[TriLUG] Remote Desktop Woes

[Matt Flyer via TriLUG]

Considering the recent weather event, I decided that today would be a good
day to try to work remotely.  For the last several hours, I have been
attempting to establish a remote desktop session and have been running
into a real head scratcher.

The linux box that I want to remote into is running Centos 7 and is
integrated into (joined) an Active Directory domain. It successfully
performs AD authentication and when I am at my workstation on the LAN
running Ubuntu, Remmina will establish a remote desktop connection just
fine.

Working remotely from home, I am connected via the VPN. I can "hit" the
machine on the network, but I can't seem to get a remote desktop
connection directly to it.

What DOES work is that I am able to establish a remote desktop connection
to one of the Windows servers and from there use the (windows) Remote
Desktop Client to pull up the Centos 7 desktop and authenticate using my
AD credentials just fine.  I just can't go directly from the Linux box
over the VPN.

I have tried KRDC, Remmina, and Vinagre, all of which simply fail with a
generic error message; except KRDC first asks for a user and then a
password, but it always fails (the password is correct).

I am not sure how to even troubleshoot or log the issue.  All I get is a
"that did not work" message, which is very windows-esque.

Any thoughts or suggestions?