Concept Guide
To send the COMMUNITY attribute to BGP neighbors, use the following command.
• Enable the software to send the router’s COMMUNITY attribute to the BGP neighbor or peer group specied.
CONFIG-ROUTER-BGP mode
neighbor {ip-address | ipv6-address | peer-group-name} send-community [extended | standard]
extended- Allows to send the extended community attribute to a BGP neighbor or peer group.
standard- Allows to send the standard community attribute to a BGP neighbor or peer group.
To view the BGP conguration, use the show config command in CONFIGURATION ROUTER BGP mode.
If you want to remove or add a specic COMMUNITY number from a BGP path, you must create a route map with one or both of the
following statements in the route map. Then apply that route map to a BGP neighbor or peer group.
1 Enter ROUTE-MAP mode and assign a name to a route map.
CONFIGURATION mode
route-map map-name [permit | deny] [sequence-number]
2 Congure a set lter to delete all COMMUNITY numbers in the IP community list.
CONFIG-ROUTE-MAP mode
set comm-list community-list-name delete
OR
set community {community-number | local-as | no-advertise | no-export | none}
Congure a community list by denying or permitting specic community numbers or types of community.
• community-number: use AA:NN format where AA is the AS number (2 or 4 Bytes) and NN is a value specic to that
autonomous system.
• local-AS: routes with the COMMUNITY attribute of NO_EXPORT_SUBCONFED and are not sent to EBGP peers.
• no-advertise: routes with the COMMUNITY attribute of NO_ADVERTISE and are not advertised.
• no-export: routes with the COMMUNITY attribute of NO_EXPORT.
• none: remove the COMMUNITY attribute.
• additive: add the communities to already existing communities.
3 Return to CONFIGURATION mode.
CONFIG-ROUTE-MAP mode
exit
4 Enter the ROUTER BGP mode.
CONFIGURATION mode
router bgp as-number
5 Apply the route map to the neighbor or peer group’s incoming or outgoing routes.
CONFIG-ROUTER-BGP mode
neighbor {ip-address | ipv6-address | peer-group-name} route-map map-name {in | out}
Example of the show ip bgp community Command
To view the BGP conguration, use the show config command in CONFIGURATION ROUTER BGP mode. To view a route map
conguration, use the
show route-map command in EXEC Privilege mode.
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Border Gateway Protocol (BGP)