }
 
       // dst NAT
-      init_ed_k (&kv16, ip->dst_address, vnet_buffer (b)->ip.reass.l4_dst_port,
-                ip->src_address, vnet_buffer (b)->ip.reass.l4_src_port,
-                rx_fib_index, ip->protocol);
+      init_ed_k (&kv16, ip->dst_address.as_u32,
+                vnet_buffer (b)->ip.reass.l4_dst_port, ip->src_address.as_u32,
+                vnet_buffer (b)->ip.reass.l4_src_port, rx_fib_index,
+                ip->protocol);
       if (!clib_bihash_search_16_8 (&sm->flow_hash, &kv16, &value16))
        {
          next_worker_index = ed_value_get_thread_index (&value16);
@@ -2883,17 +2904,16 @@ nat44_ed_get_out2in_worker_index (vlib_buffer_t *b, ip4_header_t *ip,
                                  u32 rx_fib_index, u8 is_output)
 {
   snat_main_t *sm = &snat_main;
-  clib_bihash_kv_8_8_t kv, value;
   clib_bihash_kv_16_8_t kv16, value16;
 
-  u32 proto, next_worker_index = 0;
+  u8 proto, next_worker_index = 0;
   u16 port;
   snat_static_mapping_t *m;
   u32 hash;
 
-  proto = ip_proto_to_nat_proto (ip->protocol);
+  proto = ip->protocol;
 
-  if (PREDICT_FALSE (proto == NAT_PROTOCOL_ICMP))
+  if (PREDICT_FALSE (IP_PROTOCOL_ICMP == proto))
     {
       ip4_address_t lookup_saddr, lookup_daddr;
       u16 lookup_sport, lookup_dport;
@@ -2902,8 +2922,9 @@ nat44_ed_get_out2in_worker_index (vlib_buffer_t *b, ip4_header_t *ip,
            b, ip, &lookup_saddr, &lookup_sport, &lookup_daddr, &lookup_dport,
            &lookup_protocol))
        {
-         init_ed_k (&kv16, lookup_saddr, lookup_sport, lookup_daddr,
-                    lookup_dport, rx_fib_index, lookup_protocol);
+         init_ed_k (&kv16, lookup_saddr.as_u32, lookup_sport,
+                    lookup_daddr.as_u32, lookup_dport, rx_fib_index,
+                    lookup_protocol);
          if (PREDICT_TRUE (
                !clib_bihash_search_16_8 (&sm->flow_hash, &kv16, &value16)))
            {
@@ -2917,9 +2938,10 @@ nat44_ed_get_out2in_worker_index (vlib_buffer_t *b, ip4_header_t *ip,
        }
     }
 
-  init_ed_k (&kv16, ip->src_address, vnet_buffer (b)->ip.reass.l4_src_port,
-            ip->dst_address, vnet_buffer (b)->ip.reass.l4_dst_port,
-            rx_fib_index, ip->protocol);
+  init_ed_k (&kv16, ip->src_address.as_u32,
+            vnet_buffer (b)->ip.reass.l4_src_port, ip->dst_address.as_u32,
+            vnet_buffer (b)->ip.reass.l4_dst_port, rx_fib_index,
+            ip->protocol);
 
   if (PREDICT_TRUE (
        !clib_bihash_search_16_8 (&sm->flow_hash, &kv16, &value16)))
@@ -2937,18 +2959,18 @@ nat44_ed_get_out2in_worker_index (vlib_buffer_t *b, ip4_header_t *ip,
   /* first try static mappings without port */
   if (PREDICT_FALSE (pool_elts (sm->static_mappings)))
     {
-      init_nat_k (&kv, ip->dst_address, 0, 0, 0);
-      if (!clib_bihash_search_8_8
-         (&sm->static_mapping_by_external, &kv, &value))
+      m = nat44_ed_sm_o2i_lookup (sm, ip->dst_address, 0, 0, proto);
+      if (m)
        {
-         m = pool_elt_at_index (sm->static_mappings, value.value);
-         next_worker_index = m->workers[0];
-         goto done;
+         {
+           next_worker_index = m->workers[0];
+           goto done;
+         }
        }
     }
 
