Configuring ICP Caching 123Configuring ICPCachingIn addition to Parent Caching the Webcache supports ICP Caching. This isan older and more error-prone protocol but is supported by a wide varietyof legacy devices.3Com recommends that you use Parent Caching in preference to ICPCaching unless you have an existing network of ICP caches that you wishto maintain.To enable and configure ICP Caching:1 Log in to the Web interface.2 Click Caching on the Toolbar.3 Select ICP Control > Setup ICP in the Navigation Tree.4 Ensure that the Enable ICP box is checked.5 Set the ICP Mode to: Only Receive Queries — if the Webcache is only to be used as atop-level cache with no peers, that is if the Webcache will not have toquery any other caches.If configured to Only Receive Queries, the Webcache will respond toincoming ICP requests from other cache devices, but will never initiateany. If the Webcache does not have the requested content it will godirectly to the origin server or to a Parent Cache depending on itsconfiguration. This can be a useful setting when adding a Webcache toan existing legacy ICP environment. Send/Receive Queries — if the Webcache is not the top-level cache orif the Webcache is the top-level cache but has peer caches, that is ifthe Webcache needs to query a parent or peer before responding tothe client.If configured to Send and Receive Queries, the Webcache will act as a fullICP cache. If the Webcache does not have the requested content it willquery any other caches defined in the ICP peer list before going directlyto the origin server or to an configured Parent Caches6 Set ICP Port to the port number on which you want your Webcache tolisten for ICP communication.dua1611-5aaa04.book Page 123 Friday, November 29, 2002 8:56 PM
