Introduction To Routing Policy; Routing Policy And Policy Routing - 3Com MSR 50 Series Configuration Manual

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Introduction to
Routing Policy
Routing Policy and
Policy Routing
R
OUTING
A routing policy is used on a router for route inspection, filtering, attributes
modifying when routes are received, advertised, or redistributed.
When configuring routing policy, go to these sections for information you are
interested in:
"Introduction to Routing Policy" on page 991
■
"Routing Policy Configuration Task List" on page 993
■
"Defining Filtering Lists" on page 993
■
"Configuring a Routing Policy" on page 996
■
"Displaying and Maintaining the Routing Policy" on page 1000
■
"Routing Policy Configuration Example" on page 1000
■
"Troubleshooting Routing Policy Configuration" on page 1005
■
n
Routing policy described in this chapter contains both IPv4 routing policy and IPv6
routing policy. Configurations of the two are similar, and differences are described
in related sections.
A routing policy is used on the router for route inspection, filtering, attributes
modifying when routes are received, advertised, or redistributed.
Policy routing is a routing mechanism based on the user-defined policies.
This chapter describes only routing policy configuration and usage, refer to
Unicast Policy Routing Configuration" on page 639
When distributing or receiving routing information, a router can apply some policy
to filter routing information. For example, a router handles only routing
information that matches some criteria, or a routing protocol redistributes from
other protocols only routes matching some criteria and modifies some attributes
of these routes to satisfy its needs.
To implement a routing policy, you need define a set of match criteria according to
attributes in routing information, such as destination address, advertising router's
address and so on. The match criteria can be set beforehand and then apply them
to a routing policy for route distribution, reception and redistribution.
P C
OLICY ONFIGURATION
for policy routing information.
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