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Windows XP Internet Connection Sharing

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Microsoft first introduced Internet Connection Sharing (ICS) in Windows 98 Second Edition. With ICS you can share a single Internet Connection across your (home) network, making it easier to connect to the Internet from your Networked computers.

There are several 3rd party products available, which let you do the same thing. The advantage of a 3rd party product over the Microsoft offering is that they are generally more user-friendly, and can be customized to suit your needs. For the average home user, however, Microsoft's ICS should be a good alternative.

In Windows 98SE you needed to perform several steps (including a separate install of ICS) to get ICS up and running. In Windows XP, ICS is "built-in", all you have to do is activate it.

To use ICS to share your Internet connection, the host computer (the computer used to access the Internet) must have two network adapters: one network adapter configured to connect to the internal network, and one network adapter or modem configured to connect to the Internet.

To setup ICS, follow the steps below.

On the host computer (the computer used to access the Internet)

  1. Make sure you are logged on as Administrator or Owner
  2. Click Start > Control Panel
  3. In Control Panel, click Network and Internet Connections and next, click Network Connections
  4. Right-click the connection that you use to connect to the Internet, and click Properties
  5. Select the Advanced tab
  6. Under the heading Internet Connection Sharing, click the check box Allow other network users to connect through this computer's Internet connection
  7. If you are sharing a dial-up Internet connection, you may choose to select the Establish a dial-up connection whenever a computer on my network attempts to access the Internet check box. In this case you do not have to dial a connection from the host computer when other computers on the network want to access the Internet.
  8. When you click OK, the following message appears:
  9.  
  10. 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, you should set them to obtain their IP addresses automatically. Are you sure you want to enable Internet Connection Sharing?
  11.  
  12. 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 static IP address of 192.168.0.1 and a subnet mask of 255.255.255.0

On the client computer (any computer that needs to connect to the host which has the Internet connection)

To connect to the Internet using the shared connection you must first check the LAN Adapter IP Configuration then configure the client computer:

  1. Log on to the client computer as Administrator or Owner
  2. Click Start > Control Panel
  3. In Control Panel, click Network and Internet Connections and next, click Network Connections
  4. Right-click the connection that you use to connect to the Internet, and click Properties
  5. On the General tab, in the This connection uses the following items list, click Internet Protocol (TCP/IP), and then click Properties
  6. In the Internet Protocol (TCP/IP) Properties dialog box, check Obtain an IP address automatically (if it is not already selected), and then click OK
  7.  
  8. Note: You can also assign a unique static IP address in the range of 192.168.0.2 to 192.168.0.254. For example, you can assign the following static IP address, subnet mask, and default gateway:
  9.  
  10. IP Address 192.168.0.2
    Subnet mask 255.255.255.0
    Default gateway 192.168.0.1
  11.  
  12. In the Local Area Connection Properties dialog box click OK
  13. Close the Control Panel

The Default gateway has to be the same for every client computer; it is pointing to the host. The IP Address has to be different for each client.

To configure the client computer to use the shared Internet connection:

  1. Click Start > Control Panel
  2. In Control Panel, click Network and Internet Connections next, click Internet Options
  3. In the Internet Properties dialog box, select the Connections tab
  4. Click the Setup button
  5. The New Connection Wizard starts
  6. On the Welcome to the New Connection Wizard page, click Next
  7. Select Connect to the Internet, and then click Next
  8. Select Set up my connection manually, and then click Next
  9. Select Connect using a broadband connection that is always on, and then click Next
  10. On the Completing the New Connection Wizard page, click Finish
  11. Close the Control Panel

When you now start an Internet application (for example a Web browser), the client computer will attempt to connect to the Internet using the host computer's shared Internet connection.

In most cases the Obtain an IP address automatically setting will work fine, but if you are having problems, you might try setting the IP addresses manually.

Troubleshooting

When you enable Internet Connection Sharing on the host computer, the host computer's LAN adapter is automatically assigned the IP address of 192.168.0.1. Because of this, 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 is assigned the same IP address, an IP conflict occurs and one of the network adapters is disabled 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 is used by ICS, 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.

Microsoft Knowledge Base Articles Relating to Windows XP ICS

Here is a list of Microsoft Knowledge Base articles dealing with ICS issues in Windows XP.

304176 -

You Are Prompted to Disconnect from the Internet Each Time You Shut Down Windows XP

308006 -

Troubleshooting Internet Connection Sharing in Windows XP

309524 -

How to Configure Windows XP ICS for an Internal PPTP Server

309642 -

How to Configure a Static Client for Windows XP Internet Connection Sharing

310651 -

Using Internet Connection Sharing with User Profiles

311070 -

Time-Out Error Message When You Attempt to Connect to the Web Through Internet Connection Sharing

311074 -

Dial-Up Connection in ICS Does Not Prompt to Disconnect on Client

319661 -

Connectivity Problems on ICS Clients When You Use a PPPoE Connection on a Windows XP ICS Host

321644 -

Internet Connection Sharing Clients Cannot Connect If Host Is Using an AOL Dial-Up Connection

323710 -

"Unable to Connect" Error Message Using MIRC and ICS in Windows XP

827328 -

"Error 1068" Error Message When You Try to Turn On Internet Connection Sharing



Last Updated: December 15, 2003