12.3  Content Rating System (Kerio Web Filter)

The Kerio Web Filter module enables WinRoute to rate web page content. Each page is sorted into predefined categories. Access to the page will be either permitted or denied according to this classification.

Kerio Web Filter uses a dynamic worldwide database which includes URLs and classification of web pages. This database is maintained by special servers that perform page ratings. Whenever a user attempts to access a web page, WinRoute sends a request on the page rating. According to the classification of the page the user will be either allowed or denied to access the page. To speed up URL rating the data that have been once acquired can be stored in the cache and kept for a certain period.

Note: A special license is bound with Kerio Web Filter (subscription). Unless WinRoute includes subscription for this module, the module behaves as a trial version only (this means that it is automatically disabled after 30 days from the WinRoute installation and options in the Kerio Web Filter tab will not be available). For detailed information about the licensing policy, read chapter 4  Product Registration and Licensing4  Product Registration and Licensing.

Kerio Web Filter configuration

The Kerio Web Filter module can be set and configured through the Kerio Web Filter tab in Configuration → Content Filtering → HTTP Policy.

Kerio Web Filter configuration

Figure 12.6. Kerio Web Filter configuration


Enable Kerio Web Filter

use this option to enable/disable the Kerio Web Filter module for classification of websites.

If Kerio Web Filter is disabled:

Categorize each page regardless of HTTP rules

If this option is enabled, Kerio Web Filter categorization will be applied to any web pages (i.e. to all HTTP requests processed by the HTTP protocol inspector).

Categorization of all pages is necessary for statistics of the categories of visited web pages (see chapter 21  Kerio StaR - statistics and reporting). If you do not intend to keep these statistics, it is recommended disable this option (categorization of all web pages might be demanding and it might decrease WinRoute performance).

Servers (Web sites) not to be rated by the module can be specified in Kerio Web Filter white list. Use the Add button to open a dialog where a new item (server or a Web page) can be added.

Server

Use the Server item to specify web sites not to be classified by the Kerio Web Filter. The following items can be specified:

  • server name (e.g. www.kerio.com). Server name represents any URL at a corresponding server,

  • address of a particular webpage without protocol specification (http://) — e.g. www.kerio.com/index.html,

  • URL using wildcard matching (e.g. *.ker?o.*). An asterisk stands for any number of characters (even zero), a*.ker?o.* question-mark represents just one symbol.

Description

Comments for the items defined. For reference only.

Kerio Web Filter use

To enable classification of Websites by the Kerio Web Filter module, this module must be running and all corresponding parameters must be set.

Whenever WinRoute processes a URL rule that requires classification of pages, the Kerio Web Filter module is activated. The usage will be better understood through the following example that describes a rule denying all users to access pages containing job offers.

On the URL Rules tab in Configuration → Content Filtering → HTTP Rules, define a rule by using image 12.7  Kerio Web Filter rule as guidance:

Kerio Web Filter rule

Figure 12.7. Kerio Web Filter rule


The is rated by Kerio Web Filter rating system is considered the key parameter. The URL of each opened page will be rated by the ISS OrangeWeb Filter module. Access to each page matching with a rating category included in the database will be denied.

Use the Select Rating button to open a dialog where Kerio Web Filter rating categories can be chosen. Select the Job Search / Job offers rating category (pages including job offers).

Selection of Kerio Web Filter categories

Figure 12.8. Selection of Kerio Web Filter categories


Note:

  1. You can define multiple URL rules that will use the Kerio Web Filter rating technology. Multiple categories may be used for each rule.

  2. We recommend you to unlock rules that use the Kerio Web Filter rating system (the Users can Unlock this rule option in the Advanced tab). This option will allow users to unlock pages blocked for incorrect classification. All unlock queries are logged into the Filter log — here you can monitor whether unlock queries were appropriate or not.