Specifications

2-282
Catalyst 4500 Series Switch Cisco IOS Command Reference—Release IOS XE 3.3.0XO(15.1(1)XO)
OL_28738 -01
Chapter 2 Cisco IOS Commands for the Catalyst 4500 Series Switches
ip wccp
Usage Guidelines T his command instructs a router to enable or disable the support for the specified service number or the
web-cache service name. A service number can be from 0 to 254. Once the service number or name is
enabled, the router can participate in the establishment of a service group.
When the no ip wccp command is entered, the router terminates participation in the service group,
deallocates space if none of the interfaces still has the service configured, and terminates the WCCP task
if no other services are configu red.
The keywords following the web-cache keyword and the service-number argument are optio nal and may
be specified in any order, but only may be specified once. The following sections outline the specific
usage of each of the optional forms of this command.
ip wccp {web-cach e | service-num ber} group-address multicast-address
A WCCP group address can be configured to set up a multicast address that cooperating routers and web
caches can use to exchange WCCP protocol messages. If such an address is used, IP multicast routing
must be enabled so that the messages that use the configured group (multicast) addresses are received
correctly.
This option instructs the router to use the specified multicast IP address to coalesce the “I See You”
responses for the “Here I Am” me ssages tha t it has rece ived on t his grou p address . The re sponse is sent
to the group address as well. The default is for no group address to be configured, in which case all “Here
I Am” message s are responded t o wi th a uni cast r eply.
ip wccp {web-cache | service-number} redirect-list access-list
This option instructs the router to use an access list to control the traffic that is redirected to the web
caches of the service group s pecified by t he service n ame given. The access-list argument specifies either
the number or the name of a standard or extended access list. The access list itself specifies which traffic
is permitted to be redirected. The default is for no redirect list to be configured (all traffic is redirected).
WCCP requires that the following protocol and ports not be filtered by any access lists:
• User D atagram Pr otocol ( UDP) (protoc ol type 17) port 2048 . This po rt is used for contr ol signaling.
Blocking this type of traffic will prevent WCCP from establishing a connection between the router
and cache engines.
ip wccp {web-cach e | service-number} group-list acce ss -l is t
This option instructs the router to use an access list to control the cache engines that are allowed to
participate in the specified service group. The access-list argument specifies either the number of a
standard or extended access list or the name of any type of named access list. The access list itself
specifies which cache engines are permitted to participate in the service group. The default is for no
group list to be configured, in which case all cache engines may participate in the service group.
Note The ip wccp {web-cache | service-number} group-list command syntax resembles the ip wccp
{web-ca che | service-number} group-listen command, but these are entirely different commands. The
ip wccp group-listen command is an interface configuration command used to configure an interface to
listen for multicast notifications from a cache cluster. Refer to the description of the ip wccp
group-listen command in the Cisco IOS IP Application Services Command Refe rence.
ip wccp {web-cach e | service-num ber} password password
This option instructs the router to use MD5 authentication on the messages received from the service
group specified by the service name given. Use this form of the command to set the password on the
router. You must also c onfigure the sam e password separate ly on ea ch web cache. The passw ord can be