TABLE OF CONTENTS Everything old becomes new again. The goal of this chapter is to take the well-known Open Systems Interconnect (OSI) model and use it to present security topics in a new and unique way. While each of the subsequent chapters focuses on one individual layer, this chapter offers a high-level overview of the entire book.
This book is compiled of issues and concerns that security professionals must deal with on a daily basis. We look at common attack patterns and how they are made possible. Many attacks occur because of poor protocol design; others occur because of poor programming or lack of forethought when designing code. Finally, the tools that are useful for identifying and analyzing exploits and exposures are discussed the tools you will return to time and time again.
| Warning | Many of the tools discussed in this book can be used by both security professionals and hackers. Always make sure you have the network owner s permission before using any of these tools, which will save you from many headaches and potential legal problems. |
The following sections examine protocol analyzers and the Intrusion Detection Systems (IDSes), which are the two main tools used throughout this book.
Protocol analyzers (or sniffers) are powerful programs that work by placing the host system s network card into promiscuous mode, thereby allowing it to receive all of the data it sees in that particular collision domain. Passive sniffing is performed...
