OpenSSH as popularly known is used for gaining secure access to remote computer and gain terminal access and transfer files. OpenSSH is set of client server program where all communication between client and server is encrypted. Since all communication is encrypted in OpenSSH, this makes it more secure than other similar tools like telnet or ftp. This is very helpful if you want to control several computers from single computer.
Installation SSH server in Linux
Use default installer in case RHEL/Fedora/Centos use yum for installation
yum -y install openssh-server openssh-client
In latest distribution of RHEL/Fedora/Centos DNF is used as default package manager, in this case use command
dnf install httpd-manual -y
Once installation of server and client is done, you will need to configure your client. Note that client is required for connection of remote server i.e. the system from which you are going to connect remote server must have client software installed.
Configure OpenSSH server
Although no specific configuration is required for connecting OpenSSH server. Still you can change port used for making connection enhance security, also you may disable remote root login.
Disable remote root login
Open the sshd_config file with your favourite text editor, its located in /etc/ssh/sshd_config. Now you have to change PermitRootLogin directive to no.
Change port for connecting OpenSSH server
To change port you have to change directives it. Open configuration file in editor and find line for ports and change it number desired.
# What ports, IPs and protocols we listen for Port 79
After making any changes in configuration file you need restart you OpenSSH server.
Restarting OpenSSH server
To restart OpenSSH server you need to use your default service manager to restart it. Most of latest distributions of Linux are using systemctl
systemctl restart ssh restart
In case you are using an older distribution use
Now all you need is IP address of system and client software to connect to system using SSH.