Summary
In this chapter, we discussed the many ways we can passively perform security monitoring on our ICS environment. We learned which typical passive security monitoring technologies there are and some of the common tools using these technologies, to show us the state of security in our environment.
The exercises in this chapter had us set up a pfSense firewall, a Security Onion sensor, and a Forescout SilentDefense (eyeInsight) IDS deployment, all of which will help us perform targeted searches and threat-hunting activities in upcoming chapters.
In the next chapter, we are going to get a bit more intrusive with the ICS environment, when we start interrogating things with active security monitoring activities and tools.
