Cabletron Systems SmartSwitch manual 162

Chapter 10: BGP Configuration Guide

Notes on Using Route Reflection

•Two types of route reflection are supported:

–By default, all routes received by the route reflector from a client are sent to all internal peers (including the client’s group, but not the client itself).

–If the no-client-reflect option is enabled, routes received from a route reflection client are sent only to internal peers that are not members of the client's group. In this case, the client's group must itself be fully meshed.

In either case, all routes received from a non-client internal peer are sent to all route reflection clients.

•Typically, a single router acts as the reflector for a cluster of clients. However, for redundancy, two or more may also be configured to be reflectors for the same cluster. In this case, a cluster ID should be selected to identify all reflectors serving the cluster, using the clusterid option. Gratuitous use of multiple redundant reflectors is not advised, since it can lead to an increase in the memory required to store routes on the redundant reflectors’ peers.

•No special configuration is required on the route reflection clients. From a client's perspective, a route reflector is simply a normal IBGP peer. Any BGP version 4 speaker can be a reflector client.

•It is necessary to export routes from the local AS into the local AS when acting as a route reflector.

To accomplish this, routers SSR10 and SSR11 have the following line in their configuration files:

ip-router policy redistribute from-proto bgp source-as 64901 to- proto bgp target-as 64901

•If the cluster ID is changed, all BGP sessions with reflector clients will be dropped and restarted.

162 SmartSwitch Router User Reference Manual