CHAPTER 11

Troubleshooting and Error Messages

Troubleshooting an IP Network
Error Messages

This chapter tells how to troubleshoot an Internet Protocol (IP) network. It also lists and explains error messages. Consult with your network administrator for further information.

# Troubleshooting an IP Network

Follow these guidelines while troubleshooting an IP network:

- Always begin at the network interface layer and work up to the application layer.

- Make sure protocols at each layer of the Internet protocol suite can communicate with the layer above and below it.

#### To troubleshoot an IP network

1. Ping successfully.

If you can ping successfully, you have verified IP communications between the network interface layer and the internet layer. The Ping command uses the Address Resolution Protocol (ARP) to resolve the IP address to a hardware address for each echo request and echo reply.

2. Establish a session with a host.

If you can establish a session, you have verified TCP/IP session communications from the network interface layer through the application layer.

Note If you are unable to resolve a problem, you may need to use an IP analyzer (such as Microsoft Network Monitor) to view network activity at each layer.

The first goal in troubleshooting is to make sure you can successfully ping an IP address. Ping a host with its host name only after you can successfully ping the host with its IP address.

#### To troubleshoot the network interface and internet layers by using the Ping command

1. Ping the loopback address to verify that TCP/IP was installed and loaded correctly.

If this step is unsuccessful, verify that the system was restarted after TCP/IP was installed and configured.

2. Ping your IP address to verify that it was configured correctly.

If this step is unsuccessful, view the configuration by using the Network application in the Windows NT Control Panel to verify that the address was entered correctly, and verify that the IP address is valid and that it follows addressing guidelines.

3. Ping the IP address of the default gateway to verify that the gateway is functioning and configured correctly.

If this step is unsuccessful, verify that you are using the correct IP address and subnet mask.

4. Ping the IP address of a remote host to verify the connection to the wide area network.

If this step is unsuccessful:

- Make sure that IP routing is enabled.

- Verify that the IP address of the default gateway is correct.

- Make sure that the remote host is functional.

- Verify that the link between routers is operational.

After you can successfully ping the IP address, ping the host name to verify that the name is configured correctly in the HOSTS file.

## Verifying TCP/IP Session Communications

The next goal in troubleshooting is to successfully establish a session. Use one of the following methods to verify communications between the network interface layer and the application layer.

To establish a session with a Windows NT–based computer or other RFC-compliant NetBIOS-based host, make a connect with the Net use or Net view command. If this step is unsuccessful:

- Verify that the destination (target) host is NetBIOS-based.

- Confirm that the scope ID on the destination host matches that of the source host.

- Verify that you used the correct NetBIOS name.

- If the destination host is on a remote network, check the LMHOSTS file for the correct entry.

To establish a session with a non-RFC-compliant NetBIOS-based host, use the Telnet or FTP utility to make a connection. If this step is unsuccessful:

- Verify that the destination host is configured with the Telnet daemon or FTP daemon.

- Confirm that you have the correct permissions on the destination host.

- Check the HOSTS file for a valid entry if you are connecting using a host name.

# Error Messages

A home directory already exists for this service. Creating a new home directory will cause the existing directory to no longer be a home directory. An alias will be created for the existing home directory.

This message is a warning only. It appears when the new home directory you are trying to add already exists. The maximum number of home directories allowed is one per virtual root.

Invalid Server Name

While trying to connect to a server, you typed an invalid server name. Try to connect again and make sure you type the name correctly.

More than 1 home directory was found. An automatic alias will be generated instead.

When getting the directory entries from the server, Internet Service Manager has determined that a duplicate exists. This duplicate may have been added by using the Registry Editor or in some other way.

No administerable services found.

While trying to connect to a server, you typed the name of a server that has no installed services that Internet Service Manager can administer. That is, WWW, FTP, and gopher services have not been installed on the computer you connected to.

The alias you have given is invalid for a non-home directory.

You’re trying to assign the alias ‘/’ to a non-home directory. This alias automatically means home.

The connection attempt failed because there’s a version conflict between the server and client software.

This message is an RPC error message. The RPC interface does not match what is expected. This should happen only if you are running a beta admininstration tool or server. The official error is RPC_S_UNKNOWN_IF.

The service configuration DLL ‘filename’ failed to load correctly.

The named service configuration DLL (for example, W3scfg.dll) failed to load. The DLL or one if its dependencies could be missing or corrupted. Generally this is a setup problem. Run the Setup program and select Remove All, then reinstall Microsoft Internet Information Server.

Unable to connect to target machine.

This message is an RPC error message that appears while executing an API. The computer could be offline. The system error was EPT_S_NOT_REGISTERED or RPC_S_SERVER_UNAVAILABLE.

Unable to create directory.

The directory name or path you typed in in the New Directory Name box cannot be created. It could be an invalid path, or a file may already exist that has this name.

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