Windows 2000 Quick Fixes

Restrict traffic through your PC without a firewall

A firewall is one of the best lines of defense against unauthorized or unwanted network traffic coming from the Internet or your local intranet. But firewalls can be expensive and difficult to set up. While the security options for TCP/IP included with Windows 2000 can’t take the place of a dedicated firewall, they can go a long way toward protecting a system from all but the most concerted attacks.

Use simple IP filters

Windows 2000 lets you configure IP filters that determine the type of traffic that reaches your computer. You can configure filters to restrict traffic for specific TCP ports, UDP ports, or IP protocols. IP filters apply to all adapters in the computer, filtering traffic on a global basis. You configure filters individually on an inclusive basis. In other words, you either permit all traffic of the specified type or allow only those ports you’ve explicitly specified.

Setting filters effectively requires that you know which ports you want to allow in to the computer. If you enable filtering but forget to include a required port, network functions supported by that port won’t work until you add the port to the filter list. To view a complete port list, connect to Microsoft’s web site at http://windows.microsoft.com/windows2000/reskit/webresources.

To configure IP filters, follow these steps:

1. Open the Network and Dial-Up Connections folder, right-click the interface in question, and choose Properties.

2. Double-click ...