It looks much the same in 2000 pro; pinched from
here:
How to Configure the ICS Host Computer
The ICS host computer provides a connection through the second network adapter to the existing TCP/IP network. Log on as member of the Administrators group to set up the ICS host computer.
1. Click Start, click Settings, and then click Network and Dial-up Connections.
2. Right-click Local Area Connection (the network card that you just installed), and then rename it "The Internet Connection".
In the Network and Dial-up Connections dialog box, two connections are displayed (for different network adapters), The Internet Connection and Local Area Connection.
3. Right-click The Internet Connection and click Properties.
4. Click the General tab, and then verify that Client for Microsoft Networks and Internet Protocol (TCP/IP) are displayed.
5. Click the Sharing tab, and then click to select the Enable Internet Connection Sharing for this Connection check box.
NOTE: Make sure that firewall software or other Internet sharing software from a third-party manufacturer has been removed.
6. Click OK and exit to the desktop.
How to Configure the Windows 2000 Client
Log on as a member of the Administrators group to set up the Windows 2000 Professional clients that will share the Internet. 1. Click Start, select Settings, and then click Network and Dial-up Connections.
2. Right-click Local Area Connection and click Properties.
3. Click the General tab, and then verify that Client for Microsoft Networks and Internet Protocol (TCP/IP) are displayed.
4. Click Internet Protocol (TCP/IP), and then click Properties.
5. Click Obtain an IP address automatically, and then click Obtain DNS server address automatically (if these options are not already selected).
6. Click Advanced, and then make sure that the various lists on the IP Settings, DNS, and WINS tabs are all empty.
ICS provides these settings.
7. Click OK and exit to the desktop.