BleepingComputer.com: Windows authentication fails for an hour each day.

Hi

I'm not sure if this is the place to ask the question and if not, please feel free to redirect me internally or even externally.

I've got this work situation that I don't know the full story about as I don't know the details about our network, but I can describe what I am experiencing.

Many (every?) day between 10AM and 11:30AM (pacific), my webmail/mailhost (MS exchange) session asks me to reauthenticate by typing in my username and password again. However, no matter what I type, it rejects my submission and continues to ask for it. If I then give up and come back around 11:30AM, I can enter the correct information and it will be accepted no problem.

This happens not only on a machine that I VPN from to get into the work network, but also on machines (linux and windows) that are inside the work network that I can VNC into.

What works during the witching hour?
1) If I already have a VPN session open, it does not go down. So I can still traverse parts of my work network that don't require windows authentication.
2) My cell phone's mail program (on Android) is still able to receive emails

What doesn't work?
1) Any website in my work network that requires windows authentication, which includes the webmail, and other internal webpages.

What I haven't tried?
1) I don't have Outlook set up, so I can't be certain of its status but I assume that won't work either.

My IT has never seen this issue, and they say that my account from their side is clean (not frozen, nor locked out and the password is current). They thought maybe I had too many VPN sessions open, but this happens even when I only have one open.

Anyway, just wondering if anyone has seen this before or if there's anything that I can suggest to my IT team to try out.

Thanks

Sounds like your IT department may have some automatic maintainance going on at that hour. Since the domain controller that is authenticating your sessions are not available your current session cannot be verified and the any additional requests are rejected because the domain controller isn't available. The reason you VPN works is that it is probably using a different server for the VPN access and since your session is active you have already extablished the proper security keys on that server. Hence it has no need to re-establish your identity through the domain controller. With out knowing their entire set up it would be impossible for me to venture a better theory than that but it should be a good place to start.