Error Message: Telnet Server allows NTLM authentication only

Applies To: Windows Server 2008

This problem typically occurs when the user's Telnet client is configured to only perform password authentication, and the Telnet server requires NTLM authentication.

Diagnosis

The administrator can configure Telnet Server to support NTLM authentication, password authentication, or both. Because password authentication sends the user ID and password in plain text across the network where it could be easily intercepted, it is considered by many administrators to be a security risk, and is disabled. If a Telnet client does not support NTLM authentication, or supports it but is configured not to use it, then the connection attempt is terminated by the server.

Resolution

Ensure that your Telnet client supports the same authentication types as the Telnet server to which you are connecting, and that those authentication types are enabled.

To enable NTLM authentication, see Configure How the Client Authenticates to a Telnet Server in the Telnet Operations Guide.

Verification

To see the authentication types your client currently uses, switch to Telnet command mode, type the command display, and then press ENTER.

To switch to Telnet command mode, see Switch Between Session Mode and Command Mode in the Telnet Operations Guide.

See Also

Concepts

Error Message: The user has not been granted the requested logon type at this computer
Error Message: Access Denied - Specified user is not a member of the TelnetClients group
Error Message: The user's password must be changed before logging in the first time
Error Message: Error while connecting to the host - could not open a connection to host on port 23
You Cannot Connect to Network Drives by Using Current Logon Credentials
You Cannot Access Drive Letters Mapped by Others in Separate Telnet Sessions
Characters and Lines on the Telnet Client Display are Misaligned
The Cursor Loses Alignment with the Prompt
System Error 1058: Telnet Service Fails to Start