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Date: Tue, 12 May 2009 16:36:35 -0500
From: "Rick C. Petty" <rick-freebsd2008@kiwi-computer.com>
To: David Samms <dsamms@nw-ds.com>
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Cc: freebsd-stable@freebsd.org
Subject: Re: TCP differences in 7.2 vs 7.1
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On Tue, May 12, 2009 at 05:31:01PM -0400, David Samms wrote:
> 
> Setting sysctl net.inet.tcp.tso=0 resolved the issue completely.   What 
> does sysctl net.inet.tcp.tso=0 do?

# sysctl -d net.inet.tcp.tso
net.inet.tcp.tso: Enable TCP Segmentation Offload

I had a similar problem with a different NIC.  This option controls whether
we offload segmenting to the NIC.  My NIC seemed to be limited by the
number of interrupts which could be delivered.  You can also do this on a
card-by-card basis using "ifconfig <interface> -tso".

-- Rick C. Petty