nat: use correct data types for memory sizes
[vpp.git] / src / plugins / nat / nat.c
index e7d59f7..8e20df4 100755 (executable)
 #include <nat/nat_det.h>
 #include <nat/nat64.h>
 #include <nat/nat66.h>
-#include <nat/dslite.h>
-#include <nat/nat_reass.h>
 #include <nat/nat_inlines.h>
+#include <nat/nat44/inlines.h>
 #include <nat/nat_affinity.h>
+#include <nat/nat_syslog.h>
+#include <nat/nat_ha.h>
 #include <vnet/fib/fib_table.h>
 #include <vnet/fib/ip4_fib.h>
+#include <vnet/ip/reass/ip4_sv_reass.h>
+#include <vppinfra/bihash_16_8.h>
 
 #include <vpp/app/version.h>
 
 snat_main_t snat_main;
 
-/* *INDENT-OFF* */
+fib_source_t nat_fib_src_hi;
+fib_source_t nat_fib_src_low;
 
+/* *INDENT-OFF* */
 /* Hook up input features */
+VNET_FEATURE_INIT (nat_pre_in2out, static) = {
+  .arc_name = "ip4-unicast",
+  .node_name = "nat-pre-in2out",
+  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa",
+                              "ip4-sv-reassembly-feature"),
+};
+VNET_FEATURE_INIT (nat_pre_out2in, static) = {
+  .arc_name = "ip4-unicast",
+  .node_name = "nat-pre-out2in",
+  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa",
+                               "ip4-dhcp-client-detect",
+                              "ip4-sv-reassembly-feature"),
+};
+VNET_FEATURE_INIT (snat_in2out_worker_handoff, static) = {
+  .arc_name = "ip4-unicast",
+  .node_name = "nat44-in2out-worker-handoff",
+  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa"),
+};
+VNET_FEATURE_INIT (snat_out2in_worker_handoff, static) = {
+  .arc_name = "ip4-unicast",
+  .node_name = "nat44-out2in-worker-handoff",
+  .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"),
+  .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",
+  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa","ip4-sv-reassembly-feature",
                                "ip4-dhcp-client-detect"),
 };
 VNET_FEATURE_INIT (ip4_nat_classify, static) = {
   .arc_name = "ip4-unicast",
   .node_name = "nat44-classify",
-  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa"),
+  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa","ip4-sv-reassembly-feature"),
 };
 VNET_FEATURE_INIT (ip4_snat_det_in2out, static) = {
   .arc_name = "ip4-unicast",
   .node_name = "nat44-det-in2out",
-  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa"),
+  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa","ip4-sv-reassembly-feature"),
 };
 VNET_FEATURE_INIT (ip4_snat_det_out2in, static) = {
   .arc_name = "ip4-unicast",
   .node_name = "nat44-det-out2in",
-  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa",
+  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa","ip4-sv-reassembly-feature",
                                "ip4-dhcp-client-detect"),
 };
 VNET_FEATURE_INIT (ip4_nat_det_classify, static) = {
   .arc_name = "ip4-unicast",
   .node_name = "nat44-det-classify",
-  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa"),
+  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa","ip4-sv-reassembly-feature"),
 };
 VNET_FEATURE_INIT (ip4_nat44_ed_in2out, static) = {
   .arc_name = "ip4-unicast",
   .node_name = "nat44-ed-in2out",
-  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa"),
+  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa","ip4-sv-reassembly-feature"),
 };
 VNET_FEATURE_INIT (ip4_nat44_ed_out2in, static) = {
   .arc_name = "ip4-unicast",
   .node_name = "nat44-ed-out2in",
-  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa",
+  .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"),
-};
-VNET_FEATURE_INIT (ip4_snat_in2out_worker_handoff, static) = {
-  .arc_name = "ip4-unicast",
-  .node_name = "nat44-in2out-worker-handoff",
-  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa"),
-};
-VNET_FEATURE_INIT (ip4_snat_out2in_worker_handoff, static) = {
-  .arc_name = "ip4-unicast",
-  .node_name = "nat44-out2in-worker-handoff",
-  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa",
-                               "ip4-dhcp-client-detect"),
+  .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"),
+  .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"),
+  .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",
+  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa","ip4-sv-reassembly-feature",
                                "ip4-dhcp-client-detect"),
 };
 VNET_FEATURE_INIT (ip4_snat_hairpin_dst, static) = {
   .arc_name = "ip4-unicast",
   .node_name = "nat44-hairpin-dst",
-  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa"),
+  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa","ip4-sv-reassembly-feature"),
 };
 VNET_FEATURE_INIT (ip4_nat44_ed_hairpin_dst, static) = {
   .arc_name = "ip4-unicast",
   .node_name = "nat44-ed-hairpin-dst",
-  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa"),
+  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa","ip4-sv-reassembly-feature"),
 };
 
 /* Hook up output features */
 VNET_FEATURE_INIT (ip4_snat_in2out_output, static) = {
   .arc_name = "ip4-output",
   .node_name = "nat44-in2out-output",
-  .runs_after = VNET_FEATURES ("acl-plugin-out-ip4-fa"),
+  .runs_after = VNET_FEATURES ("acl-plugin-out-ip4-fa","ip4-sv-reassembly-output-feature"),
 };
 VNET_FEATURE_INIT (ip4_snat_in2out_output_worker_handoff, static) = {
   .arc_name = "ip4-output",
   .node_name = "nat44-in2out-output-worker-handoff",
-  .runs_after = VNET_FEATURES ("acl-plugin-out-ip4-fa"),
+  .runs_after = VNET_FEATURES ("acl-plugin-out-ip4-fa","ip4-sv-reassembly-output-feature"),
 };
 VNET_FEATURE_INIT (ip4_snat_hairpin_src, static) = {
   .arc_name = "ip4-output",
   .node_name = "nat44-hairpin-src",
-  .runs_after = VNET_FEATURES ("acl-plugin-out-ip4-fa"),
+  .runs_after = VNET_FEATURES ("acl-plugin-out-ip4-fa","ip4-sv-reassembly-output-feature"),
 };
 VNET_FEATURE_INIT (ip4_nat44_ed_in2out_output, static) = {
   .arc_name = "ip4-output",
   .node_name = "nat44-ed-in2out-output",
-  .runs_after = VNET_FEATURES ("acl-plugin-out-ip4-fa"),
+  .runs_after = VNET_FEATURES ("ip4-sv-reassembly-output-feature"),
+  .runs_before = VNET_FEATURES ("acl-plugin-out-ip4-fa"),
 };
 VNET_FEATURE_INIT (ip4_nat44_ed_hairpin_src, static) = {
   .arc_name = "ip4-output",
   .node_name = "nat44-ed-hairpin-src",
-  .runs_after = VNET_FEATURES ("acl-plugin-out-ip4-fa"),
+  .runs_after = VNET_FEATURES ("ip4-sv-reassembly-output-feature"),
+  .runs_before = VNET_FEATURES ("acl-plugin-out-ip4-fa"),
 };
 
 /* Hook up ip4-local features */
@@ -169,12 +189,13 @@ VNET_FEATURE_INIT (ip4_nat44_ed_hairpinning, static) =
 
 VLIB_PLUGIN_REGISTER () = {
     .version = VPP_BUILD_VER,
-    .description = "Network Address Translation",
+    .description = "Network Address Translation (NAT)",
 };
 /* *INDENT-ON* */
 
 void
-nat_free_session_data (snat_main_t * sm, snat_session_t * s, u32 thread_index)
+nat_free_session_data (snat_main_t * sm, snat_session_t * s, u32 thread_index,
+                      u8 is_ha)
 {
   snat_session_key_t key;
   clib_bihash_kv_8_8_t kv;
@@ -185,16 +206,25 @@ nat_free_session_data (snat_main_t * sm, snat_session_t * s, u32 thread_index)
 
   if (is_fwd_bypass_session (s))
     {
+      if (snat_is_unk_proto_session (s))
+       {
+         ed_key.proto = s->in2out.port;
+         ed_key.r_port = 0;
+         ed_key.l_port = 0;
+       }
+      else
+       {
+         ed_key.proto = snat_proto_to_ip_proto (s->in2out.protocol);
+         ed_key.l_port = s->in2out.port;
+         ed_key.r_port = s->ext_host_port;
+       }
       ed_key.l_addr = s->in2out.addr;
       ed_key.r_addr = s->ext_host_addr;
-      ed_key.l_port = s->in2out.port;
-      ed_key.r_port = s->ext_host_port;
-      ed_key.proto = snat_proto_to_ip_proto (s->in2out.protocol);
       ed_key.fib_index = 0;
       ed_kv.key[0] = ed_key.as_u64[0];
       ed_kv.key[1] = ed_key.as_u64[1];
       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &ed_kv, 0))
-       nat_log_warn ("in2out_ed key del failed");
+       nat_elog_warn ("in2out_ed key del failed");
       return;
     }
 
@@ -222,7 +252,7 @@ nat_free_session_data (snat_main_t * sm, snat_session_t * s, u32 thread_index)
       ed_kv.key[0] = ed_key.as_u64[0];
       ed_kv.key[1] = ed_key.as_u64[1];
       if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &ed_kv, 0))
-       nat_log_warn ("out2in_ed key del failed");
+       nat_elog_warn ("out2in_ed key del failed");
       ed_key.l_addr = s->in2out.addr;
       ed_key.fib_index = s->in2out.fib_index;
       if (!snat_is_unk_proto_session (s))
@@ -235,27 +265,185 @@ nat_free_session_data (snat_main_t * sm, snat_session_t * s, u32 thread_index)
       ed_kv.key[0] = ed_key.as_u64[0];
       ed_kv.key[1] = ed_key.as_u64[1];
       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &ed_kv, 0))
-       nat_log_warn ("in2out_ed key del failed");
+       nat_elog_warn ("in2out_ed key del failed");
+
+      if (!is_ha)
+       nat_syslog_nat44_sdel (s->user_index, 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->in2out.protocol, is_twice_nat_session (s));
     }
   else
     {
       kv.key = s->in2out.as_u64;
       if (clib_bihash_add_del_8_8 (&tsm->in2out, &kv, 0))
-       nat_log_warn ("in2out key del failed");
+       nat_elog_warn ("in2out key del failed");
       kv.key = s->out2in.as_u64;
       if (clib_bihash_add_del_8_8 (&tsm->out2in, &kv, 0))
-       nat_log_warn ("out2in key del failed");
+       nat_elog_warn ("out2in key del failed");
+
+      if (!is_ha)
+       nat_syslog_nat44_apmdel (s->user_index, s->in2out.fib_index,
+                                &s->in2out.addr, s->in2out.port,
+                                &s->out2in.addr, s->out2in.port,
+                                s->in2out.protocol);
+    }
+
+  if (snat_is_unk_proto_session (s))
+    return;
+
+  if (!is_ha)
+    {
+      /* log NAT event */
+      snat_ipfix_logging_nat44_ses_delete (thread_index,
+                                          s->in2out.addr.as_u32,
+                                          s->out2in.addr.as_u32,
+                                          s->in2out.protocol,
+                                          s->in2out.port,
+                                          s->out2in.port,
+                                          s->in2out.fib_index);
+
+      nat_ha_sdel (&s->out2in.addr, s->out2in.port, &s->ext_host_addr,
+                  s->ext_host_port, s->out2in.protocol, s->out2in.fib_index,
+                  thread_index);
+    }
+
+  /* Twice NAT address and port for external host */
+  if (is_twice_nat_session (s))
+    {
+      key.protocol = s->in2out.protocol;
+      key.port = s->ext_host_nat_port;
+      key.addr.as_u32 = s->ext_host_nat_addr.as_u32;
+      snat_free_outside_address_and_port (sm->twice_nat_addresses,
+                                         thread_index, &key);
+    }
+
+  if (snat_is_session_static (s))
+    return;
+
+  ed_bihash_kv_t bihash_key;
+  clib_memset (&bihash_key, 0, sizeof (bihash_key));
+  bihash_key.k.dst_address = s->ext_host_addr.as_u32;
+  bihash_key.k.dst_port = s->ext_host_port;
+  bihash_key.k.src_address = s->out2in.addr.as_u32;
+  bihash_key.k.src_port = s->out2in.port;
+  bihash_key.k.protocol = s->out2in.protocol;
+  clib_bihash_add_del_16_8 (&sm->ed_ext_ports, &bihash_key.kv,
+                           0 /* is_add */ );
+
+  snat_free_outside_address_and_port (sm->addresses, thread_index,
+                                     &s->out2in);
+}
+
+void
+nat44_free_session_data (snat_main_t * sm, snat_session_t * s,
+                        u32 thread_index, u8 is_ha)
+{
+  snat_session_key_t key;
+  nat_ed_ses_key_t ed_key;
+  clib_bihash_kv_16_8_t ed_kv;
+  snat_main_per_thread_data_t *tsm =
+    vec_elt_at_index (sm->per_thread_data, thread_index);
+
+  if (is_fwd_bypass_session (s))
+    {
+      if (snat_is_unk_proto_session (s))
+       {
+         ed_key.proto = s->in2out.port;
+         ed_key.r_port = 0;
+         ed_key.l_port = 0;
+       }
+      else
+       {
+         ed_key.proto = snat_proto_to_ip_proto (s->in2out.protocol);
+         ed_key.l_port = s->in2out.port;
+         ed_key.r_port = s->ext_host_port;
+       }
+
+      ed_key.l_addr = s->in2out.addr;
+      ed_key.r_addr = s->ext_host_addr;
+      ed_key.fib_index = 0;
+      ed_kv.key[0] = ed_key.as_u64[0];
+      ed_kv.key[1] = ed_key.as_u64[1];
+
+      if (PREDICT_FALSE
+         (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &ed_kv, 0)))
+       nat_elog_warn ("in2out_ed key del failed");
+      return;
+    }
+
+  /* session lookup tables */
+  if (is_affinity_sessions (s))
+    nat_affinity_unlock (s->ext_host_addr, s->out2in.addr,
+                        s->in2out.protocol, s->out2in.port);
+  ed_key.l_addr = s->out2in.addr;
+  ed_key.r_addr = s->ext_host_addr;
+  ed_key.fib_index = s->out2in.fib_index;
+  if (snat_is_unk_proto_session (s))
+    {
+      ed_key.proto = s->in2out.port;
+      ed_key.r_port = 0;
+      ed_key.l_port = 0;
+    }
+  else
+    {
+      ed_key.proto = snat_proto_to_ip_proto (s->in2out.protocol);
+      ed_key.l_port = s->out2in.port;
+      ed_key.r_port = s->ext_host_port;
+    }
+  ed_kv.key[0] = ed_key.as_u64[0];
+  ed_kv.key[1] = ed_key.as_u64[1];
+
+  if (PREDICT_FALSE (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &ed_kv, 0)))
+    nat_elog_warn ("out2in_ed key del failed");
+
+  ed_key.l_addr = s->in2out.addr;
+  ed_key.fib_index = s->in2out.fib_index;
+
+  if (!snat_is_unk_proto_session (s))
+    ed_key.l_port = s->in2out.port;
+
+  if (is_twice_nat_session (s))
+    {
+      ed_key.r_addr = s->ext_host_nat_addr;
+      ed_key.r_port = s->ext_host_nat_port;
+    }
+
+  ed_kv.key[0] = ed_key.as_u64[0];
+  ed_kv.key[1] = ed_key.as_u64[1];
+
+  if (PREDICT_FALSE (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &ed_kv, 0)))
+    nat_elog_warn ("in2out_ed key del failed");
+
+  if (!is_ha)
+    {
+      nat_syslog_nat44_sdel (s->user_index, 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->in2out.protocol, is_twice_nat_session (s));
     }
 
   if (snat_is_unk_proto_session (s))
     return;
 
