Who's Really on Your Network?

Network Access Control (NAC) has been around for decades, yet it has never been asked to solve problems on the scale organisations face today. 

What was once primarily a networking control now sits at the intersection of identity, device security and operational resilience.T

Implementing NAC was a relatively well-defined exercise. Corporate laptops connected to corporate networks from corporate offices, with a limited number of managed devices and a clear understanding of who owned them. Authentication was important, compliance checks were relatively straightforward, and once a device was admitted to the network, it was generally trusted to remain there.

That operating model has largely disappeared with enterprise networks now in constant motion. Employees move between offices, home networks and customer sites. Contractors require temporary access to business systems. Manufacturing equipment, CCTV, environmental controls, medical devices and IoT sensors all demand connectivity, often without supporting modern endpoint security tools. Cloud services have blurred traditional network boundaries, while acquisitions and digital transformation programmes have introduced further complexity into already fragmented environments.

For many security teams, the challenge is no longer granting access. It is maintaining confidence that every connected user and device continues to deserve it.

This is reflected in the conversations taking place across the industry. Increasingly, Network Access Control is being discussed alongside identity security, Zero Trust and continuous risk assessment rather than simply network infrastructure. The emphasis has shifted from authenticating a connection to continuously validating trust throughout the lifetime of that connection.

Evolutionary significance

Compromised credentials remain one of the most common routes into enterprise environments, while unmanaged or poorly configured devices continue to provide opportunities for attackers once inside. In both cases, the initial connection may appear entirely legitimate. The value of modern NAC lies in its ability to combine identity, device posture, certificates, vulnerability status and organisational policy to make more informed decisions about what access should look like in practice.

The organisations seeing the greatest benefit are often those treating NAC as part of a wider security ecosystem rather than a standalone networking project. Integration with identity providers, endpoint detection platforms, vulnerability management tools and security operations allows access policies to adapt as the security posture of users and devices changes. Trust becomes dynamic rather than static, reducing the window of opportunity when a device or account is compromised.

This is particularly relevant as organisations continue to connect assets that security teams do not directly manage. Operational technology, healthcare equipment, smart buildings and industrial control systems are expanding rapidly, yet many cannot support traditional security agents. Visibility, therefore, becomes almost as valuable as enforcement. Simply knowing what has appeared on the network, whether it should be there and who owns it provides security teams with operational intelligence they have historically struggled to obtain.

Network Access Control has never attracted the same attention as newer security technologies, but perhaps that has worked in its favour. While much of the industry has focused on the latest platform or AI capability, NAC has steadily evolved into a practical control that supports identity security, operational resilience and Zero Trust strategies without demanding the spotlight.

As enterprise environments become increasingly distributed and connected, understanding who is on the network, what they are using and whether they should still have access remains one of the most valuable pieces of intelligence a security team can possess.

Community Note

Network Access Control continues to evolve alongside Zero Trust, identity security and modern enterprise networking. If you have practical experience with NAC, device identity, network segmentation or access policy design and would like to share your expertise with the MYREDFORT community, we'd love to hear from you.

Please contact our Community Editor, Sam Redwood, at sam.redwood@myredfort.com.