The OpenSSH of Linux

What is OpenSSH?

The purpose of SSH (secure SHell) is to provide secure remote logins and other security services on unsecured networks.
OpenSSH is a free open source implementation of the SSH protocol, the default SSH protocol is version 2 (RSA and DSA Support).
The user authentication method supported by OpenSSH has the user password authentication and user key authentication based on PAM. Workflow for SSHthe logon process is very similar to the session established using Rlogin or Telnet. When connected, SSH uses a key fingerprint system to verify the authenticity of the server. The user will be asked to enter Yes for confirmation only on the first connection, and the subsequent connection will validate the pre-saved key fingerprint. If the saved fingerprint does not match what you received at logon, a warning will be given. The fingerprint is stored in the ~/.ssh/known_hosts, and for the SSHv2 fingerprint, it is ~/.ssh/known_hosts2 installation of OpenSSH on Linux 1,Ubuntu16.04 under the OpenSSH installation To Install the ssh-client command:

Install openssh-client

To Install the Ssh-server command:

Install Openssh-server

determine if SSH has been started

PS -e | grep SSH

2, the OpenSSH configuration

sudo gedit/etc/ssh/sshd_config

Ssh-server configuration file is located in/Etc/ssh/sshd_config, where you can define the SSH service port, the default port is 22, by modifying this file can modify the default SSH listening port and other parameters, and then restart the SSH service after the effective:

sudo /etc/init.d/ssh restart

3. the client connects to the server remotely via SSHafter the SH service starts, you can login, login command format: SSH [email protected]
Example: SSH [email protected]
Follow the prompts to enter the password for test to log in remotely.

-------------------------------------------------------------------------------------------- Reference Blog: http://www.linuxidc.com/Linux/2015-05/117377.htm

The OpenSSH of Linux