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Date: Thu, 24 May 2007 21:59:41 +0200
From: Andre Oppermann <andre@freebsd.org>
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To: Gleb Smirnoff <glebius@FreeBSD.org>
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Cc: net@FreeBSD.org
Subject: Re: TCP problems after 124 days of uptime?
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Gleb Smirnoff wrote:
>   Yesterday two of our web servers running 6.2-PRERELEASE experienced
> problems with accepting TCP connections. A small percentage of SYN
> packets was ignored. The packets were seen in tcpdump output, but not
> processed by TCP stack. No accept queue overflows occured, according
> to 'netstat -sp tcp'.
> 
> Failing to find any clue I have rebooted one of them, and after
> reboot is started to work flawlessly. Reboot also helped the second
> one. Both servers were booted at the same time - 124 days ago.
> 
> Any ideas, any similar reports?

ticks is a 32 bit signed integer and TCP isn't really aware of it
going negative and rolling over.  This is something I'm working on
fixing in -current.  Haven't analyzed all potential cases there yet.

-- 
Andre