2009/1/29 Francesco Pasqualini <[email protected]>

> On Wed, Jan 28, 2009 at 5:37 PM, Brett Parker
> <[email protected]>wrote:
>
> > On 28 Jan 11:26, Francesco Pasqualini wrote:
> > > net/ipv4/tcp_window_scaling=0
> >
> > If that fixes it it suggests that you're hitting a broken
> > firewall/router on the way that doesn't pass on TCP/IP window scaling
> > information and breaks it...
>
>
> I agree !
>
> But I don't know what I have to fix at firewall level ?
>
> What are the tcp/udp port involved ?
>
> The exim4 is behind a firewall in a DMZ with private IP adress NAT (port
> fowarding).
>
> Unfotunately we have only 1 public IP (the firewall one)
>
> Maybe I have to  forward some port (ICMP ?? but then I cannot ping the
> firewall) from the firewall to the mail server.
>
> What you think ?
>
>
I have had these problems before but it was related to the firewall dropping
packets where the window scaling was not 100% compliant. But I later found
that the load balancer was padding the Ethernet frame but it was not the
correct length.

This was using a Fortigate with an NP2 accelerated NIC's and and Foundry
Load Balancer.

Just out of interest what is being used in your environment?

--
ESP
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