Network Access Control (NAC) is a security framework that controls who or what can access a network. It enforces authentication, compliance checks, and security policies before granting entry to devices or users.
What is NAC?
NAC ensures only authorized and compliant devices gain network access. It authenticates users and devices, checks for security posture, and blocks or quarantines non-compliant systems.
Why is NAC Important?
- Security: prevents unauthorized devices from entering.
- Compliance: ensures systems meet policies (e.g., antivirus, patches).
- Visibility: provides IT teams with insights into all connected devices.
How Does NAC Work?
- Authentication – verifies device and user identity.
- Compliance Check – ensures device health meets requirements.
- Policy Enforcement – grants or denies access.
- Monitoring – tracks behavior continuously.
NAC vs Firewall
A firewall controls data flow within a network. NAC controls entry to the network. Together, they provide layered defense.
Use Cases
- Securing BYOD (Bring Your Own Device) environments.
- Enforcing compliance in regulated industries.
- Preventing unauthorized IoT devices from connecting.
Related Terms
See also: [Network Controller], [Network Interface Controller], [Network Controller Driver], [Adaptive Network Control].
Frequently Asked Questions
It can be both—appliances, cloud-based solutions, or integrated with controllers.
No. Modern NAC solutions are optimized to enforce policies without latency.
It enforces access rules, isolates risky devices, and ensures compliance.
