Department of Information Technology

How to use X-Deep/32 and Putty to access the unix-system securely.

Configuring X-Deep/32

  • Start the X-server, either with the icon on the desktop or from the Start-menu.
  • When asked to select which network interface(s) to use please choose to only listen to the loopback interface ( If you only plan to access X though ssh, it is a good idea to not show this dialog every time.
  • Again if you only plan to run X through ssh you can remove the checks for XDM.
  • You should now have a grey window covering the entire desktop.
    • Click on the X-server icon in the "quick launch" field in the lower right corner.
  • A "X-Deep/32" window is now presented to you.
  • Choose "Edit->X-server Options" to get the configuration options. A number of options has to be modified to get the best out of this X-server.
  • On the first tab (Miscellaneous) you should activate "Simulate 8 bit PseudoColor Visual" if you have problems with older X-applications. Please only activate if you really need it.
  • Press the "Input"-tab.
    • If you have a swedish keyboard you should make sure you have a X-keymap matching your keyboard. Press "Select Keymap File" and choose the
    • If you only have a old two-button mouse, it might be a good idea to enable "Emulate 3 button mouse".
  • Press the "Security"-tab and "Enable Access Control" to get better security.
  • If you wish to run an entire desktop (like KDE) though ssh the you are done with the X-setting. Otherwise I assume you want to use Windows as the window-manager for X-applications to.
    • Press the "Windows Modes"-tab.
    • Choose "Multiple MS Window Mode" and make sure "Display root window" is not active.
  • Press OK, the X-server must now restart. When that is done, start Putty.

Configuring putty

  • In the "PuTTY Configuration"-window go to "Connection->SSH->X11" and activate "Enable X11 forwarding".
  • Go back to "Sessions". Type in the host (and why not save this session settings for future use) and login.

I recommend to test with a simple application (like xclock) to verify that everything works.

What to do if it doesn't work ...

If you can't get xclock (or any other X-program) to work, and you get a error message like this:

X connection to localhost:10.0 broken (explicit kill or server shutdown).

Likely causes:

  1. The X-server (X-Deep) is not running.
    The X-Deep icon should be present in the "quick launch" field if it is running.
  2. Old version of Putty.
    Please make sure you run at least version 0.58 of Putty.
  3. Local firewall on your machine blocks traffic on the loopback interface ( so that Putty and X-Deep/32 cannot communicate with each other.
    If possible, turn off the firewall temporary and test if that is the case.
  4. (Unlikely) if Putty was started before X-Deep/32, it might possibly have problem to establish the X11-tunnel to X-Deep/32.
    Restart Putty.

If you can't get xclock (or any other X-program) to work, and you get a error message like this:

Error: Can't open display:

Likely causes:

  1. The X11 forwarding in Putty has not been activated.
    Make sure you have followed the instructions and restart putty.

Where to look for more information about X-Deep/32

Updated  2006-03-22 18:28:53 by Joel Fredrikson.