Troubleshooting problems communicating with a server on the Internet using a dial-up networking connection in Windows 2000, Windows NT 4.0, or Windows NT

This article describes how to troubleshoot problems communicating with servers on the Internet using an Internet browser, FTP, or Telnet. This article assumes that you are able to connect and log on to your Internet service provider (ISP) successfully.

You may experience problems communicating with a server on the Internet for any of the following reasons:

• The server is not functioning properly or has been temporarily removed from the Internet.
• Your Internet browser is not configured properly.
• The TCP/IP configuration for your dial-up connection to your ISP is incorrect.
• Your ISP's Domain Name Service (DNS) server is not working properly.

To determine and resolve the problem you are experiencing, follow the procedures in each of the following sections in order. After you finish each procedure, check to see if you can communicate with servers on the Internet successfully.

Try a known good server

If you cannot communicate with a specific server on the Internet, attempt to connect to the Microsoft Web site using its fully qualified domain name (FQDN): An FQDN consists of a host name and a domain name. If you can connect to the Microsoft Web site using its FQDN, your computer's TCP/IP configuration is correct.

If you are able to connect to the Microsoft Web site and you are unable to connect to another specific Internet site after several attempts, the other site may not be functioning properly or may be temporarily removed from the Internet. Try to connect to some different Web sites. If you are able to connect to some Web sites, but you cannot connect to other Web sites, contact your ISP for assistance. Your ISP may be able to help you determine the cause of the problem.

If you are not able to connect to any Web sites, there may be a problem with your Internet browser's configuration or with the TCP/IP configuration for your dial-up connection to your ISP.

Verify browser configuration

Verify that your Internet browser is configured to connect to the Internet using your dial-up connection to your ISP and that your Internet browser is not configured to connect through a proxy server.

Disable the multilinking protocol

If you have the Multilinking protocol (MP) enabled and your ISP's Point-to-Point protocol (PPP) server does not support the Multilinking protocol, you may not be able to communicate with servers on the Internet. Contact your ISP to determine whether you should disable the Multilinking protocol. If you use MSN, The Microsoft Network, as your ISP, disable the Multilinking protocol.

To disable the Multilinking protocol, use the appropriate method:

• If Windows NT 4.0 Service Pack 1 or no service pack is installed, you can disable the Multilinking protocol by disabling LCP extensions. To do so, follow these steps:
  1. Click Start, point to Programs, point to Accessories, and then click Dial-Up Networking.
  2. Click the phone book entry for your ISP in the Phonebook Entry To Dial box.
  3. Click More, and then click Edit Entry And Modem Properties.
  4. On the Server tab, click to clear the Enable PPP LCP Extensions check box, and then click OK.
• If Windows NT 4.0 Service Pack 2 (SP2) is installed, see the following article in the Microsoft Knowledge Base:
  ARTICLE-ID: 161368

  (http://support.microsoft.com/kb/161368/EN-US/ )

  
  TITLE : Service Pack 2 may cause loss of connectivity in remote access
• If Windows NT 4.0 Service Pack 3 (SP3) or later is installed, the Multilinking protocol is automatically disabled for dial-up connections that do not require the Multilinking protocol.

Confirm your IP address

If your ISP has assigned to you a static IP address, verify that the TCP/IP configuration for your dial-up connection to your ISP contains the correct information provided by your ISP. To do so, follow these steps:

1. Connect to your ISP.
2. Type the following command at a command prompt:
   ipconfig /all
   The IPCONFIG /ALL command displays Windows TCP/IP settings for all network adapters and modem connections. The address for a modem connection is displayed as "NDISWAN<x> adapter" where <x> is a number. The default gateway for the NDISWAN<x> adapter is the same as the IP address; this is typical and by design. More than one NDISWAN<x> adapter may be displayed. Any NDISWAN<x> adapters not currently in use display zeros for the IP address.
3. If the IP address displayed for your dial-up connection to your ISP does not match the IP address provided by your ISP, change your IP address to match the settings provided by your ISP. To do so, follow these steps:
   1. Click Start, point to Programs, point to Accessories, and then click Dial-Up Networking.
   2. Click the phone book entry for your ISP in the Phonebook Entry To Dial box.
   3. Click More, and then click Edit Entry And Modem Properties.
   4. Click the Server tab, and then click TCP/IP Settings.
   5. Change TCP/IP settings to match the settings provided by your ISP, click OK, and then click OK again.

Enable the "Use default gateway on remote network" option

If you connect to a local network using a network adapter and to your ISP using a modem simultaneously, configure your dial-up connection so that any routing conflicts are resolved in favor of your dial-up connection to your ISP. To do so, follow these steps:

1. Click Start, point to Programs, point to Accessories, and then click Dial-Up Networking.
2. Click the phone book entry for your ISP in the Phonebook Entry To Dial box.
3. Click More, and then click Edit Entry And Modem Properties.
4. Click the Server tab, and then click TCP/IP Settings.
5. Click the Use default gateway on remote network check box, and then click OK.
6. Click OK.

