User manual

Network Setup
120
Note
The SG unit’s web cache uses port 3128 by default.
Enter 3128 in Port, select Bypass proxy for local addresses and click OK.
Peers
The SG unit’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.
Click Advanced, Peers, then New.
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 SG unit’s web cache (as described above) from Type and click Apply.
ICAP client
The SG unit’s ICAP client allow you to utilise a third-party ICAP server as an intermediary
between LAN PCs browsing the web and/or traffic incoming from the web. Outgoing web
requests or incoming web traffic is passed off to the ICAP server for processing before
being returned to the requesting LAN PC.
The ICAP server may process outgoing web requests from a LAN PC using a REQMOD
service, or incoming web traffic from an external web server using a RESPMOD service.
A typical function of a REQMOD service would be URL filtering, a typical function of a
RESPMOD service would be virus scanning.
Click Advanced then ICAP Client.