Re: [squid-users] Timeout reaching www.ampq.com

lör 2006-11-04 klockan 15:11 +0100 skrev Mark Elsen:
> >
> > My tests indicate the site has a broken firewall, tripping over the TCP
> > window scaling option. You can get around this by tuning down the max
> > parameter (the third parameter) in /proc/sys/net/ipv4/tcp_rmem, but I
> > would recommend you contact the owner of the site and inform them about
> > the problem.
> >
> >
>
> Hendrik, are you using a tool which is available in the public domain ?
> If so, which one ?

Linux & wireshark or tcpdump, nothing fancy. Just cycling over the
common pitfalls until it's found.

echo 0 >/proc/sys/net/ipv4/tcp_ecn

If it now works, then it's a broken firewall not capable of handling the
ECN option.

echo 0 >/proc/sys/net/ipv4/tcp_window_scaling

If it now works, then it's a broken firewall or load balancer not
capable of handling TCP window scaling. Note: This exact setting is only
for diagnosis, not production use as it seriously cripples TCP
performance. For production tcp_rmem max should be tuned to a level that
the broken firewalls is avoided..

echo 0 >/proc/sys/net/ipv4/tcp_timestamps

If it now works then it's a broken load balancer not capable of handling
the timestamp option properly.

All of the above is extensions to TCP/IP to more effectively handle long
distance connections or network overload conditions.

Regards
Henrik