How to Open/Allow incoming firewall port on Ubuntu 20.04 examples
- Open incoming TCP port 53 to any source IP address:
$ sudo ufw allow from any to any port 53 proto tcp - Open incoming TCP port 443 to only specific source IP address eg. 10.1.1.222:
$ sudo ufw allow from 10.1.1.222 to any port 443 proto tcp - Open incoming UDP port 53 to source subnet eg. 10.1.1.0/8:
$ sudo ufw allow from 10.1.1.0/8 to any port 53 proto udp - Open incoming TCP ports 20 and 21 from any source, such as when running an FTP server:
$ sudo ufw allow from any to any port 20,21 proto tcp - Open port for a specific web server such as Apache or Nginx execute the bellow Linux command:
$ sudo ufw allow in "Apache Full" $ sudo ufw allow in "Nginx Full" - Open port for a specific service such as SSH:
$ sudo ufw allow in ssh
