Troubleshooting guide

1-4
Cisco Wide Area Application Services Configuration Guide
OL-26579-01
Chapter 1 Configuring Traffic Interception
Information About WCCP Interception
Additionally, limit the amount of bandwidth that can be received on the LAN-side interface of the router,
to help the router keep its interface queues less congested and provide better performance and lower CPU
utilization. Set the maximum interface bandwidth on the router to no more than 10 times the WAN
bandwidth capacity. For instance, if the WAN link is a T1, the LAN interface and WAE LAN interface
bandwidth should be throttled to 10 * T1 = 10 * 1.544 Mbps, or approximately 15 Mbps. See the
Cisco IOS documentation for more information.
This section contains the following topics:
• Guidelines for Configuring WCCP, page 1-4
• Guidelines for File Server Access Methods, page 1-6
Guidelines for Configuring WCCP
When you configure transparent redirection on a WAE using WCCP Version 2, follow these guidelines:
• Intercept and redirect packets on the inbound interface whenever possible.
• Use WCCP GRE or generic GRE as the egress method if you want to place WAEs on the same
VLAN or subnet as clients and servers. This topology is not allowed when using the IP forwarding
egress method.
• Branch WAEs must not have their packets encrypted or compressed and should be part of the
“inside” Network Address Translation (NAT) firewall if one is present.
• Use Layer 2 redirection as the packet forwarding method if you are using Catalyst 6500 series
switches or Cisco 7600 series routers. Use Layer 3 GRE packet redirection if you are using any other
Cisco series router.
• When you configure WCCP for use with the Hot Standby Router Protocol (HSRP), you must
configure the WAE with the HSRP or the Virtual Router Redundancy Protocol (VRRP) virtual router
address as its default gateway, and the WAE WCCP router-list with the primary address of the
routers in the HSRP group.
• CEF is required for WCCP and must be enabled on the router.
• Place branch WAEs on the client side of the network to minimize client-side packets through the
router.
• Use WCCP passwords to avoid denial-of-service attacks. For more information, see the “Setting a
Service Group Password on a Router” section on page 1-10.
• Use WCCP redirect lists for new implementations to limit client or server populations. For more
information, see the “Configuring IP Access Lists on a Router” section on page 1-9.
• You must configure the WAE to accept redirected packets from one or more WCCP-enabled routers.
• To configure basic WCCP, you must enable the WCCP service on at least one router in your network
and on the WAE or ANC that you want the traffic redirected to. It is not necessary to configure all
of the available WCCP features or services to get your WAE up and running. For an example of how
to complete a basic WCCP configuration on routers and WAEs in a branch office and data center,
see the Cisco Wide Area Application Services Quick Configuration Guide.
• You must configure the routers and WAEs to use WCCP Version 2 instead of WCCP Version 1
because WCCP Version 1 only supports web traffic (port 80).