On Mon, Sep 22, 2003 at 03:40:44PM +0200, Johann Spies wrote:
> I have the same situation - and it is not related to exim I think. So
> far I have identified 7 servers that refuse smtp-connection to one of
> our three mail servers while it is not the case with the other two. I
> can for example telnet to most of those servers on port 25 from
> maties1 and maties2 but not from maties3.
>
> I suspect firewall problems but so far I have not been able to
> determine the exact cause. In the mean time I route mail for those
> domains from maties3 to the other two to deliver.
After reading some kernel documentation I checked and saw that maties3
differs from maties1 and maties2:
"cat /proc/sys/net/ipv4/tcp_ecn" :
maties1 0
maties2 0
maties3 1
The kernel documentation for the variable invovled says:
Note that, on the Internet, there are many broken firewalls which
refuse connections from ECN-enabled machines, and it may be a while
before these firewalls are fixed.
Doing a
> echo "0" > /proc/sys/net/ipv4/tcp_ecn
on maties3 enabled me to telnet to port 25 of 6 of the 7 problem
servers which refused maties3 in the past. The 7th is refusing all
three my servers.
Regards
Johann
--
Johann Spies Telefoon: 021-808 4036
Informasietegnologie, Universiteit van Stellenbosch
"Though he slay me, yet will I trust in him..."
Job 13:15
--
Johann Spies Telefoon: 021-808 4036
Informasietegnologie, Universiteit van Stellenbosch
"Though he slay me, yet will I trust in him..."
Job 13:15
