ZyXEL Communications Internet Security Gateway ZyWALL 100, User Manual

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ZyWALL Series Internet Security Gateway
Content Filtering Screens 13-5
Figure 13-2 Content Filtering Lookup Procedure
Step 1.
A computer sends an HTTP request to a web server.
Step 2. The ZyWALL looks up the web site in its local database. If an attempt to access the web site was
made in the past, a record of that web site’s rating will be in the ZyWALL’s cache. The
ZyWALL either blocks or forwards the request based on the rating policy you configure.
If the ZyWALL doesn’t have a record of the web site, it will query the lookup server and
simultaneously send the request to the web server.
Step 3. The lookup server sends the rating information back to the ZyWALL, which then either forwards
or blocks the web content. The web site address is then also stored in the ZyWALL’s content
filtering cache.
13.4 A Procedure to Enable External Database Content Filtering
The following is an example procedure for using external database content filtering.
Step 1. Enable content filtering in the Content Filtering General screen.
Step 2. In the Content Filtering Categories screen, register for external database content filtering.
Step 3. In the Content Filtering Categories screen, select Enable External Database Content
Filtering .
Step 4. In the Content Filtering Categories screen, select Block Matched Web Pages .
Step 5.
In the Content Filtering Categories screen, select categories to block.