Active Directory: NLTEST Testing Whowill and FindUser
While having problems with Exchange 2010 and 2003 seeing each other, I decided to verify that my Active Directory (and firewall) wasn't part of the problem.
Here's a Proof of Familiarity video for, I guess, Active Directory Familiarity in which I run the NLTEST command to verify that my trust is trustworthy. The Windows Server with the purple-ish background and the regular command prompt is the Server 2003 Domain Controller and the PowerShell prompt is the Server 2008 (and, thus, Exchange 2010) Domain Controller.
I primarily ran the nltest /whowill command to determine if a user could be authenticated. I ran the nltest /finduser command to see if either server had the capability to locate a specific user and in which domain he/she was located.