Cisco Cisco Packet Data Interworking Function (PDIF)
Routing
▀ BGP-4 Routing
▄ ASR 5000 System Administration Guide, StarOS Release 18
288
BGP Communities and Extended Communities
Route filtering based on a BGP community or extended community (route target) via CLI Route Map Configuration
mode commands.
mode commands.
BGP Communities
Configuring a BGP Community
A BGP community is a group of destinations that share some common attribute. Each destination can belong to multiple
communities. Autonomous system administrators define to which communities a destination belongs.
communities. Autonomous system administrators define to which communities a destination belongs.
You configure a BGP community via a Context Configuration mode command.
config
context context_name
ip community-list { named named_list | standard identifier }
{ deny | permit } { internet | local-AS | no-advertise | no-export | value
AS-community_number AS-community_number AS-community_number ...}
{ deny | permit } { internet | local-AS | no-advertise | no-export | value
AS-community_number AS-community_number AS-community_number ...}
{ internet | local-AS | no-advertise | no-export | value
AS-community_number AS-community_number AS-community_number ...}
AS-community_number AS-community_number AS-community_number ...}
{ internet | local-AS | no-advertise | no-export | value
AS-community_number AS-community_number AS-community_number ...}
AS-community_number AS-community_number AS-community_number ...}
You can permit or deny the following BGP community destinations.
internet – Advertise this route to the internet community, and any router that belongs to it.
local-AS – Use in confederation scenarios to prevent sending packets outside the local autonomous system (AS).
no-advertise – Do not advertise this route to any BGP peer, internal or external.
no-export – Do not advertise to external BGP (eBGP) peers. Keep this route within an AS.
value
AS-community_number
– Specifies a community string in AS:NN format, where AS = 2-byte AS-
community hexadecimal number and NN = 2-byte hexadecimal number (1 to 11 characters).
You can enter multiple destinations and AS community numbers for each community. For additional information, see
the Command Line Interface Reference.
the Command Line Interface Reference.
Multiple community-list entries can be attached to a community-list by adding multiple permit or deny clauses for
various community strings. Up to 64 community-lists can be configured in a context.
various community strings. Up to 64 community-lists can be configured in a context.