Planning information to consider as you read this chapter

Decisions to be made

In this chapter, you will determine the following:

How the appliance fits into your current L4 or L7 switch or WCCP router deployment
The implications of using third-party proxy-cache servers in your deployment
How to achieve failover with the transparency method you choose
If you are deploying transparency with a WCCP router, the type and number of required WCCP service groups
Whether you want to redirect traffic using the default ports
Whether you need to set up transparent proxy authentication for HTTP
What type of security measures (if any) you want to use with your redirection device
Whether you need to modify transparent redirection to meet a specific need, such as client-server authentication

Information to gather before continuing

Before continuing with the NetCache configuration, ensure that you have the following information:

Protocols that you want to transparently proxy
If you are deploying transparent proxying with an L4 or L7 switch, the L4 or L7 switch configuration documentation
If you are deploying transparency with WCCP routers
- The number, type, and properties of the WCCP service groups that you need to create, including the WCCP password for each service group, if desired
- Cisco IOS specifications for configuring your WCCP routers
- If you are using unicast transmission, the IP addresses of the WCCP routers
- If you are using multicast transmission, one or more multicast IP addresses to be used when configuring your service groups.
  Multicast IP addresses do not need to be unique among service groups. The same multicast IP address can be used for all service groups.
- If you plan to use load balancing over the appliance interfaces, record the IP addresses of the interfaces over which this appliance will deliver data to clients
  Network Appliance recommends using the WCCP Appliance IP Addresses for Load Balancing option for MMS and RTSP streaming media.

When to use the optional transparency features

The following table provides reasons that you might want to modify transparency and describes the NetCache feature you can use to accomplish your goal.

If you want to...	You can use these features...
Enable your users to have direct contact with Web servers that have a large amount of uncacheable data	IP forwarding
Ensure that client requests arrive at the origin server with the client IP address as the source address (for example, because the server requires IP-based authentication)	IP forwarding URL forwarding IP spoofing Dynamic forwarding
Allow streaming media content providers to measure how many distinct users are viewing their content	IP spoofing for MMS, RTSP, or both
Ensure that the term proxy-cache server does not appear in NetCache error messages	Stealth mode

To learn more about these features, see Section E, Additional transparency features.