Configuring Policy-Based Routing (PBR):
You can configure PBR by following these steps. Some of the steps may be omitted depending on your application for PBR. For this example, note the set condition options listed is step 3 (answers are bolded).
Step1
Define and configure the route map needed for the policy. This is accomplished with the route-map command, as discussed previously.
Step2
Define and configure the match statements the route map will use. The most common match statements used are the following:
match ip address [access-list number]
The match ip address is used to call a standard, extended, or expanded-range ACL.
match length [min_packet_length_0-2147483647] [max_packet_length_0-2147483647] The match length is used to match the Layer 3 packet length, in bytes, with all associated headers and trailers included. You must enter the minimum and maximum packet length.
Use the match length command to policy route traffic based on packet size. You can deploy this to route traffic with large or small packet sizes to specific areas of the network.
Step3
Configure and define the new routing policy with set commands. Multiple set commands may be used; if multiple commands are used, they are executed in the following order:
set ip {precedence [value_0-7 | name] | tos [value_0-8 | name]}
set ip next-hop ip_address
set interface interface_name
set ip default next-hop ip_address
set default interface interface_name
Set ip precedence {[1-7]|[routine|critical|flash|flash-
override|immediate|internet|network|priority]}