Be mindful of the Current Time

If you ever run into one of those messages “The current time on the computer and the current time on the network are different” when trying to log on, you will probably try to log on on the domain controller and try to assess in which amount the time got desynchronised in your domain or between domains in your forrest.  As you might know, Active Directory is picky about time, because the Kerberos authentication does not accept timestamps that differ more than 5 minutes between the machine that is trying to host the login and the domain controller.