Ip Route Policy Overview - 3Com 4500 PWR 26-Port Configuration Manual

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IP Route Policy Configuration
Wh n configuring an IP route policy, go to the e

IP Route Policy Overview

IP Route Policy Configuration Task List
Displaying IP Route Policy
IP Route Policy Configuration Example
Trouble shooting IP Route Policy
The term router in this chapter refers to a router in a generic sense or an Ethernet switch running a
ro uting protocol.
IP Route Policy Overview
Introd uction 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 fro
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 base
destination address and source address of the information. The matching rules can be set in advance
an d then used in the routing policies to advertise, receive, and import routes.
Filter s
A routing protocol can reference an ACL, IP-prefix, or route policy to filter routing information. The
follo wing sections describe these filters.
ACL
You can specify a range of IP addresses or
destination network addresses or next-hop addresses in r
into a route policy to filter routing information.
se sections for information you are interested in:
subnets when defining an ACL so as to match the
outing information. You can reference an ACL
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m another
d on such attributes as