Peer group consept

oxzgan

I read tht peer groups can either used in ibgp peers or ebgp peers.
My doubt is if i use peer group in ibgp ( same as ) do i need to have direct ibgp peers among one another ( all ibgp peers ) and cant use Route refelctor.
in simple words if we use Route refelctor some ibgp members wont have direct connection , routes will refect from RR( route reflector ) to other peers.So can i use peer group configuration , while use RR,

on my searches i saw if we disable #bgp client-to-client refelction we can use peer group . can any body share their ideas?

Ryan82

I believe I understand what you are asking.

So you can apply a peer group to your neighbors as needed. For instance you could apply something like this on your RR for each of your clients:

neighbor IBGP_RR_CLIENTS peer-group
neighbor IBGP_RR_CLIENTS update-source lo0
neighbor IBGP_RR_CLIENTS route-reflector-client
neighbor IBGP_RR_CLIENTS remote-as 10

Then

neighbor 2.2.2.2 peer-group IBGP_RR_CLIENTS
neighbor 3.3.3.3 peer-group IBGP_RR_CLIENTS

The use of peer groups does not necessitate a full mesh amongst the ibgp peers whether they are directly connected or not. The same rules apply as before. You either need to have a full ibgp mesh or make use of RR's.

If you had some peers that had some different characteristics, you could either create another peer-group to use for those neighbors, use the original peer-group but manually define the changes at the neighbor level (such as the only change needing to be update-source lo1) which will override what is defined at the peer group level, or not use a peer-group at all for that neighbor.

I hope I explained this clearly and this is what you are looking for

oxzgan

Thanks for the reply.
Can you refer this , am i misunderstood?
" Important Note: This configuration does not use peer groups. Do not use peer groups if the clients inside a cluster do not have direct iBGP peers among one another and the clients exchange updates through the RR. If you configure peer groups, a potential withdrawal to the source of a route on the RR transmits to all clients inside the cluster. This transmission can cause problems.

The router subcommand bgp client-to-client reflection is enabled by default on the RR. If you turn off BGP client-to-client reflection on the RR and you make redundant BGP peering between the clients, you can safely use peer groups."

source : BGP Case Studies - Cisco Systems

Forsaken_GA

This limitation is no longer present.

BGP Peer Groups [IP Routing] - Cisco Systems

Check that link, then look under the section Limitations of Peer Groups, and read it thoroughly.

oxzgan

Forsaken_GA wrote: »

This limitation is no longer present.

BGP Peer Groups [IP Routing] - Cisco Systems

Check that link, then look under the section Limitations of Peer Groups, and read it thoroughly.

thnks ...now i got it