How to Set Up SSH Access for Users on Ubuntu 24.04

Secure Shell (SSH) is a critical tool for managing remote servers securely. In this guide, we will walk through the process of setting up SSH access for users on Ubuntu 24.04.

Prerequisites

• A system running Ubuntu 24.04.
• A user with sudo privileges.
• SSH installed on both the client and server.

Step 1: Install OpenSSH Server

First, ensure the SSH server is installed and running:

sudo apt update && sudo apt install -y openssh-server

After installation, verify that the SSH service is active:

sudo systemctl status ssh

If the service is not running, start and enable it:

sudo systemctl enable --now ssh

Step 2: Create a New User

If the user does not already exist, create one:

sudo adduser newuser

Then, add the user to the sudo group if administrative privileges are needed:

sudo usermod -aG sudo newuser

Step 3: Configure SSH Access

Ensure the new user can access the server via SSH by switching to their account and creating the .ssh directory:

sudo -u newuser mkdir -p /home/newuser/.ssh
sudo -u newuser chmod 700 /home/newuser/.ssh

Step 4: Set Up SSH Key Authentication (Recommended)

For secure access, set up SSH key authentication:

Generate an SSH key pair on the client machine:

<code>ssh-keygen -t ed25519 -C "newuser@yourserver"</code>

Copy the public key to the server:

ssh-copy-id newuser@yourserver_ip

Alternatively, manually copy the key:

cat ~/.ssh/id_ed25519.pub | ssh newuser@yourserver_ip 'mkdir -p ~/.ssh && cat >> ~/.ssh/authorized_keys'

Set correct permissions:

sudo chmod 600 /home/newuser/.ssh/authorized_keys sudo chown -R newuser:newuser /home/newuser/.ssh

Step 5: Configure SSH Server Settings

Edit the SSH daemon configuration file:

sudo nano /etc/ssh/sshd_config

Make the following adjustments for improved security:

Disable root login:

PermitRootLogin no

Allow only specific users:

AllowUsers newuser

Disable password authentication (only if key-based authentication is set up):

PasswordAuthentication no

Save and exit the file, then restart SSH:

sudo systemctl restart ssh

Step 6: Test SSH Access

From a client machine, test the SSH connection:

ssh newuser@yourserver_ip

If using an SSH key, ensure the private key is in ~/.ssh/ and has the correct permissions (chmod 600 ~/.ssh/id_ed25519).

Step 7: (Optional) Configure a Firewall

If UFW (Uncomplicated Firewall) is enabled, allow SSH traffic:

sudo ufw allow OpenSSH
sudo ufw enable
sudo ufw status

Conclusion

Setting up SSH access on Ubuntu 24.04 is essential for secure remote management. By configuring key-based authentication and restricting access, you enhance the security of your server. Regularly review SSH logs (sudo journalctl -u ssh) and apply updates (sudo apt update && sudo apt upgrade -y) to maintain security.

FAQ

1. How can I check if SSH is running on my server?

You can check the status of the SSH service with:

sudo systemctl status ssh

2. What should I do if SSH connection is refused?

• Ensure SSH is installed and running: sudo systemctl start ssh
• Verify the firewall allows SSH: sudo ufw allow OpenSSH
• Check if the correct user has SSH access in /etc/ssh/sshd_config.

3. How do I change the default SSH port?

Edit /etc/ssh/sshd_config and modify:

Port 2222

Then restart SSH:

sudo systemctl restart ssh

4. How can I disable password authentication completely?

Edit /etc/ssh/sshd_config and set:

PasswordAuthentication no

Restart SSH to apply changes:

sudo systemctl restart ssh

5. How do I allow multiple users to connect via SSH?

Add multiple usernames to the AllowUsers directive in /etc/ssh/sshd_config, e.g.:

AllowUsers user1 user2 user3

Restart SSH:

sudo systemctl restart ssh

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Anastasios Antoniadis

Editor-in-Chief at Beyond Tech Now

Anastasios Antoniadis is the Editor in Chief of Beyond Tech Now, where he leads a diverse team of writers and analysts delivering industry-breaking news, hands-on product reviews, and thoughtful commentary on emerging technologies. With over a decade of experience in digital media, John has a proven track record of shaping editorial vision and driving engagement through high-quality, reader-focused content. He is particularly passionate about the intersection of AI, cybersecurity, and consumer electronics—striving to make complex tech topics accessible to a global audience. When he’s not collaborating with writers or liaising with tech leaders, Anastasios can be found experimenting with the latest gadgets or sharing insights at tech conferences around the world.

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