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Q201194: How to Configure Telnet NTLM Authentication

Article: Q201194
Product(s): Microsoft Windows NT
Version(s): 2.0,4.0
Operating System(s): 
Keyword(s): kbenv
Last Modified: 10-AUG-2001

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The information in this article applies to:

- Microsoft Windows NT Server version 4.0 
- Microsoft Windows NT Services for UNIX Add-On Pack 
- Microsoft Windows Services for UNIX, version 2.0 
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SUMMARY
=======

The Telnet server in Windows NT Services for UNIX can be set to use Windows NT
LAN Manager (NTLM) authentication only. This ability provides increased security
during the Telnet authentication and prevents telnet user credentials from being
passed as clear text over the network.

MORE INFORMATION
================

When the Telnet server is set to enable only NTLM authentication, only Telnet
clients that support NTLM authentication Telnet protocol may be able to connect
to the Telnet server.

Presently, only the Console Telnet client from Windows NT Services for UNIX
supports NTLM authentication. The basic Telnet client included in Windows NT 4.0
does not support NTLM authentication.

When the client is configured for NTLM authentication, the user may not have to
enter his or her user name/password. Logging on may happen automatically for all
domain authenticated users who have been granted telnet logon local user rights
on the server.

To set the Telnet server to use only NTLM authentication, follow these steps:

1. Click Start, click Run, type "tlntadmn" (without the quotation marks), and
  then click OK.

2. Select Display, and then select Change Registry Settings.

3. Select NTLM.

4. Change the NTLM value to 2 for NTLM ONLY.

5. Restart the Telnet server.

NOTE: NTLM value 0 is NTLM not available. The Telnet server does only clear text
authentication. NTLM value 1 is NTLM or logon prompt where NTLM is tried before
the logon prompt. If the client supports NTLM, but authentication stops
responding, the server may then send the logon prompt. If the client does not
support NTLM, the server sends the logon prompt.

To set the Telnet client to use only NTLM authentication:

1. Click Start, click Run, type "telnet" (without the quotation marks), and then
  click OK.

2. Type "set NTLM" (without the quotation marks), and then press ENTER.

3. This option may now require the Telnet client to use NTLM authentication.

NOTE: In User Manager for Domains, if the "User must change password at next
logon" password option is set for the user, an attempt to log on to the Telnet
server fails when NTLM authentication is used. The user must log on to the
domain directly, change his or her password, and then log on through telnet.

Additional query words:

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Keywords          : kbenv 
Technology        : kbWinNTsearch kbWinNT400search kbWinNTSsearch kbWinNTS400search kbWinNTS400 kbWinNTServicesUnix kbWinServiceUNIX200 kbWinServiceUNIXSearch
Version           : :2.0,4.0
Issue type        : kbinfo

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