Queuing and Prioritization with PF

[RW]

On Thu, 5 Jun 2008 21:07:49 -0400
Schiz0 <schiz0phrenic21 at gmail.com> wrote:

> Hey,
> 
> I have pf running as the firewall on a web and IRC box. I'd like to
> setup a bit of prioritization. I want ssh to be a higher priority than
> any other traffic. I've read up on Class Based Queuing and Priority
> Queuing.  If I understand it correctly, priority queuing will transfer
> ALL packets with higher priority before ANY of the lower-priority
> packets. So if I'm transferring a file via SCP, all other traffic will
> stop until the transfer is complete? I don't want other traffic to
> stop completely, I just want ssh to have a higher priority. Should I
> use class-based then?


Possibly, but from what you have said I think you can get away with
priority queueing using TOS. ALTQ allows you to specify two queues per
rule. The first is for normal traffic, and the second is for empty acks
and packets with a "low-delay" TOS.  If you specify the same two
queues for all TCP traffic then you should get prioritization for
interactive SSH, but not SCP. Take a look at pf.conf(5) for examples.