When attempting to connect to SQL Server (2012), I get a login failed error message. The error log on the server reports:

Logon        Error: 18456, Severity: 14, State: 5.
Logon        Login failed for user 'MYDOMAIN\mswart'. Reason: Could not find a login matching the name provided. [CLIENT: 192.168.---.--]

However, I expected to be able to login based on my membership to a group MYDOMAIN\MYTEAM

I'm able to login when MYDOMAIN\mswart is created as a login.

The SQL Server machine has joined domain OTHERDOMAIN and the SQL Server service account is also a member of OTHERDOMAIN.

Maybe I'm not looking at the right thing. I'm looking for troubleshooting steps I can take to narrow down the issue so I can understand why I can't log in.

Aaron Bertrand's post Troubleshooting Error 18456 was almost useful... in the comments, it looks like a Gary Mazzone experienced the same issue.

  • Do you have cross-domain trusts set up? Are you remoting (RDP) into the OTHERDOMAIN server to make your connection? Or can you begin the connection from a MYDOMAIN desktop?
    – RLF
    Oct 16, 2014 at 15:28
  • Cross-domain trusts were set up properly Oct 16, 2014 at 18:13

1 Answer 1


In my case I was able to narrow down my trouble by working with my sysadmin about how the group was defined.

Knowing that the SQL Server was hosted on a machine that had joined another domain and was running with a user account on that other domain, we looked at the Group Scopes in active directory.

My user could authenticate properly after the scope was changed to universal.

If I find an authoritative source on SQL Server's behavior with respect to these domain group types, I'll be sure to update this answer.


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