CHAPTER 28 Firewalls
What You Will Learn
In this chapter, you will learn how firewalls add security to TCP/IP networks. We’ll be working with both kinds of router-based firewalls: packet filters and stateful inspection.
You will learn about the types of dedicated firewalls that run on purpose-built hardware. We’ll also examine firewall architectures and the use of DMZs. And because filtering works exactly the same with IPv6 as with IPv4, we will not have a special section on IPv6 firewalls.
If all data traveled the Internet encrypted inside VPNs, and all hosts only sent or received such data, the Internet would be a safer place. But the reality is messy—very messy—and denial of service attacks, hacker raids, spyware, spam, viruses, and worms ...