An access control vestibule is a physical security concept that limits personnel access to a restricted area within a data center. It is a small room or hallway that has two doors: one that leads to the outside and one that leads to the restricted area. The doors are controlled by an electronic lock that requires authentication, such as a card reader, biometric scanner, or keypad. Only authorized personnel can enter the vestibule and access the restricted area. References: CompTIA Server+ Certification Exam Objectives, Domain 5.0:
Security, Objective 5.1: Given a scenario, apply physical security methods to a server.