UFW commands on Ubuntu/Debian for Port Open & Close

• Open a port: sudo ufw allow 22

• Close a port: sudo ufw deny 22

• Allow a range of ports: sudo ufw allow 22:53

• Add a rule: sudo ufw insert 1 allow 80

• Remove a rule: sudo ufw delete deny 22

• Check UFW status: sudo ufw status

• Check UFW rule number: sudo ufw status numbered

• Start UFW: sudo ufw enable

• Disable UFW: sudo ufw disable

• Reset firewall rules: sudo ufw reset