Network Access Control (NAC) is a security solution that enforces policy on devices that access networks to increase network visibility and reduce risk. It supports network visibility and access management through policy enforcement on devices and users of corporate networks. NAC systems can deny network access to noncompliant devices, place them in a quarantined area, or give them only restricted access to computing resources, thus keeping insecure nodes from infecting the network.
NAC solutions help organizations control access to their networks through capabilities such as:
- Ensuring that non-employees have access privileges to the network that are separate from those of employees.
- Compliance for all employee-owned devices before accessing the network (BYOD).
- Applying defined profiling and access policies for IoT devices.
- Sharing contextual information with third-party security components and responding to cybersecurity alerts by automatically enforcing security policies that isolate compromised endpoints.
NAC is critical for modern businesses because it allows organizations to monitor the devices and users trying to access the enterprise network and controls who can access the network, including denying access to those users and devices that don’t comply with security policies. NAC solutions and tools help companies control network access, ensure compliance, and strengthen their IT infrastructure.
There are two types of NAC:
- Pre-admission: evaluates access attempts and only allows entry to authorized devices and users.
- Post-admission: re-authenticates users trying to enter a different part of the network; also restricts lateral movement to limit the damage from cyber attacks.
A network access server performs authentication and authorization functions by verifying user credentials and ensuring that authorized users can access the resources they need.
NAC tools are proactive and designed to stop unauthorized access before it happens, protecting an organization’s network and assets. They can also support network load balancing, resource management, and user sessions.
In summary, NAC is an essential component of network security that helps organizations manage and secure access to their networks, ensuring that only compliant and authorized users and devices can connect and interact with network resources.