Having an SSH server can be incredibly useful; you can access a “headless” server without a monitor, get shell access to your system from anywhere in the world, transfer files without using FTP, securely tunnel VNC or web browsing, safely restart a locked-up system, and a lot more. However, improperly setting up a SSH server can leave your system vulnerable. Here’s how to install a secure SSH server (specifically OpenSSH) on Ubuntu or other Debian-based distributions.
The SSH client software is installed in Ubuntu by default. If you’re not familiar with it, then you’re probably not ready to set up the server.
What you do need to install is the OpenSSH server, which allows SSH clients to connect to your computer. Do this by installing the package openssh-server. Click here to install the SSH server, or use this terminal command:
sudo apt-get install openssh-server