Now I understand. You are reusing "a socket". After a TCP socket is closed, data can still be going around and the default behaviour is to wait for a while before reusing that socket. The raw API does not use sockets, but the behaviour is the same. The waiting time varies from full hosts to embedded machines, I've seen from 4 minutes to 4 seconds.
I don't know if there is any workaround to this, you surely will be able to shorten this time if you can't wait, and maybe Simon or any other might lead to a compile option to provide a workaround if there is one; the default is to wait or design for an extra "socket". _______________________________________________ lwip-users mailing list lwip-users@nongnu.org https://lists.nongnu.org/mailman/listinfo/lwip-users
