Troubleshooting guide

1-5
Cisco Wide Area Application Services Configuration Guide
OL-26579-01
Chapter 1 Configuring Traffic Interception
Information About WCCP Interception
• After enabling WCCP on the router, you must configure the TCP promiscuous mode service on the
router and the WAE, as described in the Cisco Wide Area Application Services Quick Configuration
Guide. The service IDs are configurable on the WAE and you can choose a pair of numbers different
from the default of 61 and 62 to allow the router to support multiple WCCP farms because the WAEs
in different farms can use different service IDs. The router configuration must use WCCP service
IDs that match those configured on the WAEs in each farm that it is supporting.
• In order for the WAE to function in TCP promiscuous mode, the WAE uses WCCP Version 2
services 61 and 62 (the service IDs are configurable). These two WCCP services are represented by
the canonical name tcp-promiscuous on the WAE.
• You can use CLI commands to configure basic WCCP on both the routers and the WAEs or ANCs,
or you can use CLI commands to configure the router for WCCP and use the WAAS Central
Manager to configure basic WCCP on the WAEs or ANCs. In the configuration example provided
in the Cisco Wide Area Application Services Quick Configuration Guide, the wccp global
configuration command is used to configure basic WCCP on the WAEs or ANCs.
We recommend that you use the WAAS CLI to complete the initial basic configuration of WCCP on
your first branch WAE and data center WAE, as described in the Cisco Wide Area Application
Services Quick Configuration Guide. After you have verified that WCCP transparent redirection is
working properly, you can use the WAAS Central Manager to modify this basic WCCP
configuration or configure additional WCCP settings (for example, load balancing) for a WAE. For
more information, see the “Configuring WCCP on WAEs” section on page 1-11. After you have
configured basic WCCP on the router, you can configure advanced WCCP features on the router, as
described in the “Configuring Advanced WCCP Features on Routers” section on page 1-6.
• To ensure consistency among WAEs, we recommend that you configure WCCP settings on one
device and then use the Copy Settings taskbar icon from within the WCCP configuration window
to copy the settings to other devices in your network. You should copy the settings only to WAEs in
the same WCCP service farm, AppNav Controller group (ANCG), or WAAS node group (WNG),
since WCCP settings may need to be different in different farms or service groups.
• When you add a new router to an existing WCCP router farm or WCCP service group, the new router
will reset existing connections. Until WCCP reestablishes path redirections and assignments,
packets are sent directly to the client (as expected).
• The router must support the redirect and return methods configured on the WAE. If the router does
not support the configured methods, the WAE will not join the WCCP router farm. If you have a mix
of routers in the farm, only those routers that support the configured methods will join the farm.
• The WAE only joins the WCCP farm if the assignment method configured on the WAE is supported
by the router. (The strict assignment method is always enforced with version 4.4.1 and later.)
• A WAE joins a WCCP farm only if it is seen by all the configured routers in the farm. If there is a
link failure with any one of the routers, the farm reconfigures and the WAE is removed from the
farm.
• All WAEs in a WCCP farm must use the same pair of WCCP service IDs (the default is 61 and 62),
and these IDs must match all routers that are supporting the farm. A WAE with different WCCP
service IDs is not allowed to join the farm and an alarm is raised. Likewise, all WAEs in a farm must
use the same value for the failure detection timeout. A WAE raises an alarm if you configure it with
a mismatching value.
• VPN routing and forwarding (VRF)-aware WCCP scalability is as follows:
– The maximum number of WAEs supported by a single VRF instance is 32.
– The maximum number of VRF instances supported by the router is router dependent.
– VRF-aware WCCP is supported only on specific releases of Cisco IOS software. Ensure that the
router is running a release of Cisco IOS software that supports VRF-aware WCCP.