The Community attribute is a private BGP route attribute. It is transmitted between BGP peers and is not restricted within an AS. The Community attribute allows a group of BGP devices in multiple ASs to share the same routing policies, which simplifies routing policy applications and facilitates routing policy management and maintenance. A BGP device can add or change the community attributes of routes to be advertised.
Enable Community Exchange with Peer
The set protocols bgp neighbor send-community command enables community and/or extended community exchange with the specified neighbor. When this command is configured for the peer-group, then all the neighbors that are part of peer-group will send the community values to the peers.
The following example allows community values to be sent to a specific neighbor.
admin@XorPlus# set protocols bgp ipv4-unicast neighbor 2.2.2.2 send-community both admin@XorPlus# commit
Apply a Routing Policy to Routes Advertised
The set protocols bgp neighbor route-map command applies a route map to incoming or outgoing routes. It can be used to configure the route map for modifying the community attribute of the route.
admin@XorPlus# set protocols bgp ipv4-unicast neighbor 2.2.2.2 in route-map map1 admin@XorPlus# commit