<https://ftlinuxcourse.com/firewall-iptables-no-linux-parte-01-tabelas-cadeias-e-regras#webpage>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://ftlinuxcourse.com/firewall-iptables-no-linux-parte-01-tabelas-cadeias-e-regras>