Network Access Control (NAC) is a security approach that enforces policy compliance on devices before they're granted access to a network. It's designed to keep unauthorized and non-compliant devices from accessing network resources. NAC solutions perform several key functions: 1. Authentication: Verifies the identity of users and devices attempting to connect to the network through credentials, certificates, or other authentication methods. 2. Assessment: Evaluates the security posture of connecting devices by checking for updated antivirus software, patch levels, firewall status, and other security requirements. 3. Authorization: Determines what network resources the device can access based on user identity and device security status. 4. Remediation: If a device fails to meet security requirements, NAC can automatically redirect it to a quarantine area where necessary updates can be applied. NAC implementations typically fall into three categories: - Pre-admission NAC: Checks devices before allowing network access - Post-admission NAC: Continuously monitors devices after they've connected - Agent vs. Agentless: Agent-based solutions install software on endpoints, while agentless solutions scan devices remotely Common NAC protocols and standards include: - 802.1X: An IEEE standard for port-based network access control - RADIUS/TACACS+: Authentication protocols often used with NAC - TNC (Trusted Network Connect): An open architecture for NAC Benefits of implementing NAC include reduced risk of malware infections, prevention of unauthorized access, enforcement of security policies, and simplified regulatory compliance. For the CompTIA Network+ exam, understanding NAC's role in overall network security architecture is essential, along with knowing how it integrates with other security controls like firewalls and IDS/IPS systems.

Network Access Control (NAC) is a security approach that enforces policy compliance on devices before they're granted access to a network. It's designed to keep unauthorized and non-compliant devices…

Concepts covered: Authorization, Network Access Servers, Access Control Models, RADIUS, VPN and Remote Access Security, Network Policy, Endpoint Security, Vulnerability Management, Port Security, Intrusion Prevention System (IPS), 802.1X