CompTIA Network+ (N10-009)Network SecurityMedium

A company wants to ensure that any device connecting to its network first has up-to-date antivirus definitions and OS patches before being granted full network access. Which technology should be implemented?

  1. AVLAN tagging
  2. BPort mirroring
  3. CDHCP snooping
  4. DNetwork access control (NAC)
Show answer & explanation

Correct answer: D. Network access control (NAC)

Network Access Control (NAC) performs posture assessment, checking device compliance (patch level, antivirus status) before granting or restricting network access, often placing non-compliant devices into a quarantine VLAN.

Why the other options are wrong

  • A. VLAN tagging segments traffic but doesn't assess device compliance.
  • B. Port mirroring copies traffic for monitoring, it doesn't control access.
  • C. DHCP snooping prevents rogue DHCP servers, unrelated to posture checks.

Network Access Control (NAC)

A security solution that enforces policy compliance (e.g., patch level, antivirus) on devices before granting them network access.

  • Performs posture/health assessment of endpoints
  • Can quarantine non-compliant devices to a remediation VLAN
  • Often integrates with 802.1X for authentication plus posture checking

Memory trick: NAC is the bouncer checking your health pass before entry.

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