ECS4660-28F_Management Guide-R03

Table Of Contents
C
HAPTER
51
| IP Routing Commands
Border Gateway Protocol (BGPv4)
– 1841
COMMAND USAGE
Route reflection from this device is enabled by default, but is only
functional if a client has been configured with the neighbor
route-reflector-client command.
Route reflection is not required if all of the routers in an AS are fully
meshed as normally required by interior BGP. However, to make interior
BGP more scalable, route reflection or confederations can be used.
Route reflection uses one or more route reflectors to reflect routes
between specified clients within a cluster. Clients within a reflector
cluster therefore need not be fully meshed, and the exchange of
routing information is thereby reduced since the clients need not
communicate with any routers outside of the cluster.
Routing information from an external BGP router is advertised to all
cluster clients and non-client peers. Information from a non-client peer
is advertised to all clients. And information from cluster members is
reflected to all routing peers, both inside and outside of the cluster.
using this model, the local AS can be divided into many clusters.
Use the bgp cluster-id command to designate route reflectors within
the same cluster so that route reflectors can recognize updates from
other route reflectors in the same cluster.
EXAMPLE
Console(config-router)#bgp client-to-client reflection
Console(config-router)#
RELATED COMMANDS
neighbor route-reflector-client (1876)
bgp cluster-id (1841)
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.