How to obtain how much CPU take packet check on ipfw

Sat Nov 13 21:53:31 UTC 2010

> From owner-freebsd-questions at freebsd.org  Sat Nov 13 13:49:50 2010
> Date: Sat, 13 Nov 2010 20:03:55 +0200
> From: =?windows-1251?B?yu7t/Oru4iDF4uPl7ejp?= <kes-kes at yandex.ru>
> To: freebsd-questions at freebsd.org
> Subject: How to obtain how much CPU take packet check on ipfw
>
> Hi, Freebsd-questions.
>
> How to obtain how much CPU time take packet traversing via firewall?

Some particular packet, or just a 'typical' packet?

The latter number is -much- easier to get thant the former.

See how much CPU time ipfw used during a given interval.
See how many packets were handled during that same interval.

Divide the first number by the second.  this will give you 'average'
cpu tie per packet.