TODO

nftables
========
https://wiki.debian.org/nftables

* nftables is a framework by the Netfilter Project that provides
  packet filtering, network address translation (NAT) and other packet
  mangling.
* Two of the most common uses of nftables is to provide firewall
  support and NAT.
* nftables replaces the iptables framework.

Moving from iptables to nftables
--------------------------------
https://wiki.nftables.org/wiki-nftables/index.php/Moving_from_iptables_to_nftables


firewalld
=========
https://firewalld.org/

* RHEL 7, CentOS 7, Fedora 18 and newer

firewalld – Manage arbitrary ports/services with firewalld
----------------------------------------------------------
https://docs.ansible.com/ansible/latest/modules/firewalld_module.html
* Not tested on any Debian based system.

Using Firewalld on Ubuntu 18.04
-------------------------------
https://computingforgeeks.com/install-and-use-firewalld-on-ubuntu-18-04-ubuntu-16-04/

man firewalld
-------------
http://manpages.ubuntu.com/manpages/bionic/man1/firewalld.1.html
* firewalld provides a dynamically managed firewall with support for
  network/firewall zones to define the trust level of network
  connections or interfaces.
* firewalld has a D-Bus interface for firewall configuration of
  services and applications.  It also has a command line client for
  the user. Services or applications already using D-Bus can request
  changes to the firewall with the D-Bus interface directly.

docs
====

* Complete docs/annotation/vars