Check the transfer light

If you connect to a local network using a network adapter and to your ISP using a modem simultaneously, a conflict between your network adapter and your modem can prevent your modem from sending information to servers on the Internet. To verify that TCP/IP packets are being routed through your modem to your ISP, follow these steps:

1. Connect and log on to your ISP.
2. Right-click the Dial-Up Networking Monitor icon on the taskbar.
3. Click Open Dial-Up Monitor, and then click the Preferences tab.
4. Under Show Status Lights, click As a window on the desktop.
5. Use the PING command to cause your modem to send information. To do so, type the following command at a command prompt:
   ping <IP address>
   where <IP address> is the IP address of a known good server on the Internet. If you do not know the IP address of a server on the Internet, use the IP address for ftp.microsoft.com, 207.46.133.140.

Dial-Up Networking Monitor shows the modem status lights in a window. If the transfer (Tx) light in Dial-Up Networking Monitor flashes when you ping a server on the Internet, TCP/IP information is being routed through your modem to your ISP.

If the transfer (Tx) light in Dial-Up Networking Monitor does not flash when you ping a server on the Internet, packets are not being routed through your modem. Verify that the IP address assigned to you by your ISP for your dial-up connection is not the same as the IP address for your network adapter or loopback driver (if installed). Also, the IP address of your network adapter or loopback driver should not be on the same network as the IP address assigned to you by your ISP for your dial-up connection.

To display Windows TCP/IP settings for all network adapter and modem connections, follow these steps:

1. Connect and log on to your ISP.
2. Type ipconfig /all at a command prompt.

The address for a modem connection is displayed as "NDISWAN<x> adapter" where <x> is a number. The default gateway for the NDISWAN<x> adapter is the same as the IP address; this is normal and by design. More than one NDISWAN<x> adapter may be displayed. Any NDISWAN<x> adapters not currently in use display zeros for the IP address. Verify that the TCP/IP settings for your network adapter and your dial-up connection are not in conflict.

To change the TCP/IP settings of your network adapter or loopback driver, start the Network tool in Control Panel. The Network tool is only for your network adapters. When you are configuring the IP address for your Dial-Up adapter, all configuration should be performed in the Dial-Up Networking tool.

Check the receive light

Verify that a response is returned from the server on the Internet that you are trying to communicate with. To do so, follow these steps:

1. Connect to your ISP.
2. Right-click the Dial-Up Networking Monitor icon on the taskbar.
3. Click Open Dial-Up Monitor, and then click the Preferences tab.
4. Under Show Status Lights, click As a window on the desktop.
5. Use the PING command to cause your modem to send information. To do so, type the following command at a command prompt:
   ping <IP address>
   where <IP address> is the IP address of a known good server on the Internet. If you do not know the IP address of a server on the Internet, use the IP address for ftp.microsoft.com, 207.46.133.140.

Dial-Up Networking Monitor shows the modem status lights in a window. If the receive (Rx) light in Dial-Up Networking Monitor does not flash when you ping a server on the Internet, packets are not being received from your ISP. Contact your ISP for assistance.

If the receive (Rx) light in Dial-Up Networking Monitor flashes when you ping a server on the Internet, but you still cannot connect to the server using its FQDN, there may be a name resolution problem.

Test name resolution

A Domain Name Service (DNS) server provides host name resolution. If you cannot connect to a server on the Internet using its fully qualified domain name (FQDN), there may be a problem with the DNS configuration of your dial-up connection to your ISP or with your ISP's DNS server.

To determine if there is a problem with the DNS configuration of your dial-up connection to your ISP, follow these steps:

1. Type ipconfig /all at a command prompt to display the IP address of your DNS server. If the IP address for your DNS server is not displayed, contact your ISP to obtain the IP address for your DNS server.
2. Verify that you can communicate with your DNS server by pinging your DNS server's IP address. You should see a reply similar to the following:

      Pinging ###.###.###.### with 32 bytes of data:
   
      Reply from ###.###.###.###: bytes=32 time=77ms TTL=28
      Reply from ###.###.###.###: bytes=32 time=80ms TTL=28
      Reply from ###.###.###.###: bytes=32 time=78ms TTL=28
      Reply from ###.###.###.###: bytes=32 time=79ms TTL=28
   						

   The series of number signs (###.###.###.###) represents the IP address of the DNS server.

If you cannot ping the IP address of your DNS server successfully, contact your ISP to verify that you have the correct IP address for your DNS server and that your DNS server is functioning properly.

If you can ping the IP address of your DNS server, but cannot connect to a server on the Internet using its FQDN, your DNS server may not be resolving host names properly. If more than one DNS server is available for your ISP, configure your computer to use a different DNS server. If using another DNS server resolves the problem, contact your ISP to correct the problem with the original DNS server.