   /* unknown protocol */
-  if (PREDICT_FALSE (proto == NAT_PROTOCOL_OTHER))
+  if (PREDICT_FALSE (nat44_ed_is_unk_proto (proto)))
     {
       /* use current thread */
       next_worker_index = vlib_get_thread_index ();
@@ -2961,7 +2983,7 @@ 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;
@@ -2969,18 +2991,19 @@ nat44_ed_get_out2in_worker_index (vlib_buffer_t *b, ip4_header_t *ip,
        {
          /* if error message, then it's not fragmented and we can access it */
          ip4_header_t *inner_ip = (ip4_header_t *) (echo + 1);
-         proto = ip_proto_to_nat_proto (inner_ip->protocol);
+         proto = inner_ip->protocol;
          void *l4_header = ip4_next_header (inner_ip);
          switch (proto)
            {
-           case NAT_PROTOCOL_ICMP:
+           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 NAT_PROTOCOL_UDP:
-           case NAT_PROTOCOL_TCP:
-             port = ((tcp_udp_header_t *) l4_header)->src_port;
+           case IP_PROTOCOL_UDP:
+             /* breakthrough */
+           case IP_PROTOCOL_TCP:
+             port = ((nat_tcp_udp_header_t *) l4_header)->src_port;
              break;
            default:
              next_worker_index = vlib_get_thread_index ();
@@ -2992,11 +3015,9 @@ nat44_ed_get_out2in_worker_index (vlib_buffer_t *b, ip4_header_t *ip,
   /* try static mappings with port */
   if (PREDICT_FALSE (pool_elts (sm->static_mappings)))
     {
-      init_nat_k (&kv, ip->dst_address, port, 0, proto);
-      if (!clib_bihash_search_8_8
-         (&sm->static_mapping_by_external, &kv, &value))
+      m = nat44_ed_sm_o2i_lookup (sm, ip->dst_address, port, 0, proto);
+      if (m)
        {
-         m = pool_elt_at_index (sm->static_mappings, value.value);
          if (!is_sm_lb (m->flags))
            {
              next_worker_index = m->workers[0];
@@ -3070,8 +3091,8 @@ 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);
@@ -3126,30 +3147,13 @@ nat44_ed_db_init (u32 translations, u32 translation_buckets)
 {
   snat_main_t *sm = &snat_main;
   snat_main_per_thread_data_t *tsm;
-  u32 static_mapping_buckets = 1024;
-  u32 static_mapping_memory_size = 64 << 20;
 
   reinit_ed_flow_hash ();
 
-  clib_bihash_init_8_8 (&sm->static_mapping_by_local,
-                       "static_mapping_by_local", static_mapping_buckets,
-                       static_mapping_memory_size);
-  clib_bihash_set_kvp_format_fn_8_8 (&sm->static_mapping_by_local,
-                                    format_static_mapping_kvp);
-
-  clib_bihash_init_8_8 (&sm->static_mapping_by_external,
-                       "static_mapping_by_external", static_mapping_buckets,
-                       static_mapping_memory_size);
-  clib_bihash_set_kvp_format_fn_8_8 (&sm->static_mapping_by_external,
-                                    format_static_mapping_kvp);
-
-  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);
     }
 }
 
@@ -3161,26 +3165,6 @@ nat44_ed_worker_db_free (snat_main_per_thread_data_t *tsm)
   vec_free (tsm->per_vrf_sessions_vec);
 }
 
