diff --git a/src/api/api_lib.c b/src/api/api_lib.c
index df99c17f..c4740aaa 100644
--- a/src/api/api_lib.c
+++ b/src/api/api_lib.c
@@ -286,6 +286,8 @@ netconn_peer(struct netconn *conn, struct ip_addr **addr,
   case NETCONN_UDPLITE:
   case NETCONN_UDPNOCHKSUM:
   case NETCONN_UDP:
+    if ((conn->pcb.udp->flags & UDP_FLAGS_CONNECTED) == 0)
+     return -1;
     *addr = &(conn->pcb.udp->remote_ip);
     *port = conn->pcb.udp->remote_port;
     break;
@@ -345,6 +347,7 @@ netconn_bind(struct netconn *conn, struct ip_addr *addr,
   memp_freep(MEMP_API_MSG, msg);
   return conn->err;
 }
+
 /*-----------------------------------------------------------------------------------*/
 err_t
 netconn_connect(struct netconn *conn, struct ip_addr *addr,
@@ -375,6 +378,26 @@ netconn_connect(struct netconn *conn, struct ip_addr *addr,
   memp_freep(MEMP_API_MSG, msg);
   return conn->err;
 }
+
+err_t
+netconn_disconnect(struct netconn *conn)
+{
+  struct api_msg *msg;
+  
+  if(conn == NULL) {
+    return ERR_VAL;
+  }
+
+  if((msg = memp_mallocp(MEMP_API_MSG)) == NULL) {
+    return ERR_MEM;
+  }
+  msg->type = API_MSG_DISCONNECT;
+  msg->msg.conn = conn;  
+  api_msg_post(msg);
+  memp_freep(MEMP_API_MSG, msg);
+  return conn->err;
+
+}
 /*-----------------------------------------------------------------------------------*/
 err_t
 netconn_listen(struct netconn *conn)
diff --git a/src/api/api_msg.c b/src/api/api_msg.c
index 165ffdf4..1b84e0de 100644
--- a/src/api/api_msg.c
+++ b/src/api/api_msg.c
@@ -71,7 +71,6 @@ recv_udp(void *arg, struct udp_pcb *pcb, struct pbuf *p,
     pbuf_free(p);
     return;
   }
-
   if(conn->recvmbox != SYS_MBOX_NULL) {
     buf = memp_mallocp(MEMP_NETBUF);
     if(buf == NULL) {
@@ -370,6 +369,26 @@ do_connect(struct api_msg_msg *msg)
     break;
   }
 }
+
+static void
+do_disconnect(struct api_msg_msg *msg)
+{
+
+  switch(msg->conn->type) {
+#if LWIP_UDP
+  case NETCONN_UDPLITE:
+    /* FALLTHROUGH */
+  case NETCONN_UDPNOCHKSUM:
+    /* FALLTHROUGH */
+  case NETCONN_UDP:
+    udp_disconnect(msg->conn->pcb.udp);
+    break;
+#endif 
+  case NETCONN_TCP:
+    break;
+  }
+}
+
 /*-----------------------------------------------------------------------------------*/
 static void
 do_listen(struct api_msg_msg *msg)
@@ -524,6 +543,7 @@ static api_msg_decode decode[API_MSG_MAX] = {
   do_delconn,
   do_bind,
   do_connect,
+  do_disconnect,
   do_listen,
   do_accept,
   do_send,
diff --git a/src/api/sockets.c b/src/api/sockets.c
index ac14d5d7..cbaf573f 100644
--- a/src/api/sockets.c
+++ b/src/api/sockets.c
@@ -172,11 +172,14 @@ lwip_connect(int s, struct sockaddr *name, int namelen)
   if(sock == NULL) {
     return -1;
   }
-  
-  remote_addr.addr = ((struct sockaddr_in *)name)->sin_addr.s_addr;
-  remote_port = ((struct sockaddr_in *)name)->sin_port;
-  
-  err = netconn_connect(sock->conn, &remote_addr, ntohs(remote_port));
+ 
+  if (((struct sockaddr_in *)name)->sin_family == AF_UNSPEC) {
+    err = netconn_disconnect(sock->conn);
+  } else {  
+    remote_addr.addr = ((struct sockaddr_in *)name)->sin_addr.s_addr;
+    remote_port = ((struct sockaddr_in *)name)->sin_port;
+    err = netconn_connect(sock->conn, &remote_addr, ntohs(remote_port));
+  }  
 
   if(err != ERR_OK) {
     /* errno = ... */
@@ -343,7 +346,7 @@ lwip_sendto(int s, void *data, int size, unsigned int flags,
   struct lwip_socket *sock;
   struct ip_addr remote_addr, *addr;
   u16_t remote_port, port;
-  int ret;
+  int ret,connected;
 
   sock = get_socket(s);
   if(sock == NULL) {
@@ -351,7 +354,7 @@ lwip_sendto(int s, void *data, int size, unsigned int flags,
   }
   
