diff --git a/src/vnet/session/transport.c b/src/vnet/session/transport.c
index 8554c73..0020d74 100644
--- a/src/vnet/session/transport.c
+++ b/src/vnet/session/transport.c
@@ -566,7 +566,8 @@
  * table to mark the pair as used.
  */
 int
-transport_alloc_local_port (u8 proto, ip46_address_t * ip)
+transport_alloc_local_port (u8 proto, ip46_address_t *lcl_addr,
+			    transport_endpoint_cfg_t *rmt)
 {
   u16 min = 1024, max = 65535;	/* XXX configurable ? */
   transport_main_t *tm = &tp_main;
@@ -594,8 +595,18 @@
 	    break;
 	}
 
-      if (!transport_endpoint_mark_used (proto, ip, port))
+      if (!transport_endpoint_mark_used (proto, lcl_addr, port))
 	return port;
+
+      /* IP:port pair already in use, check if 6-tuple available */
+      if (session_lookup_connection (rmt->fib_index, lcl_addr, &rmt->ip, port,
+				     rmt->port, proto, rmt->is_ip4))
+	continue;
+
+      /* 6-tuple is available so increment lcl endpoint refcount */
+      transport_share_local_endpoint (proto, lcl_addr, port);
+
+      return port;
     }
   return -1;
 }
@@ -683,7 +694,7 @@
    */
   if (rmt_cfg->peer.port == 0)
     {
-      port = transport_alloc_local_port (proto, lcl_addr);
+      port = transport_alloc_local_port (proto, lcl_addr, rmt_cfg);
       if (port < 1)
 	return SESSION_E_NOPORT;
       *lcl_port = port;
diff --git a/src/vnet/session/transport.h b/src/vnet/session/transport.h
index 6e8b22a..3cd64c9 100644
--- a/src/vnet/session/transport.h
+++ b/src/vnet/session/transport.h
@@ -246,10 +246,10 @@
 transport_proto_vft_t *transport_protocol_get_vft (transport_proto_t tp);
 void transport_update_time (clib_time_type_t time_now, u8 thread_index);
 
-int transport_alloc_local_port (u8 proto, ip46_address_t * ip);
-int transport_alloc_local_endpoint (u8 proto, transport_endpoint_cfg_t * rmt,
-				    ip46_address_t * lcl_addr,
-				    u16 * lcl_port);
+int transport_alloc_local_port (u8 proto, ip46_address_t *ip,
+				transport_endpoint_cfg_t *rmt);
+int transport_alloc_local_endpoint (u8 proto, transport_endpoint_cfg_t *rmt,
+				    ip46_address_t *lcl_addr, u16 *lcl_port);
 void transport_share_local_endpoint (u8 proto, ip46_address_t * lcl_ip,
 				     u16 port);
 int transport_release_local_endpoint (u8 proto, ip46_address_t *lcl_ip,
diff --git a/src/vnet/tcp/tcp.c b/src/vnet/tcp/tcp.c
index c0445b9..6e0c147 100644
--- a/src/vnet/tcp/tcp.c
+++ b/src/vnet/tcp/tcp.c
@@ -764,11 +764,13 @@
 }
 
