SnapGear 2.0.1 - Manual (Page 107)

Web Cache
103
Peers
The CyberGuard SG appliance’s web cache can be configured to share cached objects
with, and access objects cached by, other web caches.
Web caches communicate using the Internet Cache Protocol (ICP). ICP is used to
exchange hints about the existence of URLs in neighbour caches. Caches exchange ICP
queries and replies to gather information to use in selecting the most appropriate location
from which to retrieve an object.
First of all, the messages transmitted by a cache to locate a specific object are sent to
Sibling caches, which are placed at the same level in the hierarchy. Then, the caches
placed at the Parent level are queried if the replies from sibling caches did not succeed.
Enter the host or IP address of an ICP capable web cache peer in Host, then select its
relationship to the CyberGuard SG appliance’s web cache (as described above) from
Type and click Apply.
Set up LAN PCs to Use the Web Cache
Once the web cache has been set up, PCs on the LAN must have their browsers
configured appropriately.
In Internet Explorer, select Internet Options from the Tools menu. Select the
Connections tab and click LAN Settings. Under Proxy Server, check Use proxy
server… and enter the IP address of your CyberGuard SG appliance in Address.
Note
The CyberGuard SG appliance’s web cache uses port 3128 by default.
Enter 3128 in Port, select Bypass proxy for local addresses and click OK.