The corporate network perimeter is not what is used to be.
A decade ago, companies focused on securing the perimeter, making sure that the inside of the network remained a safe, trusted environment, while attempting to create a digital wall to keep out the Internet vandals. Security professionals realized over time that defense-in-depth should extend within the network, because attackers inevitably get inside. In addition, with employees bringing in mobile devices and nomadic employees working from a variety of unsecured locations outside the corporate network, the definition of the perimeter has changed.
Analysts and some security firms talked about the end of the perimeter, coining the abstruse term “de-perimeterization.” Instead of going away, however, an organization’s security perimeter has simply become more distributed, says Jody Brazil, president and chief technology officer of FireMon, a configuration and policy management firm.
“Instead of thinking about a big circle around your entire enterprise, you need to start thinking about little circles around critical elements of your network,” he says. “A little circle around your data center, a little circle around your point-of-sale systems, and a little circle around your mobile users. Instead of one big perimeter, you end up with these smaller segmentations–you can think of them as mini-perimeters.”