net.inet.tcp.tso=1 still neceesary with fxp was Re: TCP differences in 7.2 vs 7.1

Michael L. Squires mikes at
Wed May 20 21:55:36 UTC 2009

I started having speed problems after shifting from 7.1-STABLE to 
7.1-PRERELEASE.  They have continued with 7.2-STABLLE.

Reverting to the 7.1-STABLE kernel eliminated the problem.

After downloading 7.2-STABLE from at about 10:40 AM EST
on 5/20/2009, doing a buildworld/buildkernel/installkernel/installworld
cycle I still need to execute "net.inet.tcp.tso=1" to elminate throughput
problems between my home system (on Comcast) and my office PC (connected
via a Time-Warner connection).  This also affects connections to other
systems; downloading Web pages ( speeds up after I change the TSO

The box in question runs NAT and has an fxp (Intel Pro100) interface connected 
to a Comcast cable modem and an em (Intel Pro1000) interface connected to the 
internal network.

There are no network errors in "netstat -i" on either interface.

The "if_fxp.c" code appears to be the May 7 version.

This is the dmesg entry for the card in question.  The system is a dual Xeon
Supermicro 1U box, 1GB RAM, single 300GB IDE hard drive.

fxp0: <Intel 82551 Pro/100 Ethernet> port 0xe400-0xe43f mem 0xfebfd000-0xfebfdfff,0xfeb80000-0xfeb9ffff irq 27 at device 7.0 on pci0
miibus0: <MII bus> on fxp0

Mike Squires

More information about the freebsd-stable mailing list