Single logon attempt is counted as two logon attempts in Active Directory in Windows Server 2012

Applies to: Windows Server 2012 DatacenterWindows Server 2012 DatacenterWindows Server 2012 Standard

Symptoms


The user accounts are locked out although your expectation is that the account lockout threshold isn't reached yet. Additionally, in the security event log, events are logged.

Cause


This issue occurs because the logon attempt for Microsoft Kerberos protocol and Microsoft NTLM protocol operates. This results in two authentication queries against Active Directory. Therefore, the count of incorrect password increases by two instead of by one. 

Resolution


Status


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

References


Learn about the terminology that Microsoft uses to describe software updates.

More Information


For more information about how to manage account lockout settings and monitoring, see Configuring Account Lockout.