TCP stack in FreeBSD poor performance in 100MB to Gigabit environment.

Kris Kennaway kris at
Fri Jul 4 18:30:37 UTC 2008

Hwa Hing wrote:
> Hash: SHA1
> I also had such problem with FreeBSD-7 Stable-SMP with 4 port Intel
> 1GBit NIC em Driver and with Packet Filter, ALTQ enabled.

But it doesn't sound like you are testing the same thing at all.

> I tested with iperf from network a to network b. I found freebsd droping
> packets and the transfer speed in routed mode is only 2 mbit/s compare
> to linux router which able to forward the traffic at almost full speed.

Check that the software isn't making invalid Linux-specific assumptions 
about e.g. socket buffer sizes.


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