Dear readers, I appear to have set a Paranoid Penguin record—six months spent on one article series. (It has consisted of five installments, with a one-month break between the second and third pieces.

Every self-respecting Linux guru should be familiar with firewalls and how to install and configure them. With this in mind, Linux gurus also should be curious about how firewalls function and how to ...

In our first installment, we described why you need a Linux-based network appliances. Today, we’re going to start construction. (Please see the Introduction to this series for hardware requirements.) ...

The ufw (uncomplicated firewall) represents a serious simplification to iptables and, in the years that it’s been available, has become the default firewall on systems such as Ubuntu and Debian. And, ...

My firewall is set to "deny by default" for incoming traffic. Is that all there is to it or do I need to add certain rules to keep my PC secure? Is the Linux firewall like the Windows firewall? What ...