To install the OpenSSH server on Debian Linux 9, 10, or 11, you can use the apt-get command to install the openssh-server package.
To install the openssh-server package, open a terminal and run the following command:
sudo apt-get update sudo apt-get install openssh-server
This will install the OpenSSH server and its dependencies.
Once the installation is complete, the OpenSSH server will be automatically started. You can verify that the OpenSSH server is running by using the systemctl command:
systemctl status ssh
This will show the status of the OpenSSH server and any error messages, if any.
To allow incoming connections to the OpenSSH server, you may need to open the SSH port (port 22) in the firewall. You can use the ufw command to open the SSH port:
sudo ufw allow ssh
This will allow incoming connections to the OpenSSH server through the firewall.
To connect to the OpenSSH server from a remote machine, you can use the ssh command. For example, to connect to the OpenSSH server with the IP address 192.168.1.100 using the username user, you can use the following command:
ssh user@192.168.1.100
You will be prompted for the password of the user account.
Keep in mind that the OpenSSH server is a powerful tool that allows you to remotely access and manage your system over the network. It is important to secure the OpenSSH server by setting strong passwords for all user accounts and disabling password authentication for root. You can also enable two-factor authentication for added security.