Common Network Attack Strategies

By Edward Tetz from Cisco Networking All-in-One For Dummies

Two main types of attacks take place on a network: those that are run from inside the network and those that try to make their way in from the network’s perimeter.

Although everyone wants to trust the people that they work with, a large number of attacks occur from within your network. These attacks may be from employees or from non-employees who are in your building, and on your network.

Although much of the focus on security deals with the perimeter of your network and the access points, you must not forget about the inside of your network and what you can do to defend yourself after the attacker is inside. The most common types of internal attacks are packet sniffing, man in the middle, cached credentials, masquerade, and network scanning.

Attacks that start from outside a network fall into a couple of categories: They tend to be either denial of services (DoS) or attempts to gain access and exploit a system. In many cases, these are both one and the same. When your devices are running correctly, they have space to log data and access attempts, and applications — especially the security applications — all have enough memory to operate.

Many of the attacks in the DoS category flood the systems with so much data that these data logs overflow (so you cannot see what the attacker is attempting), and security applications or processes run out of memory and possibly shut down or malfunction. When your system has nonfunctioning security applications and a lack of logging, the attacker can take control of that system to further her access on your network.