You can configure proxy server chains through the Routing tab on the Web Proxy Service dialog box. Only client requests for the Web Proxy service can be routed upstream because only the Web Proxy service uses caching.
Tip: WinSock and Socks Proxy Services do not support caching, chaining, or upstream routing.
To configure upstream routing, follow these steps:
1. Open the Internet Service Manager.
2. Double-click the Web Proxy service icon.
3. Click the Routing tab. By default, the Routing tab is configured only with the name of your proxy server and the Use Direction Connection radio button is selected. However, in Figure 2, the options have been modified as an example.
4. Ensure that the correct local server computer name appears in the “Use this Http Via Header alias for the local server.”
5. In the Upstream Routing section choose one of the following:
“Use direct connection” to route all Web Proxy client requests that aren’t resolved by the local Web cache to the Internet.
“Use Web Proxy or array” to route all Web Proxy client requests that aren’t resolved by the local Web cache upstream to another Proxy Server computer or array.
6. If you’re routing to an upstream Web Proxy or array, click the Modify button to configure the Advanced Routing Options dialog box (Figure 3). In this dialog box, you can configure the name of the upstream proxy server or array and the TCP port on which to contact it (usually 80).
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