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Cisco 7600 Series Router Cisco IOS Software Configuration Guide—12.1E
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Chapter 35      Configuring Web Cache Services Using WCCP
Configuring WCCP
For network configurations where redirected traffic needs to traverse an intervening router, the router 
being traversed must be configured to perform IP multicast routing. You must configure the following 
two components to enable traversal over an intervening router:
• Enable IP multicast routing using the ip multicast routing interface configuration command.
• Enable the interfaces to which the cache engines will connect to receive multicast transmissions 
using the ip wccp group-listen interface configuration command (note that earlier Cisco IOS 
versions required the use of the ip pim interface configuration command).
Using Access Lists for a WCCP Service Group
To configure the router to use an access list to determine which traffic should be directed to which cache 
engines, perform this task in global configuration mode:
To disable caching for certain clients, perform this task in global configuration mode:
Setting a Password for a Router and Cache Engines
MD5 password security requires that each router and cache engine that wants to join a service group be 
configured with the service group password. The password can consist of up to seven characters. Each 
cache engine or router in the service group will authenticate the security component in a received WCCP 
packet immediately after validating the WCCP message header. Packets failing authentication will be 
discarded.
Step 2
Router(config)# interface type number 
Specifies the interface to be configured for multicast 
reception.
Step 3
Router(config-if)# ip wccp {web-cache | 
service-number} group-listen 
Enables the reception of IP multicast packets (content 
originating from the cache engines) on the interface 
specified in Step 2. 
Command Purpose
Command Purpose
Step 1
Router(config)# access-list access-list permit ip 
host host-address [destination-address | 
destination-host | any]
Creates an access list that enables or disables traffic 
redirection to the cache engine.
Step 2
Router(config)# ip wccp web-cache group-list 
access-list 
Indicates to the router from which IP addresses of cache 
engines to accept packets.
Command Purpose
Step 1
Router(config)# access-list access-list permit ip 
host host-address [destination-address | 
destination-host | any]
Creates an access list that enables or disables traffic 
redirection to the cache engine.
Step 2
Router(config)# ip wccp web-cache redirect-list 
access-list 
Sets the access list used to enable redirection.