ZyXEL Communications HS100/HS100W manual Parental Control Group Edit Filter

HomeSafe User’s Guide

	Table 12-1 Parental Control
LABEL	DESCRIPTION
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12.5 Parental Control Group Edit Filter

The HomeSafe content filtering allows you to block services and block web sites by URL keywords that you specify, for example, you can block access to all web sites with the word “bad” in the URL by specifying “bad’ as a keyword.

12.5.1 Content Filtering with an External Server

Your HomeSafe uses an application services company that provides outsourced content filtering. If you enable the content filter, your HomeSafe will have access to an external database, which contains dynamically updated ratings of millions of web sites.

The content filtering lookup process is described below.

Figure 12-5 Content Filtering Lookup Procedure

1.A computer sends an HTTP request to a web server.

2.The HomeSafe looks up the web site in its cache. If an attempt to access the web site was made in the past, a record of that web site’s category will be in the HomeSafe’s cache. The HomeSafe either blocks or forwards the request based on how you configure the category based content filtering.

The HomeSafe drops a URL record from the content filter cache after the content filter cache timeout period (default 72 hours). All of the URL records are also cleared from the local cache when the HomeSafe reboots. You can use ip urlfilter webControl cache timeout on the command line to change the timeout period.

If the HomeSafe doesn’t have a record of the web site, it will query the external content filtering server and simultaneously send the request to the web server.

The external content filtering database may change a web site’s category or rate a previously uncategorized web site.

3.The external content filtering server sends the category information back to the HomeSafe, which then either forwards or blocks the web content. The web site address is then also stored in the HomeSafe’s content filtering cache.

Pre-defined categories have a filtering process based on ports and services.

1.A computer sends service-based request.

2.The HomeSafe looks up the port that this service uses.

12-6 Parental Control