We have a number of small routers in co-lo sites that peer with B2B partners. As more of our partners move to cloud, we are considering a consolidation effort and putting all of our peering routers in a cloud exchange site on a single HA pair of routers. Now, each existing B2B peering router uses a unique private ASN to EBGP peer with partners and they, in turn, EBGP peer with our extranet perimeter ASNs for security vetting and other stuff.
We looked for a medium-density router (or L3-switch) that can replace multiple small routers (b2b-only, no internet), but we need to retain all of our existing ASNs and peerings. As it turns out, there are many routers that can do VRFs but you cannot put a unique ASN on each VRF so replicating the old environment isn't quite that straightforward. The BGP remote-as looks to be a possible alternative solution, but we've never used it in production and we are unsure of the caveats. Taken at face value, it looks like we can mimic the multi-router/unique-ASN environment we have today on a single platform. However, networking is rarely as smooth as that so I'm asking some of the BGP gurus... what are the pros/cons of doing using remote-as? If anyone here uses it extensively, we could really use some feedback if you run into challenges or hidden surprises that we wouldn't normally think of beforehand. Thanks in advance! LFOD
