A Complete Guide on How to Host an SSH Server on Ubuntu

Hello Dev, are you struggling to host an SSH server on Ubuntu? Do you want to learn how to do it like a pro? Then you are in the right place. In this guide, we will show you how to host an SSH server on Ubuntu in easy and simple steps. So, let’s get started.

Table of Contents

1. Introduction
2. Why Host an SSH Server on Ubuntu?
3. Prerequisites
4. Installing Ubuntu Server
5. Installing OpenSSH Server on Ubuntu
6. Configuring SSH Server on Ubuntu
7. Creating SSH Keys
8. Connecting to SSH Server on Ubuntu
9. Securing SSH Server on Ubuntu
10. Using SSH for Remote Access
11. Using SSH for File Transfer
12. Using SSH for Port Forwarding
13. Setting up SSH Tunneling
14. Common SSH Commands
15. FAQs
16. Conclusion
17. References

Introduction

Secure Shell (SSH) is a network protocol that allows secure encrypted communication between two devices. It is widely used by system administrators and developers to manage remote servers and devices. In this guide, we will show you how to host an SSH server on Ubuntu, one of the most popular Linux operating systems.

Why Host an SSH Server on Ubuntu?

There are several reasons why you might want to host an SSH server on Ubuntu.

• Remote access: SSH allows you to access your Ubuntu server from anywhere in the world as long as you have an internet connection.
• File transfer: SSH allows you to transfer files between your local machine and the Ubuntu server securely.
• Port forwarding: SSH allows you to forward ports from the remote server to your local machine, which can be useful for accessing services running on the server remotely.
• Tunneling: SSH allows you to create secure tunnels between two devices, which can be useful for accessing remote services securely.
• Security: SSH uses encryption to ensure that your remote connections are secure and cannot be intercepted by malicious actors.

Now that you know why you might want to host an SSH server on Ubuntu, let’s look at the prerequisites.

Prerequisites

Before we begin, you will need the following:

• An Ubuntu server – this can be a physical machine or a virtual machine running Ubuntu
• A user account on the Ubuntu server with sudo privileges
• A working internet connection
• A local machine running a terminal emulator such as PuTTY or Terminal (for macOS and Linux)

Once you have these prerequisites, you can move on to the next step, which is installing Ubuntu server.

Installing Ubuntu Server

The first step to hosting an SSH server on Ubuntu is to install the Ubuntu server operating system.

1. Download the Ubuntu server ISO image from the official website.
2. Create a bootable USB drive or DVD using the ISO image.
3. Insert the USB drive or DVD into the computer where you want to install Ubuntu server.
4. Boot the computer from the USB drive or DVD.
5. Follow the on-screen instructions to install Ubuntu server.

Once you have installed Ubuntu server, you can move on to the next step, which is installing OpenSSH server on Ubuntu.

Installing OpenSSH Server on Ubuntu

OpenSSH server is the software that allows remote clients to connect to your Ubuntu server using SSH.

1. Open a terminal on your Ubuntu server.
2. Update your package list by running the following command: sudo apt update
3. Install OpenSSH server by running the following command: sudo apt install openssh-server

Once the installation is complete, you can move on to the next step, which is configuring SSH server on Ubuntu.

Configuring SSH Server on Ubuntu

Before you can start using SSH to connect to your Ubuntu server, you need to configure the SSH server to allow remote connections.

1. Open the SSH server configuration file by running the following command: sudo nano /etc/ssh/sshd_config
2. Find the line that says #Port 22 and uncomment it by removing the # symbol. This will allow SSH connections on port 22, the default SSH port.
3. If you want to use a different port for SSH, you can change the port number on this line.
4. Find the line that says #PermitRootLogin prohibit-password and uncomment it by removing the # symbol. This will allow root user to login via SSH.
5. If you want to disable root login, change the value to no.
6. Save and close the file by pressing Ctrl+X, followed by Y, and then Enter.
7. Restart the SSH server by running the following command: sudo systemctl restart sshd

Now that you have configured the SSH server, you can move on to the next step, which is creating SSH keys.

Creating SSH Keys

SSH keys are a more secure way to connect to your Ubuntu server than using a password. SSH keys use public-key cryptography to authenticate the client and server.

1. Open a terminal on your local machine.
2. Generate a new SSH key by running the following command: ssh-keygen
3. Follow the on-screen instructions to generate the key. The default options are usually fine.
4. Copy the public key to your Ubuntu server by running the following command: ssh-copy-id username@ubuntu-server
5. Replace username with your username on the Ubuntu server and ubuntu-server with the IP address or hostname of your Ubuntu server.
6. Enter your user password when prompted.

Now that you have created SSH keys, you can move on to the next step, which is connecting to SSH server on Ubuntu.

Connecting to SSH Server on Ubuntu

To connect to your Ubuntu server using SSH, you need to use a terminal emulator on your local machine.

1. Open a terminal on your local machine.
2. Type the following command to connect to your Ubuntu server: ssh username@ubuntu-server
3. Replace username with your username on the Ubuntu server and ubuntu-server with the IP address or hostname of your Ubuntu server.
4. If this is your first time connecting to the server, you will be prompted to verify the server’s fingerprint. Type yes to continue.
5. Enter your user password when prompted.

Congratulations! You have successfully connected to your Ubuntu server using SSH.

Securing SSH Server on Ubuntu

SSH is a secure protocol, but there are still some steps you can take to make it even more secure.

