What are the best practices for configuring NAC policies and roles?

1 Understand your network

Before you implement NAC, you need to have a clear understanding of your network topology, devices, users, and applications. You can use tools like network scanners, asset inventories, and user directories to collect this information. This will help you define the network zones, segments, and access levels that you want to enforce with NAC.

2 Choose your NAC method

NAC can be implemented in various ways, depending on your network infrastructure and security requirements. For example, 802.1X is a standard protocol that uses certificates or credentials to authenticate devices and users before granting access to the network. Furthermore, DHCP servers can be used to check device identity and compliance before assigning an IP address. Additionally, VPN servers can be employed to verify device identity and compliance prior to allowing connection to the network. Lastly, if a device fails the check, it may be assigned a quarantine IP address, denied access, disconnected, or restricted.

3 Define your NAC policies and roles

NAC policies are the rules that determine how devices and users are authorized, authenticated, and monitored on the network, while NAC roles are the groups of devices and users that share the same access rights and restrictions. You can define your NAC policies and roles based on various factors, such as device type (e.g. laptops, smartphones, printers, IoT devices), device ownership (e.g. owned by the organization or employees), device posture (e.g. health and compliance with security standards like antivirus, firewall, encryption, patch level), user identity (e.g. verified with sources like Active Directory, LDAP, RADIUS), user role (e.g. administrators, managers, staff, students), and network location (e.g. internal, external, wireless, VPN).

4 Configure your NAC enforcement points

NAC enforcement points are the devices or software that apply the NAC policies and roles to the network traffic. These can be inline devices, such as firewalls, gateways, and proxies, which inspect traffic passing through them and block, redirect, or modify it based on the NAC policies and roles. Out-of-band devices communicate with network switches or access points and instruct them to enforce the NAC policies and roles. Agent-based software agents run on devices to monitor the device posture, report to the NAC server, and restrict device access based on the NAC policies and roles.

5 Monitor and audit your NAC system

NAC is not a one-time solution, but rather a continuous process requiring monitoring and auditing. Collecting and analyzing NAC logs and alerts can help detect any anomalies, violations, or incidents on the network. Additionally, it is essential to update and review NAC policies and roles regularly to reflect any changes in the network environment, devices, users, or applications. Periodic scans and audits of network devices and users should be conducted to ensure compliance with NAC policies and roles. Lastly, it is important to test and evaluate your NAC system performance, functionality, and security to identify any gaps or issues that need improvement.