D-Link NetDefendOS User Manual page 551

2. For Anti-Virus Cache Lifetime enter the value 15
3. Click OK
Disabling the Cache
The administrator can disable the cache by setting the lifetime to zero. The CLI command to do
this is:
gw-world:/> set Settings MiscSettings AVCache_Lifetime=0
Disabling the cache is not recommended as it will decrease anti-virus performance and prevent
browser informational pages being displayed for HTTP traffic when downloads are blocked.
However, it may be useful in some scenarios.
Cache Statistics
The CLI avcache command provides a way to examine and manage the cache. To view the size of
the current cache contents, use the command with no parameters:
gw-world:/> avcache
Anti-virus cache size : 5 entries.
Cache hit count
The values displayed by the command are:
• Anti-virus cache size
This is the total number of unique file URL entries in the cache. Each entry corresponds to a
requested file download that was blocked because it triggered an anti-virus signature.
• Cache hit count
This is the number of successful cache lookups that have been performed. In other words, the
number of times a URL has been found already in the cache. This counter is not incremented
when a URL enters the cache for the first time.
The counter is zeroed after a NetDefendOS restart. It can also be zeroed by disabling the
cache then re-enabling. This is done by changing the value of the setting AVCache_Lfetime to
zero and then back to a positive value.
Clearing the Cache
To clear the cache, the avcache command can be used with the -clear option:
gw-world:/> avcache -clear
Note: The cache is flushed after signature updates
The anti-virus cache is flushed after an update of the local copy of the anti-virus
signature database.
: 8 hits.
551
Chapter 6: Security Mechanisms