Zitat von Victoriano Giralt <[email protected]>:
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 13/04/11 17:16, Wietse Venema wrote:Victoriano Giralt:Wireshark shows "TCP window full" several times while Postfix is dutifully trying to send the messages and finally the connection is reset at TCP level.This may be the infamous window scaling problem. See below for workaround.Thank you Wietse. No joy :( I've upgraded to 2.8.2 and set tcp_windowsize following Postfix documentation. I've fully stopped Postfix, verified by a process list, and started again. The symptoms persist :( Anyhow, I'll pass the information on to the networking team in case there have been any recent changes on the routers.
We once had a similar problem with a remote site constantly timeing out at receiving bigger messages from them. They had a new firewall from a well known company with a setting called "extended protocol test" or something like that. A trace on our side showed that this option lead to trouble when a bunch of not yet SACKed segments where "on the wire" eg. still missing. At some point some of the segments where never retransmitted from the remote side leading to connection stall and timeout. You might try disable SACK but be aware that performance might suffer :-( To really find out what is going on you will need a trace from your side and the remote side of the connection.
Regards Andreas
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