Firewalld

FirewallD is DBUS-enabled firewall software for Linux, which works on top of the in-kernel iptables firewall. It was created by RedHat, but it is available on many Linux distributions, including in Gentoo as.

From the project homepage:


 * 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.

Its documentation is available on the project website in HTML format.

Configuration
Configuration may be modified with ; changes will remain in effect until the service is restarted. To persist changes, either: or:
 * Run after  is in the desired state
 * Include the flag with a given command. Running  will be required for the changes with  to take effect.