How to configure Internet Connection Sharing in Windows XP

How to use Internet Connection Sharing
To use Internet Connection Sharing to share your Internet connection, the host computer must have one network adapter that is configured to connect to the internal network, and one network adapter or modem that is configured to connect to the Internet.

On the host computer
On the host computer, follow these steps to share the Internet connection:

1. Log on to the host computer as Administrator or as Owner.
2. Click Start, and then click Control Panel.
3. Click Network and Internet Connections.
4. Click Network Connections.
5. Right-click the connection that you use to connect to the Internet. For example, if you connect to the Internet by using a modem, right-click the connection that you want under Dial-up.
6. Click Properties.
7. Click the Advanced tab.
8. Under Internet Connection Sharing, select the Allow other network users to connect through this computer's Internet connection check box.
9. If you are sharing a dial-up Internet connection, select the Establish a dial-up connection whenever a computer on my network attempts to access the Internet check box if you want to permit your computer to automatically connect to the Internet.
10. Click OK. You receive the following message:
When Internet Connection Sharing is enabled, your LAN adapter will be set to use IP address 192.168.0.1. Your computer may lose connectivity with other computers on your network. If these other computers have static IP addresses, it is a good idea to set them to obtain their IP addresses automatically. Are you sure you want to enable Internet Connection Sharing?
11. Click Yes.

The connection to the Internet is shared to other computers on the local area network (LAN). The network adapter that is connected to the LAN is configured with a static IP address of 192.168.0.1 and a subnet mask of 255.255.255.0


On the client computer
To connect to the Internet by using the shared connection, you must confirm the LAN adapter IP configuration, and then configure the client computer. To confirm the LAN adapter IP configuration, follow these steps:

1. Log on to the client computer as Administrator or as Owner.
2. Click Start, and then click Control Panel.
3. Click Network and Internet Connections.
4. Click Network Connections.
5. Right-click Local Area Connection, and then click Properties.
6. Click the General tab, click Internet Protocol (TCP/IP) in the This connection uses the following items list, and then click Properties.
7. In the Internet Protocol (TCP/IP) Properties dialog box, click Obtain an IP address automatically (if it is not already selected), and then click OK.
8. In the Local Area Connection Properties dialog box, click OK.
9. Quit Control Panel.


Troubleshooting
When you turn on Internet Connection Sharing on the host computer, the host computer's LAN adapter is automatically assigned the IP address of 192.168.0.1. Therefore, one of the following situations may occur:

* IP address conflict
Each computer on the LAN must have a unique IP address. If more than one computer has the same IP address, an IP conflict occurs, and one of the network adapters turns off until the conflict is resolved. To resolve this conflict, configure the client computer to automatically obtain an IP address, or assign it a unique IP address.
* Loss of network connectivity
If your network is configured with a different IP address range than Internet Connection Sharing uses, you will lose network connectivity with the host computer. To resolve this issue, configure the client computers to automatically obtain an IP address, or assign each client computer a unique IP address in the range of 192.168.0.2 to 192.168.0.254.