Chapter 1. Security Threats

With the increase of hacking attacks, worms, viruses, and other networking threats, security is a major problem in today's networks. 10 to 15 years ago, security was a simple problem requiring simple solutions; in those days, the Internet was small and had only a small number of universities and government agencies connected to it. Aging passwords were used to protect accounts, and simple packet-filtering firewalls were used to restrict traffic flows. However, today is a different world from more than a decade ago. With the explosion of the Internet, the proliferation of software applications, and the ingenuity of hackers, security has become a complex problem that requires a well-thought-out security solution to deal with it. The security solution must be capable of dealing with the security threats that your network will face, but it also must allow your company to reach its business goals and must be flexible enough to adapt to network topology and technology changes.

This chapter contains a brief overview of the kinds of threats that you will face in securing your network, as well as some generic solutions that you can use to deal with these threats. Understanding these topics will greatly help you choose and implement the correct Cisco security feature on your router. The main purpose of this book is to explain how to use a Cisco perimeter router as a complete firewall solution or as a component of a firewall solution. The end of the chapter explains the Cisco Security Model, which is used to implement security solutions.