When people connect to their VPN, this could simply allow them to access shared files. But alternatively, this could also mean that they wish to create a virtual session, on the remote desktop of one of their servers. The latter exists under the terms VNC, RDP, XRDP, and several others.
On my main Linux server named ‘Phoenix’, I have the XRDP service installed, which is the Linux equivalent of RDP. But one main drawback of this method, of remotely accessing a desktop, is the fact that XRDP does not allow file-sharing, specifically in the version of this protocol that runs out-of-the-box from the package manager. I have read that certain custom-compiled versions support this, but do recall that this service is a mess to custom-compile, and to set up in such a way that it runs reliably. So I stick to the packaged version for now, and do not obtain file-sharing.
There exists a closed-source application named NoMachine NX, which we could use to bridge this gap. But while their paid software subscriptions are very expensive (from my perspective), their Free software version has some big disadvantages.
First of all, even their Free version can be run in client or in server mode. I think that this is terrific. But in server mode – which affords access to the local machine desktop from elsewhere – there is no built-in support for SSH protocol. There is only the unencrypted NX protocol, for which their service listens.
Secondly, not every computer is strong enough to run NoMachine NX in server mode. On the computer ‘Phoenix’ I have a fragile X-server, and this service has actually crashed my X-server. Not only that, but allowing this service to run on reboot, consistently prevents my X-server from starting. It gets its hooks into the session so early on boot, that the X-server crashes, before the user is even asked for a graphical log-in.
On the plus side, there are ways of solving both problems.