-static void
-nat44_ed_db_free ()
-{
-  snat_main_t *sm = &snat_main;
-  snat_main_per_thread_data_t *tsm;
-
-  pool_free (sm->static_mappings);
-  clib_bihash_free_16_8 (&sm->flow_hash);
-  clib_bihash_free_8_8 (&sm->static_mapping_by_local);
-  clib_bihash_free_8_8 (&sm->static_mapping_by_external);
-
-  if (sm->pat)
-    {
-      vec_foreach (tsm, sm->per_thread_data)
-       {
-         nat44_ed_worker_db_free (tsm);
-       }
-    }
-}
-
 void
 nat44_ed_sessions_clear ()
 {
@@ -3189,100 +3173,105 @@ 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)
 {
-  clib_bihash_kv_8_8_t kv, value;
-  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 (rp->addr_only && 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;
-    }
+}
 
-  init_nat_k (&kv, *address, rp->addr_only ? 0 : rp->e_port,
-             sm->outside_fib_index, rp->addr_only ? 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 (clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv, &value))
-    {
-      m = 0;
-    }
-  else
+  for (i = 0; i < vec_len (sm->addr_to_resolve); i++)
     {
-      m = pool_elt_at_index (sm->static_mappings, value.value);
-    }
+      rp = sm->addr_to_resolve + i;
 
-  if (is_delete)
-    {
-      if (m)
-       {
-         rv = nat44_ed_del_static_mapping (rp->l_addr, address[0], rp->l_port,
-                                           rp->e_port, rp->proto, rp->vrf_id,
-                                           ~0, rp->flags);
-       }
-    }
-  else
-    {
-      if (!m)
+      if ((rp->sw_if_index == sw_if_index) && (rp->is_twice_nat == twice_nat))
        {
-         rv = nat44_ed_add_static_mapping (
-           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 (out)
+           {
+             *out = i;
+           }
+         return 0;
        }
-      // else: don't trip over lease renewal, static config
-    }
-  if (rv)
-    {
-      nat_elog_notice_X1 (sm, "nat44_ed_del_static_mapping returned %d", "i4",
-                         rv);
     }
+  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
@@ -3292,69 +3281,78 @@ 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 *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))
        {
+         u32 fib_index =
+           ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
+         vec_foreach (ap, sm->addresses)
+           {
+             if ((fib_index == ap->fib_index) &&
+                 (address->as_u32 == ap->addr.as_u32))
+               {
+                 if (!is_delete)
+                   {
+                     ap->addr_len = address_length;
+                     ap->sw_if_index = sw_if_index;
+                     ap->net.as_u32 = (ap->addr.as_u32 >> (32 - ap->addr_len))
+                                      << (32 - ap->addr_len);
+
+                     nat_log_debug (
+                       "pool addr %U binds to -> sw_if_idx: %u net: %U/%u",
+                       format_ip4_address, &ap->addr, ap->sw_if_index,
+                       format_ip4_address, &ap->net, ap->addr_len);
+                   }
+                 else
+                   {
+                     ap->addr_len = ~0;
+                   }
+                 break;
+               }
+           }
          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 (rp->addr_only)
-           {
-             continue;
-           }
-         if (rp->sw_if_index == sw_if_index)
-           {
-             rv = nat44_ed_add_static_mapping (
-               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_elog_notice_X1 (sm, "add_static_mapping 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;
+       }
     }
 }
 
@@ -3364,34 +3362,34 @@ 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;
@@ -3403,62 +3401,24 @@ 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
@@ -3486,7 +3446,8 @@ nat44_ed_del_session (snat_main_t *sm, ip4_address_t *addr, u16 port,
   else
     tsm = vec_elt_at_index (sm->per_thread_data, sm->num_workers);
 
