Logging in with external VNC clients

The default and recommended way to graphically connect to the desktop is with our Web Desktop feature.

If you would like to use a different external VNC client (which must support encrypted connections, for example realvnc viewer [free] ), you need to take extra steps to secure the connection.
Please follow these instructions:

External VNC with SSH tunnels
  1. Set up ssh-keys for your local laptop/desktop:
      Adding SSH keys to the Jetstream Atmosphere environment.
  2. Start/Reboot/Redeploy your instance to activate the SSH_keys
  3. Once your instance comes up, login via "ssh" using your favorite terminal app (e.g. Putty, Mac Terminal) from the local machine that matches the SSH_keys.
    Instructions for finding your instance's IP_number are in the SSH instructions.
    Type: ssh <username>@<instance_IP>
  4. Set a password for your username while logged in to the instance. 
    Type: sudo passwd <username>
  5. Starting an SSH-tunnel from your local machine to the VNC desktop:
    Either exit from your ssh or otherwise start a new terminal session and then
    Type: ssh -L <localhost port, try 5901>:<instance_IP_number>:<instance port, try 5901> -N <username>@<instance_IP_number> a,b
    eg. ssh -L 5901: -N jsmith@

    NOTE: the terminal session will appear to hang, but that's because it's busy connecting your instance's desktop to your local machine.
    Generally, using local port 5901 and remote port 5901 should work as long as no VNC servers are running locally, and only the default VNC server is running on your instance.
  6.  Use realvnc viewer (free) to connect to localhost:5901 with your <username> and the password you just set. a,b
  7.  When finished with the VNC, please disconnect your VNC session via the Real VNC viewer or by closing the VNC window on your host computer.
    DO NOT LOGOUT INSIDE THE DESKTOP OF THE VM: this will make your VNC unusable until you manually restart the VNC.

    Disconnecting your VNC session via the Real VNC viewer:

  8. Return to the terminal app running the SSH-tunnel and close it (ctrl-c or close the window).

a Note: the default VNC session will only work for the user that launched the instance.
              Other user accounts on that instance that wish to have an individual desktop will have to start their own VNC manually.
              Additionally, the port number will generally increase by 1 for every active desktop: 1st desktop = 5901, 2nd desktop = 5902. Please use the appropriate port number in the commands above.

b Note: If you are on a Mac OS X based machine and you get a warning about AppleScreenSharing, then cancel the connect, close the tunnel, and restart it with ONLY the localhost-port increased to 5902 or higher:
                e.g. Typessh -L 5902: -N jsmith@ , then try your VNC_Viewer Client again but specify localhost:5902 (or whatever port you chose).
                seeing the AppleScreenSharing message means if you proceed, your computer may to try to connect recursively to your local screen over and over which will result in a loop which may hang your screen

Resizing VNC sessions

Note on resizing:
From the command line inside your instance use :

xrandr -s 1920x1080

to get a larger screen; adjust the numbers to get the screen size that you need.

xrandr works reliably in many Linux operating systems.

Valid screen resolutions are:


To become root

Enter 'sudo su -' at the command prompt or type 'sudo command' and replace command with the command for which you want to use sudo.