Error 18456. State 6 "Attempting to use an NT account name with SQL Server Authentication."

Question

2010-05-06 17:21:22.30 Logon Error: 18456, Severity: 14, State: 6. 2010-05-06 17:21:22.30 Logon Login failed for user . Reason: Attempting to use an NT account name with SQL Server Authentication. [CLIENT: ]

The authentication mode is "Mixed". And its MS SQL Server 2008.

What might be the issue? Do you think the user name was not configured properly?

Is there any link available for giving the right privileges and configuring the user account? So that I can check the rights and privileges for the acc I am using...

thanks

Answer 1

This problem is down to you passing NT / Windows account information in an application that expects you to be using SQL Server authentication.

Is it an in-house application or a third party application? How are you telling it what user ID to use?

For example, SQLCMD has two ways of connecting - either submit a userID & password (switches -U and -P respectively), in which case it uses SQL authentication, or tell it to use Trusted authentication (switch -E) in which case it passes over your windows login credentials.

To generate the equivalent error with SQLCMD, you would run SQLCMD -S -U -P .

If it's an in-house application, check the Connection String, and have a look at http://www.connectionstrings.com for further information.

If it's a third party application, then if it uses an ODBC DSN, then have a look at the settings for that and make sure it works stand-alone (there's a helpful "Test Connection" button). Or have a look for the database connection information in the applications config files / registry settings / whatever. Otherwise check the manual!

Answer 2

Are you trying to use the SQL Server login mode with an NT name/password? Not allowed. SQL Server security logins only, in the SQL Server login mode.

Use the Windows login mode (it does not allow any password, and must be the current windows user).

Otherwise, create the NT user as a login for security & database rights in SQL Server.

If you are trying to do a Windows login with a different user name, you have to impersonate or run the program as that user. SQL Server has no ability to use Windows logins other than the current user.