VPN Service Provider Deployment Considerations
In previous chapters, we've discussed three basic deployment options for BGP within an autonomous system:
Running iBGP full mesh between all of the BGP speakers within the autonomous system.
Running route reflectors to reduce the full mesh while maintaining full routing information at every BGP speaker in the autonomous system.
Breaking the autonomous system up into subAS's, creating a confederation of autonomous systems that appear to be a single AS to external networks.
Routes with additional attributes to support MPLS/BGP VPNs are exchanged in the normal way between BGP speakers, so we are going to have the same issues with scaling and deployment. While a full mesh of BGP peers are the simplest ...