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Date:      Tue, 6 Jan 2009 08:16:01 +0000 (GMT)
From:      Robert Watson <rwatson@FreeBSD.org>
To:        Lin Jui-Nan Eric <ericlin@tamama.org>
Cc:        freebsd-net@freebsd.org, stable@freebsd.org
Subject:   Re: TCP packet out-of-order problem
Message-ID:  <alpine.BSF.2.00.0901060813240.12075@fledge.watson.org>
In-Reply-To: <47713ee10901052025y26d342f6me0aea946a49b6f0a@mail.gmail.com>
References:  <47713ee10812301206j12b35264o715976c154080a1b@mail.gmail.com> <47713ee10901012147k1f25c31bn512dd29b2b294ad5@mail.gmail.com> <47713ee10901012249w65c659bbp3366e4d8ef25c59d@mail.gmail.com> <alpine.BSF.2.00.0901051312370.98366@fledge.watson.org> <47713ee10901052025y26d342f6me0aea946a49b6f0a@mail.gmail.com>

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On Tue, 6 Jan 2009, Lin Jui-Nan Eric wrote:

> I thought that the system auto-tune improperly in this case.

Hmm.  Do you have a custom setting for kern.ipc.nmbclusters in loader.conf or 
sysctl.conf?  What does kern.ipc.nmbclusters configure itself to on your 
system?  Also, could you send me the output of uname -a on the system?

Thanks,

Robert N M Watson
Computer Laboratory
University of Cambridge

> On Mon, Jan 5, 2009 at 9:13 PM, Robert Watson <rwatson@freebsd.org> wrote:
>> On Fri, 2 Jan 2009, Lin Jui-Nan Eric wrote:
>>
>>> After running "netstat -s -p tcp", we found that lots of packets are
>>> discarded due to memory problems. We googled for it, and found that sysctl
>>> oid "net.inet.tcp.reass.maxsegments" became 0, therefore packets never
>>> reassembled.
>>>
>>> Then we checked our /boot/loader.conf and /etc/sysctl.conf, and found that
>>> setting kern.ipc.nmbclusters="0" makes net.inet.tcp.reass.maxsegments=0.
>>> After setting net.inet.tcp.reass.maxsegments="1600" in /boot/loader.conf,
>>> the network works perfectly now.
>>
>> Was it set to 0 through a configuration error, or did the system auto-tune
>> improperly?
>>
>> Robert N M Watson
>> Computer Laboratory
>> University of Cambridge
>>
>>>
>>> Thank you all for the help!
>>> _______________________________________________
>>> freebsd-stable@freebsd.org mailing list
>>> http://lists.freebsd.org/mailman/listinfo/freebsd-stable
>>> To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.org"
>>>
>>
>



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