• Disable root login: You should not allow root login over SSH. Instead, you should create a new user with sudo privileges and use that user to manage your Ubuntu server.
• Use SSH keys: SSH keys are more secure than passwords because they use public-key cryptography. If you must use a password, make sure it is a strong password.
• Change the default SSH port: Changing the default SSH port from 22 to a higher port number can help prevent automated attacks. However, this is not a foolproof method and should not be relied on as the only security measure.
• Use fail2ban: fail2ban is a software that can monitor SSH logs and automatically block IP addresses that have too many failed login attempts.

Now that you know how to secure your SSH server, you can move on to the next step, which is using SSH for remote access.

Using SSH for Remote Access

SSH can be used to access your Ubuntu server remotely from anywhere in the world as long as you have an internet connection.

1. Open a terminal on your local machine.
2. Type the following command to connect to your Ubuntu server: ssh username@ubuntu-server
3. Replace username with your username on the Ubuntu server and ubuntu-server with the IP address or hostname of your Ubuntu server.
4. Enter your user password when prompted.
5. You are now connected to your Ubuntu server remotely.

Now that you know how to use SSH for remote access, you can move on to the next step, which is using SSH for file transfer.

Using SSH for File Transfer

SSH can be used to transfer files between your local machine and the Ubuntu server securely.

1. Open a terminal on your local machine.
2. Type the following command to transfer a file from your local machine to the Ubuntu server: scp /path/to/local/file username@ubuntu-server:/path/to/remote/directory
3. Replace /path/to/local/file with the path to the file on your local machine, username with your username on the Ubuntu server, ubuntu-server with the IP address or hostname of your Ubuntu server, and /path/to/remote/directory with the path to the remote directory on the Ubuntu server where you want to transfer the file to.
4. Enter your user password when prompted.
5. The file will be transferred to the remote directory on the Ubuntu server.

Now that you know how to use SSH for file transfer, you can move on to the next step, which is using SSH for port forwarding.

Using SSH for Port Forwarding

SSH can be used to forward ports from the remote server to your local machine, which can be useful for accessing services running on the server remotely.

1. Open a terminal on your local machine.
2. Type the following command to forward a port from the remote server to your local machine: ssh -L local_port:remote_address:remote_port username@ubuntu-server
3. Replace local_port with the port number on your local machine where you want to forward the port to, remote_address with the IP address or hostname of the remote server where the service is running, remote_port with the port number of the service on the remote server, username with your username on the Ubuntu server, and ubuntu-server with the IP address or hostname of your Ubuntu server.
4. Enter your user password when prompted.
5. The port will be forwarded from the remote server to your local machine.

Now that you know how to use SSH for port forwarding, you can move on to the next step, which is setting up SSH tunneling.

Setting up SSH Tunneling

SSH tunneling is a technique that allows you to create secure tunnels between two devices, which can be useful for accessing remote services securely.

1. Open a terminal on your local machine.
2. Type the following command to create an SSH tunnel: ssh -L local_port:remote_address:remote_port username@ubuntu-server
3. Replace local_port with the port number on your local machine where you want to create the tunnel, remote_address with the IP address or hostname of the remote server where the service is running, remote_port with the port number of the service on the remote server, username with your username on the Ubuntu server, and ubuntu-server with the IP address or hostname of your Ubuntu server.
4. Enter your user password when prompted.
5. The tunnel will be created between your local machine and the remote server.

Now that you know how to set up SSH tunneling, you can move on to the next step, which is learning common SSH commands.

Common SSH Commands

There are several common SSH commands that you should know when using SSH.

Command	Description
ssh	Connect to a remote server using SSH
scp	Transfer files between local machine and remote server using SSH
ssh-keygen	Generate SSH keys
ssh-copy-id	Copy SSH keys to remote server
ssh-add	Add SSH keys to SSH agent
ssh-agent	Start SSH agent

Now that you know some common SSH commands, you can move on to the next step, which is the FAQs.

FAQs

Q1. What is SSH?

A1. SSH (Secure Shell) is a network protocol that allows secure encrypted communication between two devices. It is widely used by system administrators and developers to manage remote servers and devices.

Q2. How do I install OpenSSH server on Ubuntu?

A2. You can install OpenSSH server on Ubuntu by running the following command: sudo apt install openssh-server

Q3. How do I configure SSH server on Ubuntu?

A3. You can configure SSH server on Ubuntu by editing the SSH server configuration file at /etc/ssh/sshd_config.

Q4. How do I create SSH keys?

A4. You can create SSH keys using the ssh-keygen command.

Q5. How do I connect to SSH server on Ubuntu?

A5. You can connect to SSH server on Ubuntu using the ssh command.

Q6. How do I transfer files between my local machine and the Ubuntu server using SSH?

A6. You can transfer files between your local machine and the Ubuntu server using the scp command.

Q7. How do I set up SSH tunneling?

A7. You can set up SSH tunneling using the ssh -L command.

Conclusion

Congratulations! You have successfully learned how to host an SSH server on Ubuntu. We covered the installation of Ubuntu server, installation of OpenSSH server on Ubuntu, configuring SSH server on Ubuntu, creating SSH keys, connecting to SSH server on Ubuntu, securing SSH server on Ubuntu, using SSH for remote access, using SSH for file transfer, using SSH for port forwarding, setting up SSH