HOWTO establish a remote desktop on the ifarm starting from Windows

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You will have to have privilege to download and run software on your Windows machine.

Note 1: in the following port 5904 is specified (":5904" and ":4") but any number from 5901 to 5999 (:1 to :99) can be used. You will have avoid any port already in use by others.

Note 2: ifarm1401 is specified here, but the instructions should work on any ifarm node.

1. Establish an SSH tunnel to do VNC:

Do the usual double hop ssh into the ifarm (this time ifarm1401), but with special port assignments

 ssh -L5904:localhost:5904
 ssh -L5904:localhost:5904 ifarm1401

2. In that session, start a VNC server session:

 vncserver :4

You will have to choose a password. Don't re-use an important one.

3. Download the vnc viewer from

and run it. The program will likely be in your Downloads folder.

4. Select your server in VNC Viewer:

In the entry box, type


You should be prompted for your password. You should then see a virtual desktop on the ifarm at JLab.

5. Start a window manager.

In the terminal session on the desktop type

 mwm &

and the windows will have borders.

6. More terminal sessions

To start a new session, right click on the desktop and choose "New Window"

NB: You may from time to time find a conflict with other ifarm users using the same VNC port as you. The example above uses port 5904. If you encounter a conflict switch another port of the form 5900 + n. In the example, n = 4 has been chosen, but that is arbitrary. Note that when starting the server (vncserver) and connecting to the server with the viewer (VNC Viewer), you use n (e. g., vncserver :4, localhost:4) rather than the full port number. For the ssh step the full port number is required (e. g., 5904).