-  /* log NAT event */
-  snat_ipfix_logging_nat44_ses_delete (s->in2out.addr.as_u32,
-                                      s->out2in.addr.as_u32,
-                                      s->in2out.protocol,
-                                      s->in2out.port,
-                                      s->out2in.port, s->in2out.fib_index);
+  // is this correct ?
+  if (!is_ha)
+    {
+      snat_ipfix_logging_nat44_ses_delete (thread_index,
+                                          s->in2out.addr.as_u32,
+                                          s->out2in.addr.as_u32,
+                                          s->in2out.protocol,
+                                          s->in2out.port,
+                                          s->out2in.port,
+                                          s->in2out.fib_index);
+      nat_ha_sdel (&s->out2in.addr, s->out2in.port, &s->ext_host_addr,
+                  s->ext_host_port, s->out2in.protocol, s->out2in.fib_index,
+                  thread_index);
+    }
 
   /* Twice NAT address and port for external host */
   if (is_twice_nat_session (s))
@@ -270,10 +458,22 @@ nat_free_session_data (snat_main_t * sm, snat_session_t * s, u32 thread_index)
   if (snat_is_session_static (s))
     return;
 
+  ed_bihash_kv_t bihash_key;
+  clib_memset (&bihash_key, 0, sizeof (bihash_key));
+  bihash_key.k.dst_address = s->ext_host_addr.as_u32;
+  bihash_key.k.dst_port = s->ext_host_port;
+  bihash_key.k.src_address = s->out2in.addr.as_u32;
+  bihash_key.k.src_port = s->out2in.port;
+  bihash_key.k.protocol = s->out2in.protocol;
+  clib_bihash_add_del_16_8 (&sm->ed_ext_ports, &bihash_key.kv,
+                           0 /* is_add */ );
+
+  // should be called for every dynamic session
   snat_free_outside_address_and_port (sm->addresses, thread_index,
                                      &s->out2in);
 }
 
+
 snat_user_t *
 nat_user_get_or_create (snat_main_t * sm, ip4_address_t * addr, u32 fib_index,
                        u32 thread_index)
@@ -294,6 +494,9 @@ nat_user_get_or_create (snat_main_t * sm, ip4_address_t * addr, u32 fib_index,
       /* no, make a new one */
       pool_get (tsm->users, u);
       clib_memset (u, 0, sizeof (*u));
+
+      u->min_session_timeout = 0;
+
       u->addr.as_u32 = addr->as_u32;
       u->fib_index = fib_index;
 
@@ -308,7 +511,14 @@ nat_user_get_or_create (snat_main_t * sm, ip4_address_t * addr, u32 fib_index,
 
       /* add user */
       if (clib_bihash_add_del_8_8 (&tsm->user_hash, &kv, 1))
-       nat_log_warn ("user_hash keay add failed");
+       {
+         nat_elog_warn ("user_hash key add failed");
+         nat44_delete_user_with_no_session (sm, u, thread_index);
+         return NULL;
+       }
+
+      vlib_set_simple_counter (&sm->total_users, thread_index, 0,
+                              pool_elts (tsm->users));
     }
   else
     {
@@ -320,7 +530,7 @@ nat_user_get_or_create (snat_main_t * sm, ip4_address_t * addr, u32 fib_index,
 
 snat_session_t *
 nat_session_alloc_or_recycle (snat_main_t * sm, snat_user_t * u,
-                             u32 thread_index)
+                             u32 thread_index, f64 now)
 {
   snat_session_t *s;
   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
@@ -351,7 +561,7 @@ nat_session_alloc_or_recycle (snat_main_t * sm, snat_user_t * u,
 
       /* Get the session */
       s = pool_elt_at_index (tsm->sessions, session_index);
-      nat_free_session_data (sm, s, thread_index);
+      nat_free_session_data (sm, s, thread_index, 0);
       if (snat_is_session_static (s))
        u->nstaticsessions--;
       else
@@ -382,8 +592,22 @@ nat_session_alloc_or_recycle (snat_main_t * sm, snat_user_t * u,
       clib_dlist_addtail (tsm->list_pool,
                          s->per_user_list_head_index,
                          per_user_translation_list_elt - tsm->list_pool);
+
+      dlist_elt_t *global_lru_list_elt;
+      pool_get (tsm->global_lru_pool, global_lru_list_elt);
+      global_lru_list_elt->value = s - tsm->sessions;
+      s->global_lru_index = global_lru_list_elt - tsm->global_lru_pool;
+      clib_dlist_addtail (tsm->global_lru_pool, tsm->global_lru_head_index,
+                         s->global_lru_index);
+      s->last_lru_update = now;
+
+      s->user_index = u - tsm->users;
+      vlib_set_simple_counter (&sm->total_sessions, thread_index, 0,
+                              pool_elts (tsm->sessions));
     }
 
+  s->ha_last_refreshed = now;
+
   return s;
 }
 
@@ -391,69 +615,88 @@ snat_session_t *
 nat_ed_session_alloc (snat_main_t * sm, snat_user_t * u, u32 thread_index,
                      f64 now)
 {
-  snat_session_t *s;
+  snat_session_t *s = NULL;
   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
-  dlist_elt_t *per_user_translation_list_elt, *oldest_elt;
-  u32 oldest_index;
+
+  dlist_elt_t *oldest_elt;
   u64 sess_timeout_time;
+  u32 oldest_index;
 
-  if ((u->nsessions + u->nstaticsessions) >= sm->max_translations_per_user)
+  // no sessions
+  if (PREDICT_FALSE (!(u->nsessions) && !(u->nstaticsessions)))
+    goto alloc_new;
+
+  // no free sessions
+  if (PREDICT_FALSE
+      ((u->nsessions + u->nstaticsessions) >= sm->max_translations_per_user))
     {
-      oldest_index =
-       clib_dlist_remove_head (tsm->list_pool,
-                               u->sessions_per_user_list_head_index);
-      oldest_elt = pool_elt_at_index (tsm->list_pool, oldest_index);
-      s = pool_elt_at_index (tsm->sessions, oldest_elt->value);
-      sess_timeout_time =
-       s->last_heard + (f64) nat44_session_get_timeout (sm, s);
-      if (now >= sess_timeout_time)
-       {
-         clib_dlist_addtail (tsm->list_pool,
-                             u->sessions_per_user_list_head_index,
-                             oldest_index);
-         nat_free_session_data (sm, s, thread_index);
-         if (snat_is_session_static (s))
-           u->nstaticsessions--;
-         else
-           u->nsessions--;
-         s->flags = 0;
-         s->total_bytes = 0;
-         s->total_pkts = 0;
-         s->state = 0;
-         s->ext_host_addr.as_u32 = 0;
-         s->ext_host_port = 0;
-         s->ext_host_nat_addr.as_u32 = 0;
-         s->ext_host_nat_port = 0;
-       }
-      else
-       {
-         clib_dlist_addhead (tsm->list_pool,
-                             u->sessions_per_user_list_head_index,
-                             oldest_index);
-         nat_log_warn ("max translations per user %U", format_ip4_address,
-                       &u->addr);
-         snat_ipfix_logging_max_entries_per_user
-           (sm->max_translations_per_user, u->addr.as_u32);
-         return 0;
-       }
+      if (nat44_max_translations_per_user_cleanup (u, thread_index, now))
+       goto alloc_new;
+
+      nat_elog_addr (SNAT_LOG_WARNING, "[warn] max translations per user",
+                    clib_net_to_host_u32 (u->addr.as_u32));
+      snat_ipfix_logging_max_entries_per_user (thread_index,
+                                              sm->max_translations_per_user,
+                                              u->addr.as_u32);
+      return 0;
+    }
+
+  /* first try to reuse an expired session from this ip */
+  oldest_index =
+    clib_dlist_remove_head (tsm->list_pool,
+                           u->sessions_per_user_list_head_index);
+  oldest_elt = pool_elt_at_index (tsm->list_pool, oldest_index);
+  s = pool_elt_at_index (tsm->sessions, oldest_elt->value);
+
+  sess_timeout_time = s->last_heard + (f64) nat44_session_get_timeout (sm, s);
+  if (now >= sess_timeout_time ||
+      (s->tcp_close_timestamp && now >= s->tcp_close_timestamp))
+    {
+      // reuse old session
+      clib_dlist_addtail (tsm->list_pool,
+                         u->sessions_per_user_list_head_index, oldest_index);
+      s = nat44_session_reuse_old (sm, u, s, thread_index, now);
+      s->last_lru_update = now;
     }
   else
     {
-      pool_get (tsm->sessions, s);
-      clib_memset (s, 0, sizeof (*s));
-
-      /* Create list elts */
-      pool_get (tsm->list_pool, per_user_translation_list_elt);
-      clib_dlist_init (tsm->list_pool,
-                      per_user_translation_list_elt - tsm->list_pool);
+      clib_dlist_addhead (tsm->list_pool,
+                         u->sessions_per_user_list_head_index, oldest_index);
+      s = NULL;
+    }
 
-      per_user_translation_list_elt->value = s - tsm->sessions;
-      s->per_user_index = per_user_translation_list_elt - tsm->list_pool;
-      s->per_user_list_head_index = u->sessions_per_user_list_head_index;
+alloc_new:
+  /* try to free an expired session from global LRU list */
+  if (!s)
+    {
+      oldest_index = clib_dlist_remove_head (tsm->global_lru_pool,
+                                            tsm->global_lru_head_index);
+      if (~0 != oldest_index)
+       {
+         oldest_elt = pool_elt_at_index (tsm->global_lru_pool, oldest_index);
+         s = pool_elt_at_index (tsm->sessions, oldest_elt->value);
 
-      clib_dlist_addtail (tsm->list_pool,
-                         s->per_user_list_head_index,
-                         per_user_translation_list_elt - tsm->list_pool);
+         sess_timeout_time =
+           s->last_heard + (f64) nat44_session_get_timeout (sm, s);
+         if (now >= sess_timeout_time
+             || (s->tcp_close_timestamp && now >= s->tcp_close_timestamp))
+           {
+             nat_free_session_data (sm, s, thread_index, 0);
+             nat44_ed_delete_session (sm, s, thread_index, 0);
+           }
+         else
+           {
+             clib_dlist_addhead (tsm->global_lru_pool,
+                                 tsm->global_lru_head_index, oldest_index);
+           }
+         s = NULL;
+       }
+    }
+  if (!s)
+    {
+      s = nat44_session_alloc_new (tsm, u, now);
+      vlib_set_simple_counter (&sm->total_sessions, thread_index, 0,
+                              pool_elts (tsm->sessions));
     }
   return s;
 }
@@ -474,7 +717,7 @@ snat_add_del_addr_to_fib (ip4_address_t * addr, u8 p_len, u32 sw_if_index,
   if (is_add)
     fib_table_entry_update_one_path (fib_index,
                                     &prefix,
-                                    FIB_SOURCE_PLUGIN_LOW,
+                                    nat_fib_src_low,
                                     (FIB_ENTRY_FLAG_CONNECTED |
                                      FIB_ENTRY_FLAG_LOCAL |
                                      FIB_ENTRY_FLAG_EXCLUSIVE),
@@ -483,7 +726,7 @@ snat_add_del_addr_to_fib (ip4_address_t * addr, u8 p_len, u32 sw_if_index,
                                     sw_if_index,
                                     ~0, 1, NULL, FIB_ROUTE_PATH_FLAG_NONE);
   else
-    fib_table_entry_delete (fib_index, &prefix, FIB_SOURCE_PLUGIN_LOW);
+    fib_table_entry_delete (fib_index, &prefix, nat_fib_src_low);
 }
 
 int
@@ -515,11 +758,11 @@ snat_add_address (snat_main_t * sm, ip4_address_t * addr, u32 vrf_id,
   if (vrf_id != ~0)
     ap->fib_index =
       fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4, vrf_id,
-                                        FIB_SOURCE_PLUGIN_LOW);
+                                        nat_fib_src_low);
   else
     ap->fib_index = ~0;
 #define _(N, i, n, s) \
-  clib_bitmap_alloc (ap->busy_##n##_port_bitmap, 65535); \
+  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);
@@ -570,15 +813,6 @@ is_snat_address_used_in_static_mapping (snat_main_t * sm, ip4_address_t addr)
   return 0;
 }
 
-void
-increment_v4_address (ip4_address_t * a)
-{
-  u32 v;
-
-  v = clib_net_to_host_u32 (a->as_u32) + 1;
-  a->as_u32 = clib_host_to_net_u32 (v);
-}
-
 static void
 snat_add_static_mapping_when_resolved (snat_main_t * sm,
                                       ip4_address_t l_addr,
@@ -647,7 +881,7 @@ snat_add_static_mapping (ip4_address_t l_addr, ip4_address_t e_addr,
   snat_session_t *s;
   snat_static_map_resolve_t *rp, *rp_match = 0;
   nat44_lb_addr_port_t *local;
-  u8 find = 0;
+  u32 find = ~0;
 
   if (!sm->endpoint_dependent)
     {
@@ -670,7 +904,7 @@ snat_add_static_mapping (ip4_address_t l_addr, ip4_address_t e_addr,
 
          if (!addr_only)
            {
-             if (rp->l_port != l_port || rp->e_port != e_port
+             if ((rp->l_port != l_port && rp->e_port != e_port)
                  || rp->proto != proto)
                continue;
            }
@@ -741,17 +975,17 @@ snat_add_static_mapping (ip4_address_t l_addr, ip4_address_t e_addr,
          if (is_identity_static_mapping (m))
            {
               /* *INDENT-OFF* */
-              vec_foreach (local, m->locals)
-                {
-                  if (local->vrf_id == vrf_id)
-                    return VNET_API_ERROR_VALUE_EXIST;
-                }
+              pool_foreach (local, m->locals,
+              ({
+                if (local->vrf_id == vrf_id)
+                  return VNET_API_ERROR_VALUE_EXIST;
+              }));
               /* *INDENT-ON* */
-             vec_add2 (m->locals, local, 1);
+             pool_get (m->locals, local);
              local->vrf_id = vrf_id;
              local->fib_index =
                fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4, vrf_id,
-                                                  FIB_SOURCE_PLUGIN_LOW);
+                                                  nat_fib_src_low);
              m_key.addr = m->local_addr;
              m_key.port = m->local_port;
              m_key.protocol = m->proto;
@@ -772,12 +1006,13 @@ snat_add_static_mapping (ip4_address_t l_addr, ip4_address_t e_addr,
       if (vrf_id != ~0)
        fib_index =
          fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4, vrf_id,
-                                            FIB_SOURCE_PLUGIN_LOW);
+                                            nat_fib_src_low);
       /* If not specified use inside VRF id from SNAT plugin startup config */
       else
        {
          fib_index = sm->inside_fib_index;
          vrf_id = sm->inside_vrf_id;
+         fib_table_lock (fib_index, FIB_PROTOCOL_IP4, nat_fib_src_low);
        }
 
