Use a graphical client to remotely access a Linux Server

Article Title: Use a graphical client to remotely access a Linux server. Linux is a technology channel of the IT lab in China. Includes basic categories such as desktop applications, Linux system management, kernel research, embedded systems, and open source.
　　 I. Introduction
We can remotely log on to the Linux server through telnet or ssh, but all of them are character interfaces. This article describes how to remotely connect to the XFree86 Server on a Linux Server through XDMCP + XDM. You can remotely manage Linux servers in a graphic environment.
　　
　　 Ii. Basic Concepts
1. What is XFree86?
XFree86 is an open-source implementation of the X Window System. It provides a Client-Server interface for the mouse, keyboard, video card, and window graphics environment. Therefore, the client program can run on different hosts, and a Server provides the X Window Server service.
2. What is XDMCP?
XDMCP is the "X Display Manager Control Protocol" network Protocol. It establishes the connection and communication between the graphical client program and the X Window server.
3. What is XDM?
XDM is "X Display Manager". It starts the X Window server and manages logon, session, and KDE and Gnome of the graphic client program. KDE and Gnome also provide their own xdm implementations, namely, kdm and gmt1.
4. What is XFS?
XFS is the "X Font Server". A Server can provide unified fonts. Remote graphics client programs do not need to install all fonts separately.
　　
　　 Iii. configuration process
1. Our Environment
We use a computer with Mandrake Linux 8.1 installed as the X Window server. The NIC address on the server is 192.168.0.1/24. XFree86 software packages are installed together during Linux installation.
We installed X-Win32 software on another computer with Windows 2000 installed on the LAN as the client for X Window. There are also many X client programs in Windows, but most of them are commercial programs. For example, exceed only provides a 30-day trial period. The X-Win32 has no number of days limit, but can only use 30 minutes at a time, this is enough for most basic server maintenance operations, time to connect again. Free use of commercial programs cannot be too demanding
　　
2. Configure the server
(1) Configure xfs
The xfs configuration file is/etc/X11/fs/config. The content is as follows:
#
# Default font server configuration file for Mandrake Linux workstation
#
　　
# Allow a max of 4 clients to connect to this font server
Client-limit = 4
　　
# When a font server reaches its limit, start up a new one
Clone-self = off
　　
# Alternate font servers for clients to use
# Alternate-servers = foo: 7101, bar: 7102
　　
# Where to look for fonts
# Some of these are commented out, I. e. the TrueType and Type1
# Directories in/usr/share, because they arent forced to be
# Installed alongside X.
#
Catalogue =/usr/X11R6/lib/X11/fonts/misc: unscaled,
/Usr/X11R6/lib/X11/fonts/75 dpi: unscaled,
/Usr/X11R6/lib/X11/fonts/100 dpi: unscaled,
/Usr/X11R6/lib/X11/fonts/misc: unscaled,
/Usr/X11R6/lib/X11/fonts/Type1,
/Usr/X11R6/lib/X11/fonts/Speedo,
/Usr/X11R6/lib/X11/fonts/mdk: unscaled,
/Usr/share/fonts/default/Type1,
/Usr/share/fonts/ttf/big5,
/Usr/share/fonts/ttf/gb2312,
/Usr/share/fonts/ttf/decoratives,
/Usr/share/fonts/ttf/western
　　
# In 12 points, decipoints
Default-point-size = 120
　　
#100x100 and 75x75
Default-resolutions = 100,100
　　
# How to log errors
Use-syslog = on
　　
You can define the maximum number of client connections in the configuration file. The default value is 4. The configuration file also specifies the font file location. Pay special attention to the Chinese font. Otherwise, the Chinese font cannot be correctly displayed on the client.
Next, modify the/etc/rc. d/init. d/xfs file and change "-port-1" to "-port 7100", which is the default listening port of xfs. Run the following command to restart xfs:
Service xfs stop
Service xfs start
After xfs is started successfully, run the netstat-ln command to confirm that port 7100 is bound:
Tcp 0 0 0.0.0.0: 7100 0.0.0.0: * LISTEN
　　
(2) Configure xdm
The xdm configuration file is in the/etc/X11/xdm directory.
First, modify the xdm-config file and find a row: DisplayManager. requestPort: 0.
Comment this line :! DisplayManager. requestPort: 0
If this line exists, xdm will not listen to the connection of XDMCP.
Next, modify the Xaccess file, which is the configuration file for controlling client access. The modification content is as follows:
# * # Any host can get a login window
192.168.0 .*
　　
All computers in the local area can be connected.
Now you can directly use the xdm command to start the xdm service, and use the netstat-ln command to confirm that port 177 (the default xdm port) is bound:
Udp 0 0 0.0.0.0: 177 0.0.0.0 :*
　　
If you want to automatically run xdm after the server is started, you need to modify the/etc/inittab file to enter the "5" running level after the server is started. The modification is as follows:
Id: 5: initdefault:
　　
3. Use a graphical client for testing
We downloaded X-Win32 5.4, where X-Win32 5.4 is generated in program groups after it is installed in windows, with two executable programs: x-config and X-Win32.
First, use X-config to establish the connection configuration: Select "add" in the "session" area, then select the "XDMCP" connection method, and click "Next-> ", enter a name in "Session name", select "Broadcast" in "XDMCP Mode", and click "Save" to Save the configuration. Then select "Font" on the main interface of X-config and click "Add Font Server... ", enter the Server IP address 192.168.0.1 in" Host ", and confirm that" Port "is 7100.
After the configuration, you can start the X-Win32, of course you need to select "Evaluation" when starting because we are not registered. Then, select the session name you just created. A Window will display the name of the X Window server in the current network. Click "OK" on the server to display the xdm logon interface, after you log on with your Linux User Account, the X Window Graphic Interface appears, which is the same as local operations on the Linux server. Chinese characters are also displayed normally because the font on the server is used.
　　
　　 4. Other problems
1. Get X-Win32
You can download the X-Win32 software at www.starnet.com, You need to register before downloading.
　　
2. copy and paste the X Window client and Windows
The X-Win32 also provides the ability to copy and paste content in X Window and Windows to each other, making it much easier.
　　
　　 V. References
Http://www.tldp.org/HOWTO/XDMCP-HOWTO/index.html
Http://www.tldp.org/HOWTO/mini/Xterminals/index.html