Firewall Fundamentals

We have seen security guards outside shopping malls, banks, restaurants, and houses. These guards are placed at the entrances of these areas to keep a check on people coming in or going out. The purpose of maintaining this check is to ensure nobody sneaks in without being permitted. This guard acts as a wall between his area and the visitors.

A lot of incoming and outgoing traffic flows daily between our digital devices and the Internet they are connected to. What if somebody sneaks in between this massive traffic without getting caught? We would also need a security guard for our digital devices then, who can check the data coming in and going out of them. This security guard is what we call a firewall. A firewall is designed to inspect a network's or digital device’s incoming and outgoing traffic. The goal is the same as for the security guard sitting outside a building: not letting any unauthorized visitor enter a system or a network. You instruct the firewall by giving it rules to check against all the traffic. Anything that comes in or goes out of your device or network would face the firewall first. The firewall will allow or deny that traffic based on its maintained rules. Most firewalls today go beyond rule-based filtering and offer extra functionalities to protect your device or network from the outside world. We will discuss all these firewalls and perform practical lab demonstrations on a few. 

Learning Objectives

After completing the room, you will have a basic understanding of the following areas:

• The types of firewalls
• The firewall rules and its components
• Hands-on Windows built-in firewall 
• Hands-on Linux built-in firewall 

Room Prerequisites

• Networking Concepts