       if (!(out2in_only || identity_nat))
@@ -806,9 +1041,9 @@ snat_add_static_mapping (ip4_address_t l_addr, ip4_address_t e_addr,
                    {
 #define _(N, j, n, s) \
                     case SNAT_PROTOCOL_##N: \
-                      if (clib_bitmap_get_no_check (a->busy_##n##_port_bitmap, e_port)) \
+                      if (a->busy_##n##_port_refcounts[e_port]) \
                         return VNET_API_ERROR_INVALID_VALUE; \
-                      clib_bitmap_set_no_check (a->busy_##n##_port_bitmap, e_port, 1); \
+                      ++a->busy_##n##_port_refcounts[e_port]; \
                       if (e_port > 1024) \
                         { \
                           a->busy_##n##_ports++; \
@@ -818,7 +1053,7 @@ snat_add_static_mapping (ip4_address_t l_addr, ip4_address_t e_addr,
                      foreach_snat_protocol
 #undef _
                    default:
-                     nat_log_info ("unknown protocol");
+                     nat_elog_info ("unknown protocol");
                      return VNET_API_ERROR_INVALID_VALUE_2;
                    }
                  break;
@@ -861,7 +1096,7 @@ snat_add_static_mapping (ip4_address_t l_addr, ip4_address_t e_addr,
       if (identity_nat)
        {
          m->flags |= NAT_STATIC_MAPPING_FLAG_IDENTITY_NAT;
-         vec_add2 (m->locals, local, 1);
+         pool_get (m->locals, local);
          local->vrf_id = vrf_id;
          local->fib_index = fib_index;
        }
@@ -882,7 +1117,7 @@ snat_add_static_mapping (ip4_address_t l_addr, ip4_address_t e_addr,
          ip4_header_t ip = {
            .src_address = m->local_addr,
          };
-         vec_add1 (m->workers, sm->worker_in2out_cb (&ip, m->fib_index));
+         vec_add1 (m->workers, sm->worker_in2out_cb (&ip, m->fib_index, 0));
          tsm = vec_elt_at_index (sm->per_thread_data, m->workers[0]);
        }
       else
@@ -936,7 +1171,7 @@ snat_add_static_mapping (ip4_address_t l_addr, ip4_address_t e_addr,
                        continue;
 
                      nat_free_session_data (sm, s,
-                                            tsm - sm->per_thread_data);
+                                            tsm - sm->per_thread_data, 0);
                      nat44_delete_session (sm, s, tsm - sm->per_thread_data);
 
                      if (!addr_only && !sm->endpoint_dependent)
@@ -961,19 +1196,19 @@ snat_add_static_mapping (ip4_address_t l_addr, ip4_address_t e_addr,
          if (vrf_id == ~0)
            vrf_id = sm->inside_vrf_id;
 
-         for (i = 0; i < vec_len (m->locals); i++)
-           {
-             if (m->locals[i].vrf_id == vrf_id)
-               {
-                 find = 1;
-                 break;
-               }
-           }
-         if (!find)
+          /* *INDENT-OFF* */
+          pool_foreach (local, m->locals,
+          ({
+           if (local->vrf_id == vrf_id)
+              find = local - m->locals;
+         }));
+          /* *INDENT-ON* */
+         if (find == ~0)
            return VNET_API_ERROR_NO_SUCH_ENTRY;
 
-         fib_index = m->locals[i].fib_index;
-         vec_del1 (m->locals, i);
+         local = pool_elt_at_index (m->locals, find);
+         fib_index = local->fib_index;
+         pool_put (m->locals, local);
        }
       else
        fib_index = m->fib_index;
@@ -990,7 +1225,7 @@ snat_add_static_mapping (ip4_address_t l_addr, ip4_address_t e_addr,
                    {
 #define _(N, j, n, s) \
                     case SNAT_PROTOCOL_##N: \
-                      clib_bitmap_set_no_check (a->busy_##n##_port_bitmap, e_port, 0); \
+                      --a->busy_##n##_port_refcounts[e_port]; \
                       if (e_port > 1024) \
                         { \
                           a->busy_##n##_ports--; \
@@ -1000,7 +1235,7 @@ snat_add_static_mapping (ip4_address_t l_addr, ip4_address_t e_addr,
                      foreach_snat_protocol
 #undef _
                    default:
-                     nat_log_info ("unknown protocol");
+                     nat_elog_info ("unknown protocol");
                      return VNET_API_ERROR_INVALID_VALUE_2;
                    }
                  break;
@@ -1060,7 +1295,7 @@ snat_add_static_mapping (ip4_address_t l_addr, ip4_address_t e_addr,
                        continue;
 
                      nat_free_session_data (sm, s,
-                                            tsm - sm->per_thread_data);
+                                            tsm - sm->per_thread_data, 0);
                      nat44_delete_session (sm, s, tsm - sm->per_thread_data);
 
                      if (!addr_only && !sm->endpoint_dependent)
@@ -1070,8 +1305,8 @@ snat_add_static_mapping (ip4_address_t l_addr, ip4_address_t e_addr,
            }
        }
 
-      fib_table_unlock (fib_index, FIB_PROTOCOL_IP4, FIB_SOURCE_PLUGIN_LOW);
-      if (vec_len (m->locals))
+      fib_table_unlock (fib_index, FIB_PROTOCOL_IP4, nat_fib_src_low);
+      if (pool_elts (m->locals))
        return 0;
 
       m_key.addr = m->external_addr;
@@ -1169,9 +1404,9 @@ nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
                    {
 #define _(N, j, n, s) \
                     case SNAT_PROTOCOL_##N: \
-                      if (clib_bitmap_get_no_check (a->busy_##n##_port_bitmap, e_port)) \
+                      if (a->busy_##n##_port_refcounts[e_port]) \
                         return VNET_API_ERROR_INVALID_VALUE; \
-                      clib_bitmap_set_no_check (a->busy_##n##_port_bitmap, e_port, 1); \
+                      ++a->busy_##n##_port_refcounts[e_port]; \
                       if (e_port > 1024) \
                         { \
                           a->busy_##n##_ports++; \
@@ -1181,7 +1416,7 @@ nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
                      foreach_snat_protocol
 #undef _
                    default:
-                     nat_log_info ("unknown protocol");
+                     nat_elog_info ("unknown protocol");
                      return VNET_API_ERROR_INVALID_VALUE_2;
                    }
                  break;
@@ -1218,7 +1453,7 @@ nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
       kv.value = m - sm->static_mappings;
       if (clib_bihash_add_del_8_8 (&sm->static_mapping_by_external, &kv, 1))
        {
-         nat_log_err ("static_mapping_by_external key add failed");
+         nat_elog_err ("static_mapping_by_external key add failed");
          return VNET_API_ERROR_UNSPECIFIED;
        }
 
@@ -1228,7 +1463,7 @@ nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
          locals[i].fib_index =
            fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4,
                                               locals[i].vrf_id,
-                                              FIB_SOURCE_PLUGIN_LOW);
+                                              nat_fib_src_low);
          m_key.addr = locals[i].addr;
          m_key.fib_index = locals[i].fib_index;
          if (!out2in_only)
@@ -1240,7 +1475,8 @@ nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
            }
          locals[i].prefix = (i == 0) ? locals[i].probability :
            (locals[i - 1].prefix + locals[i].probability);
-         vec_add1 (m->locals, locals[i]);
+         pool_get (m->locals, local);
+         *local = locals[i];
          if (sm->num_workers > 1)
            {
              ip4_header_t ip = {
@@ -1248,7 +1484,8 @@ nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
              };
              bitmap =
                clib_bitmap_set (bitmap,
-                                sm->worker_in2out_cb (&ip, m->fib_index), 1);
+                                sm->worker_in2out_cb (&ip, m->fib_index, 0),
+                                1);
            }
        }
 
@@ -1283,7 +1520,7 @@ nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
                    {
 #define _(N, j, n, s) \
                     case SNAT_PROTOCOL_##N: \
-                      clib_bitmap_set_no_check (a->busy_##n##_port_bitmap, e_port, 0); \
+                      --a->busy_##n##_port_refcounts[e_port]; \
                       if (e_port > 1024) \
                         { \
                           a->busy_##n##_ports--; \
@@ -1293,7 +1530,7 @@ nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
                      foreach_snat_protocol
 #undef _
                    default:
-                     nat_log_info ("unknown protocol");
+                     nat_elog_info ("unknown protocol");
                      return VNET_API_ERROR_INVALID_VALUE_2;
                    }
                  break;
@@ -1308,15 +1545,15 @@ nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
       kv.key = m_key.as_u64;
       if (clib_bihash_add_del_8_8 (&sm->static_mapping_by_external, &kv, 0))
        {
-         nat_log_err ("static_mapping_by_external key del failed");
+         nat_elog_err ("static_mapping_by_external key del failed");
          return VNET_API_ERROR_UNSPECIFIED;
        }
 
       /* *INDENT-OFF* */
-      vec_foreach (local, m->locals)
-        {
+      pool_foreach (local, m->locals,
+      ({
           fib_table_unlock (local->fib_index, FIB_PROTOCOL_IP4,
-                            FIB_SOURCE_PLUGIN_LOW);
+                            nat_fib_src_low);
           m_key.addr = local->addr;
           if (!out2in_only)
             {
@@ -1325,7 +1562,7 @@ nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
               kv.key = m_key.as_u64;
               if (clib_bihash_add_del_8_8(&sm->static_mapping_by_local, &kv, 0))
                 {
-                  nat_log_err ("static_mapping_by_local key del failed");
+                  nat_elog_err ("static_mapping_by_local key del failed");
                   return VNET_API_ERROR_UNSPECIFIED;
                 }
             }
@@ -1336,14 +1573,14 @@ nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
                 .src_address = local->addr,
               };
               tsm = vec_elt_at_index (sm->per_thread_data,
-                                      sm->worker_in2out_cb (&ip, m->fib_index));
+                                      sm->worker_in2out_cb (&ip, m->fib_index, 0));
             }
           else
             tsm = vec_elt_at_index (sm->per_thread_data, sm->num_workers);
 
           /* Delete sessions */
           u_key.addr = local->addr;
-          u_key.fib_index = m->fib_index;
+          u_key.fib_index = local->fib_index;
           kv.key = u_key.as_u64;
           if (!clib_bihash_search_8_8 (&tsm->user_hash, &kv, &value))
             {
@@ -1368,16 +1605,16 @@ nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
                           (clib_net_to_host_u16 (s->in2out.port) != local->port))
                         continue;
 
-                      nat_free_session_data (sm, s, tsm - sm->per_thread_data);
+                      nat_free_session_data (sm, s, tsm - sm->per_thread_data, 0);
                       nat44_delete_session (sm, s, tsm - sm->per_thread_data);
                     }
                 }
             }
-        }
+      }));
       /* *INDENT-ON* */
       if (m->affinity)
        nat_affinity_flush_service (m->affinity_per_service_list_head_index);
-      vec_free (m->locals);
+      pool_free (m->locals);
       vec_free (m->tag);
       vec_free (m->workers);
 
@@ -1388,34 +1625,218 @@ nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
 }
 
 int
-snat_del_address (snat_main_t * sm, ip4_address_t addr, u8 delete_sm,
-                 u8 twice_nat)
+nat44_lb_static_mapping_add_del_local (ip4_address_t e_addr, u16 e_port,
+                                      ip4_address_t l_addr, u16 l_port,
+                                      snat_protocol_t proto, u32 vrf_id,
+                                      u8 probability, u8 is_add)
 {
-  snat_address_t *a = 0;
-  snat_session_t *ses;
-  u32 *ses_to_be_removed = 0, *ses_index;
+  snat_main_t *sm = &snat_main;
+  snat_static_mapping_t *m = 0;
+  snat_session_key_t m_key;
+  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_static_mapping_t *m;
-  snat_interface_t *interface;
+  snat_user_key_t u_key;
+  snat_user_t *u;
+  snat_session_t *s;
+  dlist_elt_t *head, *elt;
+  u32 elt_index, head_index, ses_index, *locals = 0;
+  uword *bitmap = 0;
   int i;
-  snat_address_t *addresses =
-    twice_nat ? sm->twice_nat_addresses : sm->addresses;
 
