Using a WCCP-enabled router for transparency

A WCCP 2.0-enabled router can send all port 80 (HTTP) traffic to the Intel NetStructure Cache Appliance, as shown in Figure 4. After the WCCP router sends port 80 traffic, the ARM readdresses port 80 to the appliance proxy port (by default, port 8080). Then the appliance processes the request as usual, retrieving the requested document from the cache if it is a hit and sending the response back to the client. Along the way, the ARM readdresses the proxy port in the response header to port 80 (undoing the readdressing it did on the way to the appliance). The user then sees the response exactly as if it were sent directly from the origin server. In addition to port 80 (HTTP) traffic, WCCP 2.0 supports more protocols including NNTP (port 119 traffic).

internet

end users

Cisco IOS router

 

all

 

all

 

80

switch or hub

Intel NetStructure Cache Appliance 1, 2, and 3

Figure 4 Using a Cisco IOS router to send port 80 traffic to several Intel NetStructure Cache Appliances

WCCP provides the following routing benefits:

The WCCP-enabled router and the appliance exchange heartbeat messages, letting each other know they are running. The WCCP router automatically reroutes port 80 and port 119 traffic if the appliance goes down.

If several appliances receive traffic from a WCCP router, WCCP balances the load among them. The group of appliances is called a WCCP cache farm.

Appendix A Caching Solutions and Performance

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Intel 1520 manual Using a WCCP-enabled router for transparency