   /* get the peer if currently connected */
-  netconn_peer(sock->conn, &addr, &port);
+  connected = (netconn_peer(sock->conn, &addr, &port) == ERR_OK);
   
   remote_addr.addr = ((struct sockaddr_in *)to)->sin_addr.s_addr;
   remote_port = ((struct sockaddr_in *)to)->sin_port;
@@ -361,7 +364,10 @@ lwip_sendto(int s, void *data, int size, unsigned int flags,
 
   /* reset the remote address and port number
      of the connection */
-  netconn_connect(sock->conn, addr, port);
+  if (connected)
+    netconn_connect(sock->conn, addr, port);
+  else
+    netconn_disconnect(sock->conn);	  
   return ret;
 }
 /*-----------------------------------------------------------------------------------*/
diff --git a/src/core/udp.c b/src/core/udp.c
index d7e49777..81608f54 100644
--- a/src/core/udp.c
+++ b/src/core/udp.c
@@ -28,7 +28,7 @@
  * 
  * Author: Adam Dunkels <adam@sics.se>
  *
- * $Id: udp.c,v 1.10 2003/01/21 14:09:31 jani Exp $
+ * $Id: udp.c,v 1.11 2003/01/22 16:18:05 jani Exp $
  */
 
 /*-----------------------------------------------------------------------------------*/
@@ -199,16 +199,15 @@ udp_input(struct pbuf *p, struct netif *inp)
       break;
     }
   }
-  /* no fully matching pcb found? */
+  /* no fully matching pcb found? then look for an unconnected pcb */
   if(pcb == NULL) {
     /* Iterate through the UDP pcb list for a pcb that matches
        the local address. */
     for(pcb = udp_pcbs; pcb != NULL; pcb = pcb->next) {
       DEBUGF(UDP_DEBUG, ("udp_input: pcb local port %d (dgram %d)\n",
 			 pcb->local_port, dest));
-      if(pcb->local_port == dest &&
-	 (ip_addr_isany(&pcb->remote_ip) ||
-	  ip_addr_cmp(&(pcb->remote_ip), &(iphdr->src))) &&
+      if((pcb->flags & UDP_FLAGS_CONNECTED) == 0 &&
+	  pcb->local_port == dest &&
 	 (ip_addr_isany(&pcb->local_ip) ||
 	  ip_addr_cmp(&(pcb->local_ip), &(iphdr->dest)))) {
 	break;
@@ -396,13 +395,14 @@ err_t
 udp_bind(struct udp_pcb *pcb, struct ip_addr *ipaddr, u16_t port)
 {
   struct udp_pcb *ipcb;
-
-  /* Insert UDP PCB into the list of active UDP PCBs. */
+  u8_t rebind = 0;
+  
+  /* Check for double bind and rebind of the same pcb */
   for(ipcb = udp_pcbs; ipcb != NULL; ipcb = ipcb->next) {
-    if(pcb == ipcb) {
-      /* Already on the list, just return. */
-      return ERR_OK;
-    }
+    if (pcb == ipcb) {
+	 rebind = 1;
+	 break;
+    }  else	 
     if (ipcb->local_port == port) {
       if(ip_addr_isany(&(ipcb->local_ip)) ||
 	 ip_addr_isany(ipaddr) ||
@@ -416,9 +416,11 @@ udp_bind(struct udp_pcb *pcb, struct ip_addr *ipaddr, u16_t port)
   ip_addr_set(&pcb->local_ip, ipaddr);
   pcb->local_port = port;
   
-  /* We need to place the PCB on the list. */
-  pcb->next = udp_pcbs;
-  udp_pcbs = pcb;
+  /* We need to place the PCB on the list if not already there. */
+  if (rebind == 0) {
+    pcb->next = udp_pcbs;
+    udp_pcbs = pcb;
+  }  
 
