[LARTC] Intermediate Interface?

[John Hanlon - Central Coast Internet]

Is there a way to force ingress traffic into appearing as egress traffic 
for the purpose of traffic shaping.

e.g.

    eth0 ------> TestMachine -------> lo ---------> TestMachine ---------> eth1

    Can you use a loopback or similar interface so that it appears that the 
data is being sent out and back in a pseudo-interface? This would allow 
egress filtering as it was passed out the loopback interface before it was 
then forwarded along to eth1.

    The reason I am trying this is I have multiple ppp0 interfaces running 
over the eth1 interface. Rather than trying to manage each one 
individually, it would be easier for my purposes to use u32 identifiers on 
a single interface in order to manage traffic.

Kind regards,

John Hanlon.
Central Coast Internet.