3.3 Network Access Control (NAC) Solutions Explained

Network Access Control (NAC) is a security solution that ensures only authorized devices can access a network. It involves a set of policies and technologies designed to enforce security requirements on all devices attempting to connect to a network. Below, we will explore three key NAC solutions: Pre-Admission, Post-Admission, and Hybrid NAC.

Pre-Admission NAC

Pre-Admission NAC solutions enforce security policies before a device is granted access to the network. This typically involves checking the device's compliance with security requirements, such as having up-to-date antivirus software, operating system patches, and proper configuration settings.

Example: When a laptop tries to connect to a corporate network, the Pre-Admission NAC solution checks if the device has the latest security patches and antivirus definitions. If the device is compliant, it is granted access; otherwise, it is denied or placed in a quarantine network until it meets the requirements.

Post-Admission NAC

Post-Admission NAC solutions enforce security policies after a device has been granted initial access to the network. This approach allows devices to connect to the network first and then continuously monitors and enforces compliance with security policies.

Example: After a device connects to the network, the Post-Admission NAC solution continuously monitors its security status. If the device becomes non-compliant, such as by failing to apply a critical security update, the NAC solution can restrict its network access or enforce remediation actions.

Hybrid NAC

Hybrid NAC solutions combine elements of both Pre-Admission and Post-Admission NAC. They provide initial access based on pre-admission checks and then continuously monitor and enforce security policies after the device is on the network.

Example: A Hybrid NAC solution first checks a device's compliance before granting access, similar to Pre-Admission NAC. Once the device is on the network, the solution continues to monitor its security posture, applying Post-Admission NAC controls to ensure ongoing compliance and security.

Understanding these NAC solutions is crucial for implementing effective network security. Each solution offers different approaches to ensuring that only compliant and secure devices can access the network, thereby protecting the organization's data and resources.