Enable Dynamic Content Filtering - D-Link NetDefend DFL-210 User Manual

6.5.4. Dynamic Content Filtering
will automatically be downloaded to D-Link's central data warehouse and automatically analyzed
using a combination of techniques including neural networks and pattern matching. Once categor-
ized, the URL is distributed to the global databases and NetDefendOS receives the category for the
URL. Dynamic Content Filtering therefore requires a minimum of administration effort.
Categorizing Pages and Not Sites
NetDefendOS dynamic filtering categorizes web pages and not sites. In other words, a web site may
contain particular pages that should be blocked without blocking the entire site. NetDefendOS
provides blocking down to the page level so that users may still access parts of websites that aren't
blocked by the filtering policy.
Enabling Dynamic Content Filtering
Dynamic Content Filtering is a feature that is enabled by taking out a separate subscription to the
service. This is an addition to the normal NetDefendOS license. For complete details of subscription
services please see Appendix A, Subscribing to Security Updates.
Once a subscription is taken out, content filtering is enabled through the HTTP Application Layer
Gateway (ALG) in combination with Services and the IP rule-set. This makes possible the setting up
of a detailed content filtering policy based on the filtering parameters that are used for rules in the IP
rule-set.
Example 6.18. Enable Dynamic Content Filtering
This example shows how to setup a dynamic content filtering policy for HTTP traffic from intnet to all-nets. The
policy will be configured to block all search sites, and this example assumes that the system is using a single NAT
rule for HTTP traffic from intnet to all-nets.
CLI
(The NAT rule is called NATHttp for the CLI example)
First, create an HTTP Application Layer Gateway (ALG) Object:
gw-world:/> add ALG ALG_HTTP content_filtering WebContentFilteringMode=Enabled
Then, create a Service object using the new HTTP ALG:
gw-world:/> add ServiceTCPUDP http_content_filtering Type=TCP DestinationPorts=80
Finally, modify the NAT rule to use the new service:
gw-world:/> set IPRule NATHttp Service=http_content_filtering
Web Interface
First, create an HTTP Application Layer Gateway (ALG) Object:
1. Go to Objects > ALG > Add > HTTP ALG
2. Specify a suitable name for the ALG, for instance content_filtering
Note
New, uncategorized URLs sent to the D-Link network are treated as anonymous sub-
missions and no record of the source of new submissions is kept.
Tip
If you would like your content filtering policy to vary depending on the time of the day,
make use of a schedule object in the corresponding IP rule. For more information,
please see Section 3.6, "Schedules".
FilteringCategories=SEARCH_SITES
ALG=content_filtering
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Chapter 6. Security Mechanisms