TCP/IP in Windows 2000 Professional

To enable ICS, you must be logged on to an account that has administrative rights.

To enable Internet Connection Sharing

1. In Control Panel, open Network and Dial-Up Connections .

2. Right-click the connection you want to share (the connection that connects to the Internet), and then click Properties .

3. On the Sharing tab, select the Enable Internet Connection Sharing for this connection check box.
   
   If the shared connection is a dial-up connection and you want the connection to dial automatically when another computer on your network attempts to use external resources, select the Enable on-demand dialing check box.

4. Click OK .
   A dialog box is displayed, indicating that the intranet's connection's IP address is set to 192.168.0.1, and warns that connectivity with other computers on the network might be lost.

5. Click Yes .

Note

If your office users need to gain access to a corporate network via a VPN server that is connected to the Internet, they need to create a PPTP-based virtual private network (VPN) connection to tunnel from the computer on the intranet to the corporate VPN server on the Internet. The VPN connection is authenticated and secure, and creating the tunneled connection allocates proper IP addresses, DNS server addresses, and WINS server addresses for the corporate network. For more information about configuring a VPN connection, see Local and Remote Network Connections in this book.

When ICS is enabled, the TCP/IP configuration is modified on the computer with the shared connection, and services related to network translation are started. Table 22.7 shows the modified system configuration on the sharing computer:

Table 22.7 ICS System Configuration Modifications

Note

You cannot modify the default configuration of ICS. This includes items such as disabling the DHCP allocator or modifying the range of private IP addresses that are handed out. If you want to modify any of these items, you must use Windows 2000 Server network address translation. For more information about network address translation as implemented in Windows 2000 Server, see Unicast IP Routing in the Internetworking Guide .

All computers on your network that access the Internet by means of Internet Connection Sharing must reconfigure their TCP/IP configurations to use DHCP. Each computer in the network is reassigned an IP address from the reserved IP address range 192.168.0.2 to 192.168.0.254, with a subnet mask of 255.255.255.0. As with the ICS-enabled computer, the change in IP address might cause you to lose connectivity with other computers in the network that use static addressing.