-  init_ed_k (&kv, *addr, port, *eh_addr, eh_port, fib_index, proto);
+  init_ed_k (&kv, addr->as_u32, port, eh_addr->as_u32, eh_port, fib_index,
+            proto);
   if (clib_bihash_search_16_8 (&sm->flow_hash, &kv, &value))
     {
       return VNET_API_ERROR_NO_SUCH_ENTRY;
@@ -3495,7 +3456,7 @@ nat44_ed_del_session (snat_main_t *sm, ip4_address_t *addr, u16 port,
   if (pool_is_free_index (tsm->sessions, ed_value_get_session_index (&value)))
     return VNET_API_ERROR_UNSPECIFIED;
   s = pool_elt_at_index (tsm->sessions, ed_value_get_session_index (&value));
-  nat_free_session_data (sm, s, tsm - sm->per_thread_data, 0);
+  nat44_ed_free_session_data (sm, s, tsm - sm->per_thread_data, 0);
   nat_ed_session_delete (sm, s, tsm - sm->per_thread_data, 1);
   return 0;
 }
@@ -3601,13 +3562,13 @@ nat_6t_flow_icmp_translate (vlib_main_t *vm, snat_main_t *sm, vlib_buffer_t *b,
 
 static_always_inline void
 nat_6t_flow_ip4_translate (snat_main_t *sm, vlib_buffer_t *b, ip4_header_t *ip,
-                          nat_6t_flow_t *f, nat_protocol_t proto,
+                          nat_6t_flow_t *f, ip_protocol_t proto,
                           int is_icmp_inner_ip4, int skip_saddr_rewrite)
 {
   udp_header_t *udp = ip4_next_header (ip);
   tcp_header_t *tcp = (tcp_header_t *) udp;
 
-  if ((NAT_PROTOCOL_TCP == proto || NAT_PROTOCOL_UDP == proto) &&
+  if ((IP_PROTOCOL_TCP == proto || IP_PROTOCOL_UDP == proto) &&
       !vnet_buffer (b)->ip.reass.is_non_first_fragment)
     {
       if (!is_icmp_inner_ip4)
@@ -3625,7 +3586,7 @@ nat_6t_flow_ip4_translate (snat_main_t *sm, vlib_buffer_t *b, ip4_header_t *ip,
          udp->dst_port = f->rewrite.sport;
        }
 
-      if (NAT_PROTOCOL_TCP == proto)
+      if (IP_PROTOCOL_TCP == proto)
        {
          ip_csum_t tcp_sum = tcp->checksum;
          tcp_sum = ip_csum_sub_even (tcp_sum, f->l3_csum_delta);
@@ -3633,7 +3594,7 @@ nat_6t_flow_ip4_translate (snat_main_t *sm, vlib_buffer_t *b, ip4_header_t *ip,
          mss_clamping (sm->mss_clamping, tcp, &tcp_sum);
          tcp->checksum = ip_csum_fold (tcp_sum);
        }
-      else if (proto == NAT_PROTOCOL_UDP && udp->checksum)
+      else if (IP_PROTOCOL_UDP == proto && udp->checksum)
        {
          ip_csum_t udp_sum = udp->checksum;
          udp_sum = ip_csum_sub_even (udp_sum, f->l3_csum_delta);
@@ -3690,7 +3651,7 @@ 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))
     {
@@ -3706,7 +3667,7 @@ 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);
@@ -3731,8 +3692,7 @@ nat_6t_flow_icmp_translate (vlib_main_t *vm, snat_main_t *sm, vlib_buffer_t *b,
              return NAT_ED_TRNSL_ERR_INNER_IP_CORRUPT;
            }
 
-         nat_protocol_t inner_proto =
-           ip_proto_to_nat_proto (inner_ip->protocol);
+         ip_protocol_t inner_proto = inner_ip->protocol;
 
          ip_csum_t old_icmp_sum = icmp->checksum;
          ip_csum_t old_inner_ip_sum = inner_ip->checksum;
@@ -3744,7 +3704,7 @@ nat_6t_flow_icmp_translate (vlib_main_t *vm, snat_main_t *sm, vlib_buffer_t *b,
 
