Posted on 2006-04-05
Last Modified: 2013-11-21
Dear Sir,
I have set-up Terminal Server Service  on Window-2000 Server . When I try to telnet on this machine from some other Window machine , I am getting a message :

"NTLM Authentication failed due to insufficient credentials . Please login with clear username and password
 Server allows NTLM authentication only
 Server has closed connection"

Due to this problem I am not able to Telnet . Kindly guide me .

B Mittal
Question by:bvmittal
    LVL 27

    Accepted Solution

    You are mixing terms: Terminal Server is not a Telnet server.

    Terminal Server allows users to connect to _graphical_ console via RDP protocol (using rdesktop or like client)
    Telnet service allows users to connect via telnet protocol, text based (using telnet command line)

    While Telnet service is embedded to standard Windows, it should be started manually and it supports only NTLM authorization (that means that you can connect to in only from telnet client with NTLM support). You may either find telnet client with NTLM authorization or to disable NTLM in Microsoft Telnet service. Standart telnet.exe doesn't support NTLM.
    For disabling NTLM in Win 2000 telnet server, look here:
    By default, the Win 2000 Telnet service requires NTLM authentication. However, if Win 2000 is configured to use Kerberos as its default authentication method, then Telnet users are not able to obtain access to domain/AD resources including network validation. To configure the Win 2000 Telnet Service to not require NTLM, run  Telnet Server Administration, select  option 3,  Display / change registry settings and then select option 7,  NTLM. Change the default setting from 2 to 0 to disable the NTLM requirement.

    LVL 27

    Expert Comment

    P.S. Telnet Administrator is located in "Programs/Administrative Tools"
    Also you should restart telnet service after changing option 7 (i.e. from command line):
    net stop telnet
    net start telnet


    Featured Post

    IT, Stop Being Called Into Every Meeting

    Highfive is so simple that setting up every meeting room takes just minutes and every employee will be able to start or join a call from any room with ease. Never be called into a meeting just to get it started again. This is how video conferencing should work!

    Join & Write a Comment

    Just about everyone has an old PC laying around.  Ask anyone in the IT industry, whether they are a professional or play in it as a hobby.  From outdated Desktops to cheap "throwaway" laptops, they are all around and not as hard to "fix up" as you m…
    I. Introduction There's an interesting discussion going on now in an Experts Exchange Group — Attachments with no extension ( This reminded me of questions tha…
    To add imagery to an HTML email signature, you have two options available to you. You can either add a logo/image by embedding it directly into the signature or hosting it externally and linking to it. The vast majority of email clients display l…
    This video is in connection to the article "The case of a missing mobile phone (". It will help one to understand clearly the steps to track a lost android phone.

    729 members asked questions and received personalized solutions in the past 7 days.

    Join the community of 500,000 technology professionals and ask your questions.

    Join & Ask a Question

    Need Help in Real-Time?

    Connect with top rated Experts

    19 Experts available now in Live!

    Get 1:1 Help Now