Do not use XDMCP

• Used by itself, XDMCP is NOT SECURE.
• Like telnet, xdmcp connections are not encrypted and can be easily eavesdropped on.
• Anything you type in, including passwords, can be captured by anyone else on the network.
• Any data you do not wish disclosed to others can be easily captured by anyone else on the network.
• Instead, encrypt your connection to the remote computer with ssh tunneling. See below.

Prerequisites

• An X11 server installed on your local machine
  • Under Windows, purchase a copy of Exceed from CU Software Licensing
  • Under MAC OS X, install the X11 which came with your copy of OS X
  • Under other unices, install XFree86 or Xorg
• A ssh client
  • Under Windows, google for and install the free TTSSH or Putty
  • Under Mac OS X, commandline ssh is built in
  • Under unices, commandline ssh is built in

Jeol

1.  You will need a user account on calico
2. Fire up your X11 server if not already running
3. Turn on X11 tunneling/forwarding in your ssh client
4. ssh to calico
5. On calico, run:

    Xnest :1 -query jeol.cnf.cornell.edu
   

   1. In the above command, if server screen :1 is in use, you should try :2 or :3 or so on
6. Login to the jeol
7. Keep in mind that your connection between calico and jeol is NOT encrypted

Cats

• If you do not really need a full CDE desktop, please do not start one.
• Instead, just run the individual X applications you need.

1. Fire up your local X11 server if not already running
2. Turn on X11 tunneling/forwarding in your ssh client
3. ssh to cats
4. To start a CDE desktop, run:

   /usr/dt/bin/Xsession
   

5. To instead just run individual X applications, just run the application. Eg. xterm

Calico

• If you do not really need a full Gnome/KDE desktop, please do not run one.
• Instead, just run the individual X applications you need.

1. Fire up your local X11 server if not already running.
2. Turn on X11 tunneling/forwarding in your ssh client
3. ssh to calico
4. To start a gnome desktop, run:

   gnome-session
   

5. To start a kde desktop, run:

   startkde
   

6. Otherwise, just execute the X application. eg xterm
   \\\\