[AusNOG] Multi-path route maps

[Joseph Goldman]

Hi List,

  In a project of ours we currently have 2 alternate paths between 2 
points of our own network.

  We wish to use route-maps to send certain traffic via the alternate 
path, which is a fairly trivial task, however we would like suggestions 
on a method to ensure the traffic is sent back via the alternate path.

  The default routes etc are all via primary path. The IP's are public 
routed IP's, so a traditional NAT table with alternate public IP won't 
be of assistance, and as we are trying to do this protocol based we 
can't change the route for these single IP's.

  External routing to the internet will all arrive back at this router, 
we just need to control the route based on the source path used.

  I believe this will be achieved with some form of different NAT table. 
The 2 links both deliver between a single pair of Cisco C3900's. I would 
appreciate if anyone who has accomplished such a thing to push me in the 
right direction of the feature name etc that I should be looking at.

Thanks,
Joe