Troubleshooting guide

1-33
Cisco Wide Area Application Services Configuration Guide
OL-26579-01
Chapter 1 Configuring Traffic Interception
Using Policy-Based Routing Interception
Note The tunnel interface is enabled for IP by provisioning an IP address, which allows it to process and
forward transit packets. If you do not want to provision an IP address, the tunnel must be IP enabled by
making it an IP unnumbered interface. This restricts the tunnel to be a point-to-point tunnel.
Point-To-Point Tunnel Configuration
This section describes how to configure a point-to-point tunnel for a single WAE instead of a multipoint
tunnel on the router. A point-to-point tunnel is enabled for IP either by making it unnumbered or by
giving it an IP address. The unnumbered method is shown in the following example router configuration:
interface gigabitEthernet 1/1
ip address 192.168.1.1 255.255.255.0
...
! Tunnel1 is an unnumbered point-to-point tunnel towards WAE1
interface Tunnel1
ip unnumbered GigabitEthernet1/1
tunnel source GigabitEthernet1/1
! tunnel destination is the IP address of WAE1
tunnel destination 10.10.10.10
ip wccp redirect exclude in
end
Using Policy-Based Routing Interception
This section contains the following topics:
• Information About Policy-Based Routing, page 1-33
• Configuring Policy-Based Routing, page 1-36
• Methods of Verifying PBR Next-Hop Availability, page 1-39
Information About Policy-Based Routing
Policy-based routing (PBR), introduced in Cisco IOS Release 11.0, allows you to implement policies
that selectively cause packets to take specific paths in the network.
PBR also provides a method to mark packets so that certain kinds of traffic receive differentiated,
preferential service when used in combination with queuing techniques enabled through the Cisco IOS
software. These queuing techniques provide an extremely powerful, simple, and flexible tool to network
managers who implement routing policies in their networks.
PBR enables the router to put packets through a route map before routing them. When configuring PBR,
you must create a route map that specifies the match criteria and the resulting action if all of the match
clauses are met. You must enable PBR for that route map on a particular interface. All packets arriving
on the specified interface matching the match clauses will be subject to PBR.
One interface can have only one route map tag; but you can have several route map entries, each with its
own sequence number. Entries are evaluated in order of their sequence numbers until the first match
occurs. If no match occurs, packets are routed as usual.
Router(config-if)# ip policy route--tag
The route map determines which packets are routed next.