Tag: cli

Here’s a comprehensive sudo ufw (Uncomplicated Firewall) cheatsheet for managing firewall rules on an Ubuntu server:

Basic UFW Commands

• Enable UFW:
  sudo ufw enable
• Disable UFW:
  sudo ufw disable
• Check UFW Status:
  sudo ufw status
• Use sudo ufw status verbose for detailed output.
• Reset UFW (removes all rules and disables UFW):
  sudo ufw reset

Allowing Connections

• Allow a Specific Port:
  sudo ufw allow <port>
• Example: sudo ufw allow 22 (allows SSH)
• Allow a Port with a Specific Protocol:
  sudo ufw allow <port>/<protocol>
• Example: sudo ufw allow 80/tcp (allows HTTP)
• Allow a Range of Ports:
  sudo ufw allow <start port>:<end port>/protocol
• Example: sudo ufw allow 1000:2000/tcp
• Allow Connections from a Specific IP:
  sudo ufw allow from <IP>
• Example: sudo ufw allow from 192.168.1.100
• Allow Connections from an IP to a Specific Port:
  sudo ufw allow from <IP> to any port <port>
• Example: sudo ufw allow from 192.168.1.100 to any port 22
• Allow Subnet:
  sudo ufw allow from <subnet>
• Example: sudo ufw allow from 192.168.1.0/24

Denying Connections

• Deny a Specific Port:
  sudo ufw deny <port>
• Example: sudo ufw deny 23 (denies Telnet)
• Deny a Port with a Specific Protocol:
  sudo ufw deny <port>/<protocol>
• Example: sudo ufw deny 80/tcp
• Deny Connections from a Specific IP:
  sudo ufw deny from <IP>
• Example: sudo ufw deny from 192.168.1.100

Deleting Rules

• Delete a Rule by Rule Number:
  sudo ufw status numbered
• Then use sudo ufw delete <rule number>
• Delete an Allow Rule:
  sudo ufw delete allow <port>
• Example: sudo ufw delete allow 22
• Delete a Deny Rule:
  sudo ufw delete deny <port>
• Example: sudo ufw delete deny 23

Advanced UFW Usage

• Enable UFW Logging:
  sudo ufw logging on
• off to disable logging.
• Set Default Policies (Deny Incoming and Allow Outgoing):
  sudo ufw default deny incoming
sudo ufw default allow outgoing
• Set Default Policies (Allow Incoming and Deny Outgoing):
  sudo ufw default allow incoming
sudo ufw default deny outgoing
• Limit Connections (Rate Limiting):
  sudo ufw limit <port>
• Example: sudo ufw limit ssh (limits SSH connections to prevent brute force attacks)
• Allow Specific Service by Name:
  sudo ufw allow <service>
• Example: sudo ufw allow OpenSSH
• App Profiles (View Available Profiles):
  sudo ufw app list
• Allow Application Profile:
  sudo ufw allow <app profile>
• Example: sudo ufw allow 'Apache Full'

Checking UFW Status and Rules

• Check UFW Status:
  sudo ufw status
• Check UFW Status in Verbose Mode:
  sudo ufw status verbose
• Check UFW Status with Rule Numbers:
  sudo ufw status numbered

Other Useful Commands

• Reload UFW to Apply Changes:
  sudo ufw reload
• Show Detailed Report:
  sudo ufw show raw
• This displays the raw iptables rules used by UFW.

This cheatsheet covers common UFW commands and options, providing a solid reference for managing firewall settings on Ubuntu.