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.