Why is teamviewer naughty?

Question

Windows

We have: windows server 2007 r2. One local network in which this server sits, 2 computers based on windows and Linux. Also a laptop with wi-fi.
All computers have teamviewer installed.
The essence of the problem:
When trying to connect to the server through teamviewer, no matter from which machine, the program swears that teamviewer is not running on the client's machine. Although it is clearly launched and functioning there.
It is only necessary to connect to the server from windows through the native rdp client or from Linux through Remmina (also rdp) and see the desktop on the screen. After that, without breaking the rdp connection, try to connect through teamviewer, everything connects fine. It is necessary to break the rdp connection, as teamviewer immediately falls off.
If you try to connect to the server through vncviewer, then there is nothing but a black screen. As soon as an active rdp connection appears, vncviewer also comes to life.
The question is how to cure it? Why don't other servers have this problem?
p.s. this is seen on both older and latest version of teamviewer.
Upd: I'm sorry. Operating on server 2008 r2.

Answer 1

This is not a problem, this is normal behavior.
And your "problematic" windows server 2007 r2, by the way, is a rather rare version, I have not even heard of such a one - it is a terminal server.
You seem to be trying to connect to a missing session, so it cannot do this due to the absence of this very session.

Answer 2

The problem is most likely a firewall or NAT or "port forwarding" (portforwarding). Timviewer can "bypass" almost all blocking, but not always. And, judging by the symptoms, just RDP - working through an open port - opens that very crack.
Start TV and monitor the network, then see what happens when you connect via RDP. For example TCPView of Sysinternals company
Yes, and still you did not describe how there "network" is arranged between machines.
I also remembered that if there is a direct connection between the computers - they are on the same local network, try connecting to the server with TV not by number but by IP address, if you have not done so yet.
In general, in short, most likely the Win 2k7 Server firewall is set to strict mode, and RDP is allowed.