To create a route map and identify it as a table map, enter commands such as following. These commands create a route map that uses
an address lter. For routes that match the IP prex list lter, the route map changes the tag value to 100 and is then considered as a
table map. This route map is applied only to routes the device places in the IP route table. The route map is not applied to all routes. This
example assumes that IP prex list p11 has already been congured.
device(config)# route-map TAG_IP permit 1
device(config-routemap TAG_IP)# match ip address prefix-list p11
device(config-routemap TAG_IP)# set tag 100
device(config-routemap TAG_IP)# router bgp
device(config-bgp)# table-map TAG_IP
Conguring cooperative BGP4 route ltering
By default, the device performs all ltering of incoming routes locally, on the device itself. You can use cooperative BGP4 route ltering
to cause the ltering to be performed by a neighbor before it sends the routes to the device. Cooperative ltering conserves resources by
eliminating unnecessary route updates and lter processing. For example, the device can send a deny lter to a neighbor, which the
neighbor uses to lter out updates before sending them to the device. The neighbor saves the resources it would otherwise use to
generate the route updates, and the device saves the resources it would use to lter out the routes.
When you enable cooperative ltering, the device advertises this capability in its Open message to the neighbor when initiating the
neighbor session. The Open message also indicates whether the device is congured to send lters, receive lters, or both, and the types
of lters it can send or receive. The device sends the lters as Outbound Route Filters (ORFs) in route refresh messages.
To congure cooperative ltering, perform the following tasks on the device and on the BGP4 neighbor:
• Congure the lter.
NOTE
Cooperative ltering is currently supported only for lters congured using IP prex
lists.
• Apply the lter as an inbound lter to the neighbor.
• Enable the cooperative route ltering feature on the device. You can enable the device to send ORFs to the neighbor, to receive
ORFs from the neighbor, or both. The neighbor uses the ORFs you send as outbound lters when it sends routes to the device.
Likewise, the device uses the ORFs it receives from the neighbor as outbound lters when sending routes to the neighbor.
• Reset the BGP4 neighbor session to send and receive ORFs.
• Perform these steps on the other device.
NOTE
If the device has inbound lters, the lters are still processed even if equivalent lters have been sent as ORFs to the
neighbor.
Enabling cooperative ltering
To congure cooperative ltering, enter commands such as the following.
device(config)# ip prefix-list Routesfrom10234 deny 10.20.0.0/24
device(config)# ip prefix-list Routesfrom10234 permit 0.0.0.0/0 le 32
device(config)# router bgp
device(config-bgp-router)# neighbor 10.2.3.4 prefix-list Routesfrom1234 in
device(config-bgp-router)# neighbor 10.2.3.4 capability orf prefixlist send
Filtering
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