I don't know what you are doing 'cause you don't say, but if you are using NO_SYS=1 there must be a main loop calling sys_check_timeouts() as frequently as possible, it takes care of all timeouts.
You should check if your frames carrying your TCP SYNs are being delivered or get lost in the driver. Another frequent source of error is not polling the receiver frequently enough, and when doing it, not retrieving ALL frames it got. The first one is a user fault, the second is a driver fault. _______________________________________________ lwip-users mailing list lwip-users@nongnu.org https://lists.nongnu.org/mailman/listinfo/lwip-users
