FIN_WAIT_2

[Robert Gogolok]

Charles Swiger wrote:
> If the TCP connection is in FIN_WAIT_2, FreeBSD may send out ACKs 
> periodicly, trying to nudge the other side to send a FIN to finish 
> closing the connection.
This is indeed the case (when I interpret the tcpdump output correct):

21:19:20.139373 IP HTTP_SERVER.http > HTTP_CLIENT.63131: . ack 
2918467318 win 0
21:19:20.139543 IP HTTP_SERVER.http > HTTP_CLIENT.63131: . ack 
2918467318 win 65535
21:24:05.098980 IP HTTP_SERVER.http > HTTP_CLIENT.63131: . ack 
2918467318 win 0
21:24:05.099151 IP HTTP_SERVER.http > HTTP_CLIENT.63131: . ack 
2918467318 win 65535
.
. AND SO ON :-)
.
22:11:34.665056 IP HTTP_SERVER.http > HTTP_CLIENT.63131: . ack 
2918467318 win 0
22:11:34.665225 IP HTTP_SERVER.http > HTTP_CLIENT.63131: . ack 
2918467318 win 65535
22:16:19.621661 IP HTTP_SERVER.http > HTTP_CLIENT.63131: . ack 
2918467318 win 0
22:16:19.621824 IP HTTP_SERVER.http > HTTP_CLIENT.63131: . ack 
2918467318 win 65535


HTTP_SERVER.http > HTTP_CLIENT.63131 is in FIN_WAIT_2 state.
After the last line it stopped and go away from FIN_WAIT_2 as expteced 
(timeout...).

And the firewall rejects/drops exactly those packages.
The client is not responding.


Greetings,
Robert!