How to Set Up a Firewall Using UFW on Linux Print

A firewall helps protect your VPS by controlling which incoming and outgoing connections are allowed. UFW(Uncomplicated Firewall) is a simple yet powerful tool available on Debian-based systems like Ubuntu.

This guide shows you how to install, configure, and manage a firewall using UFW.

Step 1: Install UFW (if not already installed)

First, connect to your server via SSH:

ssh root@your_server_ip

Then install UFW:

apt install ufw

Step 2: Check UFW Status

To see if UFW is active:

ufw status

If it’s inactive, you’ll see:

Status: inactive

Step 3: Allow SSH Access First

Before enabling the firewall, make sure SSH access is allowed, or you may lock yourself out.

ufw allow ssh

Or explicitly allow port 22 (default SSH port):

ufw allow 22

If you’re using a different SSH port (e.g., 2222):

ufw allow 2222

Step 4: Allow Other Common Services (Optional)

• HTTP (Web Server):

ufw allow http

• HTTPS (Secure Web Server):

ufw allow https

• FTP:

ufw allow ftp

You can also allow specific ports like:

ufw allow 80     # HTTP
ufw allow 443    # HTTPS

Step 5: Enable UFW

After setting your rules, activate UFW:

ufw enable

Confirm with y when prompted.

Step 6: Check Rules

To list the currently active rules:

ufw status

To get more detailed output:

ufw status verbose

Step 7: Managing UFW Rules

• Deny a port:

ufw deny 23

• Delete a rule:

ufw delete allow 80

• Disable UFW:

ufw disable

• Reset UFW (clears all rules):

ufw reset

Step 8: Allow Specific IP Address

To allow only a specific IP to access a port:

ufw allow from 203.0.113.10 to any port 22

Conclusion

Setting up a firewall using UFW is a quick and effective way to enhance your VPS security. Always ensure SSH access is allowed before enabling the firewall to avoid being locked out.

If you need help with firewall configuration or recovery access, contact Hosteons Support.