The Art of Network Architecture: Business-Driven Design

Chapter 9. Securing the Premises

Someone walks in through your front door and takes your television, so you put a lock on the front door. The next time, they break a window to get in, so you put in better window locks and hurricane glass. They bump your front door lock, so you replace it with a higher quality model that can’t be bumped. They kick the door in, so you replace the latch and jamb with stronger ones...

Security, in the real world, is like this—threat and attack, closing holes, and reacting to attacks. It’s a never-ending cycle (or even war) between attacker and defender; the attacker is always trying to find some new vulnerability to take advantage of, and the defender is always trying to remove vulnerabilities before they are exploited. ...