Troubleshooting BGP Route-Reflection Issues

Troubleshooting BGP Route-Reflection Issues

Route reflectors (RR), discussed in RFCs 1966 and 2796, are used to avoid IBGP full mesh in an AS, as required by RFC 1771. Route reflection ensures that all IBGP speakers in an AS receive BGP updates from all parts of the network without having to run IBGP between all the routers in the network. Route reflection reduces the number of required IBGP connections and also offers faster convergence in an IBGP network when compared with a full-mesh IBGP network.

Route-reflector clients (RRCs) typically peer IBGP with one or more RR, and they can have EBGP connections unconditionally. Logical BGP connections between RR and RRC typically follow the physical connection topology. These are some of the common rules that help BGP operators troubleshoot BGP route-reflector issues.

This section discusses various issues seen in BGP networks related to route reflection. The most common problems in route-reflection networks are as follows :

• Configuration mistakes

• An extra BGP updated stored by a route-reflector client

• Convergence time improvement for route reflectors and clients

• Loss of redundancy between route reflectors and route-reflector clients