          switch (inner_proto)
            {
-           case NAT_PROTOCOL_UDP:
+           case IP_PROTOCOL_UDP:
              udp = (udp_header_t *) (inner_ip + 1);
              if (!it_fits (vm, b, udp, sizeof (*udp)))
                {
@@ -3765,7 +3725,7 @@ nat_6t_flow_icmp_translate (vlib_main_t *vm, snat_main_t *sm, vlib_buffer_t *b,
              new_icmp_sum = ip_csum_fold (new_icmp_sum);
              icmp->checksum = new_icmp_sum;
              break;
-           case NAT_PROTOCOL_TCP:
+           case IP_PROTOCOL_TCP:
              tcp = (tcp_header_t *) (inner_ip + 1);
              if (!it_fits (vm, b, tcp, sizeof (*tcp)))
                {
@@ -3786,7 +3746,10 @@ nat_6t_flow_icmp_translate (vlib_main_t *vm, snat_main_t *sm, vlib_buffer_t *b,
              new_icmp_sum = ip_csum_fold (new_icmp_sum);
              icmp->checksum = new_icmp_sum;
              break;
-           case NAT_PROTOCOL_ICMP:
+           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);
@@ -3794,19 +3757,21 @@ 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;
                    }
@@ -3825,7 +3790,7 @@ nat_6t_flow_icmp_translate (vlib_main_t *vm, snat_main_t *sm, vlib_buffer_t *b,
 static_always_inline nat_translation_error_e
 nat_6t_flow_buf_translate (vlib_main_t *vm, snat_main_t *sm, vlib_buffer_t *b,
                           ip4_header_t *ip, nat_6t_flow_t *f,
-                          nat_protocol_t proto, int is_output_feature,
+                          ip_protocol_t proto, int is_output_feature,
                           int is_i2o)
 {
   if (!is_output_feature && f->ops & NAT_FLOW_OP_TXFIB_REWRITE)
@@ -3833,7 +3798,7 @@ nat_6t_flow_buf_translate (vlib_main_t *vm, snat_main_t *sm, vlib_buffer_t *b,
       vnet_buffer (b)->sw_if_index[VLIB_TX] = f->rewrite.fib_index;
     }
 
-  if (NAT_PROTOCOL_ICMP == proto)
+  if (IP_PROTOCOL_ICMP == proto)
     {
       if (ip->src_address.as_u32 != f->rewrite.saddr.as_u32)
        {
@@ -3861,7 +3826,7 @@ nat_6t_flow_buf_translate (vlib_main_t *vm, snat_main_t *sm, vlib_buffer_t *b,
 nat_translation_error_e
 nat_6t_flow_buf_translate_i2o (vlib_main_t *vm, snat_main_t *sm,
                               vlib_buffer_t *b, ip4_header_t *ip,
-                              nat_6t_flow_t *f, nat_protocol_t proto,
+                              nat_6t_flow_t *f, ip_protocol_t proto,
                               int is_output_feature)
 {
   return nat_6t_flow_buf_translate (vm, sm, b, ip, f, proto, is_output_feature,
@@ -3871,114 +3836,86 @@ nat_6t_flow_buf_translate_i2o (vlib_main_t *vm, snat_main_t *sm,
 nat_translation_error_e
 nat_6t_flow_buf_translate_o2i (vlib_main_t *vm, snat_main_t *sm,
                               vlib_buffer_t *b, ip4_header_t *ip,
-                              nat_6t_flow_t *f, nat_protocol_t proto,
+                              nat_6t_flow_t *f, ip_protocol_t proto,
                               int is_output_feature)
 {
   return nat_6t_flow_buf_translate (vm, sm, b, ip, f, proto, is_output_feature,
                                    0 /* is_i2o */);
 }
 
-u8 *
-format_nat_6t (u8 *s, va_list *args)
+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,
+                      ip4_address_t *xdaddr, u16 xdport, u8 proto, u8 is_add,
+                      u8 is_twicenat)
 {
-  nat_6t_t *t = va_arg (*args, nat_6t_t *);
+  syslog_msg_t syslog_msg;
+  fib_table_t *fib;
 
-  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;
-}
+  if (!syslog_is_enabled ())
+    return;
 
-u8 *
-format_nat_ed_translation_error (u8 *s, va_list *args)
-{
-  nat_translation_error_e e = va_arg (*args, nat_translation_error_e);
+  if (syslog_severity_filter_block (SADD_SDEL_SEVERITY))
+    return;
 
