A route learned by one ibgp peer won’t be advertised to another ibgp peer. This is called BGP split horizon rule. This rule is used to avoid loop in ibgp cases.
To mitigate this, we have following option by which one ibgp learned routes can be advertised to another ibgp peer.
- BGP full mesh
- BGP confederation
- BGP route-reflector
In this article we will discuss about the 3rd option i.e BGP route-reflector.
BGP route reflector rule.
Whenever a RR learn route from its client it adds two attributes to the route.
- Cluster id – (32-bit identifier, which can be set, by defaults its bgp router-id)
- Originator id- (router id of client who send the route)