-  /* Find SNAT address */
-  for (i = 0; i < vec_len (addresses); i++)
+  if (!sm->endpoint_dependent)
+    return VNET_API_ERROR_FEATURE_DISABLED;
+
+  m_key.addr = e_addr;
+  m_key.port = e_port;
+  m_key.protocol = proto;
+  m_key.fib_index = 0;
+  kv.key = m_key.as_u64;
+  if (!clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv, &value))
+    m = pool_elt_at_index (sm->static_mappings, value.value);
+
+  if (!m)
+    return VNET_API_ERROR_NO_SUCH_ENTRY;
+
+  if (!is_lb_static_mapping (m))
+    return VNET_API_ERROR_INVALID_VALUE;
+
+  /* *INDENT-OFF* */
+  pool_foreach (local, m->locals,
+  ({
+    if ((local->addr.as_u32 == l_addr.as_u32) && (local->port == l_port) &&
+        (local->vrf_id == vrf_id))
+      {
+        match_local = local;
+        break;
+      }
+  }));
+  /* *INDENT-ON* */
+
+  if (is_add)
     {
-      if (addresses[i].addr.as_u32 == addr.as_u32)
+      if (match_local)
+       return VNET_API_ERROR_VALUE_EXIST;
+
+      pool_get (m->locals, local);
+      clib_memset (local, 0, sizeof (*local));
+      local->addr.as_u32 = l_addr.as_u32;
+      local->port = l_port;
+      local->probability = probability;
+      local->vrf_id = vrf_id;
+      local->fib_index =
+       fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4, vrf_id,
+                                          nat_fib_src_low);
+
+      if (!is_out2in_only_static_mapping (m))
        {
-         a = addresses + i;
-         break;
+         m_key.addr = l_addr;
+         m_key.port = l_port;
+         m_key.fib_index = local->fib_index;
+         kv.key = m_key.as_u64;
+         kv.value = m - sm->static_mappings;
+         if (clib_bihash_add_del_8_8 (&sm->static_mapping_by_local, &kv, 1))
+           nat_elog_err ("static_mapping_by_local key add failed");
        }
     }
-  if (!a)
-    return VNET_API_ERROR_NO_SUCH_ENTRY;
-
-  if (delete_sm)
+  else
     {
-      /* *INDENT-OFF* */
+      if (!match_local)
+       return VNET_API_ERROR_NO_SUCH_ENTRY;
+
+      if (pool_elts (m->locals) < 3)
+       return VNET_API_ERROR_UNSPECIFIED;
+
+      fib_table_unlock (match_local->fib_index, FIB_PROTOCOL_IP4,
+                       nat_fib_src_low);
+
+      if (!is_out2in_only_static_mapping (m))
+       {
+         m_key.addr = l_addr;
+         m_key.port = l_port;
+         m_key.fib_index = match_local->fib_index;
+         kv.key = m_key.as_u64;
+         if (clib_bihash_add_del_8_8 (&sm->static_mapping_by_local, &kv, 0))
+           nat_elog_err ("static_mapping_by_local key del failed");
+       }
+
+      if (sm->num_workers > 1)
+       {
+         ip4_header_t ip = {
+           .src_address = local->addr,
+         };
+         tsm = vec_elt_at_index (sm->per_thread_data,
+                                 sm->worker_in2out_cb (&ip, m->fib_index,
+                                                       0));
+       }
+      else
+       tsm = vec_elt_at_index (sm->per_thread_data, sm->num_workers);
+
+      /* Delete sessions */
+      u_key.addr = match_local->addr;
+      u_key.fib_index = match_local->fib_index;
+      kv.key = u_key.as_u64;
+      if (!clib_bihash_search_8_8 (&tsm->user_hash, &kv, &value))
+       {
+         u = pool_elt_at_index (tsm->users, value.value);
+         if (u->nstaticsessions)
+           {
+             head_index = u->sessions_per_user_list_head_index;
+             head = pool_elt_at_index (tsm->list_pool, head_index);
+             elt_index = head->next;
+             elt = pool_elt_at_index (tsm->list_pool, elt_index);
+             ses_index = elt->value;
+             while (ses_index != ~0)
+               {
+                 s = pool_elt_at_index (tsm->sessions, ses_index);
+                 elt = pool_elt_at_index (tsm->list_pool, elt->next);
+                 ses_index = elt->value;
+
+                 if (!(is_lb_session (s)))
+                   continue;
+
+                 if ((s->in2out.addr.as_u32 != match_local->addr.as_u32) ||
+                     (clib_net_to_host_u16 (s->in2out.port) !=
+                      match_local->port))
+                   continue;
+
+                 nat_free_session_data (sm, s, tsm - sm->per_thread_data, 0);
+                 nat44_delete_session (sm, s, tsm - sm->per_thread_data);
+               }
+           }
+       }
+
+      pool_put (m->locals, match_local);
+    }
+
+  vec_free (m->workers);
+
+  /* *INDENT-OFF* */
+  pool_foreach (local, m->locals,
+  ({
+    vec_add1 (locals, local - m->locals);
+    if (sm->num_workers > 1)
+      {
+        ip4_header_t ip;
+        ip.src_address.as_u32 = local->addr.as_u32,
+        bitmap = clib_bitmap_set (bitmap,
+                                  sm->worker_in2out_cb (&ip, local->fib_index, 0),
+                                  1);
+      }
+  }));
+  /* *INDENT-ON* */
+
+  ASSERT (vec_len (locals) > 1);
+
+  local = pool_elt_at_index (m->locals, locals[0]);
+  local->prefix = local->probability;
+  for (i = 1; i < vec_len (locals); i++)
+    {
+      local = pool_elt_at_index (m->locals, locals[i]);
+      prev_local = pool_elt_at_index (m->locals, locals[i - 1]);
+      local->prefix = local->probability + prev_local->prefix;
+    }
+
+  /* Assign workers */
+  if (sm->num_workers > 1)
+    {
+      /* *INDENT-OFF* */
+      clib_bitmap_foreach (i, bitmap, ({ vec_add1(m->workers, i); }));
+      /* *INDENT-ON* */
+    }
+
+  return 0;
+}
+
+int
+snat_del_address (snat_main_t * sm, ip4_address_t addr, u8 delete_sm,
+                 u8 twice_nat)
+{
+  snat_address_t *a = 0;
+  snat_session_t *ses;
+  u32 *ses_to_be_removed = 0, *ses_index;
+  snat_main_per_thread_data_t *tsm;
+  snat_static_mapping_t *m;
+  snat_interface_t *interface;
+  int i;
+  snat_address_t *addresses =
+    twice_nat ? sm->twice_nat_addresses : sm->addresses;
+
+  /* Find SNAT address */
+  for (i = 0; i < vec_len (addresses); i++)
+    {
+      if (addresses[i].addr.as_u32 == addr.as_u32)
+       {
+         a = addresses + i;
+         break;
+       }
+    }
+  if (!a)
+    return VNET_API_ERROR_NO_SUCH_ENTRY;
+
+  if (delete_sm)
+    {
+      /* *INDENT-OFF* */
       pool_foreach (m, sm->static_mappings,
       ({
           if (m->external_addr.as_u32 == addr.as_u32)
@@ -1432,13 +1853,13 @@ snat_del_address (snat_main_t * sm, ip4_address_t addr, u8 delete_sm,
       /* Check if address is used in some static mapping */
       if (is_snat_address_used_in_static_mapping (sm, addr))
        {
-         nat_log_notice ("address used in static mapping");
+         nat_elog_notice ("address used in static mapping");
          return VNET_API_ERROR_UNSPECIFIED;
        }
     }
 
   if (a->fib_index != ~0)
-    fib_table_unlock (a->fib_index, FIB_PROTOCOL_IP4, FIB_SOURCE_PLUGIN_LOW);
+    fib_table_unlock (a->fib_index, FIB_PROTOCOL_IP4, nat_fib_src_low);
 
   /* Delete sessions using address */
   if (a->busy_tcp_ports || a->busy_udp_ports || a->busy_icmp_ports)
@@ -1449,7 +1870,7 @@ snat_del_address (snat_main_t * sm, ip4_address_t addr, u8 delete_sm,
           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);
+                nat_free_session_data (sm, ses, tsm - sm->per_thread_data, 0);
                 vec_add1 (ses_to_be_removed, ses - tsm->sessions);
               }
           }));
@@ -1466,7 +1887,6 @@ snat_del_address (snat_main_t * sm, ip4_address_t addr, u8 delete_sm,
     }
 
 #define _(N, i, n, s) \
-  clib_bitmap_free (a->busy_##n##_port_bitmap); \
   vec_free (a->busy_##n##_ports_per_thread);
   foreach_snat_protocol
 #undef _
@@ -1536,18 +1956,20 @@ snat_interface_add_del (u32 sw_if_index, u8 is_inside, int is_del)
       else if (sm->deterministic)
        feature_name = is_inside ? "nat44-det-in2out" : "nat44-det-out2in";
       else if (sm->endpoint_dependent)
-       feature_name = is_inside ? "nat44-ed-in2out" : "nat44-ed-out2in";
+       {
+         feature_name = is_inside ? "nat-pre-in2out" : "nat-pre-out2in";
+       }
       else
        feature_name = is_inside ? "nat44-in2out" : "nat44-out2in";
     }
 
   if (sm->fq_in2out_index == ~0 && !sm->deterministic && sm->num_workers > 1)
-    sm->fq_in2out_index = vlib_frame_queue_main_init (sm->in2out_node_index,
-                                                     NAT_FQ_NELTS);
+    sm->fq_in2out_index =
+      vlib_frame_queue_main_init (sm->handoff_in2out_index, NAT_FQ_NELTS);
 
   if (sm->fq_out2in_index == ~0 && !sm->deterministic && sm->num_workers > 1)
-    sm->fq_out2in_index = vlib_frame_queue_main_init (sm->out2in_node_index,
-                                                     NAT_FQ_NELTS);
+    sm->fq_out2in_index =
+      vlib_frame_queue_main_init (sm->handoff_out2in_index, NAT_FQ_NELTS);
 
   if (!is_inside)
     {
@@ -1558,7 +1980,7 @@ snat_interface_add_del (u32 sw_if_index, u8 is_inside, int is_del)
             {
               if (is_del)
                 {
-                  outside_fib->refcount--;
+                 outside_fib->refcount--;
                   if (!outside_fib->refcount)
                     vec_del1 (sm->outside_fibs, outside_fib - sm->outside_fibs);
                 }
@@ -1605,8 +2027,8 @@ feature_set:
                 else if (sm->endpoint_dependent)
                   {
                     del_feature_name = "nat44-ed-classify";
-                    feature_name = !is_inside ?  "nat44-ed-in2out" :
-                                                 "nat44-ed-out2in";
+                    feature_name = !is_inside ?  "nat-pre-in2out" :
+                                                 "nat-pre-out2in";
                   }
                 else
                   {
@@ -1614,6 +2036,9 @@ feature_set:
                     feature_name = !is_inside ?  "nat44-in2out" : "nat44-out2in";
                   }
 
+               int rv = ip4_sv_reass_enable_disable_with_refcnt (sw_if_index, 0);
+               if (rv)
+                 return rv;
                 vnet_feature_enable_disable ("ip4-unicast", del_feature_name,
                                              sw_if_index, 0, 0, 0);
                 vnet_feature_enable_disable ("ip4-unicast", feature_name,
@@ -1632,6 +2057,9 @@ feature_set:
               }
             else
               {
+               int rv = ip4_sv_reass_enable_disable_with_refcnt (sw_if_index, 0);
+               if (rv)
+                 return rv;
                 vnet_feature_enable_disable ("ip4-unicast", feature_name,
                                              sw_if_index, 0, 0, 0);
                 pool_put (sm->interfaces, i);
@@ -1668,8 +2096,9 @@ feature_set:
               }
             else if (sm->endpoint_dependent)
               {
-                del_feature_name = !is_inside ?  "nat44-ed-in2out" :
-                                                 "nat44-ed-out2in";
+                del_feature_name = !is_inside ?  "nat-pre-in2out" :
+                                                 "nat-pre-out2in";
+
                 feature_name = "nat44-ed-classify";
               }
             else
@@ -1678,6 +2107,9 @@ feature_set:
                 feature_name = "nat44-classify";
               }
 
+           int rv = ip4_sv_reass_enable_disable_with_refcnt (sw_if_index, 1);
+           if (rv)
+             return rv;
             vnet_feature_enable_disable ("ip4-unicast", del_feature_name,
                                          sw_if_index, 0, 0, 0);
             vnet_feature_enable_disable ("ip4-unicast", feature_name,
@@ -1708,6 +2140,10 @@ feature_set:
   vnet_feature_enable_disable ("ip4-unicast", feature_name, sw_if_index, 1, 0,
                               0);
 
+  int rv = ip4_sv_reass_enable_disable_with_refcnt (sw_if_index, 1);
+  if (rv)
+    return rv;
+
   if (is_inside && !sm->out2in_dpo)
     {
       if (sm->endpoint_dependent)
@@ -1758,6 +2194,10 @@ snat_interface_add_del_output_feature (u32 sw_if_index,
   snat_interface_t *i;
   snat_address_t *ap;
   snat_static_mapping_t *m;
+  nat_outside_fib_t *outside_fib;
+  u32 fib_index = fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
+                                                      sw_if_index);
+
 
   if (sm->deterministic ||
       (sm->static_mapping_only && !(sm->static_mapping_connection_tracking)))
@@ -1771,10 +2211,47 @@ snat_interface_add_del_output_feature (u32 sw_if_index,
   }));
   /* *INDENT-ON* */
 
+  if (!is_inside)
+    {
+      /* *INDENT-OFF* */
+      vec_foreach (outside_fib, sm->outside_fibs)
+        {
+          if (outside_fib->fib_index == fib_index)
+            {
+              if (is_del)
+                {
+                 outside_fib->refcount--;
+                  if (!outside_fib->refcount)
+                    vec_del1 (sm->outside_fibs, outside_fib - sm->outside_fibs);
+                }
+              else
+                outside_fib->refcount++;
+              goto feature_set;
+            }
+        }
+      /* *INDENT-ON* */
+      if (!is_del)
+       {
+         vec_add2 (sm->outside_fibs, outside_fib, 1);
+         outside_fib->refcount = 1;
+         outside_fib->fib_index = fib_index;
+       }
+    }
+
+feature_set:
   if (is_inside)
     {
       if (sm->endpoint_dependent)
        {
+         int rv =
+           ip4_sv_reass_enable_disable_with_refcnt (sw_if_index, !is_del);
+         if (rv)
+           return rv;
+         rv =
+           ip4_sv_reass_output_enable_disable_with_refcnt (sw_if_index,
+                                                           !is_del);
+         if (rv)
+           return rv;
          vnet_feature_enable_disable ("ip4-unicast", "nat44-ed-hairpin-dst",
                                       sw_if_index, !is_del, 0, 0);
          vnet_feature_enable_disable ("ip4-output", "nat44-ed-hairpin-src",
@@ -1782,6 +2259,15 @@ snat_interface_add_del_output_feature (u32 sw_if_index,
        }
       else
        {
+         int rv =
+           ip4_sv_reass_enable_disable_with_refcnt (sw_if_index, !is_del);
+         if (rv)
+           return rv;
+         rv =
+           ip4_sv_reass_output_enable_disable_with_refcnt (sw_if_index,
+                                                           !is_del);
+         if (rv)
+           return rv;
          vnet_feature_enable_disable ("ip4-unicast", "nat44-hairpin-dst",
                                       sw_if_index, !is_del, 0, 0);
          vnet_feature_enable_disable ("ip4-output", "nat44-hairpin-src",
@@ -1792,6 +2278,13 @@ snat_interface_add_del_output_feature (u32 sw_if_index,
 
   if (sm->num_workers > 1)
     {
+      int rv = ip4_sv_reass_enable_disable_with_refcnt (sw_if_index, !is_del);
+      if (rv)
+       return rv;
+      rv =
+       ip4_sv_reass_output_enable_disable_with_refcnt (sw_if_index, !is_del);
+      if (rv)
+       return rv;
       vnet_feature_enable_disable ("ip4-unicast",
                                   "nat44-out2in-worker-handoff",
                                   sw_if_index, !is_del, 0, 0);
@@ -1803,13 +2296,31 @@ snat_interface_add_del_output_feature (u32 sw_if_index,
     {
       if (sm->endpoint_dependent)
        {
-         vnet_feature_enable_disable ("ip4-unicast", "nat44-ed-out2in",
+         int rv =
+           ip4_sv_reass_enable_disable_with_refcnt (sw_if_index, !is_del);
+         if (rv)
+           return rv;
+         rv =
+           ip4_sv_reass_output_enable_disable_with_refcnt (sw_if_index,
+                                                           !is_del);
+         if (rv)
+           return rv;
+         vnet_feature_enable_disable ("ip4-unicast", "nat-pre-out2in",
                                       sw_if_index, !is_del, 0, 0);
          vnet_feature_enable_disable ("ip4-output", "nat44-ed-in2out-output",
                                       sw_if_index, !is_del, 0, 0);
        }
       else
        {
+         int rv =
+           ip4_sv_reass_enable_disable_with_refcnt (sw_if_index, !is_del);
+         if (rv)
+           return rv;
+         rv =
+           ip4_sv_reass_output_enable_disable_with_refcnt (sw_if_index,
+                                                           !is_del);
+         if (rv)
+           return rv;
          vnet_feature_enable_disable ("ip4-unicast", "nat44-out2in",
                                       sw_if_index, !is_del, 0, 0);
          vnet_feature_enable_disable ("ip4-output", "nat44-in2out-output",
@@ -1820,11 +2331,11 @@ snat_interface_add_del_output_feature (u32 sw_if_index,
 fq:
   if (sm->fq_in2out_output_index == ~0 && sm->num_workers > 1)
     sm->fq_in2out_output_index =
-      vlib_frame_queue_main_init (sm->in2out_output_node_index, 0);
+      vlib_frame_queue_main_init (sm->handoff_in2out_output_index, 0);
 
   if (sm->fq_out2in_index == ~0 && sm->num_workers > 1)
     sm->fq_out2in_index =
-      vlib_frame_queue_main_init (sm->out2in_node_index, 0);
+      vlib_frame_queue_main_init (sm->handoff_out2in_index, 0);
 
