Key Points
- Zero trust emphasizes continuous verification, limiting network access by user role and device context, ensuring no implicit trust for internal users.
- RADIUS and digital certificates verify each device, preventing credential-based attacks and improving authentication accuracy in zero trust environments.
- Zero trust networks employ VLAN segmentation and runtime policy enforcement via RADIUS to control access, reduce risks, and limit attackers’ reach within network zones.
- SecureW2’s Cloud RADIUS, with dynamic policy capabilities and certificate-based authentication, enables seamless zero trust implementation across remote and hybrid networks.
Network security has traditionally focused on keeping threats out, with less attention on what happens once something gets through. Zero trust changes that.
Zero-Trust 802.1X networks are built on continuous verification of every user and device, every time they request access. This essentially means no user or device gets a free pass.
This guide covers why RADIUS is central to zero trust, how network segmentation limits risk, and what dynamic policy enforcement looks like in practice.
What Is a Zero-Trust 802.1X Network?
Zero trust is a security philosophy that can be boiled down to “never trust, always verify.” Since this is an ongoing process, at SecureW2 we refer to this as continuous trust.
Traditional network security relies on strong perimeter defense, such as firewalls, virtual private network (VPN), and robust RADIUS authentication security, preferably with digital certificates. The goal is to stop any threats before they reach the vulnerable parts of your network.
The problem is that this paradigm assumes that all users on your network are trusted and authorized to access any resources contained within. Few protections exist against internal attacks, whether from an external attacker who infiltrated your defenses or a disgruntled employee.
Zero trust demands that security doesn’t stop at authentication. Users and devices should be constantly monitored, limited to only the necessary resources and applications, and must undergo verification for each access request.
Why Is RADIUS Required for Zero-Trust Security?
Note: A remote authentication dial-in user service (RADIUS) server is a fundamental part of 802.1X authentication security whether you’re operating under zero-trust principles or not. It’s the first line of defense against malicious actors looking to penetrate your network.
Not all RADIUS servers are created equal. A managed Cloud RADIUS like the one that SecureW2 offers has different features and capabilities than a DIY RADIUS based on FreeRADIUS or AD CS. Those additional features can be the difference between an effective zero-trust network and a mediocre cybersecurity strategy.
3 Key Design Steps for a Zero-Trust 802.1X Network
Zero trust is a layered strategy built on three core components:
- Certificate-based authentication, which verifies every user and device identity
- Network segmentation, which limits what each user can access
- Dynamic policy enforcement, which ensures access decisions are made in real time
Here’s how they work.
Certificate-Based Authentication
Digital X.509 certificates should be mandatory for zero trust network authentication because they are inextricably tied to the identity of a user or device, allowing you to verify the client with much greater accuracy than passwords alone.
Info: Passwords are often shared, lost, or cracked. Certificates can’t be removed from a device and they are virtually uncrackable due to the public key cryptography they employ.
Server certificate validation is an example of a zero-trust policy implemented by certificates, but from the direction of the client to the network controller. Configured devices check the identity of the access point before sending credentials for authentication.
Network Segmentation
Dividing users into groups with similar permission levels is a core tenet of zero trust. Developers don’t need access to payroll software, and HR doesn’t need access to source code.
Sorting users into groups with identical permission levels compartmentalizes both resources and risk.
Network segmentation is typically achieved through virtual local area networks (VLANs). Users and devices should be assigned a VLAN through the RADIUS that only contains the essentials necessary for their role. Any hacker that gains access to the VLAN will be limited in their potential impact.
Dynamic Policy Enforcement
Policy enforcement is the mechanism through which users and devices are usually sorted into VLANs, but there’s room to expand on the policies for a more secure internal environment. With the SecureW2 Cloud RADIUS, you can perform dynamic, runtime-level policy enforcement.
By adding customizable attributes to client profiles stored in the directory, users can be dynamically sorted into appropriate VLANs or authorized for other services like VPN. The SecureW2 Cloud RADIUS not only references the certificate revocation list but can perform LDAP-like user lookup on the directory at the moment of authentication to enforce real-time policy decisions.
To learn more about the SecureW2 Dynamic Policy Engine and the advantages of runtime-level policy enforcement for EAP-TLS authentication, contact our experts.
The Future of Remote Access Requires a Cloud RADIUS
The shift to remote work has fundamentally changed how organizations think about network security. Zero trust policies will be more important than ever to secure networks as users access them from dispersed locations, widening the trust gap.
An enterprise-grade Cloud RADIUS solution with digital certificate-based authentication is the most efficient way to protect your network and employees. The SecureW2 JoinNow Platform can integrate with your existing network infrastructure so that the upgrade is both affordable and simple.
SecureW2 has options for organizations of all sizes. See our pricing to find the right fit.
