What are security zones?

Internet Explorer 4.0 divides your Internet world into zones, so that you can assign a Web site to a zone with a suitable security level.

You can tell which zone the current Web page is in by looking at the right side of the Internet Explorer status bar. Whenever you attempt to open or download content from the Web, Internet Explorer checks the security settings for that Web site's zone.

There are four different zones:

• Local Intranet zone: This zone contains any addresses that don't require a proxy server. The addresses included in this zone are defined by the system administrator in the Internet Explorer Administrator's Kit (IEAK). The default security level for the Local Intranet zone is Medium.
• Trusted Sites zone: This zone contains sites you trust—sites that you believe you can download or run files from without worrying about damage to your computer or data. You can assign sites to this zone. The default security level for the Trusted Sites zone is Low.
• Restricted Sites zone: This zone contains sites you don't trust—that is, sites that you're not sure whether you can download or run files from without damage to your computer or data. You can assign sites to this zone. The default security level for the Restricted Sites zone is High.

• Internet zone: By default, this zone contains anything that is not on your computer or an intranet, or assigned to any other zone. The default security level for the Internet zone is Medium.

In addition, any files already on your local computer are assumed to be completely safe, and no security settings are applied to them. This allows you to open and run files and programs on your computer without prompting or interruption. You cannot assign a folder or drive on your computer to a security zone.

Setting up security zones requires you to:

• Set a security level for each zone

• Assign a Web site to a security zone

How you assign security levels and Web sites is completely up to you. The actions for each level are already defined, but you can also create custom settings for the security level.

Generally, you would trust Web sites on an intranet the most, and would probably set your security setting to Low for that zone. Most programs could then be run or downloaded from those sites with little or no notification.

On the other hand, Web sites in the Restricted Sites zone may be those from which you want to avoid running or opening any scripts or active content.