   /* *INDENT-OFF* */
   pool_foreach (i, sm->output_feature_interfaces,
@@ -1891,6 +2402,7 @@ snat_set_workers (uword * bitmap)
     ({
       vec_add1(sm->workers, i);
       sm->per_thread_data[sm->first_worker_index + i].snat_thread_index = j;
+      sm->per_thread_data[sm->first_worker_index + i].thread_index = i;
       j++;
     }));
   /* *INDENT-ON* */
@@ -1901,6 +2413,83 @@ snat_set_workers (uword * bitmap)
   return 0;
 }
 
+static void
+snat_update_outside_fib (u32 sw_if_index, u32 new_fib_index,
+                        u32 old_fib_index)
+{
+  snat_main_t *sm = &snat_main;
+  nat_outside_fib_t *outside_fib;
+  snat_interface_t *i;
+  u8 is_add = 1;
+  u8 match = 0;
+
+  if (new_fib_index == old_fib_index)
+    return;
+
+  if (!vec_len (sm->outside_fibs))
+    return;
+
+  /* *INDENT-OFF* */
+  pool_foreach (i, sm->interfaces,
+    ({
+      if (i->sw_if_index == sw_if_index)
+        {
+          if (!(nat_interface_is_outside (i)))
+           return;
+          match = 1;
+        }
+    }));
+
+  pool_foreach (i, sm->output_feature_interfaces,
+    ({
+      if (i->sw_if_index == sw_if_index)
+        {
+          if (!(nat_interface_is_outside (i)))
+           return;
+          match = 1;
+        }
+    }));
+  /* *INDENT-ON* */
+
+  if (!match)
+    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;
+      }
+  }
+
+  vec_foreach (outside_fib, sm->outside_fibs)
+  {
+    if (outside_fib->fib_index == new_fib_index)
+      {
+       outside_fib->refcount++;
+       is_add = 0;
+       break;
+      }
+  }
+
+  if (is_add)
+    {
+      vec_add2 (sm->outside_fibs, outside_fib, 1);
+      outside_fib->refcount = 1;
+      outside_fib->fib_index = new_fib_index;
+    }
+}
+
+static void
+snat_ip4_table_bind (ip4_main_t * im,
+                    uword opaque,
+                    u32 sw_if_index, u32 new_fib_index, u32 old_fib_index)
+{
+  snat_update_outside_fib (sw_if_index, new_fib_index, old_fib_index);
+}
 
 static void
 snat_ip4_add_del_interface_address_cb (ip4_main_t * im,
@@ -1938,32 +2527,87 @@ snat_init (vlib_main_t * vm)
   uword *bitmap = 0;
   u32 i;
   ip4_add_del_interface_address_callback_t cb4;
-  vlib_node_t *error_drop_node;
+  vlib_node_t *node;
 
   sm->vlib_main = vm;
   sm->vnet_main = vnet_get_main ();
   sm->ip4_main = im;
   sm->ip4_lookup_main = lm;
-  sm->api_main = &api_main;
+  sm->api_main = vlibapi_get_main ();
   sm->first_worker_index = 0;
   sm->num_workers = 0;
   sm->num_snat_thread = 1;
   sm->workers = 0;
   sm->port_per_thread = 0xffff - 1024;
   sm->fq_in2out_index = ~0;
+  sm->fq_in2out_output_index = ~0;
   sm->fq_out2in_index = ~0;
-  sm->udp_timeout = SNAT_UDP_TIMEOUT;
-  sm->tcp_established_timeout = SNAT_TCP_ESTABLISHED_TIMEOUT;
-  sm->tcp_transitory_timeout = SNAT_TCP_TRANSITORY_TIMEOUT;
-  sm->icmp_timeout = SNAT_ICMP_TIMEOUT;
+
   sm->alloc_addr_and_port = nat_alloc_addr_and_port_default;
   sm->addr_and_port_alloc_alg = NAT_ADDR_AND_PORT_ALLOC_ALG_DEFAULT;
   sm->forwarding_enabled = 0;
   sm->log_class = vlib_log_register_class ("nat", 0);
-  error_drop_node = vlib_get_node_by_name (vm, (u8 *) "error-drop");
-  sm->error_node_index = error_drop_node->index;
+  sm->log_level = SNAT_LOG_ERROR;
   sm->mss_clamping = 0;
 
+  node = vlib_get_node_by_name (vm, (u8 *) "error-drop");
+  sm->error_node_index = node->index;
+
+  node = vlib_get_node_by_name (vm, (u8 *) "nat-pre-in2out");
+  sm->pre_in2out_node_index = node->index;
+  node = vlib_get_node_by_name (vm, (u8 *) "nat-pre-out2in");
+  sm->pre_out2in_node_index = node->index;
+
+  node = vlib_get_node_by_name (vm, (u8 *) "nat-pre-in2out");
+  sm->pre_in2out_node_index = node->index;
+
+  node = vlib_get_node_by_name (vm, (u8 *) "nat-pre-out2in");
+  sm->pre_out2in_node_index = node->index;
+
+  node = vlib_get_node_by_name (vm, (u8 *) "nat44-in2out");
+  sm->in2out_node_index = node->index;
+  node = vlib_get_node_by_name (vm, (u8 *) "nat44-in2out-output");
+  sm->in2out_output_node_index = node->index;
+  node = vlib_get_node_by_name (vm, (u8 *) "nat44-in2out-fast");
+  sm->in2out_fast_node_index = node->index;
+  node = vlib_get_node_by_name (vm, (u8 *) "nat44-in2out-slowpath");
+  sm->in2out_slowpath_node_index = node->index;
+  node = vlib_get_node_by_name (vm, (u8 *) "nat44-in2out-output-slowpath");
+  sm->in2out_slowpath_output_node_index = node->index;
+
+  node = vlib_get_node_by_name (vm, (u8 *) "nat44-ed-in2out");
+  sm->ed_in2out_node_index = node->index;
+  node = vlib_get_node_by_name (vm, (u8 *) "nat44-ed-in2out-slowpath");
+  sm->ed_in2out_slowpath_node_index = node->index;
+
+  node = vlib_get_node_by_name (vm, (u8 *) "nat44-out2in");
+  sm->out2in_node_index = node->index;
+  node = vlib_get_node_by_name (vm, (u8 *) "nat44-out2in-fast");
+  sm->out2in_fast_node_index = node->index;
+
+  node = vlib_get_node_by_name (vm, (u8 *) "nat44-ed-out2in");
+  sm->ed_out2in_node_index = node->index;
+  node = vlib_get_node_by_name (vm, (u8 *) "nat44-ed-out2in-slowpath");
+  sm->ed_out2in_slowpath_node_index = node->index;
+
+  node = vlib_get_node_by_name (vm, (u8 *) "nat44-det-in2out");
+  sm->det_in2out_node_index = node->index;
+  node = vlib_get_node_by_name (vm, (u8 *) "nat44-det-out2in");
+  sm->det_out2in_node_index = node->index;
+
+  node = vlib_get_node_by_name (vm, (u8 *) "nat44-hairpinning");
+  sm->hairpinning_node_index = node->index;
+  node = vlib_get_node_by_name (vm, (u8 *) "nat44-hairpin-dst");
+  sm->hairpin_dst_node_index = node->index;
+  node = vlib_get_node_by_name (vm, (u8 *) "nat44-hairpin-src");
+  sm->hairpin_src_node_index = node->index;
+  node = vlib_get_node_by_name (vm, (u8 *) "nat44-ed-hairpinning");
+  sm->ed_hairpinning_node_index = node->index;
+  node = vlib_get_node_by_name (vm, (u8 *) "nat44-ed-hairpin-dst");
+  sm->ed_hairpin_dst_node_index = node->index;
+  node = vlib_get_node_by_name (vm, (u8 *) "nat44-ed-hairpin-src");
+  sm->ed_hairpin_src_node_index = node->index;
+
   p = hash_get_mem (tm->thread_registrations_by_name, "workers");
   if (p)
     {
@@ -2007,6 +2651,16 @@ snat_init (vlib_main_t * vm)
 
   nat_dpo_module_init ();
 
+  /* Init counters */
+  sm->total_users.name = "total-users";
+  sm->total_users.stat_segment_name = "/nat44/total-users";
+  vlib_validate_simple_counter (&sm->total_users, 0);
+  vlib_zero_simple_counter (&sm->total_users, 0);
+  sm->total_sessions.name = "total-sessions";
+  sm->total_sessions.stat_segment_name = "/nat44/total-sessions";
+  vlib_validate_simple_counter (&sm->total_sessions, 0);
+  vlib_zero_simple_counter (&sm->total_sessions, 0);
+
   /* Init IPFIX logging */
   snat_ipfix_logging_init (vm);
 
@@ -2015,12 +2669,21 @@ snat_init (vlib_main_t * vm)
   if (error)
     return error;
 
-  dslite_init (vm);
+  nat66_init (vm);
+
+  ip4_table_bind_callback_t cbt4 = {
+    .function = snat_ip4_table_bind,
+  };
+  vec_add1 (ip4_main.table_bind_callbacks, cbt4);
 
-  nat66_init ();
+  nat_fib_src_hi = fib_source_allocate ("nat-hi",
+                                       FIB_SOURCE_PRIORITY_HI,
+                                       FIB_SOURCE_BH_SIMPLE);
+  nat_fib_src_low = fib_source_allocate ("nat-low",
+                                        FIB_SOURCE_PRIORITY_LOW,
+                                        FIB_SOURCE_BH_SIMPLE);
 
-  /* Init virtual fragmenentation reassembly */
-  return nat_reass_init (vm);
+  return error;
 }
 
 VLIB_INIT_FUNCTION (snat_init);
@@ -2048,21 +2711,55 @@ snat_free_outside_address_and_port (snat_address_t * addresses,
     {
 #define _(N, i, n, s) \
     case SNAT_PROTOCOL_##N: \
-      ASSERT (clib_bitmap_get_no_check (a->busy_##n##_port_bitmap, \
-        port_host_byte_order) == 1); \
-      clib_bitmap_set_no_check (a->busy_##n##_port_bitmap, \
-        port_host_byte_order, 0); \
+      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_snat_protocol
 #undef _
     default:
-      nat_log_info ("unknown protocol");
+      nat_elog_info ("unknown protocol");
       return;
     }
 }
 
+static int
+nat_set_outside_address_and_port (snat_address_t * addresses,
+                                 u32 thread_index, snat_session_key_t * k)
+{
+  snat_address_t *a = 0;
+  u32 address_index;
+  u16 port_host_byte_order = clib_net_to_host_u16 (k->port);
+
+  for (address_index = 0; address_index < vec_len (addresses);
+       address_index++)
+    {
+      if (addresses[address_index].addr.as_u32 != k->addr.as_u32)
+       continue;
+
+      a = addresses + address_index;
+      switch (k->protocol)
+       {
+#define _(N, j, n, s) \
+        case SNAT_PROTOCOL_##N: \
+          if (a->busy_##n##_port_refcounts[port_host_byte_order]) \
+            return VNET_API_ERROR_INSTANCE_IN_USE; \
+         ++a->busy_##n##_port_refcounts[port_host_byte_order]; \
+          a->busy_##n##_ports_per_thread[thread_index]++; \
+          a->busy_##n##_ports++; \
+          return 0;
+         foreach_snat_protocol
+#undef _
+       default:
+         nat_elog_info ("unknown protocol");
+         return 1;
+       }
+    }
+
+  return VNET_API_ERROR_NO_SUCH_ENTRY;
+}
+
 int
 snat_static_mapping_match (snat_main_t * sm,
                           snat_session_key_t match,
@@ -2077,8 +2774,9 @@ snat_static_mapping_match (snat_main_t * sm,
   snat_static_mapping_t *m;
   snat_session_key_t m_key;
   clib_bihash_8_8_t *mapping_hash = &sm->static_mapping_by_local;
-  u32 rand, lo = 0, hi, mid;
+  u32 rand, lo = 0, hi, mid, *tmp = 0, i;
   u8 backend_index;
+  nat44_lb_addr_port_t *local;
 
   m_key.fib_index = match.fib_index;
   if (by_external)
@@ -2111,49 +2809,73 @@ snat_static_mapping_match (snat_main_t * sm,
        {
          if (PREDICT_FALSE (lb != 0))
            *lb = m->affinity ? AFFINITY_LB_NAT : LB_NAT;
-         if (m->affinity)
+         if (m->affinity && !nat_affinity_find_and_lock (ext_host_addr[0],
+                                                         match.addr,
+                                                         match.protocol,
+                                                         match.port,
+                                                         &backend_index))
            {
-             if (nat_affinity_find_and_lock (ext_host_addr[0], match.addr,
-                                             match.protocol, match.port,
-                                             &backend_index))
-               goto get_local;
-
-             mapping->addr = m->locals[backend_index].addr;
-             mapping->port =
-               clib_host_to_net_u16 (m->locals[backend_index].port);
-             mapping->fib_index = m->locals[backend_index].fib_index;
+             local = pool_elt_at_index (m->locals, backend_index);
+             mapping->addr = local->addr;
+             mapping->port = clib_host_to_net_u16 (local->port);
+             mapping->fib_index = local->fib_index;
              goto end;
            }
-       get_local:
-         hi = vec_len (m->locals) - 1;
-         rand = 1 + (random_u32 (&sm->random_seed) % m->locals[hi].prefix);
+         // pick locals matching this worker
+         if (PREDICT_FALSE (sm->num_workers > 1))
+           {
+             u32 thread_index = vlib_get_thread_index ();
+              /* *INDENT-OFF* */
+              pool_foreach_index (i, m->locals,
+              ({
+                local = pool_elt_at_index (m->locals, i);
+
+                ip4_header_t ip = {
+                 .src_address = local->addr,
+               };
+
+               if (sm->worker_in2out_cb (&ip, m->fib_index, 0) ==
+                   thread_index)
+                  {
+                    vec_add1 (tmp, i);
+                  }
+              }));
+              /* *INDENT-ON* */
+             ASSERT (vec_len (tmp) != 0);
+           }
+         else
+           {
+              /* *INDENT-OFF* */
+              pool_foreach_index (i, m->locals,
+              ({
+                vec_add1 (tmp, i);
+              }));
+              /* *INDENT-ON* */
+           }
+         hi = vec_len (tmp) - 1;
+         local = pool_elt_at_index (m->locals, tmp[hi]);
+         rand = 1 + (random_u32 (&sm->random_seed) % local->prefix);
          while (lo < hi)
            {
              mid = ((hi - lo) >> 1) + lo;
-             (rand > m->locals[mid].prefix) ? (lo = mid + 1) : (hi = mid);
+             local = pool_elt_at_index (m->locals, tmp[mid]);
+             (rand > local->prefix) ? (lo = mid + 1) : (hi = mid);
            }
-         if (!(m->locals[lo].prefix >= rand))
+         local = pool_elt_at_index (m->locals, tmp[lo]);
+         if (!(local->prefix >= rand))
            return 1;
-         if (PREDICT_FALSE (sm->num_workers > 1))
-           {
-             ip4_header_t ip = {
-               .src_address = m->locals[lo].addr,
-             };
-             if (sm->worker_in2out_cb (&ip, m->fib_index) !=
-                 vlib_get_thread_index ())
-               goto get_local;
-           }
-         mapping->addr = m->locals[lo].addr;
-         mapping->port = clib_host_to_net_u16 (m->locals[lo].port);
-         mapping->fib_index = m->locals[lo].fib_index;
+         mapping->addr = local->addr;
+         mapping->port = clib_host_to_net_u16 (local->port);
+         mapping->fib_index = local->fib_index;
          if (m->affinity)
            {
              if (nat_affinity_create_and_lock (ext_host_addr[0], match.addr,
                                                match.protocol, match.port,
-                                               lo, m->affinity,
+                                               tmp[lo], m->affinity,
                                                m->affinity_per_service_list_head_index))
-               nat_log_info ("create affinity record failed");
+               nat_elog_info ("create affinity record failed");
            }
+         vec_free (tmp);
        }
       else
        {
@@ -2238,9 +2960,9 @@ nat_alloc_addr_and_port_default (snat_address_t * addresses,
                       portnum = (port_per_thread * \
                         snat_thread_index) + \
                         snat_random_port(1, port_per_thread) + 1024; \
-                      if (clib_bitmap_get_no_check (a->busy_##n##_port_bitmap, portnum)) \
+                      if (a->busy_##n##_port_refcounts[portnum]) \
                         continue; \
-                      clib_bitmap_set_no_check (a->busy_##n##_port_bitmap, portnum, 1); \
+                     --a->busy_##n##_port_refcounts[portnum]; \
                       a->busy_##n##_ports_per_thread[thread_index]++; \
                       a->busy_##n##_ports++; \
                       k->addr = a->addr; \
@@ -2257,7 +2979,7 @@ nat_alloc_addr_and_port_default (snat_address_t * addresses,
          foreach_snat_protocol
 #undef _
        default:
-         nat_log_info ("unknown protocol");
+         nat_elog_info ("unknown protocol");
          return 1;
        }
 
