@ Admin - Suppose someone tries to hack (SSH) into your computer (Linux) can they do so without the root Username and Password? If not what is the whole point of Firewall. Maybe it would be useful to stop access of miscellaneous software from accessing Internet and trying to share sensitive information (like a trojan) But wait, all the software (Pretty Much ) come from App. Store/ Reliable sources anyway, so the chances of having these software on Linux system are very low. So My question is - How useful is Firewall, except for the fact that it Will consume resources like CPU and Ram to Run in the background. I have never used Firewall, since I dont know last few years and never had any problem on my Linux Laptop.