To open up a new port (e.g., 80,21,22,3306 ) permanently, use these commands.
sudo firewall-cmd --zone=public --add-port=80/tcp --permanent sudo firewall-cmd --zone=public --add-port=3306/tcp --permanent sudo firewall-cmd --zone=public --add-port=21/tcp --permanent sudo firewall-cmd --zone=public --add-port=22/tcp --permanent sudo firewall-cmd --reload
Without “–permanent” flag, the firewall rule would not persist across reboots.
Check the updated rules with
$ firewall-cmd --list-all