Re: [lwip-users] Closing tcp-Connection

[Sergio R. Caprile]

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".