Brocade BigIron RX Series Configuration Guide - Manual (Page 962)

884 BigIron RX Series Configuration Guide
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Filtering
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The value that the software substitutes for peer-address depends on whether the route map is
used for inbound filtering or outbound filtering:
• When you use the set ip next-hop peer-address command in an inbound route map filter,
peer-address substitutes for the neighbor’s IP address.
• When you use the set ip next-hop peer-address command in an outbound route map filter,
peer-address substitutes for the local IP address of the BGP4 session.
NOTE
You can use this command for a peer group configuration.
Deleting a community from a BGP4 route
To delete a community from a BGP4 route’s community attributes field, enter commands such as
the following.
BigIron RX(config)# ip community-list standard std_3 permit 12:99 12:86
BigIron RX(config)# route-map bgp6 permit 1
BigIron RX(config-routemap bgp6)# match ip address 1
BigIron RX(config-routemap bgp6)# set comm-list std_3 delete
The first command configures a community ACL containing community numbers 12:99 and 12:86.
The remaining commands configure a route map that matches on routes whose destination
network is specified in ACL 1, and deletes communities 12:99 and 12:86 from those routes. The
route does not need to contain all the specified communities in order for them to be deleted. For
example, if a route contains communities 12:86, 33:44, and 66:77, community 12:86 is deleted.
Syntax: set comm-list <acl> delete
The <acl> parameter specifies the name of a community list ACL.
Configuring cooperative BGP4 route filtering
By default, the device performs all filtering of incoming routes locally, on the device itself. You can
use cooperative BGP4 route filtering to cause the filtering to be performed by a neighbor before it
sends the routes to the device. Cooperative filtering conserves resources by eliminating
unnecessary route updates and filter processing. For example, the device can send a deny filter to
its neighbor, which the neighbor uses to filter 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 filter out the routes.
When you enable cooperative filtering, 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 configured to send filters, receive filters or both, and the types of filters it can send or
receive. The device sends the filters as Outbound Route Filters (ORFs) in Route Refresh messages.
To configure cooperative filtering, perform the following tasks on the device and on its BGP4
neighbor:
• Configure the filter.
NOTE
The current release supports cooperative filtering only for filters configured using IP prefix lists.
• Apply the filter as in inbound filter to the neighbor.