On Configuring BGP Route Reflectors

The Border Gateway Protocol (BGP) is the standard protocol for exchanging routing information between border routers of Autonomous Systems (ASes) in today's Internet. Within an AS, border routers exchange externally-learned BGP route advertisements via Internal-BGP (I-BGP) peerings. Naive solutions for these I-BGP peering sessions (e.g., based on full-mesh topologies) simply cannot scale to the sizes of modern AS networks. Carefully designed route-reflector configurations can drastically reduce the total number and connection cost of the required I-BGP sessions.