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  • 1.  BGP Route Reflector Design

    Posted 03-19-2011 06:58

    Hi Expert

     

    I have some questions on designing of RR in BGP.

     

    1- Is it possible that one router could be RR of two cluster? It is a valid desgin

    2- In what cases, When RR attaches the cluster-id? Particularly when it takes the routes from clients and give it to non-client then it attaches the cluster-id or not?

    3- In one cluster there are two RR for redundancy and both have same cluster id. My question is that when it is recommended that both RR would be the client of each other OR we can make normal BGP neighbour OR there is not need to making neighbourship between them?

     

    Looking forward for response.

     

    Thanks



  • 2.  RE: BGP Route Reflector Design
    Best Answer

    Posted 03-19-2011 14:08

    1- Is it possible that one router could be RR of two cluster? It is a valid desgin

    Sure, it's a perfectly valid design. You just need to configure two separate bgp peer groups with a different cluster-id set.

     

    2- In what cases, When RR attaches the cluster-id? Particularly when it takes the routes from clients and give it to non-client then it attaches the cluster-id or not?

    Every time it reflects the route. RR reflects route from non-client to all clients and from one client to all non-clients and other clients. Refer to RFC2796 (page 4) for details.


    3- In one cluster there are two RR for redundancy and both have same cluster id. My question is that when it is recommended that both RR would be the client of each other OR we can make normal BGP neighbour OR there is not need to making neighbourship between them?

    There's no need for a peering to exist between to RR in one cluster. When one of them attaches cluster-id, the other has to drop the route (loop avoidance mechanism). It's recommended to use two RR in two different clusters for redundancy purposes.

     

     



  • 3.  RE: BGP Route Reflector Design

    Posted 03-20-2011 01:20

    Hi

     

    Thanks for the reply. I just want to ask one more thing that if there are two RR in one cluster having same cluster-id and if we make normal BGP neighbourship between them (non-client of each other) then this will create some problem or this is a valid desgin?

     

    Thanks



  • 4.  RE: BGP Route Reflector Design

    Posted 03-20-2011 02:26

    It's a valid design. It won't cause any problems.



  • 5.  RE: BGP Route Reflector Design

    Posted 03-21-2011 10:33

    When you have two RRs in the same cluster, they need to peer as non-clients for full redundancy.



  • 6.  RE: BGP Route Reflector Design

    Posted 04-05-2011 00:21

    Thanks Dough. You are perfectly right 🙂