> > > > We are using LWIP in an ecos based environment. We are having > > problems with LWIP TCP. The udp part is communicating successfully to > > a external TCP/IP stack from our system. But while using TCP client to > > connect to a external TCP server from with in the system, it is not > > working. The tcp_connect results in a SYNC to the external server. The > > server acks with a SYNC -ACK. Then a RST goes from the LWIP instead of > > an ACK to complete the initialization handshake.
Hmm, that is strange. It sends a RST, and then immediately follows that with the correct ACK to the SYNACK. There is some odd ARP traffic going on too - it ARPs before sending the SYN (which is expected) but then sends another ARP request before sending the RST and ACK. At the top of the trace it is sending ARP requests asking for the replies to be sent to 0.0.0.0 which is obviously wrong. I'm not an expert on the ARP code in lwIP, so can't really comment about that - perhaps someone else can help there. There are only a few places in the stack that send a RST packet. The simplest way to find out why it is sending a RST is to turn on some debugging print statements in each of these. Once we know why it sends the RST, fixing the problem should be much easier. Kieran _______________________________________________ lwip-users mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/lwip-users
