Show description

If their attack fails, they will likely go elsewhere and keep trying. Additional risk comes from the fact that they often use these tools with little to no knowledge of the target environment, so attacks can wind up causing unintended results. These attacks are usually detectable with current security tools. Structured attacks are more worrisome because they are conducted by hackers with significant skill. They are able to discover new vulnerabilities in systems by executing complex actions that the system designers did not protect against.

Qxd 12 9/18/03 4:33 PM Page 12 Part I • Introduction to Network Security & Firewalls not authorized to access the systems. Firewalls were the primary focus of these efforts. ). Perimeter defense is still vitally important, given the increased threat level from outside the network. However, it is simply no longer adequate by itself. The insider is potentially more dangerous than outsiders because he or she has a level of access that the outsider does not—to both facilities and systems. Many organizations lack the internal preventive controls and other countermeasures to adequately defend against this threat.

You can only take steps to protect your network and its resources from those who “break and enter” networks for fun or profit. This is truer today than in the past because networks have more ways in than they once did. A medium-sized or large network can have multiple dial-in servers, virtual private network (VPN) servers, and a dedicated full-time Internet connection. Even a small network is likely to be connected to the Internet part of the time. This matter is often left up to facilities managers and plant security departments or outsourced to security guard companies.