Extended Community Lists - Juniper JUNOSE 11.0.X IP SERVICES Configuration Manual

JUNOSe 11.0.x IP Services Configuration Guide
set community

Extended Community Lists

The router supports the BGP extended community attribute defined in
Internet draft BGP Extended Communities Attribute
draft-ietf-idr-bgp-ext-communities-07.txt (February 2004 expiration). This attribute
enables the definition of a type of IP extended community and extended community
list unrelated to the community list that uses regular expressions.
NOTE: IETF drafts are valid for only six months from the date of issuance. They must
be considered as works in progress. For the latest drafts, please see the IETF Web
site at http://www.ietf.org.
BGP devices can use the extended community attribute to control routes much like
they use the community attribute to determine routes that they accept, reject, or
redistribute. A BGP device can append the extended community attribute to a route
that does not have the attribute before it advertises the route. For routes that do have
the attribute, BGP can modify the attribute.
ip extcommunity-list
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Community Lists
Use to set the community attribute in BGP updates.
You can specify a community list number in the range 1–4294967295, or in the
new community format of AA:NN, or you can specify one of the following
well-known communities:
local-as Prevents advertisement outside the local AS
no-advertise Prevents advertisement to any peer
no-export Prevents advertisement beyond the BGP confederation boundary
Alternatively, you can use the list keyword to specify the name of a community
list that you previously created with the ip community-list command.
You can use this command with inbound, outbound, and redistribution route
maps.
Use the none keyword to remove the community attribute from a route.
Example
host1(config)#route-map 1
host1(config-route-map)#set community no-advertise
Use the no version to remove the set clause from a route map.
See set community.
Use to create an extended community list for BGP and control access to it.
A route can belong to any number of communities, so an extended community
list can have many entries comprising many communities.