Slow network performance (em0 & catalyst 2950)

Roman Serbski mefystofel at
Sun Jan 21 09:30:45 UTC 2007

Hello list,

I am facing with really slow network performance (nfs/ftp) under
FreeBSD 6.2-PRERELEASE with em0 NIC connected to Cisco Catalyst 2950
switch. The transfer speed is ~150-200kbps for nfs, ftp and httpd.
Here is more information about my setup:

em0: <Intel(R) PRO/1000 Network Connection Version - 6.1.4> port
0xdc00-0xdc3f mem 0xfcfa0000-0xfcfbffff irq 54 at device 4.0 on pci3

inet netmask 0xfffffff0 broadcast
ether 00:04:23:c7:61:3a
media: Ethernet autoselect (100baseTX <full-duplex>)
status: active

The server is connected to Cisco Catalyst 2950 switch (latest IOS)
with 'auto' set for duplex and speed. 'sh int' shows 100baseTX and

I googled two threads with the similar symptoms:

Tried everything mentioned there, but it didn't help. I tried to set
100baseTX and full-duplex both on FreeBSD and Cisco - same slow
throughput. Also tried to play with sysctl - no luck. netstat -i
doesn't show anything suspicious:

Name    Mtu Network       Address              Ipkts Ierrs    Opkts Oerrs  Coll
em0    1500 <Link#1>      00:04:23:c7:61:3a    21401     0    31364     0     0

Anyone with the similar problem? I am ready to provide more detailed
information and I would highly appreciate your assistance!

Thank you in advance.

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