Summary

This chapter provided a brief introduction to IDS and IPS, including the need for them and the role these systems play in the defense-in-depth strategy. The chapter then discussed the different types of IDS, the current state of the art in the field, and some of the key metrics used to evaluate IDS and IPS.

In the following chapter, we will look at Snort, one of the most popular open source IDS/IPS and discuss the evolution of Snort from its early stage to where it is now.