Defense in Depth

What specifics can you offer regarding the defense-in-depth (DiD) approach and the impact it has upon the various detection systems that might be employed? In regards to detection systems and the importance of testing them, what methods can be utilized to ensure the system perform to appropriate needs, expectations, and specifications?

The post should be at least 350 words. Please use the link below as well as the attachments as sources. APA format.

https://securitytoday.com/articles/2012/02/01/principles-for-intrusion-detection.aspx

Chapter 6 of:

https://web-b-ebscohost-com.ezproxy1.apus.edu/ehost/ebookviewer/ebook?sid=d6eb2b21-ea75-43a3-b5f2-7671c74174ca%40pdc-v-sessmgr01&ppid=pp_129&vid=0&format=EB