Thursday, November 19, 2009

INE Vol 1 - Lab 14 - finished - Back to Back VRF

Pretty straight forward lab on using 2 routers and a single Fast Ethernet interface, dot1q trunked or "router on a stick", to exchange VRF information for 2 ASes to interconnect CEs. Yeah, that's a long sentence. So the 2 CE's span 2 different BGP ASes, and the 2 BGP ASes meet at a single point where the 2 routers share a dot1q FE trunk. The sub interfaces of the FE are configured like CE connections, meaning that the links are configured for a specific vrf on both routers. Then there are 2 BGP peering sessions for each VRF in the IPv4 table. RDs for the VRFs are the same even if the BGP Peering isn't direct.

The BGP peering point just looks like a connection to another CE on each AS.

Good lab, have a feeling a similar configuration is done for VRF-Lite and I'll see it when I do that lab.