 static int
-tcp_alloc_custom_local_endpoint (tcp_main_t * tm, ip46_address_t * lcl_addr,
-				 u16 * lcl_port, u8 is_ip4)
+tcp_alloc_custom_local_endpoint (ip46_address_t *lcl_addr, u16 *lcl_port,
+				 transport_endpoint_cfg_t *rmt)
 {
+  tcp_main_t *tm = vnet_get_tcp_main ();
   int index, port;
-  if (is_ip4)
+
+  if (rmt->is_ip4)
     {
       index = tm->last_v4_addr_rotor++;
       if (tm->last_v4_addr_rotor >= vec_len (tcp_cfg.ip4_src_addrs))
@@ -784,7 +786,7 @@
       clib_memcpy_fast (&lcl_addr->ip6, &tcp_cfg.ip6_src_addrs[index],
 			sizeof (ip6_address_t));
     }
-  port = transport_alloc_local_port (TRANSPORT_PROTO_TCP, lcl_addr);
+  port = transport_alloc_local_port (TRANSPORT_PROTO_TCP, lcl_addr, rmt);
   if (port < 1)
     return SESSION_E_NOPORT;
   *lcl_port = port;
@@ -794,7 +796,6 @@
 static int
 tcp_session_open (transport_endpoint_cfg_t * rmt)
 {
-  tcp_main_t *tm = vnet_get_tcp_main ();
   tcp_connection_t *tc;
   ip46_address_t lcl_addr;
   u16 lcl_port;
@@ -805,27 +806,13 @@
    */
   if ((rmt->is_ip4 && vec_len (tcp_cfg.ip4_src_addrs))
       || (!rmt->is_ip4 && vec_len (tcp_cfg.ip6_src_addrs)))
-    rv = tcp_alloc_custom_local_endpoint (tm, &lcl_addr, &lcl_port,
-					  rmt->is_ip4);
+    rv = tcp_alloc_custom_local_endpoint (&lcl_addr, &lcl_port, rmt);
   else
     rv = transport_alloc_local_endpoint (TRANSPORT_PROTO_TCP,
 					 rmt, &lcl_addr, &lcl_port);
 
   if (rv)
-    {
-      if (rv != SESSION_E_PORTINUSE)
-	return rv;
-
-      if (session_lookup_connection (rmt->fib_index, &lcl_addr, &rmt->ip,
-				     lcl_port, rmt->port, TRANSPORT_PROTO_TCP,
-				     rmt->is_ip4))
-	return SESSION_E_PORTINUSE;
-
-      /* 5-tuple is available so increase lcl endpoint refcount and proceed
-       * with connection allocation */
-      transport_share_local_endpoint (TRANSPORT_PROTO_TCP, &lcl_addr,
-				      lcl_port);
-    }
+    return rv;
 
   /*
    * Create connection and send SYN
diff --git a/src/vnet/udp/udp.c b/src/vnet/udp/udp.c
index 4553701..7147fa3 100644
--- a/src/vnet/udp/udp.c
+++ b/src/vnet/udp/udp.c
@@ -362,44 +362,30 @@
   rv = transport_alloc_local_endpoint (TRANSPORT_PROTO_UDP, rmt, &lcl_addr,
 				       &lcl_port);
   if (rv)
-    {
-      if (rv != SESSION_E_PORTINUSE)
-	return rv;
-
-      if (udp_connection_port_used_extern (lcl_port, rmt->is_ip4))
-	return SESSION_E_PORTINUSE;
-
-      /* If port in use, check if 5-tuple is also in use */
-      if (session_lookup_connection (rmt->fib_index, &lcl_addr, &rmt->ip,
-				     lcl_port, rmt->port, TRANSPORT_PROTO_UDP,
-				     rmt->is_ip4))
-	return SESSION_E_PORTINUSE;
-
-      /* 5-tuple is available so increase lcl endpoint refcount and proceed
-       * with connection allocation */
-      transport_share_local_endpoint (TRANSPORT_PROTO_UDP, &lcl_addr,
-				      lcl_port);
-      goto conn_alloc;
-    }
+    return rv;
 
   if (udp_is_valid_dst_port (lcl_port, rmt->is_ip4))
     {
       /* If specific source port was requested abort */
       if (rmt->peer.port)
-	return SESSION_E_PORTINUSE;
+	{
+	  transport_release_local_endpoint (TRANSPORT_PROTO_UDP, &lcl_addr,
+					    lcl_port);
+	  return SESSION_E_PORTINUSE;
+	}
 
       /* Try to find a port that's not used */
       while (udp_is_valid_dst_port (lcl_port, rmt->is_ip4))
 	{
-	  lcl_port = transport_alloc_local_port (TRANSPORT_PROTO_UDP,
-						 &lcl_addr);
+	  transport_release_local_endpoint (TRANSPORT_PROTO_UDP, &lcl_addr,
+					    lcl_port);
+	  lcl_port =
+	    transport_alloc_local_port (TRANSPORT_PROTO_UDP, &lcl_addr, rmt);
 	  if (lcl_port < 1)
 	    return SESSION_E_PORTINUSE;
 	}
     }
 
-conn_alloc:
-
   /* We don't poll main thread if we have workers */
   thread_index = transport_cl_thread ();