Why Wireshark/Ethereal sniffer doesn't detect ACK packets as TCP
keepalive probes when TCP retransmission of data packets occurs?
Anyway TCP keepalive mechanism works well, it sends the RST packet due
to connection timeout at the expected time.
My application sends messages every 10 sec. on TCP connection, TCP
keepalive idle time is 12sec, TCP keepalive probe interval is 8 and
TCP keepalive probe count is 8. I triggered the TCP keepalive
mechanism removing the ethernet cable.

Thanks,
Elpi