Why You Need Both NAC and ZTNA in Your Security Strategy

In today’s hybrid, cloud-first world, securing enterprise networks requires more than just one tool. Two critical solutions often compared, or mistakenly thought to replace one another, are Network Access Control (NAC) and Zero Trust Network Access (ZTNA). While each has its own focus, the truth is that they complement each other. For a truly robust zero trust security model, you need both.

NAC: The First Line of Defense

NAC (Network Access Control) protects the onboarding or access to your network. It ensures that any device (laptop, phone, printer, camera, OT controller, etc.) that tries to connect via wired, Wi-Fi, or VPN is identified, authenticated, and granted the right level of access based on policy. NAC covers all endpoints, including unmanaged and IoT devices that ZTNA can’t secure.

• Works at the network layer Covers all device types (corporate, BYOD, IoT, OT)
• Authenticates based on identity, device posture, and context (location, time, access method)
• Quarantines/remediates risky or non-compliant devices automatically
• Ensures compliance with HIPAA, PCI, GDPR, etc.

In short, NAC acts like the security guard at the door-ensuring only safe, verified devices step inside the building. Without this layer, organizations risk giving entry to rogue, compromised, or unmanaged devices.

ZTNA: Enforcing Least Privilege Everywhere

ZTNA (Zero Trust Network Access) protects the destination or access to the application. Once a verified user or device is online, ZTNA ensures they can only reach the specific applications they’re allowed to use, rather than the entire network. It’s the modern replacement for VPNs, built around identity, context, and continuous verification. ZTNA is application-focused, granting users access only to the specific resources they need, when they need them, and under strict conditions.

• Works at the application layer
• Provides secure access for remote or hybrid workers
• Granular access to apps (not the full network, unlike VPN)
• Built for managed endpoints (laptops, phones, tablets)
• Uses micro-segmentation + continuous monitoring to reduce attack surface

ZTNA aligns perfectly with the “never trust, always verify” principle, especially for cloud apps and remote work scenarios where traditional network perimeters no longer apply.

Why NAC Alone Isn’t Enough

While NAC is vital, it has limitations in a modern, distributed environment:

• Limited to the network perimeter: NAC secures access at the point of network entry but offers little control once a device is connected. Users and devices may still move laterally and access resources they don’t need.
• NAC primarily operates at Layers 2 and 3 (network connectivity), but cannot enforce fine-grained application-level restrictions.
• Blind to remote and cloud environments: NAC was built for on-premises networks, so it struggles to provide visibility or control over users connecting remotely or directly to cloud services, where most work now happens.

This is where ZTNA’s application-centric approach becomes essential.

Why ZTNA Alone Isn’t Enough

Conversely, organizations that try to rely only on ZTNA overlook key risks:

• ZTNA doesn’t verify device posture with the same depth as NAC. A compromised or non-compliant endpoint might still obtain access.
• Unmanaged IoT or guest devices that never authenticate via identity systems could still connect to the network if no NAC is present.
• ZTNA protects applications, but without NAC, organizations lack visibility into what’s physically and virtually connected to the infrastructure.

ZTNA builds a strong superstructure of access control-but it must rest on the foundation that NAC provides.

NAC + ZTNA: A Layered Zero Trust Model

Together, NAC and ZTNA deliver a layered, complementary approach:

• NAC ensures device integrity before granting any network access.
• ZTNA ensures least privilege access once the device and user are validated.
• Combined, they close gaps that either solution alone would leave open.

Think of NAC as the bouncer at the door and ZTNA as the escort guiding guests only to their assigned seats. One keeps intruders out; the other ensures trusted insiders stay within their lanes.

The Future Is Hybrid

Industry analysts note that while ZTNA adoption is accelerating, NAC remains indispensable for many enterprises-especially those with large on-premises footprints, IoT deployments, or stringent compliance needs. Organizations pursuing zero trust architectures will find that NAC strengthens their foundation, while ZTNA extends controls seamlessly to cloud apps and remote users. The result is a comprehensive zero trust framework: trusted devices plus trusted access, enforced everywhere. The debate between NAC and ZTNA often frames them as competitors-but in reality, they’re partners. NAC provides the assurance that only compliant devices connect to your network. ZTNA then enforces strict, context-aware policies on what those devices and their users can access. By combining the two, organizations achieve a true zero-trust architecture: one that balances endpoint hygiene with granular, least-privilege access. In today’s threat landscape, that layered approach isn’t optional-it’s essential.