UFW Essentials: Common Firewall Rules and Commands
Introductio for UFW Essentials
UFW (uncomplicated firewall) is a firewall configuration tool that runs on top of iptables, included by default within Ubuntu distributions. It provides a streamlined interface for configuring common firewall use cases via the command line.
This cheat sheet-style guide provides a quick reference to common UFW use cases and commands, including examples of how to allow and block services by port, network interface, and source IP address.
How To Use This Guide for UFW Essentials
- This guide is in cheat sheet format with self-contained command-line snippets.
- Jump to any section that is relevant to the task you are trying to complete.
- Highlighted text in commands should refer to IP addresses from your network.
- Check your current UFW ruleset with
sudo ufw status
orsudo ufw status verbose
.
Verify UFW Status
To check if UFW is enabled, run:
sudo ufw status
Output:
Status: inactive
Enable UFW
If the firewall is inactive, enable it using:
sudo ufw enable
Output:
Firewall is active and enabled on system startup
Use sudo ufw status verbose
to see what is blocked or allowed:
Status: active
Logging: on (low)
Default: deny (incoming), allow (outgoing), deny (routed)
New profiles: skip
Disable UFW
To disable the firewall service, run:
sudo ufw disable
Note: This will fully disable the firewall service on your system.
UFW Essentials: Block an IP Address
To block all network connections from a specific IP address:
sudo ufw deny from 203.0.113.100
Output:
Rule added
Allow an IP Address
To allow all network connections from a specific IP address:
sudo ufw allow from 203.0.113.101
Output:
Rule added
Delete UFW Rule
To delete a rule, use:
sudo ufw delete allow from 203.0.113.101
Alternatively, use rule ID:
sudo ufw delete 1
Allow HTTP and HTTPS Traffic
To allow both HTTP and HTTPS traffic:
sudo ufw allow proto tcp from any to any port 80,443
Output:
Rule added
Conclusion for UFW Essentials
UFW is a powerful tool that enhances server security when configured correctly. It simplifies managing firewall rules efficiently. Use this guide as a quick reference for common firewall rules. With UFW, you can easily allow or block specific ports and IP addresses. Customize your server’s traffic to meet unique needs securely. Proper configuration ensures reliable protection against unauthorized access attempts.