The default Ubuntu firewall is ufw, with is short for "uncomplicated firewall.” Ufw is a frontend for the typical Linux iptables commands but it is developed in such a way that basic firewall tasks can be performed without the knowledge of iptables. Additionally, ufw can be managed from a graphical interface. In this article you will learn how to enable and disable firewall on Ubuntu 20.04 LTS Focal Fossa Linux.
This is a companion discussion topic for the original entry at https://linuxconfig.org/how-to-enable-disable-firewall-on-ubuntu-20-04-lts-focal-fossa-linux