use these reference Knapp, &amp Langill. (2015). Industrial Net

use these reference Knapp, & Langill. (2015). Industrial Network Security :Securing Critical Infrastructure Networks for Smart Grid, SCADA, and Other Industrial Control Systems 2nd Ed. New York: Elsevier Inc.(you need to mention page number in citation.)For this discussion, read Guide to Increased Security in Industrial Control Systems Section B07-Create a multilayer defence (defence-in-depth) in industrial control systems 27 and then post your thoughts on the following topic:Explain how using a layered approach to security is required to deal with today’s advanced threats.Define what you feel is using a layered approach to security as it applies to Industrial Control SystemsProvide an example of how having two layers of defense might be able to thwart an attack that would have been successful with only one layerExplain how perimeter defense systems and interior defense systems can combine to create a layered approach