| With the proliferation of wireless access points (WAPs), virtual private networks (VPNs), and extranets, it’s becoming increasingly difficult to determine where your network begins and ends. Add this complexity to common economic factors, such as company mergers and acquisitions, and now you have a tangled web of interconnected segments and networks that you will need to understand. While this book aims at providing you the necessary tools to protect your network infrastructure assets, it is imperative that before we dive into the details you have a good understanding of how your network is designed.
Having a commanding knowledge of your network topology today is no simple feat. We are often reminded of a financial services company at which we performed some consulting work.This company has grown over the past few years by acquiring related financial companies. At the end of the day, this team of network engineers had to manage over 300 Frame Relay lines, over 100 Microsoft Windows NT 4.0 domains, and numerous Internet access points (IAPs).To add insult to injury, these networks are not static environments; in fact, there are numerous routing changes and firewall modifications made on a daily basis.The only saving grace this team of dedicated foot soldiers has are solid topology diagrams detailing each Frame Relay network and IAP, and a comprehensive list of all of their outwardly facing IP addresses.
While these tools sound like networking basics, we are constantly surprised at the number of IT departments that are without this information. Without knowing how your network is laid out, or understanding which segments touch the Internet directly, it will be nearly impossible for you to begin locking down your network devices. If you are not armed with these tools already, this chapter will help you find your external IP address presence and help you get a handle on understanding the differences between your core network segments and those that lie on your perimeter. Chapter 2, “Assessing Your Current Network,” will help provide you with those all-important topology maps if you aren’t fortunate enough to have them in your toolbox already. Furthermore, the end goal of this chapter is to arrive at common language that can be easily understood, and used throughout the entirety of the book. |