Cisco Systems ASA5515K9, ASA 5500 Configuring Web Cache Services Using WCCP

CHAPT ER
40-1
Cisco ASA 5500 Series Configuration Guide using the CLI
40
Configuring Web Cache Services Using WCCP
This chapter describes how to configure web caching services using WCCP, and includes the following
sections:
•Information About WCCP, page40-1
•Guidelines and Limitations, page40-1
•Licensing Requirements for WCCP, page40-2
•Enabling WCCP Redirection, page40-3
•WCCP Monitoring Commands, page40-4
•Feature History for WCCP, page40-4
Information About WCCP
The purpose of web caching is to reduce latency and network traffic. Previously-accessed web pages are
stored in a cache buffer, so if users need the page again, they can retrieve it from the cache instead of the
web server.
WCCP specifies interactions between the ASA and external web caches. The feature transparently
redirects selected types of traffic to a group of web cache engines to optimize resource usage and lower
response times. The ASA only supports WCCP Version 2.
Using an ASA as an intermediary eliminates the need for a separate router to do the WCCP redirection,
because the ASA redirects requests to cache engines. When the ASA determines that a packet needs
redirection, it skips TCP state tracking, TCP sequence number randomization, and NAT on these traffic
flows.
Guidelines and Limitations
The following WCCPv2 features are supported for the ASA:
•Redirection of multiple TCP and UDP port-destined traffic.
•Authentication for cache engines in a service group.
•Multiple cache engines in a service group.
•GRE encapsulation.
The following WCCPv2 features are not supported for the ASA: