Reference Guide

Border Gateway Protocol IPv4 (BGPv4) | 223
If you want to remove or add a specific 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. Use these commands in the following sequence, starting in the
CONFIGURATION mode:
To view the BGP configuration, use the
show config command in CONFIGURATION ROUTER BGP
mode. To view a route map configuration, use the
show route-map command in EXEC Privilege mode.
Use the
show ip bgp community command in EXEC Privilege mode as shown in the following example
to view BGP routes matching a certain community number or pre-defined BGP community.
FTOS>show ip bgp community
BGP table version is 3762622, local router ID is 10.114.8.48
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
* i 3.0.0.0/8 195.171.0.16 100 0 209 701 80 i
*>i 4.2.49.12/30 195.171.0.16 100 0 209 i
Step Command Syntax Command Mode Purpose
1 route-map map-name
[permit | deny]
[sequence-number]
CONFIGURATION Enter the ROUTE-MAP mode and assign a name
to a route map.
2
set comm-list
community-list-name delete
CONFIG-ROUTE-MAP Configure a set filter to delete all COMMUNITY
numbers in the IP Community list.
set community
{community-number |
local-as | no-advertise |
no-export | none}
CONFIG-ROUTE-MAP Configure a Community list by denying or
permitting specific 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 specific 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
exit
CONFIG-ROUTE-MAP Return to the CONFIGURATION mode.
4
router bgp as-number CONFIGURATION Enter the ROUTER BGP mode.
5
neighbor {ip-address |
peer-group-name}
route-map map-name {in |
out}
CONFIG-ROUTER-BGP Apply the route map to the neighbor or peer
group’s incoming or outgoing routes.