Troubleshooting IP Configuration

If you have trouble installing Microsoft TCP/IP on your computer, follow the suggestions in the error messages. You can also use the ping utility to isolate network hardware problems and incompatible configurations, allowing you to verify a physical connection to a remote computer.

Use the ping utility to test both the host name and the IP address of the host. For the syntax and description of the ping command, see Appendix A, "TCP/IP Utilities Reference."

To test TCP/IP using the ping utility

1. If the computer was configured using DHCP, use ipconfig to learn the IP address.
2. Use ping to check the loopback address by typing ping 127.0.0.1 and pressing ENTER at the command prompt. The computer should respond immediately.

   If ping is not found or the command fails, check the event log with Event Viewer and look for problems reported by Setup or the TCP/IP service.

3. To determine whether you configured IP properly, use ping with the IP address of your computer, your default gateway, and a remote host.

If you cannot use ping successfully at any point, check the following:

• The computer was restarted after TCP/IP was installed and configured
• The local computer's IP address is valid and appears correctly in the TCP/IP Configuration dialog box
• The IP address of the default gateway and remote host are correct
• IP routing is enabled and the link between routers is operational

If you can use ping to connect to other Windows NT computers on a different subnet but cannot connect through File Manager or with net use \\server\share, check the following:

• The computer is WINS-enabled (if the network includes WINS servers).
• The WINS server addresses are correct, and the WINS servers are functioning.
• The correct computer name was used.
• The target host uses NetBIOS. If not, you must use FTP or Telnet to make a connection; in this case, the target host must be configured with the FTP server daemon or Telnet server daemon, and you must have correct permissions on the target host.
• The scope ID on the target host is the same as the local computer.
• A router exists between your system and the target system.
• LMHOSTS contains correct entries, so that the computer name can be resolved. For more information, see "Troubleshooting Name Resolution Problems" later in this chapter.
• The computer is not configured to use WINS.