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From: Robert Watson <rwatson@FreeBSD.org>
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To: Lin Jui-Nan Eric <ericlin@tamama.org>
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Cc: freebsd-net@freebsd.org, stable@freebsd.org
Subject: Re: TCP packet out-of-order problem
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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!
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