Modern Network Access Control (NAC) systems use posture checks to verify device security status before granting network access. This process ensures that connected hosts meet security requirements, such as active antivirus software, installed OS updates, and the absence of malicious processes.
The traditional approach relies on installing a dedicated agent on each device to collect system data. While effective, this method often faces challenges in large organizations, including software conflicts with existing security tools like DLP or EDR, high deployment costs, and performance issues on low-power hardware.
Agentless scanning offers an alternative by using standard remote management protocols like WinRM for Windows or SSH for Linux. This method allows NAC systems to verify device status, such as domain membership or service activity, without requiring additional software installation on the endpoint.
The agentless approach is particularly relevant for BYOD scenarios, guest access, and specialized equipment like industrial controllers or medical devices where agent installation is prohibited. It also simplifies compliance in highly regulated environments, such as critical information infrastructure (CII) and government sectors.
In sectors like industrial control systems (ICS) or state-regulated environments, installing new software often triggers mandatory, costly re-certification processes. Consequently, organizations frequently adopt a hybrid model, combining agent-based and agentless methods to balance security requirements with operational constraints.
