Part 1: Connect remotely to GNOME session using VNC
In Part 1, we saw how can we connect to a remote Linux machine from either a Windows machine or another Linux machine using the VNC protocol. In order to connect to the remote Linux machine one should already be logged into a GNOME/KDE session on the remote machine otherwise you won’t be able to connect. You can use any VNC client software like VNCViewer in Windows or GVNCViewer in Linux. You need to install an configure the vino-server on your remote Linux machine which takes less than 1 minute.
Part 2: Connect to GDM or KDM login screen using VNC
Part 2 was an extension of Part 1 in which we overcome the obstacle of first logging into the remote Linux system before we can connect to it remotely. It is really annoying that we have to physically go to the remote Linux system and log in ourselves manually, every time we restart the machine, so that we can log into it remotely. We solve this problem by running the vino-server when a login manager like GDM kicks in. All the changes are done in the GDM configuration files like /etc/gdm/gdm.conf and /etc/gdm/Init/Default.
Part 3: Connect to remote Linux server with XDMCP protocol
In Part 1 and Part 2 there is a huge limitation that we have to share the desktop screen with the main console on the remote Linux system. As a result of this two users cannot simultaneously log into the remote Linux machine and carry out their activity on their own i.e. without sharing their desktop screens. We overcome this limitation by using the XDMCP protocol instead of VNC protocol used in Part 1 and Part 2. With XDMCP two users who have account on the remote Linux machine can log in at the same time with individual desktops. Also suppose a person (Administrator/root) who is physically sitting on the remote Linux machine can also have his/her own desktop.
We can easily do this by first enabling the XDMCP protocol on the remote Linux machine and then using a X Window program like Xming on a Windows machine to connect to the remote Linux machine.
Part 4: Connect to remote Linux server with XDMCP protocol from another Linux machine
Part 4 was an extension of Part 3. In Part 4 we learn how to connect to the remote Linux host from another Linux machine. We don’t require any special software, unlike Xming in Windows, in order to connect to the remote machine from a Linux machine. We can simply use the in-built X (Xorg) server that comes with any standard Linux distribution.
I sincerely hope that this series on learning how to connect remotely to a Linux host from either a Windows or a Linux machine using different protocols like VNC and XDMCP was been useful to you. Please leave a comment/feedback if you have one. In future I will try to cover similar topics like these using different methods/protocols.