Finding a User’s Authenticating DC

Q: Is there an easy way to find a user’s authenticating domain controller (DC)?

A: An authenticating DC, which is also referred to as a user’s logon server, validates a user’s Windows logon credentials. An easy way to find a user’s authenticating DC is to check the contents of the environment variables that are available in a user’s logon session. To do so, open a command prompt window and type “set l.” This command brings up all the environment variables that start with an L. The user’s authenticating DC is listed on the LOGONSERVER= line.