Access Control Fundamentals

15.2. Intrusion Prevention System

The traditional IDS only detects that something bad may be taking place and sends an alert. The goal of an IPS is to detect this activity and not allow the traffic to gain access to the target in the first place.

An IPS is a preventative and proactive technology, whereas an IDS is a detective and after-the-fact technology.

There has been a long debate on IPS and it turned out to be an extension of IDS and everything that holds for IDS also holds for IPS apart for IPS being preventative and IDS being detective. 

Honey Pots