Question about experiences with BGP remote-AS

[LF OD <bz_siege_01 () hotmail com>]

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