Date: Sun, 28 Sep 2008 16:53:00 -0400 From: Gary Palmer <gpalmer@freebsd.org> To: "firmdog@gmail.com" <firmdog@gmail.com> Cc: stable@freebsd.org, net@freebsd.org Subject: Re: 7.1-PRERELEASE : bad network performance (nfe0) Message-ID: <20080928205300.GF60230@in-addr.com> In-Reply-To: <fa1676af0809281043k269b3d78sbf1e8006f2aa282e@mail.gmail.com> References: <wptzc1gu9v.fsf@heho.snv.jussieu.fr> <fa1676af0809281043k269b3d78sbf1e8006f2aa282e@mail.gmail.com>
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On Sun, Sep 28, 2008 at 01:43:12PM -0400, firmdog@gmail.com wrote: > I have the same problem on a Dell Poweredge SC440 when I transferred over > 50GB > from a FreeBSD 5.4 box to my new Dell running 7.1. Used a crossover cable > and > the link was 1000 full duplex, but could only get about 10M/s. Very odd. > Did a > tcpdump and saw lots of bad checksum errors. > > What other troubleshooting steps can we take? What could be the problem? Please post the first few lines of ifconfig for bge0. I'm suspecting you'll see something like em1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 options=1b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING> (yes, I know thats an em, not bge, but I don't have any bge's around here) Note that the options line say that receive and transmit checksum offloading is enabled. This means that for packets transmitted by this system, tcpdump will show checksum errors as the kernel is not generating the checksums, the ethernet card will. Since tcpdump is seeting the packet before the ethernet card does its magic, you get the checksum errors on transmit. Received packets should be fine though. Regards, Gary
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