Advice on RR clusters deployment

[albert_coll]

Hello,

In a BGP autonomous system with several Route Reflector clusters into it, should all BGP clusters be fully Meshed?

I read design docs of hierarchical RR architectures, where a backbone RR cluster is the hub of several “spoke” regional RR clusters, so that every regional RR cluster maintains one or two peering sessions with members of the hub RR cluster, but not with other BGP peers in neighboring Regional RR clusters.

But there are some other docs which says that in a BGP AS, all the existing BGP clusters must establish a full mesh peering topology with at least one member of every cluster.

I would really appreciate any advice about that.

Kind regards.

Albert.

[saurjosh]

Hello Albert,

RR design complete depends upon your needs.

You may have couple of normal iBGP peering between clusters for redundancy along with backbone route integrity.

Keep below in mind..i am sure you know these already.

• iBGP routers are divided into Route Reflectors, Route Reflector clients and non-client Peers.
• Routes received from a Route-Reflector-client is reflected to other clients and non-client neighbors.
• Routes received from non-client neighbors are reflected to Route-Reflector-client neighbors only.
• Setting the Originator-ID attribute in the reflected update if it is not already set.
• Adding the Cluster-ID  to the Cluster-list attribute in the reflected update.
• A Route Reflector reflects routes considered as best routes only. If more than one update is received for the same destination,  only the BGP best route is reflected.
• A Route Reflector is not allowed to change any attributes of the reflected routes including the next-hop attribute.

HTH