To configure Windows 2000 Server to be a router for a LAN:
1. Run Administrative Tools / Routing and Remote Access.
2. Using the Action menu, press Configure and Enable Routing and Remote Access.
3. Complete the wizard.
4. Right-click the server that you want to be a router and press Properties.
5. On the General tab, check the Router box.
6. Press Local area network (LAN) routing only and press OK.
You may need additional configuration to properly route IP traffic. See the following Microsoft Knowledge Base articles: