Remote Desktop allows us to see and even control the desktop of another computer from your PC. For example, we have a shop and want to view and control some video security cameras that are connected to a computer from another point in our house.
This can be done by means of a local network and over the internet, but only if the computer you want to view and control has a static IP.
Nowadays, almost everyone is behind a “rooter” that provides a dynamic IP, which varies each time the system boots. If that is the case, rooter settings must be changed from a web browser by entering the following in the address bar: http://192.168.0.1/ (for example) and change the type of IP (static). Port 5900 should be open also, which is the one to be used, as the rooter usually has a firewall.
Each rooter has a different way of configuration, so a little googling or a call to support service may be required.
CONTROLLING A COMPUTER WITH UBUNTU FROM ANOTHER ONE WITH UBUNTU
From now on, and to avoid confusion, the computer to be controlled will be called “SERVER” and the computer from which the user connects will be the “CLIENT”.
Ubuntu uses the “VNC” protocol but there is another protocol, called “SSH + NX” that can be used with encryption. In this article the VNC option will be described as it is the one that is installed.
Configuring the Server
The first thing to do is to configure the server to give the appropriate permissions, so that a remote user can access it. By clicking on “System -> Preferences -> Remote Desktop” a window will open, showing the following settings:
Activate “Allow other users to view your desktop” and the system begins checking the computer connectivity. This may take some time and will provide with the IP address to be used to connect to the server (do not forget).
“Allow other users to control your desktop” -> must be activated if it is required that the client has full access. If the client should only have “view” permissions, this option must be deactivated. This would be the case if it is wanted to show someone how to do something in Ubuntu, for example.
“Each access to this computer must be confirmed”-> To be activate in the case that there is always someone on the Server computer (i.e, if we want to teach someone what we do), but no one is usually present so it is important to consider not to activate it.
“Require user to enter a password” -> Typical configuration is to activate it and write (8 characters). If this is not set, anyone who knows the server IP, will be able to control the computer, which is not usually desired.
“Configure the network to automatically accept connections” -> Typically activated, so that the port 5900 is open and the system is configured properly.
“Notification Tray” frame:
Always show an icon.
Show an icon only when someone is connected.
Never show an icon.
When the window is closed the server is already configured and ready for the client to connect.
Access From The Client
Clicking on “Applications -> Internet -> Remote Desktop Viewer” will open the viewer, clicking on “Connect” will open another window to configure the connection:
Protocol -> must be set to VNC
Host -> to be filled in with the IP provided by the sytem when configuring the Server. If the server is on a LAN, clicking on Search will look up other computers so that they can be selected.
VNC Options -> View and scale only.
The client is ready to connect.
Screen Refresh Problems When Extra Effects Are Enabled
A typical problem is that the screen does not refresh on the client viewer. The client user moves the mouse and the pointer moves on the server, but the screen does not refresh properly.
This can be quickly solved by setting “visual effects” to “none“on the client, but any other configuration (normal or extra) doesn’t work.
A definite solution would be to get to gconf-editor-> desktop -> gnome -> remote_access and check “disable_xdamage”.