Explanation of Telnet Server Information

Use the Telnet server to avoid some errors. So what do you mean by the information generated after an error occurs? Here we will introduce these contents.

Error message: Access Denied-the specified user is not a member of the TelnetClients Group

Application to: Windows Server 2008

This problem occurs when the user account or any group it belongs to is not a member of the TelnetClients group.

Diagnosis

By default, when the Telnet server is installed for the first time, no one can access it. the Administrator of the Telnet server must create a local group named TelnetClients and add an appropriate user or group to the group.

Solution

To solve this problem, make sure that the user account or any of its groups, such as the Users Group, are members of the TelnetClients group.

Verify

After a user or group is added to the TelnetClients group, the affected user must log out and log on again to become a member of the TelnetClients group.

Error message: the user's password must be changed before the first logon.

Application to: Windows Server 2008

This problem usually occurs when a user has a new user account or the password of an existing account has expired and has not been changed.

Diagnosis

Telnet cannot accept the Expired Password, and then ask the user to change the password to complete logon to grant access permissions. on the contrary, you must log on and change the password in other ways before using the account for Telnet.

Solution

You must have an unexpired password before using the account for Telnet. You can solve this problem in several ways:

You must log on to the computer that identifies the user account using the normal Windows logon process, and then change the password as needed.

The administrator can reset the password and ensure that the password has not expired. the user account used only to access the Telnet server should be set to never expire.

Error message: the Telnet server only allows NTLM authentication.

Application to: Windows Server 2008

This problem usually occurs when configuring the user's Telnet client to only perform password authentication, but the Telnet server requires NTLM authentication.

Diagnosis

The administrator can configure the Telnet server to support NTLM authentication, password authentication, or both. because password authentication on the network may be easily intercepted in plain text form) Send user ID and password, many administrators think this is a security risk and disable it. if the Telnet client does not support NTLM authentication or is configured to not use this authentication, the server will terminate the connection attempt.

Solution

Make sure that the authentication types supported by your Telnet client are the same as those of the Telnet server that you connect to, and enable these authentication types.

Verify

To view the authentication type currently used by the client, switch to the Telnet command mode, type the command display, and then press Enter.

Error message: An error occurred while connecting to the host-unable to open the connection to the host on port 23

Application to: Windows Server 2008

This problem usually occurs when the TCP port configured to listen on the Telnet server is different from the port number tried to connect to the Telnet client.

By default, TCP port 23 is used when Telnet communicates with the server through the client. The port number can be changed by the Administrator. If the port number is changed, the client must know the port number used by the Telnet client.

Diagnosis

This error message displays the port number used to connect. This error message may be caused by the following reasons:

The TCP port used by the client in its connection attempt is different from the port configured for the Telnet server.

The Telnet server is not started, so it does not listen for the expected port number.

Solution

To solve this problem, Perform one of the following operations:

If the TCP port used by the Telnet server is not the default port 23, the Telnet client must specify the port number in the connection attempt.

Configure the Telnet server to use the expected Port Number of the Telnet client.

Verify

To confirm the port number that the Telnet server is currently listening to, run the netstat-AB command from the command prompt "Run as administrator. the output should contain entries similar to the following:

TCP [:]: 23 computername: 0 LISTENING

[Tlntsvr.exe]

This entry may also be ESTABLISHED rather than LISTENING.

The number in the second column indicates the port number that the service is listening to. If the tlntsvr.exe entry is missing, the service may not be started.