Setting Up A White And Blacklist - D-Link NetDefend DFL-210 User Manual

6.3.3. Static Content Filtering
*/*.gif
www.example.com
*example.com/*
Example 6.14. Setting up a white and blacklist
This example shows the use of static content filtering where NetDefendOS can block or permit certain web pages
based on blacklists and whitelists. As the usability of static content filtering will be illustrated, dynamic content
filtering and active content handling will not be enabled in this example.
In this small scenario a general surfing policy prevents users from downloading .exe-files. However, the D-Link
website provides secure and necessary program files which should be allowed to download.
Command-Line Interface
Start by adding an HTTP ALG in order to filter HTTP traffic:
gw-world:/> add ALG ALG_HTTP content_filtering
Then create a HTTP ALG URL to set up a blacklist:
gw-world:/> cc ALG ALG_HTTP content_filtering
gw-world:/content_filtering> add ALG_HTTP_URL
Finally, make an exception from the blacklist by creating a specific whitelist:
gw-world:/content_filtering> add ALG_HTTP_URL
Web Interface
Start by adding an HTTP ALG in order to filter HTTP traffic:
1. Go to Objects > ALG > Add > HTTP ALG
2. Enter a suitable name for the ALG, for example content_filtering
3. Click OK
Then create a HTTP ALG URL to setup a blacklist:
1. Go to Objects > ALG
2. In the table, click on the recently created HTTP ALG to view its properties
3. Click the HTTP URL tab
4. Now click Add and select HTTP ALG URL from the menu
5. Select Blacklist as the Action
Good. This will block all files with .gif as the file name extension.
Bad. This will only block the first request to the web site. Surfing to
www.example.com/index.html, for example, will not be blocked.
Bad. This will also cause www.myexample.com to be blocked since it
blocks all sites ending with example.com.
Note: The hosts and networks blacklist is separate
Web content filtering URL blacklisting is a separate concept from Section 6.7,
"Blacklisting Hosts and Networks".
URL=*/*.exe
Action=Blacklist
URL=www.D-Link.com/*.exe
Action=Whitelist
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Chapter 6. Security Mechanisms