3 before you begin – ZyXEL Communications 200 Series User Manual
Page 532
Chapter 31 Content Filtering
ZyWALL USG 100/200 Series User’s Guide
532
The ZyWALL can disable web proxies and block web features such as ActiveX controls,
Java applets and cookies.
• Customize Web Site Access
You can specify URLs to which the ZyWALL blocks access. You can alternatively block
access to all URLs except ones that you specify. You can also have the ZyWALL block
access to URLs that contain particular keywords.
Content Filtering Configuration Guidelines
When the ZyWALL receives an HTTP request, the content filter searches for a policy that
matches the source address and time (schedule). The content filter checks the policies in order
(based on the policy numbers). When a matching policy is found, the content filter allows or
blocks the request depending on the settings of the filtering profile specified by the policy.
Some requests may not match any policy. The ZyWALL allows the request if the default
policy is not set to block. The ZyWALL blocks the request if the default policy is set to block.
External Web Filtering Service
When you register for and enable the external web filtering service, 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.
Keyword Blocking URL Checking
The ZyWALL checks the URL’s domain name (or IP address) and file path separately when
performing keyword blocking.
The URL’s domain name or IP address is the characters that come before the first slash in the
URL. For example, with the URL
www.zyxel.com.tw/news/pressroom.php
, the domain name
is
www.zyxel.com.tw
.
The file path is the characters that come after the first slash in the URL. For example, with the
URL
www.zyxel.com.tw/news/pressroom.php
, the file path is
news/pressroom.php
.
Since the ZyWALL checks the URL’s domain name (or IP address) and file path separately, it
will not find items that go across the two. For example, with the URL
www.zyxel.com.tw/
news/pressroom.php
, the ZyWALL would find “tw” in the domain name
(
www.zyxel.com.tw)
. It would also find “news” in the file path (
news/pressroom.php
) but it
would not find “tw/news”.
Finding Out More
• See
for related information on these screens.
• See
for content filtering background/technical information.
31.1.3 Before You Begin
• You must configure an address object, a schedule object and a filtering profile before you
can set up a content filter policy.
• You must register the content filtering standard (in the Licensing > Registration >
Service) or trial (Licensing > Registration > Registration) service before you can use
external database content filtering (in the Anti-X > Content Filter > Filter Profiles >
Categories).