On Sat, Jun 18, 2011 at 01:30:21AM +0200, Xavier Ambrosioni wrote:
> 22:16:25.978773 IP smtp10.smtpout.orange.fr.41183 >
> passrlminisrv.cinema-voiron.fr.smtp: Flags [S], seq 105066692, win 5840,
> options [mss 1380,sackOK,TS val 2993558281 ecr 0,nop,wscale 8], length 0
> 22:16:28.978262 IP smtp10.smtpout.orange.fr.41183 >
> passrlminisrv.cinema-voiron.fr.smtp: Flags [S], seq 105066692, win 5840,
> options [mss 1380,sackOK,TS val 2993561281 ecr 0,nop,wscale 8], length 0
> 22:16:34.977258 IP smtp10.smtpout.orange.fr.41183 >
> passrlminisrv.cinema-voiron.fr.smtp: Flags [S], seq 105066692, win 5840,
> options [mss 1380,sackOK,TS val 2993567281 ecr 0,nop,wscale 8], length 0
> 22:16:41.011109 IP passrlminisrv.cinema-voiron.fr.smtp >
> smtp10.smtpout.orange.fr.41183: Flags [S.], seq 1934215990, ack 105066693,
> win 65535, options [mss 1460,nop,wscale 1,nop,nop,TS val 537443811
> ecr2993567281,sackOK,eol], length 0
> 22:16:41.051125 IP smtp10.smtpout.orange.fr.41183 >
> passrlminisrv.cinema-voiron.fr.smtp: Flags [R], seq 105066693, win 0, length 0
>
> Any idea of the root cause? Could it be an issue with my DNS configuration or
> is it related with my own smtp server?
Here's a nickel kid, buy yourself a real firewall.
More seriously, your firewall does not understand window scaling. Disable
it on your Linux system (see the list archiving for the many previous
instances). Then consider getting a firewall that works with modern
TCP stacks.
--
Viktor.
