Socket problems after DC 10.11 to 10.50 upgrade


I had a working application built using DC 10.11, with it I was experiencing occasional ethernet problems (drops connection once per hour). After seeing the list of bug fixes from DC 10.11 to 10.50 includes some TCP fixes, I have been trying to get my code running with the new compiler/libraries. I have added my custom board definitions and have the code running but the TCP sockets are no longer open. The stack is running fine as I can ping the unit and get a response, however when I try to connect to a port that should be open I get a RST flag back from the unit. Is there some other change that has been made between the versions that I need to accomodate.

Setup details:
Custom board using a 4000 processor with inbuilt ethernet.
Passive open port 1495 for communications.
Port 80 open as a webserver.
Unit is under constant control from a PC.

The original problem I was having was that about 1 per hour the unit would send a reset flag in response to a command. I couldn’t trace the source of this so tried upgrading DC version.

Any ideas what the original problem was or the upgrade problem is would be greatfully received.



I have also checked that both sock_init() and tcp_listen() are called and return with no errors. sock_error() returns 0 as well.

Also the Link LED is on and the Activity LED (on PCB) flash when trying to connect.

I am assuming it is a problem in the configuration of the board but I have no idea where to start. Any help greatly appreciated.