When accessing a Windows-based Telnet server, you can use NTLM authentication, which uses the Windows user name and password you used when you logged on the computer. If the Telnet server does not support NTLM authentication, the authentication attempt will fail and you will be prompted for a user name and password, which will be transmitted to the Telnet server unencrypted.
If your Windows password on the remote Telnet server has expired or is set at User Must Change Password at Next Log on, attempts to log on to the Telnet server using NTLM authentication will fail. To log on successfully, you must log on to the server directly and change your password, then log on through Telnet.
Because of a limitation of NTLM authentication mechanism, if you connect to a Telnet server using NTLM authentication, execution of commands which require user credentials will fail unless you provide your user name and password again. For example, you will not be able to access additional network resources using net use unless you provide your user name and password on the command line.