Remote connection Linux System Administration

Remote connection Linux System Administration
1. Why Linux systems remote connections

In a lot of training and teaching institutions usually will explain directly to the virtual machine or virtual machine interface graphical interface knowledge, which also led to a lot of students only familiar with how to operate on a virtual machine interface, not the actual work scenarios Familiar with. In fact, in the actual work scenario, users rarely have access to the physical server or virtual machine interface local window, because the server Bahrain system, have pulled IDC room hosting, cloud hosting if it is purchased, the user even not touch the server's local monitor, and this time only manage Linux systems through a remote connection. Therefore, after I installed Linux systems, learning Linux operation and maintenance of a good first step would be to configure the client software to connect remotely manage Linux systems.

Connection Tips

1.IP address

The computer will be on the Internet has a unique 32-bit address, IP address, the IP address is equivalent to the location of the server.

When we find someone, you want to know the specific address of the person, the same token, if you want to access the server connection, it must be achieved through the IP address of the server, the IP address of the server is equivalent to a specific address of the server.

LAN (only take effect in our current environment) also has an IP address reserved, usually start 192.168,10.0,172.16, IP addresses for each LAN is unique.

Note: the external network IP address - in the world where are accessible IP address. Network IP address - can only be accessed within a range of IP addresses, for example: a business, a classroom, but not absolute.

The concept is simple port

A host above may be a lot of features and services, a variety of services on the host through the port are represented. For example: Our port services for remote connections by default is 22, the service name for the SSH service used to access the web interface of the service default port number is 80, the service name for the HTTP services.

The concept of agreement

Protocol, network protocol referred to as the network protocol is a set of conventions of communication both computers must work together to comply. Such as how to establish a connection, how to identify each other. Only following the convention in order to communicate with each other exchanges between computers. Its three elements are: syntax, semantics, timing.

To make the data on the destination from the source network, the network communication participant must follow the same rules, this set of rules called a protocol (Protocol), which is reflected in the final format of the data packets transmitted over the network.

Simple to understand the different ports provide different services, corresponding to different functions, and which may have different communication methods, communication method in communication between the client and the server can be understood as a protocol.

On a host of different services are distinguished by the port. Between the port, the client and the server if different clothes communication, it may use different protocols.

Since you can find the server by IP address, you can get different services through different service port connection, and using a variety of protocols. The following table is a connection-related terms and functions substantially corresponding descriptor table.

name	Chinese name	meaning
IP	IP addresses	Whom, Where
Port	port	Doing, what services
Protocol	protocol	What language, communication

We are using a remote connection service is based on SSH protocol. SSH is a protocol developed by the IETF Network Working Group. Before data transmission, SSH first encryption by the encryption processing on-line data packet, then the data transmission, This ensures data transfer security.

SSH is a security protocol designed for remote login session, and other network services provided. Using the SSH protocol can effectively prevent information leakage remote management process, production in the current environment, most companies commonly used by SSH protocol services instead of the traditional insecure remote online software services, such as telnet (non-encrypted) Wait.

Remote connectivity tools introduced

Common tool to connect remote Linux servers have Xshell, SecureCRT, Putty etc. The most commonly used is Xshell, SecureCRT. These client connectivity tools correspond to the same SSH service sshd process on Linux servers that are connected remotely using SSH protocol, of course, they also support other protocols such as telnet and so on.

Remote MAC connection tool systems generally iTerm2 or local connection.