Ubuntu Server Setup

1. User Management

Running commands as the `root` user is dangerous. The first step is always creating a new user and granting them administrative privileges.

Create a new user

adduser new_username

The system will prompt you to enter and confirm a password. You can skip the additional informational fields by pressing Enter.

Grant Sudo Privileges

Add the newly created user to the sudo group so they can execute administrative commands:

usermod -aG sudo new_username

2. Securing SSH Access

By default, SSH allows password authentication. Switching to SSH keys and disabling root password logins drastically reduces vulnerability to brute-force attacks.

Edit SSH Configuration

Open the SSH daemon configuration file:

sudo nano /etc/ssh/sshd_config

Find the following lines and modify them accordingly:

# Disable root login via password (keys still work if configured)
PermitRootLogin prohibit-password

# Ensure password authentication is allowed for normal users
PasswordAuthentication yes

Restart SSH Service

Apply the changes by restarting the service:

sudo systemctl restart ssh

Note: Always test your connection in a new terminal window before closing your current root session!

3. Basic UFW Firewall Setup

Ubuntu's Uncomplicated Firewall (UFW) provides an easy-to-use interface for managing iptables.

Allow SSH Connections

Before enabling the firewall, you must allow SSH traffic, otherwise you will lock yourself out of the server:

sudo ufw allow OpenSSH

Enable the Firewall

sudo ufw enable
sudo ufw status

4. Package Management & Updates

Keep your server secure by regularly updating the local package index and upgrading installed software.

Update & Upgrade

sudo apt update && sudo apt upgrade -y

Remove Unused Packages

Clean up dependencies that are no longer needed:

sudo apt autoremove -y