Why is network segmentation so important? “Today, there is still more focus on the perimeter than on internal network segmentation. Network engineers don’t realize that one successful social engineering or client-side attack could mean ‘game over’ once the attacker has that foothold,” Sanders says. Segmentation based on asset importance and level of trust is one of the most effective ways to prevent many of the attacks advanced attackers — and even himself — perform once inside a target network, he says.

via Tech Insight: What Penetration Testers Find Inside Your Network – Dark Reading.