SnapGear 2.0.1 - Manual (Page 102)

Web Cache
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8. Web Cache
Note
The web cache is only available on SG575 models.
Web browsers running on PCs on your LAN can use the CyberGuard SG appliance’s
proxy-cache server to reduce Internet access time and bandwidth consumption.
A proxy-cache server implements Internet object caching. This is a way to store
requested Internet objects (i.e., data available via HTTP, FTP, and other protocols) on a
server closer to the user's network than on the remote site. Typically the proxy-cache
server eliminates the need to re-download Internet objects over the available Internet
connection when several users attempt to access the same web site simultaneously.
The objects will be available in the cache (server memory or disk) and quickly accessible
over the LAN rather than the slower Internet link.
The CyberGuard SG appliance’s web cache keeps objects cached in memory and on a
LAN network share, caches Internet name (DNS) lookups and implements negative
caching of failed requests.
Using the lightweight Internet Cache Protocol, multiple web caches can be arranged in a
hierarchy or mesh. This allows web cache peers to pull objects from each other’s
caches, further improving the performance of web access for an organisation with
multiple Internet gateway.