Internet Filter

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By default, Groovix does not filter internet traffic, but has the capability to do so. The Groovix filtering system uses a modified version of DansGuardian software. DansGuardian software is open source but uses a non-standard license that is not free for commercial use. Groovix is a licensed DansGuardian solution provider.

DansGuardian uses various lists to determine which pages are blocked and why to report back to the user why the requested page was blocked.

  • the whitelist will allow pages or whole domains regardless of their content
  • the blacklist will block pages or whole domains regardless of their content
  • the phraselist searches for phrases in page content based on separate categories

The phraselist contains a list of phrases in multiple categories on which each page is subjected to. Each phrase has a numerical value assigned to it that adds to a total for that category each time the phrase is found on a page. Each category has a threshold of how high the total phrase values found can reach before a page is considered blocked. When a page is blocked, GroovixGuardian will generate a page that reports to the user why which category triggered it.

Installing the filter

After consulting with Groovix staff you will use different workstation "types" to determine whether or not a workstation will be filtered. For example, adding filtered to /etc/groovix/type2 could trigger the download and installation of the internet filter the next time Groovix_NetCustomization is run.

Filter Customization

  • DansGuardian configuration files are installed in /etc/dansguardian/
  • The main configuration files for DansGuardian are located at /etc/dansguardian/dansguardianf1.conf and /etc/dansguardian/dansguardian.conf
  • The lists used by DansGuardian are located in /etc/dansguardian/lists/

All configuration files and lists used by DansGuardian are fully editable. The values in the configuration files and phraselists can be fully customized to fit any specific use, including which categories are active and customized values for all phrases. Include statements are frequently used to allow hierarchy and reuse.

Toggling the Filter

If you have decided to allow your staff to enable/disable filtering per workstation on demand, that can be done through the PACMon interface on the Groovix Dashboard. First, click on the machine you want to toggle the filter on. In the new window that pops up, click the link titled, filtering.

PACMon web filter access

In this page the top line states whether the filter is currently active or inactive, click on the button indicating whether you want to enable or disable the filter; it can take up to one minute for this action to take effect.

Web filter buttons
Note: disabling the filter can be done while a user is logged in and will remain disabled for the duration of their session (unless disabled manually). Groovix will automatically re-enable the filter once the user has ended their session; it is not necessary for staff to keep track and enable it for the next user.

Filter Performance

Once the filter is active, web browsing speed can be reduced significantly if your local DNS server is not capable of handling the extra lookup requests made by DansGuardian; workstations running internet filtering have at least one additional name lookup for nearly every web request. This issue can be resolved by creating a DNS cache of visited sites that the web browser will query instead of the local DNS server. Steps on how to perform this fix are located on the Filter Performance Fix page of the Administrators Guide.

See Also