Netzwerkzugriffssteuerung

Netzwerkzugriffssteuerung, often abbreviated as NAC, is a security solution that enforces policies for devices attempting to access network resources. It aims to prevent unauthorized or non-compliant devices from connecting to a network, thereby reducing the risk of security breaches and malware propagation. NAC solutions typically operate by examining devices before they are granted access. This examination can include checking for up-to-date antivirus software, operating system patches, and compliance with corporate security policies.

When a device attempts to connect to a network, the NAC system intercepts the connection. It then performs a "health check" or "posture assessment" of the device against predefined policies. If the device meets the required criteria, it is granted access to the network, often with specific permissions based on its role or user. If the device fails the assessment, it can be denied access, quarantined in a restricted network segment, or prompted to remediate the identified issues before being allowed further access.

NAC can be implemented in various ways, including agent-based and agentless methods. Agent-based NAC requires software agents to be installed on each endpoint, providing a more thorough assessment. Agentless NAC relies on existing network protocols and infrastructure to gather information about devices, making it easier to deploy but potentially offering less detailed insights. The primary goal of NAC is to ensure that only trusted and compliant devices can interact with sensitive network resources.