Sharing an Internet connection with ICS and Windows 2000 Server


I spent over a day trying to get ICS to work on a W2K host... only to find out that setting it up is totally different depending on whether you use a W2K Server or W2K Pro host.

Most documentations available on the Net don't mention that it only applies to W2K Pro, and that when using a W2K Server host, there's no need to set up a Dial-Up Connection object. Rather, all routing tasks are handled by playing with the RRAS service.


  1. Set the LAN IP configuration to a static IP address, but do not add any pointer to DNS servers on the Internet (ie. that section should only contain pointers to servers that handle your zone)
  2. In Administrative Tools, launch the DNS configurator
  3. Right click the name of the server, select the Forwarders tab, and add the DNS servers on the Internet that will resolve non-local names
  4. Install a modem, and test that it works
  5. Configure the Routing & Remote Access service: Click on Start | Program Files | Administrative Tools | Routing & Remote Access
  6. Action | Add Server...
  7. Choose "This Computer" (default)
  8. Select the "<server name> (local)" item, Action | Configure and enable routing and remote access
  9. Internet connection server (default)
  10. ICS (Default)
  11. Set up a router with NAT routing protocol
  12. Create a new demand-dial internet connection. Windows will now start the RRAS service, and prompt you to create a dial-up connection
  13. Connect using a modem, ISDN adapter, or other physical device
  14. Select the modem that you installed on the server
  15. Type in the phone number of your ISP
  16. Type in the user's name and password. The Domain  section could be an Active Directory/NT4 Domain name, but I didn't have the opportunity of trying this

    Warning: Make sure that the password you typed is correct, or the modem will connect and hang up after a couple of second, even if you set the "Hang up if idle" time-out to something more generous. Check the Event Viewer for more information if you encounter this kind of problem.
  17.  Back in the Routing and Remote Access application, check that the server is now active (green arrow)
  18. Check its properties, and make sure the General tab includes "Enable this computer as a Router/LAN and demand-dial routing" and the IP tab includes "Enable IP routing" and "Allow IP-based remote access and demand-dial connections"
  19. The modem should be listed in the Ports section of the "<server name> (local)" section.



Nothing needs to be done on client hosts besides getting their IP configuration dynamically through a DHCP server. When accessing resources located on the Internet, the server will connect to the ISP through a dial-up connection and seemlessly provide data back to the client.