How to Configure FirewallD in RHEL, CentOS and Fedora

Net-filter as we all know it’s a firewall in Linux. Firewalld is a dynamic daemon to manage firewalls with support for network zones. In the earlier version, RHEL & CentOS 6 we have been using iptables as a daemon for packet filtering framework. In RHEL/CentOS 7/8 and Fedora iptables interface is being replaced by firewalld.