As-Path Lists For Bgp; Community Lists For Bgp; Extended Community Lists For Bgp - Cisco Nexus 3000 Series Configuration Manual

Information About Route Policy Manager
S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m

AS-path Lists for BGP

You can configure an AS-path list to filter inbound or outbound BGP route updates. If the route update
contains an AS-path attribute that matches an entry in the AS-path list, the router processes the route
based on the permit or deny condition configured. You can configure AS-path lists within a route map.
You can configure multiple AS-path entries in an AS-path list by using the same AS-path list name. The
router processes the first entry that matches.

Community Lists for BGP

You can filter BGP route updates based on the BGP community attribute by using community lists in a
route map. You can match the community attribute based on a community list, and you can set the
community attribute using a route map.
A community list contains one or more community attributes. If you configure more than one community
attribute in the same community list entry, then the BGP route must match all community attributes listed
to be considered a match.
You can also configure multiple community attributes as individual entries in the community list by
using the same community list name. In this case, the router processes the first community attribute that
matches the BGP route, using the permit or deny configuration for that entry.
You can configure community attributes in the community list in one of the following formats:
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See the Cisco Nexus 3000 Series Command Reference,, for more information on regular expressions.

Extended Community Lists for BGP

Extended community lists support 4-byte AS numbers. You can configure community attributes in the
extended community list in one of the following formats:
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See the Cisco Nexus 3000 Series Command Reference,, for more information on regular expressions.
Cisco NX-OS supports generic specific extended community lists, which provide similar functionality
to regular community lists for four-byte AS numbers. You can configure generic specific extended
community lists with the following properties:
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Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
11-4
A named community attribute, such as internet or no-export.
In aa:nn format, where the first two bytes represent the two-byte AS number and the last two bytes
represent a user-defined network number.
A regular expression.
In aa4:nn format, where the first four bytes represent the four-byte AS number and the last two bytes
represent a a user-defined network number.
A regular expression.
Transitive—BGP propagates the community attributes across autonomous systems.
Nontransitive—BGP removes community attributes before propagating the route to another
autonomous system.
Chapter 11 Configuring Route Policy Manager