   DEBUGF(UDP_DEBUG, ("udp_bind: bound to port %d\n", port));
   return ERR_OK;
@@ -430,6 +432,7 @@ udp_connect(struct udp_pcb *pcb, struct ip_addr *ipaddr, u16_t port)
   struct udp_pcb *ipcb;
   ip_addr_set(&pcb->remote_ip, ipaddr);
   pcb->remote_port = port;
+  pcb->flags |= UDP_FLAGS_CONNECTED;
 
   /* Insert UDP PCB into the list of active UDP PCBs. */
   for(ipcb = udp_pcbs; ipcb != NULL; ipcb = ipcb->next) {
@@ -443,6 +446,12 @@ udp_connect(struct udp_pcb *pcb, struct ip_addr *ipaddr, u16_t port)
   udp_pcbs = pcb;
   return ERR_OK;
 }
+
+void
+udp_disconnect(struct udp_pcb *pcb)
+{
+  	pcb->flags &= ~UDP_FLAGS_CONNECTED;
+}
 /*-----------------------------------------------------------------------------------*/
 void
 udp_recv(struct udp_pcb *pcb,
@@ -474,6 +483,7 @@ struct udp_pcb *
 udp_new(void) {
   struct udp_pcb *pcb;
   pcb = memp_malloc(MEMP_UDP_PCB);
+  pcb->flags = 0;
   if(pcb != NULL) {
     memset(pcb, 0, sizeof(struct udp_pcb));
     return pcb;
diff --git a/src/include/lwip/api.h b/src/include/lwip/api.h
index 58f0dcdc..c19b903d 100644
--- a/src/include/lwip/api.h
+++ b/src/include/lwip/api.h
@@ -122,6 +122,7 @@ err_t             netconn_bind    (struct netconn *conn,
 err_t             netconn_connect (struct netconn *conn,
 				   struct ip_addr *addr,
 				   u16_t port);
+err_t             netconn_disconnect (struct netconn *conn);
 err_t             netconn_listen  (struct netconn *conn);
 struct netconn *  netconn_accept  (struct netconn *conn);
 struct netbuf *   netconn_recv    (struct netconn *conn);
diff --git a/src/include/lwip/api_msg.h b/src/include/lwip/api_msg.h
index ec8a6ded..60bd3584 100644
--- a/src/include/lwip/api_msg.h
+++ b/src/include/lwip/api_msg.h
@@ -49,6 +49,7 @@ enum api_msg_type {
   
   API_MSG_BIND,
   API_MSG_CONNECT,
+  API_MSG_DISCONNECT,
 
   API_MSG_LISTEN,
   API_MSG_ACCEPT,
diff --git a/src/include/lwip/sockets.h b/src/include/lwip/sockets.h
index 8b808b61..8899a872 100644
--- a/src/include/lwip/sockets.h
+++ b/src/include/lwip/sockets.h
@@ -56,6 +56,7 @@ struct sockaddr {
 #define SOCK_STREAM     1
 #define SOCK_DGRAM      2
 
+#define AF_UNSPEC	0
 #define AF_INET         2
 #define PF_INET         AF_INET
 
diff --git a/src/include/lwip/udp.h b/src/include/lwip/udp.h
index 10b73715..09144e2e 100644
--- a/src/include/lwip/udp.h
+++ b/src/include/lwip/udp.h
@@ -51,6 +51,7 @@ struct udp_hdr {
 
 #define UDP_FLAGS_NOCHKSUM 0x01
 #define UDP_FLAGS_UDPLITE  0x02
+#define UDP_FLAGS_CONNECTED  0x04
 
 struct udp_pcb {
   struct udp_pcb *next;
@@ -74,6 +75,7 @@ err_t            udp_bind       (struct udp_pcb *pcb, struct ip_addr *ipaddr,
 				 u16_t port);
 err_t            udp_connect    (struct udp_pcb *pcb, struct ip_addr *ipaddr,
 				 u16_t port);
+void            udp_disconnect    (struct udp_pcb *pcb);
 void             udp_recv       (struct udp_pcb *pcb,
 				 void (* recv)(void *arg, struct udp_pcb *upcb,
 					       struct pbuf *p,