Weird user authentication problem

  • Only one user is getting the following error (from eventlog):

    18452 : Login failed for user '(null)'. Reason: Not associated with a trusted SQL Server connection.

    I verified that the user in the active directory (We are using Windows authentication) and this user has been given rights to access SQL Server. But when the user tries to launch QA, the above error is being thrown.

    The same user is able to access other database servers using windows authentication.

    Please help.

  • Make sure use login configure for window authentication....

    Can the user connect using osql utiltiy??

    Try explicitly using TCP/IP protocol for while connecting..

    http://support.microsoft.com/default.aspx?scid=kb;en-us;827422&Product=sql2k

    http://support.microsoft.com/kb/840219

     

    MohammedU
    Microsoft SQL Server MVP

  • The key is that it thinks the user account is Null. Tell the user to reboot their machine. In most cases I have encountered this resolves the issue. If not, reboot the SQL Server.


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  • Whenever I've seen this in the past, the user's account was locked out. (Ie. Too many pw retries, forgot their pw, etc.)

    Chris.

    Chris.

  • ask the user to logoff and then login and access the sql server.

    Cheers,
    Sugeshkumar Rajendran
    SQL Server MVP
    http://sugeshkr.blogspot.com

  • are you doing this through .net or something like that where you have a connection string?  If you are, and the database and the files are on different servers, and there's not an explicit trust between them, then it doesn't seem to pass that information even if they are on the same domain.  What I've done is simply make a database user to the tables that you need the web interface to access, and put that info in the connection string.  Use the .net authentication to filter the users who are allowed to do certain features of the site, and access certain things in the database, and simply make the pages that do the features restricted to folders with the appropiate permissions for that role.
     
    If you aren't doing some type of cross computer authentication then I'm not sure, but maybe more informatin would help.  I can't see a restart doing anything, although that does tend to fix a lot of problems that make no sense in Windows.
     
     
  • We've tried

    1. Logoff and log back in to workstation.

    2. Restarted the machine (this worked before, but not working anymore).

    This is not through any application (.NET or VBA), he was trying to launch QA. The database and the files are on the same server.

    Here is another twist, he was able to login (windows) on from my workstation and was able to launch QA without any problem.

    Please help !!!

  • XP? Home Pro?

  • XP Pro SP 2

  • I've seen something similar when the secure channel between teh SQL server and the domain controller is broken. Can't authenticate. Is this a new user? Or someone that hasn't logged in for awhile?

    anyone else having issues?

    I know there are some utilties to check the channel. Be sure the user is actually connecting to the DC as well. Workstations cache junk and sometimes you don't really auth to the controller. Try changin a pwd.

  • hmmm, well if all updates are installed, I'm temporarily stumped

  • At our organization we have two different domains that the SQL Servers reside in and some of the clients are not in a domain at all.  You may want to check that the problem PC is in the same domain as the server.

  • Steve, how do I clean the cache on the workstation.

    1. Can you name some of those utilties to check the channel.

    2. How do I check the user is actually able to connect to the DC.

    3. The user changed the password and tried to launch QA, but failed again.

    Do you think if we reinstall SQL Server on the workstation will take care of the problem.

    Thank you Jon.

  • Have you checked that the machine time on both server and client are the same?  I had a similar issue at one client site (not SQL Server, but using Windows Authentication) where the kerberos ticket was rejected because the clock time on the client was off by several hours.  (I guess this ticket encryption is time sensitive?  I don't know, perhaps someone else more versed in network protocols might explain).



    Mark

  • does the error message come from an attempt to connect via a linked server?  the server principal name (SPN) may not be correctly identified. 


    Cheers,

    Todd

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