As you may have noticed in the previous chapters, Cisco IOS routers and switches can do much more than just forward frames and packets to their destinations; they can provide network security features. In this chapter, we'll discuss the functionality of both an Intrusion Detection System (IDS) and an Intrusion Prevention System (IPS). These technologies are very similar, however, we will take a look at their differences and the placement of each in a network topology.

In this chapter, we'll cover the following:

• The terminologies used when discussing IDS and IPS
• The characteristics of an IDS
• The characteristics of an IPS
• Configuring an IPS on a Cisco IOS router

Let's begin!