Configuring Bgp Filtering By Neighbor - Cisco 3032 Software Configuration Manual

Chapter 38 Configuring IP Unicast Routing
Command
Step 3
set ip next-hop ip-address [...ip-address]
[peer-address]
Step 4 end
Step 5
show route-map [map-name]
Step 6 copy running-config startup-config
Use the no route-map map-tag command to delete the route map. Use the no set ip next-hop ip-address
command to re-enable next-hop processing.

Configuring BGP Filtering by Neighbor

You can filter BGP advertisements by using autonomous-system-path filters, such as the as-path
access-list global configuration command and the neighbor filter-list router configuration command.
You can also use access lists with the neighbor distribute-list router configuration command.
Distribute-list filters are applied to network numbers. See the
in Routing Updates" section on page 38-105
You can use route maps on a per-neighbor basis to filter updates and to modify various attributes. You
can apply a route map to either inbound or outbound updates. Only the routes that pass the route map
are sent or accepted in updates. On both inbound and outbound updates, matching is supported based on
autonomous-system path, community, and network numbers. Autonomous-system-path matching
requires the match as-path access-list route-map command, community-based matching requires the
match community-list route-map command, and network-based matching requires the ip access-list
global configuration command.
Beginning in privileged EXEC mode, follow these steps to apply a per-neighbor route map:
Command
Step 1
configure terminal
Step 2 router bgp autonomous-system
Step 3 neighbor {ip-address | peer-group name}
distribute-list {access-list-number | name}
{in | out}
Step 4 neighbor {ip-address | peer-group name}
route-map map-tag {in | out}
Step 5 end
OL-12247-04
Purpose
(Optional) Set a route map to disable next-hop processing
In an inbound route map, set the next hop of matching routes as
•
the neighbor peering address, overriding third-party next hops.
• In an outbound route map of a BGP peer, set the next hop to the
peering address of the local router, disabling the next-hop
calculation.
Return to privileged EXEC mode.
Display all route maps configured or only the one specified to verify
configuration.
(Optional) Save your entries in the configuration file.
for information about the distribute-list command.
Purpose
Enter global configuration mode.
Enable a BGP routing process, assign it an autonomous-system
number, and enter router configuration mode.
(Optional) Filter BGP routing updates to or from neighbors as
specified in an access list.
You can also use the neighbor prefix-list router
Note
configuration command to filter updates, but you cannot use
both commands to configure the same BGP peer.
(Optional) Apply a route map to filter an incoming or outgoing
route.
Return to privileged EXEC mode.
Cisco Catalyst Blade Switch 3130 and 3032 for Dell Software Configuration Guide
Configuring BGP
"Controlling Advertising and Processing
38-57