CompTIA Security+ (SY0-701)General Security ConceptsMedium

A company redesigns its data center entrance so that an employee must badge into a small enclosed space, wait for the outer door to close, and then badge again before the inner door opens. What is this physical security control called?

  1. ABollard system
  2. BPerimeter fencing
  3. CFaraday cage
  4. DAccess control vestibule
Show answer & explanation

Correct answer: D. Access control vestibule

An access control vestibule (formerly called a mantrap) uses two interlocking doors to allow only one authenticated person through at a time, preventing tailgating.

Why the other options are wrong

  • A. Bollards are posts used to stop vehicles, not control pedestrian entry.
  • B. Perimeter fencing establishes an outer boundary but doesn't involve interlocking doors.
  • C. A Faraday cage blocks electromagnetic signals and has nothing to do with physical entry control.

Access Control Vestibule

A physical security mechanism with two interlocking doors that only allows one person to pass through at a time after authentication, preventing tailgating.

  • Formerly known as a mantrap
  • Only one door opens at a time
  • Effective anti-tailgating/piggybacking control

Memory trick: One door closes before the next opens — no tailgaters allowed.

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