Setting up a basic firewall

[hiromipaw]

Firewalls are used to make sure only certain connections to specific services are allowed. In this task you have to install and use the UFW firewall to help set firewall policies and manage exceptions.

[kushaldas]

We should do this in a Debian VM. For CentOS, there is standard firewalld or old school iptables-persistance package

[warthog9]

Advanced usage: use nftables instead of iptables / ip6tables.

Also disable firewalld / most firewall helpers, as in "servers" these are little more then annoyances