Remote control technology and practice for Linux servers

Article Title: Remote Control Technology and practice for Linux servers. 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.

With the rapid development of the Internet and the maturity of Linux enterprise applications, Linux is widely used in the server field. How to implement remote management of Linux becomes the primary task of network administrators. This article will introduce several popular Linux remote connection methods, hoping to help you.
　
Concepts and origins of Linux Remote Control Technology
　
Remote control is a technology that remotely controls another computer (controlled Host/Server) on the network, remote control is generally used to control remote computers over networks. However, in most cases, remote control is usually used in local area networks.
　
When the operator uses the master computer to control the controlled computer, it can start the application of the controlled computer just like sitting in front of the screen of the controlled computer, you can use the files and materials of the controlled computer, or even use the external printing equipment (printers) and communication equipment (modem or leased line) of the controlled computer to print and access the internet, just like using the remote control to remotely control the TV's volume, change the channel, or switch the TV.
　
Currently, the remote connection technology mainly used in Linux is roughly divided into the following three types:
　
1. Command Line-based methods
　
Linux Command: telnet. telnet can be used in both linux and windows, as long as the corresponding service is enabled. All telnet data is transmitted in plain text on the network, so there are also security risks. In actual production systems, it is basically not used, but switched to a safer ssh. however, in some cases, such as the internal local area network, telnet is useful. Ssh is similar to telnet, but data is encrypted on the network before transmission.
　
Rlogin, rsh, and other r-series commands: because of the large security risks, it is basically useless now.
　
Ssh-based client software: client tools such as Secure SSH or PUTTY use the ssh service to manage Linux servers in Windows. These client tools are easy to configure and use, however, they cannot start the program or process of the window service or achieve Remote Desktop control.
　
Note: The command line management method is suitable for initialization, Nic configuration, and other basic operations. It is not suitable for a wide range of management functions.
　
2. Web Management
　
Web management is another management tool. This method provides a simple management interface, which is suitable for management tasks with fewer functions.
　
3. graphical interface based on Management Software
　
The graphical interface based on Management Software generally requires system configuration, management, and monitoring. The graphic management method is intuitive and is an important management tool. It is suitable for complicated configuration, connecting multiple servers, and supporting a wide range of audit and log functions.
　
VNC: VNC (Virtual Network Computing, Virtual Network Computing) technology is widely used as a "productivity tool" for programmers and administrators ". Vnc must have a daemon on the server to run on each shared desktop. VNC is a client/server architecture.
　
X display manager (X display manager) -- xdm: Xdm no longer needs to add additional client software. X-Win32 is an X Window System server that allows your Windows system to run X applications or Unix systems over TCP/IP protocol. Supports OpenLook, Motif, CDE, VUE, TPD, Gnome, and other X applications running on Sun, HP, SGI, Linux, SCO, AIX, and other Unix workstations and file servers.
　
Freenx: NX is a remote display software based on the X protocol. However, to compress data of the X protocol, it is important to use the X protocol in a low-bandwidth network. Freenx is the GPL version of NX.

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