Introduction
Firewalld is a firewall management solution available for many Linux distributions which acts as a frontend for the iptables packet filtering system provided by the Linux kernel. In this guide, we will cover how to set up a firewall for your server and show you the basics of managing the firewall with the firewall-cmd administrative tool (if you'd rather use iptables with CentOS, follow this guide).
sudo firewall-cmd --zone=public --permanent --add-port=5000/tcp
sudo firewall-cmd --zone=public --permanent --add-port=4990-4999/udp
sudo firewall-cmd --zone=public --permanent --list-ports
sudo firewall-cmd --reload
firewall-cmd --get-services
firewall-cmd --zone=public --remove-port=3306/tcp --permanent
reference: www.digitalocean.com/community/t…
