pf+altq for bandwidth management

[Jeremy Tregunna]

On 16-May-07, at 11:33 AM, Lan Tran wrote:

> Hello,
>
> Is pf and altq a right combo for bandwidth limiting?  What I'm  
> trying to do is limit each IP or block of IPs to predefined  
> bandwidth.  I'm not doing traffic shaping, just wanting to prevent  
> servers from hogging all the bandwidth.
>
> My setup is as follow:
> LAN {test server} -> xl1 {FreeBSD} xl0 -> router -> net
> xl0 and xl1 are functioning as a bridge.  kernel has pf and altq  
> compiled.
>
> pf.conf:
> ext_if = "xl0"
> int_if = "xl1"
> pc = "any"
> set loginterface $ext_if
>
> # to net
> altq on $ext_if cbq bandwidth 100Mb queue { std_ext, test_ext }
> queue std_ext bandwidth 3Mb qlimit 1000 priority 5 cbq(default red  
> ecn)
> queue test_ext bandwidth 2Mb priority 1 cbq(red ecn)
>
> pass out on $ext_if from $pc to any keep state queue test_ext
> ---
> The problem I'm having is that all outbound traffic from "test  
> server" always shows around 3Mb instead of 2Mb per queue test_ext  
> ruleset.  What am I missing?

I've noticed the best precision for bandwidth limiting on cheap cards  
like realtek's (provided of course, the particular rl(4) card you're  
using is supported). Cards like fxp(4) and xl(4) I've not had great  
luck with getting them limited properly (always above or below the  
target)).

--
Jeremy Tregunna