Debian / Ubuntu
sudo apt-get install -y openssh-server
RPM based Distros, Fedora / CentOS / RedHat
sudo dnf install -y openssh-server
or use yum
sudo yum install -y openssh-server
Start ssh service
sudo systemctl start sshd
By default the SSH service should start when the system starts, but if not try the following command to enable the service on boot up.
Debian / Ubuntu
systemctl enable ssh
Fedora, CentOS, RedHat
systemctl enable sshd
Change SSH port
Not necessary, but it is a good idea to change the default ssh port. To change the port edit the sshd file.
vi /etc/ssh/sshd_config
If you change the port, you’ll need to allow it in the firewall (firewalld, iptables) and if SELinux is enabled, semanage.