The simplest test would be as follows: it should be an active close, i.e. connection close should happen on Zephyr side. Then test would expect to receive a FIN pkt, but should ignore it and not send an ACK. Then the test should verify that a FIN retransmission is received within reasonable time.
Thanks for the input.
Currenly the TCP suite is very simple and doesn't have a capability to initiate events on a peer's side of TCP connection.
I am planning to add such capability and will try to implement such a test.
