How to remotely display and control a Linux desktop from a Windows or Linux system using VNC
It is relatively straightforward to display and access a Linux desktop
from a system anywhere else on a network or the internet by using
Virtual Network Computing (VNC). This can be achieved regardless of
whether, for example, that system is running Linux, Windows or Mac OS
X.. The even more impressive thing about this is that it can be set up
for free with only a little time and knowledge.
There are three key areas to establish a VNC connection to a desktop
environment (such as KDE or GNOME) on your Linux system:
1. A VNC server installed and running on your Linux system.
2. A VNC viewer client installed on the system on which you want to
display your Linux desktop.
3. A secure shell (ssh) connection between the two systems.
In this VNC How To Guide we will take you step by step through the
process and have you driving the Linux desktop home or office Linux
system while you sit drinking coffee infront of a Windows laptop in
your local WiFi-enabled Starbucks.
Obtaining a VNC Server and Client
There are a number of ways to get VNC - some free and some not so free.
First check that VNC is not already installed on your Linux system.
Most recent releases of Linux such as Redhat Linux and Fedora Core will
come with VNC rpms on the installation CDs.
If you do not already have VNC then we recommend TightVNC which can be
obtained for free from:
https://www.tightvnc.com/download.html
Once you have VNC installed you will need to specify a password to
protect access to the VNC server. To do this run:
vncpasswd
and enter a suitable password.
Starting and Stopping the VNC Server
The next thing you need to learn how to do is start and stop the VNC
server. Start the VNC Server with the following command:
vncserver
Assuming no problems are encountered vncserver will output a message
that looks something like:
New 'myhost:1
(src)' desktop is myhost:1
Creating
default startup script /home/neil/.vnc/xstartup
Starting
applications specified in /home/neil/.vnc/xstartup
Log file is
/home/neil/.vnc/myhost:1.log
The key information here is that vncserver has started up an X server
as display :1 on system "myhost" and that it has created a
sub-directory called .vnc in the home directory of the user that
started the server containing a startup script called xstartup. In
addition it has also created a log file that can be reviewed to
diagnose any problems should the server have failed to start.
To stop the VNC server simpy run the following command:
vncserver -kill :1
where the :1 matches the display that was indicated when vncsever
started up. This will display something along the lines of:
Killing Xvnc process ID 15609
A useful point to note here is that process being killed in called
Xvnc. Xvnc is the the actual VNC server process. The vncserver command
we ran to launch the VNC server is actually a shell script that sets up
the environment prior to launching the Xvnc process.
Configuring the Desktop Environment to
be Launched by VNC
The next step is to configure what gets started up when the VNC server
is launched. As outlined previously the first time a user starts
vncserver the .vnc directory is created in their home directory. Change
directory to $HOME/.vnc and load the xstartup file into an editor. It
should appear as follows:
#!/bin/sh
# Uncomment the following two
lines for normal desktop:
# unset SESSION_MANAGER
# exec /etc/X11/xinit/xinitrc
[ -x /etc/vnc/xstartup ]
&& exec /etc/vnc/xstartup
[ -r $HOME/.Xresources ]
&& xrdb $HOME/.Xresources
xsetroot -solid grey
vncconfig -iconic &
xterm -geometry 80x24+10+10 -ls
-title "$VNCDESKTOP Desktop" &
twm &
These commands perform some basic tasks such as setting the background
of the X window, launching an X terminal window and finally launching
the twm window manager. The twm window manager is a very good
lightweight window manager. Another good lightweight manager is the
Motif Window Manager (mwm). Those familiar with the Common Desktop
Environment (CDE) on Solaris, HP and IBM systems may want to change to
the "twm &" to "mwm &" in the xstartup script.
Another option is to launch the GNOME or KDE desktop environments. To
launch the GNOME desktop environment change the twm line in xstartup to:
gnome-session
&
Similarly to launch the KDE desptop environment change the line to:
startkde &
Feel free to add other commands to the xstartup script. For example if
you would like your favorite mail tool or development IDE to launch
automatically then xstartup is the place to do it.
Installing the VNC Viewer Client
Having selected the desktop environment you would like to use the next
step is to install the client side VNC viewer. On Linux and Unix
systems the viewer is called vncviewer. Check to see if you already
have VNC installed on the client system. If it is not already installed
or you are running on Windows we once again recommend that you download
TightVNC from:
https://www.tightvnc.com/download.html
Establishing a Secure Shell connection
between the two systems
For security reasons it is recommended that the VNC communication take
place through an encrypted secure tunnel connection. On Linux or Unix
this can be achieved using the
ssh
command. On Windows we recommend that you use
PuTTY which is freely available
from:
https://www.putty.nl/download.html
By default the VNC server will communicate on port 59xx where xx
represents the display number. If
vncserver
announces that it is running as display :1 then the port being used is
5901. If it tells you it is display :2 then port 5902 is being used and
so on.
Supposing you have the VNC running on display :1 on a system called
myhost then you would need to establish an ssh connection as follows:
Linux:
ssh -L 5901:localhost:5901 myhost
Windows using PuTTY:
1. Start PuTTY, enter the hostname or IP address of the system running
VNC server. In our example this is "myhost"
2. Set the "SSH" toggle.
3. Select the "Tunnels" option from beneath SSH in the "Category" list
and enter the following information:
Source port: 5901
Destination: myhost:5901
4. Save the profile you have entered by selecting "Session" from the
Category list, entering name in the "Saved Sessions" text field and
press "Save"
5. Press the "Open" button to establish the secure connection.
In both the case of Linux and Windows you will be prompted for a
password for the user under which you are logging in.
Launching the VNC Viewer Client
Assuming all went smoothly with the VNC server installation and that
you have established a secure shell connection using the appropriate
port (in our example 5901) you can now launch the VNC viewer client. On
Linux or UNIX this is done as follows:
vncviewer
localhost:1
On Window using TightVNC simply launch the TightVNC viewer and enter
localhost:1 into the Connection details dialog and press "OK".
In both cases you will prompted for a password. This is the password
that you specified when you ran vncpasswd earlier. After short delay
you should see a large window appear dispalaying your Linux desktop and
you can work with it as if you were sitting in front of your console.
