How to Install/Enable & Connect to SSH on Ubuntu 20.04 LTS

SSH or known by its full name Secure Shell Protocol is a cryptographic network communication protocol that enables two computers to communicate securely over an unsecured network. SSH is highly used for remote login applications and command-line executables such as terminal applications.

For users wishing to connect to servers or other computers with SSH, the client and the remote connection need to both have SSH installed and enabled for this to be possible.

In the following tutorial, you will learn how to install and enable SSH on Ubuntu 20.04 LTS Focal Fossa or Server and connect to a remote PC.

Update Ubuntu System

Update your Ubuntu operating system to make sure all existing packages are up to date:

sudo apt update && sudo apt upgrade -y

Install SSH (OpenSSH)

SSH is not installed or enabled on your Ubuntu 20.04 LTS system by default.

First, run the following command in your terminal to begin the installation.

sudo apt install openssh-server -y

Once installed, enable SSH using the following command.

sudo systemctl enable --now ssh

Next, check the status of the SSH instance to make sure it is running and no errors have occurred.

systemctl status ssh

Example output:

Install/Enable & Connect to SSH on Ubuntu 22.04 LTS

Another handy trick is to use the following command to see open connections.

ss -lt

Example output:

Install/Enable & Connect to SSH on Ubuntu 22.04 LTS

Connecting to SSH Server

With SSH now installed and enabled, you can connect to a remote system, another remote PC, or a server. Remember, the SSH software must be enabled on both ends for this to work.

First, you will need to have the internal/external IP address or the hostname and preferably the username of the account connecting too, then use the ssh command to begin the connection.

ssh username@ip-address/hostname

When you connect to the remote SSH instance for the first time, you will receive the following message.

Example:

Install/Enable & Connect to SSH on Ubuntu 22.04 LTS

Type YES, then you will be prompted to enter your password; once done, press the ENTER KEY.

Example output (Connecting to Fedora 35 Remote PC):

Install/Enable & Connect to SSH on Ubuntu 22.04 LTS

As above, you have entered your password and successfully connected as instead of joshua@ubuntu, we now see joshua@fedora-35 since your terminal window is logged in to the remote session.

Do note you will see when the last login was and failed attempts demonstrated above. If you see lots of these, it means brute-force attacks are occurring, and you should look at stricter firewall rules or use something like fail2ban.

Disabling SSH (OpenSSH)

For instances where you do not need SSH running, you should always have this disabled for security purposes. Many malicious bots scan the internet for SSH instances and brute force them if they are not secure.

To disable SSH, use the following command.

sudo systemctl disable ssh --now

When you need to have SSH re-enabled, use the following command.

sudo systemctl enable ssh --now

Comments and Conclusion

In the tutorial, you have learned how to install and enable SSH (OpenSSH) on Ubuntu 20.04 LTS.

Overall, SSH is the go-to protocol compared to using other similar services such as TELNET which is not secure. However, ensure your firewalls are activated when using SSH over an open-unsecured network.



Follow LinuxCapable.com!

Like to get automatic updates? Follow us on one of our social media accounts!