Cisco Nexus 7000 Series - Access Lists; AS Numbers for BGP; AS-Path Lists for BGP; Set Changes

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Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x
OL-20002-02
Chapter 16 Configuring Route Policy Manager
Information About Route Policy Manager
• BGP parameters—Match based on AS numbers, AS-path, community attributes, or extended
community attributes.
• Prefix lists—Match based on an address or range of addresses.
• Multicast parameters—Match based on rendezvous point, groups, or sources.
• Other parameters—Match based on IP next-hop address or packet length.
Set Changes
Once a route or packet matches an entry in a route map, the route or packet can be changed based on one
or more configured set statements.
The set changes are as follows:
• BGP parameters—Change the AS-path, tag, community, extended community, dampening, local
preference, origin, or weight attributes.
• Metrics—Change the route-metric, the route-tag, or the route-type.
• Policy-based routing only—Change the interface or the default next-hop address.
• Other parameters—Change the forwarding address or the IP next-hop address.
Access Lists
IP access lists can match the packet to a number of IP packet fields such as the following:
• Source or destination IPv4 or IPv6 address
• Protocol
• Precedence
• ToS
You can use ACLs in a route map for policy-based routing only. See the Cisco Nexus 7000 Series NX-OS
Security Configuration Guide, Release 4.x for more information on ACLs.
AS Numbers for BGP
You can configure a list of AS numbers to match against BGP peers. If a BGP peer matches an AS
number in the list and matches the other BGP peer configuration, BGP creates a session. If the BGP peer
does not match an AS number in the list, BGP ignores the peer. You can configure the AS numbers as a
list, a range of AS numbers, or you can use an AS-path list to compare the AS numbers against a regular
expression.
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.