@@ -2275,9 +2997,9 @@ nat_alloc_addr_and_port_default (snat_address_t * addresses,
               portnum = (port_per_thread * \
                 snat_thread_index) + \
                 snat_random_port(1, port_per_thread) + 1024; \
-              if (clib_bitmap_get_no_check (a->busy_##n##_port_bitmap, portnum)) \
+             if (a->busy_##n##_port_refcounts[portnum]) \
                 continue; \
-              clib_bitmap_set_no_check (a->busy_##n##_port_bitmap, portnum, 1); \
+             ++a->busy_##n##_port_refcounts[portnum]; \
               a->busy_##n##_ports_per_thread[thread_index]++; \
               a->busy_##n##_ports++; \
               k->addr = a->addr; \
@@ -2288,13 +3010,13 @@ nat_alloc_addr_and_port_default (snat_address_t * addresses,
          foreach_snat_protocol
 #undef _
        default:
-         nat_log_info ("unknown protocol");
+         nat_elog_info ("unknown protocol");
          return 1;
        }
     }
 
   /* Totally out of translations to use... */
-  snat_ipfix_logging_addresses_exhausted (0);
+  snat_ipfix_logging_addresses_exhausted (thread_index, 0);
   return 1;
 }
 
@@ -2325,9 +3047,9 @@ nat_alloc_addr_and_port_mape (snat_address_t * addresses,
               A = snat_random_port(1, pow2_mask(sm->psid_offset)); \
               j = snat_random_port(0, pow2_mask(m)); \
               portnum = A | (sm->psid << sm->psid_offset) | (j << (16 - m)); \
-              if (clib_bitmap_get_no_check (a->busy_##n##_port_bitmap, portnum)) \
+             if (a->busy_##n##_port_refcounts[portnum]) \
                 continue; \
-              clib_bitmap_set_no_check (a->busy_##n##_port_bitmap, portnum, 1); \
+             ++a->busy_##n##_port_refcounts[portnum]; \
               a->busy_##n##_ports++; \
               k->addr = a->addr; \
               k->port = clib_host_to_net_u16 (portnum); \
@@ -2338,13 +3060,13 @@ nat_alloc_addr_and_port_mape (snat_address_t * addresses,
       foreach_snat_protocol
 #undef _
     default:
-      nat_log_info ("unknown protocol");
+      nat_elog_info ("unknown protocol");
       return 1;
     }
 
 exhausted:
   /* Totally out of translations to use... */
-  snat_ipfix_logging_addresses_exhausted (0);
+  snat_ipfix_logging_addresses_exhausted (thread_index, 0);
   return 1;
 }
 
@@ -2373,9 +3095,9 @@ nat_alloc_addr_and_port_range (snat_address_t * addresses,
           while (1) \
             { \
               portnum = snat_random_port(sm->start_port, sm->end_port); \
-              if (clib_bitmap_get_no_check (a->busy_##n##_port_bitmap, portnum)) \
+             if (a->busy_##n##_port_refcounts[portnum]) \
                 continue; \
-              clib_bitmap_set_no_check (a->busy_##n##_port_bitmap, portnum, 1); \
+             ++a->busy_##n##_port_refcounts[portnum]; \
               a->busy_##n##_ports++; \
               k->addr = a->addr; \
               k->port = clib_host_to_net_u16 (portnum); \
@@ -2386,13 +3108,13 @@ nat_alloc_addr_and_port_range (snat_address_t * addresses,
       foreach_snat_protocol
 #undef _
     default:
-      nat_log_info ("unknown protocol");
+      nat_elog_info ("unknown protocol");
       return 1;
     }
 
 exhausted:
   /* Totally out of translations to use... */
-  snat_ipfix_logging_addresses_exhausted (0);
+  snat_ipfix_logging_addresses_exhausted (thread_index, 0);
   return 1;
 }
 
@@ -2409,13 +3131,13 @@ nat44_add_del_address_dpo (ip4_address_t addr, u8 is_add)
   if (is_add)
     {
       nat_dpo_create (DPO_PROTO_IP4, 0, &dpo_v4);
-      fib_table_entry_special_dpo_add (0, &pfx, FIB_SOURCE_PLUGIN_HI,
+      fib_table_entry_special_dpo_add (0, &pfx, nat_fib_src_hi,
                                       FIB_ENTRY_FLAG_EXCLUSIVE, &dpo_v4);
       dpo_reset (&dpo_v4);
     }
   else
     {
-      fib_table_entry_special_remove (0, &pfx, FIB_SOURCE_PLUGIN_HI);
+      fib_table_entry_special_remove (0, &pfx, nat_fib_src_hi);
     }
 }
 
@@ -2479,7 +3201,8 @@ format_ed_session_kvp (u8 * s, va_list * args)
 }
 
 static u32
-snat_get_worker_in2out_cb (ip4_header_t * ip0, u32 rx_fib_index0)
+snat_get_worker_in2out_cb (ip4_header_t * ip0, u32 rx_fib_index0,
+                          u8 is_output)
 {
   snat_main_t *sm = &snat_main;
   u32 next_worker_index = 0;
@@ -2498,7 +3221,8 @@ snat_get_worker_in2out_cb (ip4_header_t * ip0, u32 rx_fib_index0)
 }
 
 static u32
-snat_get_worker_out2in_cb (ip4_header_t * ip0, u32 rx_fib_index0)
+snat_get_worker_out2in_cb (vlib_buffer_t * b, ip4_header_t * ip0,
+                          u32 rx_fib_index0, u8 is_output)
 {
   snat_main_t *sm = &snat_main;
   udp_header_t *udp;
@@ -2529,25 +3253,6 @@ snat_get_worker_out2in_cb (ip4_header_t * ip0, u32 rx_fib_index0)
   udp = ip4_next_header (ip0);
   port = udp->dst_port;
 
-  if (PREDICT_FALSE (ip4_is_fragment (ip0)))
-    {
-      if (PREDICT_FALSE (nat_reass_is_drop_frag (0)))
-       return vlib_get_thread_index ();
-
-      if (PREDICT_TRUE (!ip4_is_first_fragment (ip0)))
-       {
-         nat_reass_ip4_t *reass;
-
-         reass = nat_ip4_reass_find (ip0->src_address, ip0->dst_address,
-                                     ip0->fragment_id, ip0->protocol);
-
-         if (reass && (reass->thread_index != (u32) ~ 0))
-           return reass->thread_index;
-         else
-           return vlib_get_thread_index ();
-       }
-    }
-
   /* unknown protocol */
   if (PREDICT_FALSE (proto == ~0))
     {
@@ -2559,10 +3264,12 @@ snat_get_worker_out2in_cb (ip4_header_t * ip0, u32 rx_fib_index0)
     {
       icmp46_header_t *icmp = (icmp46_header_t *) udp;
       icmp_echo_header_t *echo = (icmp_echo_header_t *) (icmp + 1);
-      if (!icmp_is_error_message (icmp))
-       port = echo->identifier;
+      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;
       else
        {
+         /* 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_snat_proto (inner_ip->protocol);
          void *l4_header = ip4_next_header (inner_ip);
@@ -2607,52 +3314,216 @@ snat_get_worker_out2in_cb (ip4_header_t * ip0, u32 rx_fib_index0)
 }
 
 static u32
-nat44_ed_get_worker_out2in_cb (ip4_header_t * ip, u32 rx_fib_index)
+nat44_ed_get_worker_in2out_cb (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;
-  u32 proto, next_worker_index = 0;
-  udp_header_t *udp;
-  u16 port;
-  snat_static_mapping_t *m;
+  u32 next_worker_index = sm->first_worker_index;
   u32 hash;
 
-  /* first try static mappings without port */
-  if (PREDICT_FALSE (pool_elts (sm->static_mappings)))
-    {
-      make_sm_kv (&kv, &ip->dst_address, 0, rx_fib_index, 0);
-      if (!clib_bihash_search_8_8
-         (&sm->static_mapping_by_external, &kv, &value))
-       {
-         m = pool_elt_at_index (sm->static_mappings, value.value);
-         return m->workers[0];
-       }
-    }
-
-  proto = ip_proto_to_snat_proto (ip->protocol);
+  clib_bihash_kv_16_8_t kv16, value16;
+  snat_main_per_thread_data_t *tsm;
+  udp_header_t *udp;
 
-  /* unknown protocol */
-  if (PREDICT_FALSE (proto == ~0))
+  if (PREDICT_FALSE (is_output))
     {
-      /* use current thread */
-      return vlib_get_thread_index ();
-    }
+      u32 fib_index = sm->outside_fib_index;
+      nat_outside_fib_t *outside_fib;
+      fib_node_index_t fei = FIB_NODE_INDEX_INVALID;
+      fib_prefix_t pfx = {
+       .fp_proto = FIB_PROTOCOL_IP4,
+       .fp_len = 32,
+       .fp_addr = {
+                   .ip4.as_u32 = ip->dst_address.as_u32,
+                   }
+       ,
+      };
 
-  udp = ip4_next_header (ip);
-  port = udp->dst_port;
+      udp = ip4_next_header (ip);
 
-  if (PREDICT_FALSE (ip->protocol == IP_PROTOCOL_ICMP))
-    {
-      icmp46_header_t *icmp = (icmp46_header_t *) udp;
-      icmp_echo_header_t *echo = (icmp_echo_header_t *) (icmp + 1);
-      if (!icmp_is_error_message (icmp))
-       port = echo->identifier;
-      else
+      switch (vec_len (sm->outside_fibs))
        {
-         ip4_header_t *inner_ip = (ip4_header_t *) (echo + 1);
-         proto = ip_proto_to_snat_proto (inner_ip->protocol);
-         void *l4_header = ip4_next_header (inner_ip);
-         switch (proto)
+       case 0:
+         fib_index = sm->outside_fib_index;
+         break;
+       case 1:
+         fib_index = sm->outside_fibs[0].fib_index;
+         break;
+       default:
+            /* *INDENT-OFF* */
+            vec_foreach (outside_fib, sm->outside_fibs)
+              {
+                fei = fib_table_lookup (outside_fib->fib_index, &pfx);
+                if (FIB_NODE_INDEX_INVALID != fei)
+                  {
+                    if (fib_entry_get_resolving_interface (fei) != ~0)
+                      {
+                        fib_index = outside_fib->fib_index;
+                        break;
+                      }
+                  }
+              }
+            /* *INDENT-ON* */
+         break;
+       }
+
+      make_ed_kv (&kv16, &ip->src_address, &ip->dst_address,
+                 ip->protocol, fib_index, udp->src_port, udp->dst_port);
+
+      /* *INDENT-OFF* */
+      vec_foreach (tsm, sm->per_thread_data)
+        {
+          if (PREDICT_TRUE (!clib_bihash_search_16_8 (&tsm->out2in_ed,
+                                                      &kv16, &value16)))
+            {
+              next_worker_index += tsm->thread_index;
+
+              nat_elog_debug_handoff (
+                "HANDOFF IN2OUT-OUTPUT-FEATURE (session)",
+                next_worker_index, fib_index,
+               clib_net_to_host_u32 (ip->src_address.as_u32),
+               clib_net_to_host_u32 (ip->dst_address.as_u32));
+
+              return next_worker_index;
+            }
+        }
+      /* *INDENT-ON* */
+    }
+
+  hash = ip->src_address.as_u32 + (ip->src_address.as_u32 >> 8) +
+    (ip->src_address.as_u32 >> 16) + (ip->src_address.as_u32 >> 24);
+
+  if (PREDICT_TRUE (is_pow2 (_vec_len (sm->workers))))
+    next_worker_index += sm->workers[hash & (_vec_len (sm->workers) - 1)];
+  else
+    next_worker_index += sm->workers[hash % _vec_len (sm->workers)];
+
+  if (PREDICT_TRUE (!is_output))
+    {
+      nat_elog_debug_handoff ("HANDOFF IN2OUT",
+                             next_worker_index, rx_fib_index,
+                             clib_net_to_host_u32 (ip->src_address.as_u32),
+                             clib_net_to_host_u32 (ip->dst_address.as_u32));
+    }
+  else
+    {
+      nat_elog_debug_handoff ("HANDOFF IN2OUT-OUTPUT-FEATURE",
+                             next_worker_index, rx_fib_index,
+                             clib_net_to_host_u32 (ip->src_address.as_u32),
+                             clib_net_to_host_u32 (ip->dst_address.as_u32));
+    }
+
+  return next_worker_index;
+}
+
+static u32
+nat44_ed_get_worker_out2in_cb (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;
+  snat_main_per_thread_data_t *tsm;
+
+  u32 proto, next_worker_index = 0;
+  udp_header_t *udp;
+  u16 port;
+  snat_static_mapping_t *m;
+  u32 hash;
+
+  proto = ip_proto_to_snat_proto (ip->protocol);
+
+  if (PREDICT_TRUE (proto == SNAT_PROTOCOL_UDP || proto == SNAT_PROTOCOL_TCP))
+    {
+      udp = ip4_next_header (ip);
+
+      make_ed_kv (&kv16, &ip->dst_address, &ip->src_address,
+                 ip->protocol, rx_fib_index, udp->dst_port, udp->src_port);
+
+      /* *INDENT-OFF* */
+      vec_foreach (tsm, sm->per_thread_data)
+        {
+          if (PREDICT_TRUE (!clib_bihash_search_16_8 (&tsm->out2in_ed,
+                                                      &kv16, &value16)))
+            {
+              next_worker_index = sm->first_worker_index + tsm->thread_index;
+              nat_elog_debug_handoff ("HANDOFF OUT2IN (session)",
+                          next_worker_index, rx_fib_index,
+                         clib_net_to_host_u32 (ip->src_address.as_u32),
+                         clib_net_to_host_u32 (ip->dst_address.as_u32));
+              return next_worker_index;
+            }
+          }
+        /* *INDENT-ON* */
+    }
+  else if (proto == SNAT_PROTOCOL_ICMP)
+    {
+      nat_ed_ses_key_t key;
+
+      if (!get_icmp_o2i_ed_key (b, ip, &key))
+       {
+
+         key.fib_index = rx_fib_index;
+         kv16.key[0] = key.as_u64[0];
+         kv16.key[1] = key.as_u64[1];
+
+          /* *INDENT-OFF* */
+          vec_foreach (tsm, sm->per_thread_data)
+            {
+              if (PREDICT_TRUE (!clib_bihash_search_16_8 (&tsm->out2in_ed,
+                                                          &kv16, &value16)))
+                {
+                  next_worker_index = sm->first_worker_index +
+                                      tsm->thread_index;
+                  nat_elog_debug_handoff ("HANDOFF OUT2IN (session)",
+                              next_worker_index, rx_fib_index,
+                             clib_net_to_host_u32 (ip->src_address.as_u32),
+                             clib_net_to_host_u32 (ip->dst_address.as_u32));
+                  return next_worker_index;
+                }
+            }
+          /* *INDENT-ON* */
+       }
+    }
+
+  /* first try static mappings without port */
+  if (PREDICT_FALSE (pool_elts (sm->static_mappings)))
+    {
+      make_sm_kv (&kv, &ip->dst_address, 0, 0, 0);
+      if (!clib_bihash_search_8_8
+         (&sm->static_mapping_by_external, &kv, &value))
+       {
+         m = pool_elt_at_index (sm->static_mappings, value.value);
+         next_worker_index = m->workers[0];
+         goto done;
+       }
+    }
+
+  /* unknown protocol */
+  if (PREDICT_FALSE (proto == ~0))
+    {
+      /* use current thread */
+      next_worker_index = vlib_get_thread_index ();
+      goto done;
+    }
+
+  udp = ip4_next_header (ip);
+  port = udp->dst_port;
+
+  if (PREDICT_FALSE (ip->protocol == IP_PROTOCOL_ICMP))
+    {
+      icmp46_header_t *icmp = (icmp46_header_t *) udp;
+      icmp_echo_header_t *echo = (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;
+      else
+       {
+         /* 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_snat_proto (inner_ip->protocol);
+         void *l4_header = ip4_next_header (inner_ip);
+         switch (proto)
            {
            case SNAT_PROTOCOL_ICMP:
              icmp = (icmp46_header_t *) l4_header;
@@ -2664,7 +3535,8 @@ nat44_ed_get_worker_out2in_cb (ip4_header_t * ip, u32 rx_fib_index)
              port = ((tcp_udp_header_t *) l4_header)->src_port;
              break;
            default:
-             return vlib_get_thread_index ();
+             next_worker_index = vlib_get_thread_index ();
+             goto done;
            }
        }
     }
@@ -2672,22 +3544,27 @@ nat44_ed_get_worker_out2in_cb (ip4_header_t * ip, u32 rx_fib_index)
   /* try static mappings with port */
   if (PREDICT_FALSE (pool_elts (sm->static_mappings)))
     {
-      make_sm_kv (&kv, &ip->dst_address, proto, rx_fib_index,
+      make_sm_kv (&kv, &ip->dst_address, proto, 0,
                  clib_net_to_host_u16 (port));
       if (!clib_bihash_search_8_8
          (&sm->static_mapping_by_external, &kv, &value))
        {
          m = pool_elt_at_index (sm->static_mappings, value.value);
          if (!is_lb_static_mapping (m))
-           return m->workers[0];
+           {
+             next_worker_index = m->workers[0];
+             goto done;
+           }
 
