Securing Windows NT/2000 Servers for the Internet

Chapter 7. Maintaining Your Perimeter Network

Even after the perimeter network is implemented, I’m afraid there’s still a lot left to do. Your perimeter network changes as your business requirements do, and each change introduces new challenges. This chapter describes some methods that help maintain the security of the perimeter network and its components as your business grows and changes.

The perimeter network is a constantly changing environment. Usually, business demands drive change, but technology and security needs also play a role. For example, you must patch or upgrade your system when a new vulnerability is discovered.

Assume that you need to keep evaluating and changing the perimeter network and plan accordingly.

Setting Up Policies and Procedures

Running a perimeter network is a tough job. It involves having good policies, methodologies, and technical expertise. It also requires speed. Information travels faster and faster as the Internet grows. People can share knowledge regardless of where they are located by using tools such as IRC (Internet Relay Chat), web sites, and email. Ten years ago, it took days or weeks for hackers to spread information about their exploits around the globe. This process now takes just minutes or hours. If a skilled hacker discovers a new vulnerability and writes a program to exploit it, the program can be in the hands of thousands of less-skilled hackers^[57] within an hour. These hackers don’t even have to understand the vulnerability ...