HP ProCurve Secure Router 7203 dl Advanced Management And Configuration Manual page 704

IP Routing—Configuring RIP, OSPF, BGP, and PBR
Configuring BGP
13-90
You select the routes that the BGP interface will advertise by entering a match
command in an outbound route-map entry. (See Table 13-11.)
Table 13-11. Controlling Advertised Routes
Filtering According To
network address and/or prefix length match ip address prefix <listname>
AS path
community
metric
If you only want to filter advertised routes, you only need to enter the match
command and apply the route map to the neighbor as outbound policy (see
"Applying a Route Map Entry to a BGP Neighbor" on page 13-104).
If you want to apply an attribute to the route, you must also enter a set
command. You can apply these attributes to the routes selected by the match
command:
a community
a prepended AS path
a multi-exit discriminator metric
Filtering Advertised Routes According to Network Address. You use
a prefix list to filter routes advertised to a neighbor according to network
address and prefix length.
You can, of course, apply the prefix list directly to the neighbor as described
in "Creating Prefix Lists: Configuring Filters for Route Exchange" on page
13-78. The advantage of using a route map is that you can define permitted
routes at the same time that you configure other policies, such as those
described in the following sections.
The simplest way to configure a prefix list is to permit the exact routes that
the BGP interface should advertise.
For example, your network includes two networks. You want the router to
advertise network 10.1.0.0 /16 but not network 10.2.0.0 /16. Enter this com-
mand to configure the prefix list:
ProCurve(config)# ip prefix-list LAN1 seq 10 permit 10.1.0.0/16
Command Syntax
match as-path <listname>
match community <listname>
match metric <1-4292967295>