7.1-PRERELEASE : bad network performance (nfe0)

[firmdog at gmail.com]

On Sun, Sep 28, 2008 at 4:53 PM, Gary Palmer <gpalmer at freebsd.org> wrote:

> On Sun, Sep 28, 2008 at 01:43:12PM -0400, firmdog at 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
>


Pasted below.  When I was doing the transfer, it was 1000 full duplex and
was very slow.
This is a web/email/database server and I don't see any performance problems
yet, but
I would like to know what the problem is/was.  What else can I provide?

bge0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        options=9b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM>
        ether 00:1a:a0:23:c0:03
        inet 192.168.1.2 netmask 0xffffff00 broadcast 192.168.1.255
        media: Ethernet autoselect (100baseTX <full-duplex>)
        status: active