Applying Policies To Inbound Routes - HP ProCurve Secure Router 7203 dl Advanced Management And Configuration Manual

IP Routing—Configuring RIP, OSPF, BGP, and PBR
Configuring BGP
13-102

Applying Policies to Inbound Routes

In addition to controlling whether your router accepts routes from a neighbor,
you can configure the router to apply policies to routes that it accepts.
First, select a set of routes and then set attributes for those routes.
Selecting and Grouping Routes. Use the match commands described for
filtering inbound routes to select a set of routes.
For example, you can configure a route map entry to group together all routes
that travel through a certain AS path:
ProCurve(config)# ip as-path-list External1
ProCurve(config-as-path-list)# permit 1 2 3 4
ProCurve(config-as-path-list)# route-map ExternalIn 20
ProCurve(config-route-map)# match as-path External1
You can then configure a policy for the group of routes by setting various
attributes. (See "Setting Attributes for Selected Routes" on page 13-102.)
As always, you can use prefix lists to group routes according to their destina-
tion address. For example, you can divide the Internet into several sections
and group routes to each section together in a set. You can then configure
different attributes for sets of routes that arrive on different interfaces.
You can also match traffic according to its community. As mentioned earlier,
the communities to which a route belongs only affect the route when admin-
istrators configure policies that apply to those communities. The match
command and community list define the community or communities to which
a policy applies. The set commands (described below) actually define the
policy.
Setting Attributes for Selected Routes. Use the set commands to add
attributes to the set of routes that you have selected with the match com-
mands. Among other functions, these attributes affect which route BGP
selects as best. The attributes that you can apply to a route include:
local preference
community
To set a local preference for selected routes, enter this command from the
route map configuration mode context:
Syntax: set local-preference <value>
Enter a value between 0 and 4294967295.