Defining The Routes That A Router Can Advertise - HP 7102dl - ProCurve Secure Router Configuration Manual

IP Routing—Configuring RIP, OSPF, BGP, and PBR
Configuring BGP
15-92

Defining the Routes that a Router Can Advertise

You can control whether the BGP interface advertises a route to a neighbor
according to the route's:
network address and prefix length
AS path
community
metric
You select the routes that the BGP interface will advertise by entering a match
command in an outbound route-map entry. (See Table 15-11.)
Table 15-11. 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 15-106).
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
15-81. 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.
Command Syntax
match as-path <listname>
match community <listname>
match metric <1-4292967295>