Now that I could use the terminal server on the local network, I was interested in just how far they could reach the server directly over the Internet.
It was logical that had to be shoveled free ports in the firewall. In addition to the port for the HTTPS protocol 443, the port had to be 3389 for Remote Desktop (both TCP) passed to the server. With these settings I gel. Brazen user authentication to the Web Interface.
Unfortunately I was already in the router set up DynDNS account is not possible to directly access the applications, since the error message telling me that he could not reach the server, where I could call them directly via remote desktop.
My mistake was in the configuration of the Remote Desktop Services. There I had entered the local server name of the system. After I had now adjusted the connection settings on the DynDNS entry and conducted a reboot, I was now able to access from the Internet to the service.
Furthermore, one must be aware that due to the setting now also activate internal access to the system by default the connection over the Internet is chosen so that it can lead to a corresponding performance bottleneck on the network connection.
If you are running a similar system for more on the Internet, you should definitely make more concerned about the security point. For example, it is also possible in the configuration screen of the host server's port to adjust the tap the RDP channel on a different port, so that a direct access via DNS resolution and default port is not possible correspondingly simple.