-  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;
+  fib = fib_table_get (sfibix, FIB_PROTOCOL_IP4);
+
+  syslog_msg_init (&syslog_msg, NAT_FACILITY, SADD_SDEL_SEVERITY, NAT_APPNAME,
+                  is_add ? SADD_MSGID : SDEL_MSGID);
+
+  syslog_msg_sd_init (&syslog_msg, NSESS_SDID);
+  syslog_msg_add_sd_param (&syslog_msg, SSUBIX_SDPARAM_NAME, "%d", ssubix);
+  syslog_msg_add_sd_param (&syslog_msg, SVLAN_SDPARAM_NAME, "%d",
+                          fib->ft_table_id);
+  syslog_msg_add_sd_param (&syslog_msg, IATYP_SDPARAM_NAME, IATYP_IPV4);
+  syslog_msg_add_sd_param (&syslog_msg, ISADDR_SDPARAM_NAME, "%U",
+                          format_ip4_address, isaddr);
+  syslog_msg_add_sd_param (&syslog_msg, ISPORT_SDPARAM_NAME, "%d",
+                          clib_net_to_host_u16 (isport));
+  syslog_msg_add_sd_param (&syslog_msg, XATYP_SDPARAM_NAME, IATYP_IPV4);
+  syslog_msg_add_sd_param (&syslog_msg, XSADDR_SDPARAM_NAME, "%U",
+                          format_ip4_address, xsaddr);
+  syslog_msg_add_sd_param (&syslog_msg, XSPORT_SDPARAM_NAME, "%d",
+                          clib_net_to_host_u16 (xsport));
+  syslog_msg_add_sd_param (&syslog_msg, PROTO_SDPARAM_NAME, "%d", proto);
+  syslog_msg_add_sd_param (&syslog_msg, XDADDR_SDPARAM_NAME, "%U",
+                          format_ip4_address, xdaddr);
+  syslog_msg_add_sd_param (&syslog_msg, XDPORT_SDPARAM_NAME, "%d",
+                          clib_net_to_host_u16 (xdport));
+  if (is_twicenat)
+    {
+      syslog_msg_add_sd_param (&syslog_msg, IDADDR_SDPARAM_NAME, "%U",
+                              format_ip4_address, idaddr);
+      syslog_msg_add_sd_param (&syslog_msg, IDPORT_SDPARAM_NAME, "%d",
+                              clib_net_to_host_u16 (idport));
+    }
+
+  syslog_msg_send (&syslog_msg);
 }
 
-u8 *
-format_nat_6t_flow (u8 *s, va_list *args)
+void
+nat_syslog_nat44_sadd (u32 ssubix, u32 sfibix, ip4_address_t *isaddr,
+                      u16 isport, ip4_address_t *idaddr, u16 idport,
+                      ip4_address_t *xsaddr, u16 xsport,
+                      ip4_address_t *xdaddr, u16 xdport, u8 proto,
+                      u8 is_twicenat)
 {
-  nat_6t_flow_t *f = va_arg (*args, nat_6t_flow_t *);
+  nat_syslog_nat44_sess (ssubix, sfibix, isaddr, isport, xsaddr, xsport,
+                        idaddr, idport, xdaddr, xdport, proto, 1,
+                        is_twicenat);
+}
 
-  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;
+void
+nat_syslog_nat44_sdel (u32 ssubix, u32 sfibix, ip4_address_t *isaddr,
+                      u16 isport, ip4_address_t *idaddr, u16 idport,
+                      ip4_address_t *xsaddr, u16 xsport,
+                      ip4_address_t *xdaddr, u16 xdport, u8 proto,
+                      u8 is_twicenat)
+{
+  nat_syslog_nat44_sess (ssubix, sfibix, isaddr, isport, xsaddr, xsport,
+                        idaddr, idport, xdaddr, xdport, proto, 0,
+                        is_twicenat);
 }
 
 /*