3Com SUPERSTACK 3 WEBCACHE 3000, User Manual

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Configuring ICP Caching 123
Configuring ICP
Caching
In addition to Parent Caching the Webcache supports ICP Caching. This is
an older and more error-prone protocol but is supported by a wide variety
of legacy devices.
3Com recommends that you use Parent Caching in preference to ICP
Caching unless you have an existing network of ICP caches that you wish
to 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 a
top-level cache with no peers, that is if the Webcache will not have to
query any other caches.
If configured to Only Receive Queries, the Webcache will respond to
incoming ICP requests from other cache devices, but will never initiate
any. If the Webcache does not have the requested content it will go
directly to the origin server or to a Parent Cache depending on its
configuration. This can be a useful setting when adding a Webcache to
an existing legacy ICP environment.
■
Send/Receive Queries — if the Webcache is not the top-level cache or
if the Webcache is the top-level cache but has peer caches, that is if
the Webcache needs to query a parent or peer before responding to
the client.
If configured to Send and Receive Queries, the Webcache will act as a full
ICP cache. If the Webcache does not have the requested content it will
query any other caches defined in the ICP peer list before going directly
to the origin server or to an configured Parent Caches
6 Set ICP Port to the port number on which you want your Webcache to
listen for ICP communication.
dua1611-5aaa04.book Page 123 Friday, November 29, 2002 8:56 PM