3Com WX3000 operation manual IP Route Policy Configuration, IP Route Policy Overview, Filters

4 IP Route Policy Configuration

When configuring an IP route policy, go to these sections for information you are interested in:

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IP Route Policy Overview

IP Route Policy Configuration Task List

Displaying and Maintaining IP Route Policy

IP Route Policy Configuration Example

Troubleshooting IP Route Policy

The term router in this chapter refers to a router in a generic sense or a WX3000 series device running a routing protocol.

IP Route Policy Overview

Introduction to IP Route Policy

Route policy is technology used to modify routing information to control the forwarding path of data packets. Route policy is implemented by changing the route attributes such as reachability.

When a router distributes or receives routing information, it may need to implement some policies to filter the routing information, so as to receive or distribute only the routing information meeting given conditions. A routing protocol (RIP, for example) may need to import the routing information discovered by other protocols to enrich its routing knowledge. While importing routing information from another protocol, it possibly only needs to import the routes meeting given conditions and control some attributes of the imported routes to make the routes meet the requirements of this protocol.

For the implementation of a route policy, you need to define a set of matching rules by specifying the characteristics of the routing information to be filtered. You can set the rules based on such attributes as destination address and source address of the information. The matching rules can be set in advance and then used in the routing policies to advertise, receive, and import routes.

Filters

A routing protocol can reference an ACL, IP-prefix, or route policy to filter routing information. The following sections describe these filters.

ACL

You can specify a range of IP addresses or subnets when defining an ACL so as to match the destination network addresses or next-hop addresses in routing information. You can reference an ACL into a route policy to filter routing information.

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