Saturday, January 3, 2009

IE Vol 1: VRF-lite Complete

One would think with a name like VRF-lite, things wouldn't be too bad. That really wasn't the case. I'd hate to see what VRF-heavy looks like.

In actuality, VRF-lite refers to having VRFs without running MPLS. We're keeping separate routing tables, but are separating the traffic on the link using dot1q tags or DLCIs instead of labels.

There really weren't any tricks here, just a lot of stuff going on at the same time.

The setup starts with a basic iBGP vpnv4 session between two routers. But this time, the two BGP routers have separate subinterfaces for each vrf.

Next, the next downstream router has two subinterfaces mapped to vrf's as well. That router is running the customer IGP, but keeping them separate via subinterfaces, rather than running bgp vpnv4 to the upstream router to learn labels and sending traffic via MPLS.

So in effect, this is brining the MPLS domain one more router upstream from the edge.

1 comment:

Anonymous said...

nice and here is a configuration example