What is firewalld ?
Firewalld provides a dynamically managed firewall with support for network/firewall zones that define the trust level of network connections or interfaces. It has support for IPv4, IPv6 firewall settings, ethernet bridges and IP sets. There is a separation of runtime and permanent configuration options. It also provides an interface for services or applications to add firewall rules directly.
Features
- Complete D-Bus API
 - IPv4, IPv6, bridge and ipset support
 - IPv4 and IPv6 NAT support
 - Firewall zones
 - Predefined list of zones, services and icmptypes
 - Simple service, port, protocol, source port, masquerading, port forwarding, icmp filter, rich rule, interface and source address handlig in zones
 - Simple service definition with ports, protocols, source ports, modules (netfilter helpers) and destination address handling
 - Rich Language for more flexible and complex rules in zones
 - Timed firewall rules in zones
 - Simple log of denied packets
 - Direct interface
 - Lockdown: Whitelisting of applications that may modify the firewall
 - Automatic loading of Linux kernel modules
 - Integration with Puppet
 - Command line clints for online and offline configuration
 - Graphical configuration tool using gtk3
 - Applet using Qt4