Edge-Core AS5700-54X, Cli Reference Manual, Page: 932 / 1116

Chapter 29
| IP Routing Commands
Border Gateway Protocol (BGPv4)
– 932 –
bgp cluster-id
This command configures the cluster identifier for multiple route reflectors in the
same cluster. Use the
no form to remove the cluster identifier.
Syntax
bgp cluster-id cluster-identifier
no bgp cluster-id
cluster-identifier – The cluster identifier of this router when acting as a route
reflector. This identifier can be expressed in the form an IPv4 address or an
integer in the range of 1-4294967295.
Command Mode
Router Configuration
Default Setting
The router identifier of a lone route reflector in a cluster.
Command Usage
◆
A cluster of clients will usually have a single route reflector (RR). In that case, the
cluster can be identified by the BGP Identifier of the RR. However, this
represents a single point of failure. This command is used to designate multiple
route reflectors used within the same cluster so that they can recognize
updates from other peer route reflectors and discard them to prevent
loopbacks.
◆
All the route reflectors in the same cluster should be fully meshed and all of
them configured with identical sets of client and non-client peers.
◆
A route reflector uses the non-transitive cluster-list attribute to avoid routing
loops. A cluster-list is a sequence of cluster IDs the route has passed through.
When a RR reflects a route from its clients to non-client peers, and vice versa, it
appends this ID to the cluster list. Using this attribute, an RR can determine if
routing information has looped back to the same cluster due to mis-
configuration. If the local cluster ID is found in the cluster list, the
advertisement is ignored.
Example
Console(config-router)#bgp cluster-id 192.168.0.0
Console(config-router)#
Related Commands
bgp client-to-client reflection (931)