          hash = ip->src_address.as_u32 + (ip->src_address.as_u32 >> 8) +
            (ip->src_address.as_u32 >> 16) + (ip->src_address.as_u32 >> 24);
 
          if (PREDICT_TRUE (is_pow2 (_vec_len (m->workers))))
-           return m->workers[hash & (_vec_len (m->workers) - 1)];
+           next_worker_index =
+             m->workers[hash & (_vec_len (m->workers) - 1)];
          else
-           return m->workers[hash % _vec_len (m->workers)];
+           next_worker_index = m->workers[hash % _vec_len (m->workers)];
+         goto done;
        }
     }
 
@@ -2696,32 +3573,376 @@ nat44_ed_get_worker_out2in_cb (ip4_header_t * ip, u32 rx_fib_index)
   next_worker_index +=
     sm->workers[(clib_net_to_host_u16 (port) - 1024) / sm->port_per_thread];
 
+done:
+  nat_elog_debug_handoff ("HANDOFF OUT2IN", next_worker_index, rx_fib_index,
+                         clib_net_to_host_u32 (ip->src_address.as_u32),
+                         clib_net_to_host_u32 (ip->dst_address.as_u32));
   return next_worker_index;
 }
 
+void
+nat_ha_sadd_cb (ip4_address_t * in_addr, u16 in_port,
+               ip4_address_t * out_addr, u16 out_port,
+               ip4_address_t * eh_addr, u16 eh_port,
+               ip4_address_t * ehn_addr, u16 ehn_port, u8 proto,
+               u32 fib_index, u16 flags, u32 thread_index)
+{
+  snat_main_t *sm = &snat_main;
+  snat_session_key_t key;
+  snat_user_t *u;
+  snat_session_t *s;
+  clib_bihash_kv_8_8_t kv;
+  f64 now = vlib_time_now (sm->vlib_main);
+  nat_outside_fib_t *outside_fib;
+  fib_node_index_t fei = FIB_NODE_INDEX_INVALID;
+  snat_main_per_thread_data_t *tsm;
+  fib_prefix_t pfx = {
+    .fp_proto = FIB_PROTOCOL_IP4,
+    .fp_len = 32,
+    .fp_addr = {
+               .ip4.as_u32 = eh_addr->as_u32,
+               },
+  };
+
+  tsm = vec_elt_at_index (sm->per_thread_data, thread_index);
+
+  key.addr.as_u32 = out_addr->as_u32;
+  key.port = out_port;
+  key.protocol = proto;
+
+  if (!(flags & SNAT_SESSION_FLAG_STATIC_MAPPING))
+    {
+      if (nat_set_outside_address_and_port
+         (sm->addresses, thread_index, &key))
+       return;
+    }
+
+  u = nat_user_get_or_create (sm, in_addr, fib_index, thread_index);
+  if (!u)
+    return;
+
+  s = nat_session_alloc_or_recycle (sm, u, thread_index, now);
+  if (!s)
+    return;
+
+  s->last_heard = now;
+  s->flags = flags;
+  s->ext_host_addr.as_u32 = eh_addr->as_u32;
+  s->ext_host_port = eh_port;
+  user_session_increment (sm, u, snat_is_session_static (s));
+  switch (vec_len (sm->outside_fibs))
+    {
+    case 0:
+      key.fib_index = sm->outside_fib_index;
+      break;
+    case 1:
+      key.fib_index = sm->outside_fibs[0].fib_index;
+      break;
+    default:
+      /* *INDENT-OFF* */
+      vec_foreach (outside_fib, sm->outside_fibs)
+        {
+          fei = fib_table_lookup (outside_fib->fib_index, &pfx);
+          if (FIB_NODE_INDEX_INVALID != fei)
+            {
+              if (fib_entry_get_resolving_interface (fei) != ~0)
+                {
+                  key.fib_index = outside_fib->fib_index;
+                  break;
+                }
+            }
+        }
+      /* *INDENT-ON* */
+      break;
+    }
+  s->out2in = key;
+  kv.key = key.as_u64;
+  kv.value = s - tsm->sessions;
+  if (clib_bihash_add_del_8_8 (&tsm->out2in, &kv, 1))
+    nat_elog_warn ("out2in key add failed");
+
+  key.addr.as_u32 = in_addr->as_u32;
+  key.port = in_port;
+  key.fib_index = fib_index;
+  s->in2out = key;
+  kv.key = key.as_u64;
+  if (clib_bihash_add_del_8_8 (&tsm->in2out, &kv, 1))
+    nat_elog_warn ("in2out key add failed");
+}
+
+void
+nat_ha_sdel_cb (ip4_address_t * out_addr, u16 out_port,
+               ip4_address_t * eh_addr, u16 eh_port, u8 proto, u32 fib_index,
+               u32 ti)
+{
+  snat_main_t *sm = &snat_main;
+  snat_session_key_t key;
+  clib_bihash_kv_8_8_t kv, value;
+  u32 thread_index;
+  snat_session_t *s;
+  snat_main_per_thread_data_t *tsm;
+
+  if (sm->num_workers > 1)
+    thread_index =
+      sm->first_worker_index +
+      (sm->workers[(clib_net_to_host_u16 (out_port) -
+                   1024) / sm->port_per_thread]);
+  else
+    thread_index = sm->num_workers;
+  tsm = vec_elt_at_index (sm->per_thread_data, thread_index);
+
+  key.addr.as_u32 = out_addr->as_u32;
+  key.port = out_port;
+  key.protocol = proto;
+  key.fib_index = fib_index;
+  kv.key = key.as_u64;
+  if (clib_bihash_search_8_8 (&tsm->out2in, &kv, &value))
+    return;
+
+  s = pool_elt_at_index (tsm->sessions, value.value);
+  nat_free_session_data (sm, s, thread_index, 1);
+  nat44_delete_session (sm, s, thread_index);
+}
+
+void
+nat_ha_sref_cb (ip4_address_t * out_addr, u16 out_port,
+               ip4_address_t * eh_addr, u16 eh_port, u8 proto, u32 fib_index,
+               u32 total_pkts, u64 total_bytes, u32 thread_index)
+{
+  snat_main_t *sm = &snat_main;
+  snat_session_key_t key;
+  clib_bihash_kv_8_8_t kv, value;
+  snat_session_t *s;
+  snat_main_per_thread_data_t *tsm;
+
+  tsm = vec_elt_at_index (sm->per_thread_data, thread_index);
+
+  key.addr.as_u32 = out_addr->as_u32;
+  key.port = out_port;
+  key.protocol = proto;
+  key.fib_index = fib_index;
+  kv.key = key.as_u64;
+  if (clib_bihash_search_8_8 (&tsm->out2in, &kv, &value))
+    return;
+
+  s = pool_elt_at_index (tsm->sessions, value.value);
+  s->total_pkts = total_pkts;
+  s->total_bytes = total_bytes;
+}
+
+void
+nat_ha_sadd_ed_cb (ip4_address_t * in_addr, u16 in_port,
+                  ip4_address_t * out_addr, u16 out_port,
+                  ip4_address_t * eh_addr, u16 eh_port,
+                  ip4_address_t * ehn_addr, u16 ehn_port, u8 proto,
+                  u32 fib_index, u16 flags, u32 thread_index)
+{
+  snat_main_t *sm = &snat_main;
+  snat_session_key_t key;
+  snat_user_t *u;
+  snat_session_t *s;
+  clib_bihash_kv_16_8_t kv;
+  f64 now = vlib_time_now (sm->vlib_main);
+  nat_outside_fib_t *outside_fib;
+  fib_node_index_t fei = FIB_NODE_INDEX_INVALID;
+  snat_main_per_thread_data_t *tsm;
+  fib_prefix_t pfx = {
+    .fp_proto = FIB_PROTOCOL_IP4,
+    .fp_len = 32,
+    .fp_addr = {
+               .ip4.as_u32 = eh_addr->as_u32,
+               },
+  };
+
+  tsm = vec_elt_at_index (sm->per_thread_data, thread_index);
+
+  key.addr.as_u32 = out_addr->as_u32;
+  key.port = out_port;
+  key.protocol = proto;
+
+  if (!(flags & SNAT_SESSION_FLAG_STATIC_MAPPING))
+    {
+      if (nat_set_outside_address_and_port
+         (sm->addresses, thread_index, &key))
+       return;
+    }
+
+  key.addr.as_u32 = ehn_addr->as_u32;
+  key.port = ehn_port;
+  if (flags & SNAT_SESSION_FLAG_TWICE_NAT)
+    {
+      if (nat_set_outside_address_and_port
+         (sm->twice_nat_addresses, thread_index, &key))
+       return;
+    }
+
+  u = nat_user_get_or_create (sm, in_addr, fib_index, thread_index);
+  if (!u)
+    return;
+
+  s = nat_ed_session_alloc (sm, u, thread_index, now);
+  if (!s)
+    return;
+
+  s->last_heard = now;
+  s->flags = flags;
+  s->ext_host_nat_addr.as_u32 = s->ext_host_addr.as_u32 = eh_addr->as_u32;
+  s->ext_host_nat_port = s->ext_host_port = eh_port;
+  if (is_twice_nat_session (s))
+    {
+      s->ext_host_nat_addr.as_u32 = ehn_addr->as_u32;
+      s->ext_host_nat_port = ehn_port;
+    }
+  user_session_increment (sm, u, snat_is_session_static (s));
+  switch (vec_len (sm->outside_fibs))
+    {
+    case 0:
+      key.fib_index = sm->outside_fib_index;
+      break;
+    case 1:
+      key.fib_index = sm->outside_fibs[0].fib_index;
+      break;
+    default:
+      /* *INDENT-OFF* */
+      vec_foreach (outside_fib, sm->outside_fibs)
+        {
+          fei = fib_table_lookup (outside_fib->fib_index, &pfx);
+          if (FIB_NODE_INDEX_INVALID != fei)
+            {
+              if (fib_entry_get_resolving_interface (fei) != ~0)
+                {
+                  key.fib_index = outside_fib->fib_index;
+                  break;
+                }
+            }
+        }
+      /* *INDENT-ON* */
+      break;
+    }
+  key.addr.as_u32 = out_addr->as_u32;
+  key.port = out_port;
+  s->out2in = key;
+  kv.value = s - tsm->sessions;
+
+  key.addr.as_u32 = in_addr->as_u32;
+  key.port = in_port;
+  key.fib_index = fib_index;
+  s->in2out = key;
+
+  make_ed_kv (&kv, in_addr, &s->ext_host_nat_addr,
+             snat_proto_to_ip_proto (proto), fib_index, in_port,
+             s->ext_host_nat_port);
+  if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &kv, 1))
+    nat_elog_warn ("in2out key add failed");
+
+  make_ed_kv (&kv, out_addr, eh_addr, snat_proto_to_ip_proto (proto),
+             s->out2in.fib_index, out_port, eh_port);
+  if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &kv, 1))
+    nat_elog_warn ("out2in key add failed");
+}
+
+void
+nat_ha_sdel_ed_cb (ip4_address_t * out_addr, u16 out_port,
+                  ip4_address_t * eh_addr, u16 eh_port, u8 proto,
+                  u32 fib_index, u32 ti)
+{
+  snat_main_t *sm = &snat_main;
+  nat_ed_ses_key_t key;
+  clib_bihash_kv_16_8_t kv, value;
+  u32 thread_index;
+  snat_session_t *s;
+  snat_main_per_thread_data_t *tsm;
+
+  if (sm->num_workers > 1)
+    thread_index =
+      sm->first_worker_index +
+      (sm->workers[(clib_net_to_host_u16 (out_port) -
+                   1024) / sm->port_per_thread]);
+  else
+    thread_index = sm->num_workers;
+  tsm = vec_elt_at_index (sm->per_thread_data, thread_index);
+
+  key.l_addr.as_u32 = out_addr->as_u32;
+  key.l_port = out_port;
+  key.r_addr.as_u32 = eh_addr->as_u32;
+  key.r_port = eh_port;
+  key.proto = proto;
+  key.fib_index = fib_index;
+  kv.key[0] = key.as_u64[0];
+  kv.key[1] = key.as_u64[1];
+  if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv, &value))
+    return;
+
+  s = pool_elt_at_index (tsm->sessions, value.value);
+  nat_free_session_data (sm, s, thread_index, 1);
+  nat44_delete_session (sm, s, thread_index);
+}
+
+void
+nat_ha_sref_ed_cb (ip4_address_t * out_addr, u16 out_port,
+                  ip4_address_t * eh_addr, u16 eh_port, u8 proto,
+                  u32 fib_index, u32 total_pkts, u64 total_bytes,
+                  u32 thread_index)
+{
+  snat_main_t *sm = &snat_main;
+  nat_ed_ses_key_t key;
+  clib_bihash_kv_16_8_t kv, value;
+  snat_session_t *s;
+  snat_main_per_thread_data_t *tsm;
+
+  tsm = vec_elt_at_index (sm->per_thread_data, thread_index);
+
+  key.l_addr.as_u32 = out_addr->as_u32;
+  key.l_port = out_port;
+  key.r_addr.as_u32 = eh_addr->as_u32;
+  key.r_port = eh_port;
+  key.proto = proto;
+  key.fib_index = fib_index;
+  kv.key[0] = key.as_u64[0];
+  kv.key[1] = key.as_u64[1];
+  if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv, &value))
+    return;
+
+  s = pool_elt_at_index (tsm->sessions, value.value);
+  s->total_pkts = total_pkts;
+  s->total_bytes = total_bytes;
+}
+
 static clib_error_t *
 snat_config (vlib_main_t * vm, unformat_input_t * input)
 {
   snat_main_t *sm = &snat_main;
   nat66_main_t *nm = &nat66_main;
-  u32 translation_buckets = 1024;
-  u32 translation_memory_size = 128 << 20;
-  u32 user_buckets = 128;
-  u32 user_memory_size = 64 << 20;
-  u32 max_translations_per_user = 100;
-  u32 outside_vrf_id = 0;
-  u32 outside_ip6_vrf_id = 0;
-  u32 inside_vrf_id = 0;
+  //dslite_main_t *dm = &dslite_main;
+  snat_main_per_thread_data_t *tsm;
+
   u32 static_mapping_buckets = 1024;
-  u32 static_mapping_memory_size = 64 << 20;
+  uword static_mapping_memory_size = 64 << 20;
+
   u32 nat64_bib_buckets = 1024;
   u32 nat64_bib_memory_size = 128 << 20;
+
   u32 nat64_st_buckets = 2048;
-  u32 nat64_st_memory_size = 256 << 20;
+  uword nat64_st_memory_size = 256 << 20;
+
+  u32 user_buckets = 128;
+  uword user_memory_size = 64 << 20;
+  u32 translation_buckets = 1024;
+  uword translation_memory_size = 128 << 20;
+
+  u32 max_translations_per_user = ~0;
+
+  u32 outside_vrf_id = 0;
+  u32 outside_ip6_vrf_id = 0;
+  u32 inside_vrf_id = 0;
   u8 static_mapping_only = 0;
   u8 static_mapping_connection_tracking = 0;
-  snat_main_per_thread_data_t *tsm;
-  dslite_main_t *dm = &dslite_main;
+
+  // configurable timeouts
+  u32 udp_timeout = SNAT_UDP_TIMEOUT;
+  u32 icmp_timeout = SNAT_ICMP_TIMEOUT;
+  u32 tcp_transitory_timeout = SNAT_TCP_TRANSITORY_TIMEOUT;
+  u32 tcp_established_timeout = SNAT_TCP_ESTABLISHED_TIMEOUT;
 
