When you have more than one route reflector, change the cluster ID so that all route reflectors belong to the same cluster.
Multiple route reflectors should belong to the same cluster. By default, the value for the cluster-id command is the device ID. Use this procedure to change the device ID.
device# configure terminal
device(config)# router bgp
device(config-bgp-router)# local-as 1000
device(config-bgp-router)# cluster-id 321
device# configure terminal device(config)# router bgp device(config-bgp-router)# local-as 1000 device(config-bgp-router)# cluster-id 321