'A firewall is something we are used to with day to day intern | Jeffrey Peterson - jeff.pro

"A firewall is something we are used to with day to day internet life. There is a simple and effective one for Linux that can be setup and used in a matter of minutes. Some distros will even make sure this step is done during the beginning setup of the system. Linux Mint is a good example here."

https://www.howtoforge.com/ufw-uncomplicated-firewall-on-ubuntu/