Bridge Filter for PPPoE

Hi

I have a bridge with 2 vlans, one running PPPoE and the other is used for VoIP. I see that the bridge filter has the option to use IP firewall for PPPoE. This is where i hit a blank. Where under IP Firewall Filter and/or Mangle do I get the option to identify and mark unencrypted PPPoE packets. I know Mange marks packets but which interface do I specify?

I’m in the process of setting up QoS in the link so I want to be able to mark the VoIP and PPPoE Packets so that I can create Queue Trees to prioritize the VoIP component. I’m really having difficulty getting the PPPoE packets marked.

Any Ideas how to go about this?

The PPPoE is an interface itself in the list of interfaces.