Installing OpenSSH on Ubuntu 20.04

OpenSSH is a widely-used open-source implementation of the Secure Shell (SSH) protocol. It provides encrypted communication between two computers, allowing secure remote login and command execution. In this tutorial, we will guide you through the process of installing OpenSSH on Ubuntu 20.04.

Step 1: Update System

Before installing any new software, it is always a good practice to update the system packages to their latest versions. Open a terminal and run the following command:

sudo apt update && sudo apt upgrade

Step 2: Install OpenSSH

To install OpenSSH on Ubuntu 20.04, run the following command:

sudo apt install openssh-server

This will install the OpenSSH server package on your system.

Step 3: Configure OpenSSH

After the installation is complete, you may need to configure some settings for OpenSSH. The main configuration file for OpenSSH is located at /etc/ssh/sshd_config. You can open it with a text editor using the following command:

sudo nano /etc/ssh/sshd_config

Here, you can customize various settings such as port number, authentication methods, and more. Make sure to save the changes and exit the text editor.

Step 4: Start OpenSSH Service

Once the configuration is done, you can start the OpenSSH service using the following command:

sudo systemctl start ssh

If the service is already running, you can restart it to apply the new configuration changes:

sudo systemctl restart ssh

Step 5: Enable OpenSSH at Boot

To ensure that OpenSSH starts automatically upon system boot, run the following command:

sudo systemctl enable ssh

Step 6: Allow SSH through Firewall

If you have a firewall enabled on your Ubuntu system, you need to allow incoming SSH connections. The default SSH port is 22. Run the following command to allow SSH through the firewall:

sudo ufw allow ssh

That's it! You have successfully installed and configured OpenSSH on Ubuntu 20.04. You can now connect to your Ubuntu machine via SSH using a client like PuTTY (for Windows) or the terminal (Mac/Linux).