SSH (Secure Shell) is an encrypted and secure protocol which provides secure data transmission between client and servers. OpenSSH is the server that implements SSH protocol to provide remote server shell access. You can connect to your system remotely, perform administrative tasks and access files. Also, you can transfer files securely via scp and sftp. In this tutorial we will show you how to enable SSH on an Ubuntu 22.04 system.
How to Enable SSH on Ubuntu 22.04
If you have installed fresh Ubuntu, remote access via SSH is denied. You have to enable it for remote access. It is very easy with simple steps.
To install and enable SSH on your Ubuntu system, follow the below given steps as root or user with sudo privileges:
Step 1 – Update package index
First of all, update the package index list.
sudo apt update
Step 2 – Install OpenSSH Server
After updating the package list issue the below given command to install OpenSSH server:
sudo apt install openssh-server
It will prompt you to enter password, enter your password and hit Enter to continue to installation.
Step 3 – Verify Service
SSH service will start automatically, once the installation is finished. Verify SSH Service by checking status:
sudo systemctl status ssh
You should get output as following:
● ssh.service - OpenBSD Secure Shell server Loaded: loaded (/lib/systemd/system/ssh.service; enabled; vendor preset: enab Active: active (running) since Sun 2022-11-30 12:27:57 UTC; 1 day 13h ago Process: 890 ExecStartPre=/usr/sbin/sshd -t (code=exited, status=0/SUCCESS) Main PID: 914 (sshd) ...
You can quit by pressing q to the command prompt.
Step 4 – Allow in Firewall
If your system is secure with firewall then you should allow SSH port.
sudo ufw allow ssh
At this point, SSH is installed and you can connect to your Ubuntu system via SSH from any remote system. By default, Linux and macOS systems have SSH clients pre-installed. You can connect from a Windows machine by using an SSH client such as PuTTY.
Step 5 – Connect SSH Server
To connect your Ubuntu machine over network you can use the ssh command followed by the username and the IP address as following:
ssh USERNAME@IP_ADDRESS
Here, you should replace with your real username and ip address of the remote host.
For example, username is tecnstuff and ip address is 103.168.3.125 then you should run command as below:
ssh tecnstuff@103.168.3.125
It will show a message when you connecting first time:
The authenticity of host '103.168.3.125 (103.168.3.125)' can't be established. ECDSA key fingerprint is SHA256:cybd23mAJuNuBDunE++yowF7lgAs5a2bLFiO3qmLDPD. Are you sure you want to continue connecting (yes/no)?
Type yes and you will be asked to enter password:
Warning: Permanently added '103.168.3.125' (ECDSA) to the list of known hosts. tecnstuff@103.168.3.125's password:
On success, it will show default Ubuntu welcome message:
Welcome to Ubuntu 22.04 LTS (GNU/Linux 5.15.0-25-generic x86_64) * Documentation: https://help.ubuntu.com * Management: https://landscape.canonical.com * Support: https://ubuntu.com/advantage ...
This means you are now connected to remote system.
Disabling SSH on Ubuntu
If you would like to disable the SSH server on your Ubuntu system, just stop the SSH service by typing:
sudo systemctl disable --now ssh
Again, to re-enable it, type:
sudo systemctl enable --now ssh
Conclusion
This tutorial shown how to install and enable SSH on your Ubuntu 22.04 system. Now you can make remote session from your any client machine and do further admin tasks.
You can improve your remote machine security by changing the default SSH port, which will reduce the risk of automated attacks. To know more about SSH server read the official SSH manual page.
If you have any questions or feedback, please leave a comment below.