Cisco Catalyst 4500 Series - Configuring Policy-Based Routing

CHAPTER
40-1
Software Configuration Guide—Release IOS XE 3.6.0E and IOS 15.2(2)E
OL_28731-01
40
Configuring Policy-Based Routing
This chapter describes the tasks for configuring policy-based routing (PBR) on a Catalyst 4500 series
switch and includes these major sections:
• About Policy-Based Routing, page 40-1
• Policy-Based Routing Configuration Tasks, page 40-6
• Policy-Based Routing Configuration Examples, page 40-12
Note For complete syntax and usage information for the switch commands used in this chapter, see the Cisco
Catalyst 4500 Series Switch Command Reference and related publications at this location:
http://www.cisco.com/en/US/products/hw/switches/ps4324/index.html
If a command is not in the Catalyst 4500 Series Switch Command Reference, you can locate it in the
Cisco IOS library. See the Cisco IOS Command Reference and related publications at this location:
http://www.cisco.com/en/US/products/ps6350/index.html
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.
About Policy-Based Routing
This section contains the following subsections:
• About PBR, page 40-2
• Using Policy-Based Routing, page 40-5
PBR gives you a flexible method of routing packets by allowing you to define policies for traffic flows,
lessening reliance on routes derived from routing protocols. PBR gives you more control over routing
by extending and complementing the existing mechanisms provided by routing protocols. PBR allows
you to specify paths 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, or an
application protocol.