   sm->deterministic = 0;
   sm->out2in_dpo = 0;
@@ -2732,6 +3953,14 @@ snat_config (vlib_main_t * vm, unformat_input_t * input)
       if (unformat
          (input, "translation hash buckets %d", &translation_buckets))
        ;
+      else if (unformat (input, "udp timeout %d", &udp_timeout))
+       ;
+      else if (unformat (input, "icmp timeout %d", &icmp_timeout))
+       ;
+      else if (unformat (input, "tcp transitory timeout %d",
+                        &tcp_transitory_timeout));
+      else if (unformat (input, "tcp established timeout %d",
+                        &tcp_established_timeout));
       else if (unformat (input, "translation hash memory %d",
                         &translation_memory_size));
       else if (unformat (input, "user hash buckets %d", &user_buckets))
@@ -2769,8 +3998,8 @@ snat_config (vlib_main_t * vm, unformat_input_t * input)
        ;
       else if (unformat (input, "out2in dpo"))
        sm->out2in_dpo = 1;
-      else if (unformat (input, "dslite ce"))
-       dslite_set_ce (dm, 1);
+      //else if (unformat (input, "dslite ce"))
+      //dslite_set_ce (dm, 1);
       else if (unformat (input, "endpoint-dependent"))
        sm->endpoint_dependent = 1;
       else
@@ -2790,26 +4019,37 @@ snat_config (vlib_main_t * vm, unformat_input_t * input)
     return clib_error_return (0,
                              "out2in dpo mode available only for simple nat");
 
-  /* for show commands, etc. */
+  /* optionally configurable timeouts for testing purposes */
+  sm->udp_timeout = udp_timeout;
+  sm->tcp_transitory_timeout = tcp_transitory_timeout;
+  sm->tcp_established_timeout = tcp_established_timeout;
+  sm->icmp_timeout = icmp_timeout;
+
+  sm->min_timeout = nat44_minimal_timeout (sm);
+
+  sm->user_buckets = user_buckets;
+  sm->user_memory_size = user_memory_size;
+
   sm->translation_buckets = translation_buckets;
   sm->translation_memory_size = translation_memory_size;
+
   /* do not exceed load factor 10 */
   sm->max_translations = 10 * translation_buckets;
-  sm->user_buckets = user_buckets;
-  sm->user_memory_size = user_memory_size;
-  sm->max_translations_per_user = max_translations_per_user;
+  sm->max_translations_per_user = max_translations_per_user == ~0 ?
+    sm->max_translations : max_translations_per_user;
+
   sm->outside_vrf_id = outside_vrf_id;
   sm->outside_fib_index = fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4,
                                                             outside_vrf_id,
-                                                            FIB_SOURCE_PLUGIN_HI);
+                                                            nat_fib_src_hi);
   nm->outside_vrf_id = outside_ip6_vrf_id;
   nm->outside_fib_index = fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP6,
                                                             outside_ip6_vrf_id,
-                                                            FIB_SOURCE_PLUGIN_HI);
+                                                            nat_fib_src_hi);
   sm->inside_vrf_id = inside_vrf_id;
   sm->inside_fib_index = fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4,
                                                            inside_vrf_id,
-                                                           FIB_SOURCE_PLUGIN_HI);
+                                                           nat_fib_src_hi);
   sm->static_mapping_only = static_mapping_only;
   sm->static_mapping_connection_tracking = static_mapping_connection_tracking;
 
@@ -2828,24 +4068,38 @@ snat_config (vlib_main_t * vm, unformat_input_t * input)
     {
       if (sm->endpoint_dependent)
        {
-         sm->worker_in2out_cb = snat_get_worker_in2out_cb;
+         sm->worker_in2out_cb = nat44_ed_get_worker_in2out_cb;
          sm->worker_out2in_cb = nat44_ed_get_worker_out2in_cb;
+
+         sm->handoff_out2in_index = nat_pre_out2in_node.index;
+         sm->handoff_in2out_index = nat_pre_in2out_node.index;
+         sm->handoff_in2out_output_index = nat44_ed_in2out_output_node.index;
+
          sm->in2out_node_index = nat44_ed_in2out_node.index;
          sm->in2out_output_node_index = nat44_ed_in2out_output_node.index;
          sm->out2in_node_index = nat44_ed_out2in_node.index;
+
          sm->icmp_match_in2out_cb = icmp_match_in2out_ed;
          sm->icmp_match_out2in_cb = icmp_match_out2in_ed;
          nat_affinity_init (vm);
+         nat_ha_init (vm, nat_ha_sadd_ed_cb, nat_ha_sdel_ed_cb,
+                      nat_ha_sref_ed_cb);
        }
       else
        {
          sm->worker_in2out_cb = snat_get_worker_in2out_cb;
          sm->worker_out2in_cb = snat_get_worker_out2in_cb;
+
+         sm->handoff_out2in_index = snat_out2in_node.index;
+         sm->handoff_in2out_index = snat_in2out_node.index;
+         sm->handoff_in2out_output_index = snat_in2out_output_node.index;
+
          sm->in2out_node_index = snat_in2out_node.index;
          sm->in2out_output_node_index = snat_in2out_output_node.index;
          sm->out2in_node_index = snat_out2in_node.index;
          sm->icmp_match_in2out_cb = icmp_match_in2out_slow;
          sm->icmp_match_out2in_cb = icmp_match_out2in_slow;
+         nat_ha_init (vm, nat_ha_sadd_cb, nat_ha_sdel_cb, nat_ha_sref_cb);
        }
       if (!static_mapping_only ||
          (static_mapping_only && static_mapping_connection_tracking))
@@ -2853,6 +4107,22 @@ snat_config (vlib_main_t * vm, unformat_input_t * input)
           /* *INDENT-OFF* */
           vec_foreach (tsm, sm->per_thread_data)
             {
+             tsm->min_session_timeout = 0;
+
+              tsm->cleared = 0;
+              tsm->cleanup_runs = 0;
+              tsm->cleanup_timeout = 0;
+
+              pool_alloc (tsm->sessions, sm->max_translations);
+              pool_alloc (tsm->list_pool, sm->max_translations);
+              pool_alloc (tsm->global_lru_pool, sm->max_translations);
+
+              dlist_elt_t *head;
+              pool_get (tsm->global_lru_pool, head);
+              tsm->global_lru_head_index = head - tsm->global_lru_pool;
+              clib_dlist_init (tsm->global_lru_pool,
+                               tsm->global_lru_head_index);
+
               if (sm->endpoint_dependent)
                 {
                   clib_bihash_init_16_8 (&tsm->in2out_ed, "in2out-ed",
@@ -2866,6 +4136,9 @@ snat_config (vlib_main_t * vm, unformat_input_t * input)
                                          translation_memory_size);
                   clib_bihash_set_kvp_format_fn_16_8 (&tsm->out2in_ed,
                                                       format_ed_session_kvp);
+                  clib_bihash_init_16_8
+                  (&sm->ed_ext_ports, "ed-nat-5-tuple-port-overload-hash",
+                   translation_buckets, translation_memory_size);
                 }
               else
                 {
@@ -2979,7 +4252,7 @@ match:
                                rp->proto, !is_delete, rp->twice_nat,
                                rp->out2in_only, rp->tag, rp->identity_nat);
   if (rv)
-    nat_log_notice ("snat_add_static_mapping returned %d", rv);
+    nat_elog_notice_X1 ("snat_add_static_mapping returned %d", "i4", rv);
 }
 
 static void
@@ -3050,7 +4323,8 @@ match:
                                            rp->out2in_only, rp->tag,
                                            rp->identity_nat);
              if (rv)
-               nat_log_notice ("snat_add_static_mapping returned %d", rv);
+               nat_elog_notice_X1 ("snat_add_static_mapping returned %d",
+                                   "i4", rv);
            }
        }
       return;
@@ -3150,7 +4424,7 @@ nat44_del_session (snat_main_t * sm, ip4_address_t * addr, u16 port,
   if (sm->num_workers > 1)
     tsm =
       vec_elt_at_index (sm->per_thread_data,
-                       sm->worker_in2out_cb (&ip, fib_index));
+                       sm->worker_in2out_cb (&ip, fib_index, 0));
   else
     tsm = vec_elt_at_index (sm->per_thread_data, sm->num_workers);
 
@@ -3166,7 +4440,7 @@ nat44_del_session (snat_main_t * sm, ip4_address_t * addr, u16 port,
        return VNET_API_ERROR_UNSPECIFIED;
 
       s = pool_elt_at_index (tsm->sessions, value.value);
-      nat_free_session_data (sm, s, tsm - sm->per_thread_data);
+      nat_free_session_data (sm, s, tsm - sm->per_thread_data, 0);
       nat44_delete_session (sm, s, tsm - sm->per_thread_data);
       return 0;
     }
@@ -3194,7 +4468,7 @@ nat44_del_ed_session (snat_main_t * sm, ip4_address_t * addr, u16 port,
   if (sm->num_workers > 1)
     tsm =
       vec_elt_at_index (sm->per_thread_data,
-                       sm->worker_in2out_cb (&ip, fib_index));
+                       sm->worker_in2out_cb (&ip, fib_index, 0));
   else
     tsm = vec_elt_at_index (sm->per_thread_data, sm->num_workers);
 
@@ -3213,7 +4487,7 @@ nat44_del_ed_session (snat_main_t * sm, ip4_address_t * addr, u16 port,
   if (pool_is_free_index (tsm->sessions, value.value))
     return VNET_API_ERROR_UNSPECIFIED;
   s = pool_elt_at_index (tsm->sessions, value.value);
-  nat_free_session_data (sm, s, tsm - sm->per_thread_data);
+  nat_free_session_data (sm, s, tsm - sm->per_thread_data, 0);
   nat44_delete_session (sm, s, tsm - sm->per_thread_data);
   return 0;
 }
@@ -3250,6 +4524,35 @@ nat_set_alloc_addr_and_port_default (void)
   sm->alloc_addr_and_port = nat_alloc_addr_and_port_default;
 }
 
+VLIB_NODE_FN (nat_default_node) (vlib_main_t * vm,
+                                vlib_node_runtime_t * node,
+                                vlib_frame_t * frame)
+{
+  return 0;
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (nat_default_node) = {
+  .name = "nat-default",
+  .vector_size = sizeof (u32),
+  .format_trace = 0,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = 0,
+  .n_next_nodes = NAT_N_NEXT,
+  .next_nodes = {
+    [NAT_NEXT_DROP] = "error-drop",
+    [NAT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
+    [NAT_NEXT_IN2OUT_PRE] = "nat-pre-in2out",
+    [NAT_NEXT_OUT2IN_PRE] = "nat-pre-out2in",
+    [NAT_NEXT_IN2OUT_ED_FAST_PATH] = "nat44-ed-in2out",
+    [NAT_NEXT_IN2OUT_ED_SLOW_PATH] = "nat44-ed-in2out-slowpath",
+    [NAT_NEXT_IN2OUT_ED_OUTPUT_SLOW_PATH] = "nat44-ed-in2out-output-slowpath",
+    [NAT_NEXT_OUT2IN_ED_FAST_PATH] = "nat44-ed-out2in",
+    [NAT_NEXT_OUT2IN_ED_SLOW_PATH] = "nat44-ed-out2in-slowpath",
+  },
+};
+/* *INDENT-ON* */
+
 /*
  * fd.io coding-style-patch-verification: ON
  *