Network attacks are always preceded by a phase of information collection whereby potential attackers scan and probe the target network for vulnerabilities to determine which type of attack to attempt. This activity is known as “reconnaissance” and it is an integral and essential part of most attacks. Without reconnaissance information,
it is virtually impossible to successfully attack a network

When opening your e-business perimeters to consumers and business partners, system-level security becomes critical as a result of the increase in exposure points. In today’s computing environments, system security is a game of numbers: If you consider that hundreds of new vulnerabilities are being discovered annually, and the fact that a hacker only has to find one point of entry to access your network, it becomes clear that the odds are not in your favor and every hole needs to be patched.