Microsoft Knowledge Base Article 309798 contains the following summary:

This step-by-step article describes how to configure TCP/IP Filtering on Microsoft Windows 2000-based computers.

Windows 2000-based computers support several methods of controlling inbound access. One of the most simple and most powerful methods of controlling inbound access is by using the TCP/IP Filtering feature. TCP/IP Filtering is available on all Windows 2000-based computers that have the TCP/IP stack installed.

TCP/IP Filtering is useful from a security standpoint because it works in Kernel mode. In contrast, other methods of controlling inbound access to Windows 2000-based computers, such as by using the IPSec Policy filter and the Routing and Remote Access server, depend on User-mode processes or the Workstation and Server service.

You can layer your TCP/IP inbound access control scheme by using TCP/IP Filtering with IPSec filters and Routing and Remote Access packet filtering. This approach is especially useful if you want to control inbound and outbound TCP/IP access. TCP/IP Security controls only inbound access.