Introduction to Firewalls

If you know the basics of networking but have been mystified by firewalls, this course is for you. This course will give you the detailed fundamentals of how a stateful firewall operates and how it functions in a network.
Course info
Rating
(61)
Level
Intermediate
Updated
May 16, 2016
Duration
2h 0m
Table of contents
Description
Course info
Rating
(61)
Level
Intermediate
Updated
May 16, 2016
Duration
2h 0m
Description

Firewalls have quickly become a mandatory part of every network, and most IT professionals and developers have experienced a situation where their application isn't working on a network so it blames the firewall. This course, Introduction to Firewalls, will help you understand the basics of how they operate so that you will better understand their function in the network. First, you will learn the specific functions of a stateful firewall: the TCP state table followed by Network Address Translation. Next, you will see how these two services operate on non-specific firewall, and then see it in action on a Cisco ASA 5512 firewall. Finally, you will watch how DMZs are used and how we get pings through a firewall. By the end of this course, you will understand that a firewall is not just a "magic box," but an essential part of a network, and you'll also know how to get the most use out of them.

About the author
About the author

For nearly 20 years, Ross has taught and managed data networks.

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Section Introduction Transcripts
Section Introduction Transcripts

Course Overview
Hi everybody. My name is Ross Bagurdes, and welcome to my course, Introduction to Firewalls. I'm a network engineer with 20 years professional experience working in IT operations, specifically data networking and enterprise organizations. Firewalls are incredibly interesting devices, whose overall operation is complex, but the individual components that make it work are relatively simple. If you understand the simple components, the big picture of a firewall operation makes a lot of sense. In this course we're going to learn how the TCP state table allows traffic to flow from networks we trust to networks we don't trust, and back again. We're going to understand how we use NAT, specifically source NAT to connect private networks to the internet, and we're going to understand what a DMZ is and why we use it. By the end of this course you'll have a solid understanding of the features that make a stateful firewall operate. Before beginning the course you should be familiar with basic network functionality, including IP addressing and IP networks, TCP operation including the three-way handshake and port numbers, and the a basic understanding of packet encapsulation. From here you should feel comfortable diving into more data networking with courses on CCNA - Routing and Switching, Introduction to Wireshark, and Troubleshooting with Wireshark - Fundamental Protocol Analysis. I hope you'll join me on this journey to learn firewall operation with the Introduction to Firewalls course at Pluralsight.

Introduction
Welcome to Pluralsight, I'm Ross Bagurdes. This is Introduction to Firewalls. Before you dive into this course, you need some prereqs. You're going to need to understand the basics of IP addressing and IP subnets. Additionally, you're going to need to know how IP routing, how packets route through a network, you will need an understanding of how TCP operates, at least at the basic level with a three-way handshake, and last, you'll want to know some basics about how access control lists work. There's a few courses you can watch to get you up to speed with this. One of them is the CCNA series, the Cisco Certified Network Associate series on Pluralsight, and if you watch the first half of that, that'll cover all the information that you need to dive into this course. If you want some supplemental information to get into a deeper dive into TCP operation, I'd recommend looking at the Intro to Wireshark course, as well as the Troubleshooting Protocols with Wireshark course. Assuming you have all of that, let's dive into this course. Here's what we want to accomplish in this module. Why is it that we need firewalls? What's our firewall doing? What are zones and policies and how does that make the firewall operate the way we want it to? We're going to take a look at some desired behavior of the firewall. And then we're going to look at the TCP state table, which is the primary focus of this course to talk about stateful firewalls, and they're stateful because of this TCP state table. Let's start off.