FIN_WAIT_2 timeout

[Andre Oppermann]

Pavel Gulchouck wrote:
> 
> Hi.
> 
> I have hangs tcp-sessions in the FIN_WAIT_2 state, in which packets
> sends to remote for several days. Sockstate tells none aboute its,
> restart httpd has no effect.
> http://httpd.apache.org/docs/misc/fin_wait_2.html says that FreeBSD
> has a timeout for FIN_WAIT_2 state, but I don't see it.
> Number of such sessions grows according to uptime.
> FreeBSD 5.2.1-RELEASE-p9.
> Any suggestions?

Very strange...

Could you send the output of "sysctl -a net.inet.tcp" as well?

> root at racoon:~>netstat -na | fgrep 195.248.160.78
> tcp4       0      0  193.109.240.55.80      195.248.160.78.59843   FIN_WAIT_2
> tcp4       0      0  193.109.240.55.80      195.248.160.78.56084   FIN_WAIT_2
> tcp4       0      0  193.109.240.55.80      195.248.160.78.37466   FIN_WAIT_2
> tcp4       0      0  193.109.240.55.80      195.248.160.78.31848   FIN_WAIT_2
> [...]
> root at racoon:~>sockstat | fgrep 195.248.160.78
> root at racoon:~>netstat -na | grep -c FIN_WAIT_2
> 419
> 
> tcpdump shows:
> 
> 20:43:54.922521 hosting.itpark.com.ua.http > 195.248.160.78.48714: . ack
> 3765418226 win 0

It (re-)tries to ACK the FIN probably.

> 20:43:54.923546 hosting.itpark.com.ua.http > 195.248.160.78.48714: . ack 1 win
> 65535 (DF)

And it tries to open the window again to get out of persistent mode!?

> 20:44:09.920818 hosting.itpark.com.ua.http > 195.248.160.78.31848: . ack
> 3792205062 win 0
> 20:44:09.921773 hosting.itpark.com.ua.http > 195.248.160.78.31848: . ack 1 win
> 65535 (DF)

Any chance of finding out what kind of Operating System 195.248.160.78 is?

-- 
Andre