FreeBSD box as router adding latency

Chris Dillon cdillon at
Thu Feb 26 14:02:58 PST 2004

On Thu, 26 Feb 2004, Aloha Guy wrote:

> > What do you have HZ set to (see sysctl kern.clockrate)? I think I
> > remember your original message showing you using pipes and queues
> > and the HZ setting can affect those. Also see if your latency
> > improves if you remove all pipe and queue rules (other ipfw rules
> > are OK).
> Here is the HZ setting:
> kern.clockrate: { hz = 100, tick = 10000, profhz = 1024, stathz = 128 }
> I'm not sure how to remove the pipe since I don't think the pipe
> works until the queue is defined.  When I removed the queues that
> are configured for the pipe, the latency is back to normal though.

Like I said, remove both pipes and queues to test.  However, pipes
_can_ be used without queues, but that is irrelevant here.  Try
setting HZ to 1000 in your kernel config, recompile, reboot, and test
again.  You should see something between a slight improvement to a
ten-fold improvement.

 Chris Dillon - cdillon(at)
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