Jamieson wrote
I've spent the past few hours sifting through a ton of Event logs on the domain controllers, and it appears that the web server is only authenticating to one domain controller. Moreover, all of the authentication requests are using Kerberos, and I don't see any warnings or errors which should be affecting this. I did see some errors, but nothing surrounding times when the issue arose, and they were related to. The events were:
- 1083 - Replication warning: The directory is busy. It couldn't update object
- 13508 - File replication service is having trouble enabling replication from [server name] to [server2 name]
Normally, replication isn't anything to worry about, but since it is reporting that "the directory is busy", that implies that the server might be over-loaded.
Jamieson wrote
Assuming for a moment, that Active Directory is fine, how do I know if DotNetNuke is even attempting to authenticate? Is there a built-in DNN log to see what's happening behind the scenes, and if any error messages are generated?
Go into Admin->Event Viewer->Edit Log Settings, and enable the * task to enable logging of almost all DNN activities. Or, you can go and create your own log setting that only records login failures.
You might want to be a bit careful with logging too much though, as it puts a pretty heavy load onto your SQL server. I've had one server in the past that I had to disable extended logging because it was spending so long trying to record the login events that it would time people out while trying to log in (sound familiar?).