2. X-Window System Protocol The X Window System Protocol, also known as X Window or X Protocol, is a graphics architecture used as the graphical system on Unix systems (primarily) and Linux systems. X Window System (X Protocol) provides an inherently client/server oriented base for displaying windowed graphics. It manage a video system including "interactive" I/O devices such as mice, keyboards, and some more unusual devices. X Window System (X Protocol) has two primary versions: X10 and X11
3. X Window Display Manager XDM (in full, the X Window Display Manager) is the default display manager for the X Window System. It is a bare-bones X display manager. It was introduced with X11 Release 3 in October 1988, to support the standalone X terminals that were just coming onto the market. It was written by Keith Packard.
4. GNOME Display Manager GDM (the GNOME Display Manager) provides a simpler alternative display manager for the X Window System's XDM. GDM allows users to customize or troubleshoot settings without having to resort to a command line. Users can pick their session type on a per-login basis. GDM also features easy customization with themes.
6. X Display Manager Protocol XDMCP stands for "X Display Manager Control Protocol" and is a network protocol. It provides a way of running the X-Terminal to run on your PC (or MAC) and it uses the X Server to provide a client/server interface between display hardware (the mouse, keyboard, and video displays) and the desktop environment while also providing both the windowing infrastructure and a standardized application interface (quoted from XFree86 Project home page). The X-Terminal can be displayed with an individual window or multiple windows, based on your X window system's software capabilities and setup.
7. XDMCP & Gnome Display Manager (GDM) GDM also supports the X Display Manager Protocol (XDMCP) for managing remote displays GDM listens to UDP port 177 and will respond to QUERY and BROADCAST_QUERY requests by sending a WILLING packet to the originator. GDM can also be configured to honor INDIRECT queries and present a host chooser to the remote display. GDM will remember the user's choice and forward subsequent requests to the chosen manager. Since it is fairly easy to do denial of service attacks on the XDMCP service, GDM incorporates a few features to guard against attacks.
8. Enable XDMCP on redhat In Red Hat® Enterprise Linux® 4 and below the file /etc/X11/gdm/gdm.conf could be modified to enable xdmcp. With Red Hat Enterprise Linux 5, the location to enable xdmcp has changed. There are two ways that xdmcp can be enabled: Modify the file /etc/gdm/custom.conf and under the [xdmcp] section, add this line: Enable=true Alternately, the tool gdmsetup can be used. This is a gui-based tool to modify gdm. Once one of these two steps are done – simply run gdm-restart and then login as desired user.
9. Remote desktop Linux using XDMCP Download Xming Xming is an implementation of the X Window System for Microsoft Windows operating systems, including Windows XP, Windows Server 2003 and Windows Vista
10. Remote desktop Linux using XDMCP Step 1: Click “Next”and select “Open session via XDMCP”
15. Config file /etc/ssh/sshd_config Install PUTTY, It is a wonderful free SSH client . *Note: Installed Xming Remote desktop Linux via SSH with X11 Forwarding X11Forwarding yes
16. Remote desktop Linux via SSH with X11 Forwarding Step 1: launch Xming Click “Next” button to “Finish” ^^ , it will show below
17. Remote desktop Linux via SSH with X11 Forwarding Step 1: Black screen it will show below
18. Remote desktop Linux via SSH with X11 Forwarding Step 2: launch PUTTY Click “Open” button