Chapter 26 Configuring Policy-Based Routing; Overview Of Policy-Based Routing - Cisco 4500M Software Manual

Configuring Policy-Based Routing
This chapter describes the tasks for configuring policy-based routing (PBR) on a router and includes
these major sections:
•
•
•
For a complete description of the PBR commands in this chapter, refer to the Cisco IOS Quality of
Note
Service Solutions Command Reference at:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios123/123tcr/123tqr/
Note To identify the hardware platform or software image information associated with a feature, use the
Feature Navigator on Cisco.com to search for information about the feature or refer to the software
release notes for a specific release.

Overview of Policy-Based Routing

This section contains the following subsections:
•
•
•
PBR gives you a flexible means of routing packets by allowing you to configure a defined policy for
traffic flows, lessening reliance on routes derived from routing protocols. To this end, PBR gives you
more control over routing by extending and complementing the existing mechanisms provided by routing
protocols. PBR allows you to specify a path for certain traffic, such as priority traffic over a high-cost
link.
You can set up PBR as a way to route packets based on configured policies. For example, you can
implement routing policies to allow or deny paths based on the identity of a particular end system, an
application protocol, or the size of packets.
OL-6696-01
Overview of Policy-Based Routing, page 26-1
Policy-Based Routing Configuration Task List, page 26-3
Policy-Based Routing Configuration Examples, page 26-5
Understanding PBR, page 26-2
Understanding PBR Flow Switching, page 26-2
Using Policy-Based Routing, page 26-2
C H A P T E R
Software Configuration Guide—Release 12.2(25)EW
26
26-1