3 content filtering with an external database, 4 content filter categories, Figure 127 content filtering lookup procedure – ZyXEL Communications ZyXEL ZyWALL 2WG User Manual
Page 234
Chapter 12 Content Filtering Screens
ZyWALL 2WG User’s Guide
234
12.3 Content Filtering with an External Database
When you register for and enable external database content filtering, your ZyWALL accesses
an external database that has millions of web sites categorized based on content. You can have
the ZyWALL block, block and/or log access to web sites based on these categories. The
content filtering lookup process is described below.
Figure 127 Content Filtering Lookup Procedure
1 A computer behind the ZyWALL tries to access a web site.
2 The ZyWALL looks up the web site in its cache. If an attempt to access the web site was
made in the past, a record of that web site’s category will be in the ZyWALL’s cache.
The ZyWALL blocks, blocks and logs or just logs the request based on your
configuration.
3 Use the CONTENT FILTER Cache screen to configure how long a web site address
remains in the cache as well as view those web site addresses (see
). All of the web site address records are also cleared from the local cache when the
ZyWALL restarts.
4 If the ZyWALL has no record of the web site, it will query the external content filtering
database and simultaneously send the request to the web server.
The external content filtering database may change a web site’s category or categorize a
previously uncategorized web site.
5 The external content filtering server sends the category information back to the
ZyWALL, which then blocks and/or logs access to the web site. The web site’s address
and category are then stored in the ZyWALL’s content filtering cache.
12.4 Content Filter Categories
Click SECURITY >CONTENT FILTER > Categories to display the CONTENT FILTER
Categories screen.
Delete Range
Click Delete Range after you select the range of addresses you wish to
delete.
Apply
Click Apply to save your changes back to the ZyWALL.
Reset
Click Reset to begin configuring this screen afresh.
Table 77 SECURITY > CONTENT FILTER > General
LABEL
DESCRIPTION