1.   I cannot see the login window. 2.   The CDE login window shows up. After login, the session hangs or is terminated.

When the DISPLAY variable is manually assigned, the remote machine may not find X server (Xmanager). DISPLAY variable is set automatically by Xmanager so you do not need to manually assign it. Please check your login script (.cshrc, .profile, .login, .bashrc, and etc) and comment out the line that starts with "export DISPLAY..." or "setenv DISPLAY..." as the following statements.

How to configure Linux XDMCP(KDE/GNOME) settings for Xmanager: Affected Files Step 1. Change runlevel to enable gdm or kdm.

1. Open /etc/inittab file.
2. Change the runlevel to 5 as following:
   id:5:initdefault:

Step 2. GDM configuration (When the Linux is using gdm)

1. Open /etc/X11/gdm/gdm.conf file. (/etc/gdm/custom.conf for Fedora Core 5)
2. Go to the [xdmcp] section.
3. Set the value of Enable option to true or 1.

Step 3. KDM configuration (When the Linux is using kdm)

1. Open /etc/X11/xdm/xdm-config file.
2. Comment out "requestPort" option as following:
   DisplayManager.requestPort: 0
   ==>
   !DisplayManager.requestPort: 0
3. Open /etc/X11/xdm/Xaccess file.
4. Remove the initial "#" character for the following line:
   #* #any host can get a login window
   ==>
   * #any host can get a login window
5. Open /etc/X11/xdm/kdmrc,
   /usr/share/config/kdm/kdmrc or
   /etc/opt/kde2/share/config/kdm/kdmrc file.
6. Change the value of "Enable" option to "true".

Step 4. Firewall configuration (If the firewall has been configured)

1. Open /etc/sysconfig/ipchains file.
2. Add the following lines at the top of the file:
   -A input -p udp -s 0/0 -d 0/0 177 -j ACCEPT
   -A input -p tcp -s 0/0 -d 0/0 telnet -j ACCEPT
   -A input -p tcp -s 0/0 -d 0/0 ssh -j ACCEPT
   -A input -p tcp -s 0/0 -d 0/0 login -j ACCEPT
   -A input -p tcp -s 0/0 -d 0/0 exec -j ACCEPT
   -A input -p tcp -s 0/0 -d 0/0 shell -j ACCEPT
   -A input -p tcp -s 0/0 -d 0/0 7100 -j ACCEPT

Step 5. Restart your Linux to activate the changes.

In some GDM versions, you may have problem making Secure XDMCP connections because the connection address cannot be translated correctly. To use Secure XDMCP, change display manager to 'kdm' or 'xdm'. The following instructions show how to switch your display manager to 'kdm' or 'xdm'.

Note: You are not changing the desktop environment such as Gnome or KDE. This process will simply change the login in screen.

1. Stop the gdm process using gdm-stop or init 3 command
2. Start display manager with kdm or xdm command

In order to use XDMCP connection, CDE login should be enabled on your remote server. Follow the instructions below to enable CDE login :

1. Login as a root.
2. Enable CDE login when system boot:
   $ /usr/dt/bin/dtconfig -e [enter]
3. Reset the process: dtconfig -reset

If you want to disable the CDE login setting, do the following :