How It All Fits Together

This book explains how to implement security products from Cisco to mitigate or reduce the amount of risk that our companies and customers face. If there were a single magic button that we could press that both allowed the functionality we need and provided adequate security at the same time, that button would be a hot seller. Unfortunately, no magic button exists. However, what we do have are solid principles and guidelines that we can use to implement security on our networks today.

As you work through the rest of this book, keep in mind the concepts of confidentiality, data integrity, and availability (remember, CIA) for every single concept discussed. For example, the section on VPNs focuses on the different types of VPNs and how to implement them. You even learn how configure one of them. It is easy to get wrapped up in the details of how to do this or how to do that, but what you want to look at is which aspects of CIA a specific technology implements. In the case of VPNs, they protect the data with encryption, and so the concept of confidentiality applies. VPNs can also hash, which implements data integrity. If you are reading this book in hard-copy format, you might want to take three highlighters, one for each of the letters in CIA, and mark the technologies that address these exact issues as you encounter them in your reading of this book.

By keeping your mind open to the reasons for each and every technology we discuss, you can more easily build an overall fortress of security that everybody wants for mission-critical networks.