Eccouncil Exam 312-38 Topic 9 Question 68 Discussion

Damian is the chief security officer of Enigma Electronics. To block intruders and prevent any environmental accidents, he needs to set a two-factor authenticated keypad lock at the entrance, rig a fire

suppression system, and link any video cameras at various corridors to view the feeds in the surveillance room. What layer of network defense-in-depth strategy is he trying to follow?