Configuring Routing Policies; Overview; Filters - HP 6125XLG Configuration Manual

Configuring routing policies

Routing policies control routing paths by filtering and modifying routing information. This chapter
describes both IPv4 and IPv6 routing policies.

Overview

Routing policies can filter advertised, received, and redistributed routes, and modify attributes for specific
routes.
To configure a routing policy:
1. Configure filters based on route attributes, such as destination address and the advertising router's
address.
2. Create a routing policy and apply filters to the routing policy.

Filters

Routing policies can use the following filters to match routes.
ACL
ACLs include IPv4 ACLs and IPv6 ACLs. An ACL can match the destination or next hop of routing
information.
For more information about ACLs, see ACL and QoS Configuration Guide.
IP prefix list
IP prefix lists include IPv4 prefix lists and IPv6 prefix lists.
An IP prefix list matches the destination address of routing information. You can use the gateway option
to receive routing information only from specific routers. For more information about the gateway option,
see "Configuring RIP" and "Configuring OSPF."
An IP prefix list, identified by name, can comprise multiple items. Each item, identified by an index
number, specifies a prefix range to match. An item with a smaller index number is matched first. A route
that matches one item matches the IP prefix list.
AS path list
An AS path list matches the AS_PATH attribute of BGP routing information.
For more information about AS path lists, see "Configuring BGP."
Community list
A community list matches the COMMUNITY attribute of BGP routing information.
For more information about community lists, see "Configuring BGP."
Extended community list
An extended community list matches the extended community attribute (for example, Route-Target for
VPN) of BGP routing information.
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