What is special about Linux?
Linux, traditionally, has had worse support for the Remote Desktop Protocol (RDP) than Windows and OS X/macOS due to a smaller user base, less interest from Microsoft to ensure support and alternative protocols for connecting to Linux-environments.
What is special about portal.nmbu.no and the RDP-files found there?
Portal.nmbu.no uses Remote Desktop Gateway Pluggable Authentication and Authorization (RDP PAA). This means that users authenticate with portal.nmbu.no and can then download a RDP-file referencing the authenticated session.
Support in Linux
The FreeRDP project implemented support for RDP PAA 22.05.2018, but since then there has not been any official releases of the software. As such, users must install a newer version of FreeRDP 2.x than the ones usually found in the repositories found in the common Linux-distributions.
For more information about installing newer, prepackaged, versions: https://github.com/FreeRDP/FreeRDP/wiki/PreBuilds
Ubuntu-users can use a separate PPA repository which makes the process a little easier: https://launchpad.net/~remmina-ppa-team/+archive/ubuntu/remmina-next
Unfortunately we are not familiar with any graphical extension available for FreeRDP which supports RDP PAA as of 03.07.2018, meaning users must use Terminal or a manual shortcut to start the RDP-file downloaded from portal.nmbu.no
1: Go to https://portal.nmbu.no (you can find the portal documentation here).
2: Log in using your NMBU-credentials, use OTP to access all services.
3: Choose a service and download the RDP-file.
4: Using Terminal, enter the command below that applies to your environment
For Prebuilds: $ /opt/freerdp-nightly/bin/xfreerdp <path-to-.rdp-file>
For Ubuntu PPA: $ xfreerdp <path-to-.rdp-file>