Understanding 802.1X Security & Network Access Control

802.1x security protocol portnox

In the world of corporate networking, few technologies are as widely adopted or as critically important as 802.1X network access control. Commonly referred to as dot1X, this network protocol has become the gold standard for authentication and access control on both wired and wireless enterprise networks. But how did this once obscure standard become so vital to the security and functioning of today’s networks?

The Emergence of 802.1X Security

The 802.1X protocol was developed in the late 1990s by the Institute of Electrical and Electronics Engineers (IEEE) as part of the 802.1 group of networking standards. At the time, networks were rapidly expanding but lacked sufficient access control mechanisms. 802.1X provided a scalable way to authenticate any user or device attempting to connect to the network before allowing access.

The standard works by using a centralized authentication server that communicates with an authenticator, typically a network switch. The authenticator blocks all traffic until the connecting device or user supplies credentials that the authentication server approves. If authentication succeeds, the switch opens up access. If not, the connection is blocked.

This approach allows organizations to configure robust network access policies and ongoing authentication requirements. It also makes it easy to onboard devices while keeping out unauthorized users.

The Mass Adoption of 802.1X Security

By the early 2000s, 802.1X had proven its worth but had yet to see mass adoption. That changed with the rise of wireless networking and Wi-Fi. Securing early Wi-Fi networks was challenging, and the 802.1X method was well suited for the job. Microsoft also built support for 802.1X into Windows starting with Windows XP in 2001. These developments propelled 802.1X into wider use.

Today, 802.1X is enabled across standard wired Ethernet networks and wireless networks, including the latest Wi-Fi 6 standard. It integrates with all major operating systems, directory services like Active Directory, and authentication methods such as passwords, certificates, or tokens.

For network administrators, 802.1X ticked all the boxes: multi-vendor interoperability, flexibility, scalability, and strong security. It empowers organizations to control access to vital network resources and segment users across the network.

As long as wired and wireless enterprise networks remain crucial to business operations, 802.1X will likely continue its reign as the gold standard for network authentication. The protocol that emerged from obscurity in the early days of networking has become one of the most essential and trusted technologies keeping our networks secure.

What is the 802.1X Security?

802.1X security is a networking protocol that provides an authentication method for devices wishing to connect to a LAN or WLAN. 802.1X has exception flexibility due to the fact that it’s based on the Extensible Authentication Protocol. EAP is a highly pliable standard, as it encompasses the range of EAP authentication methods, including MD5, TLS, TTLS, LEAP, PEAP, SecurID, SIM and AKA.

An IEEE standard for port-based NAC, the 802.1X security also allows network administrators to provide access control parameters across wireless access points. The increasing dependence on wireless networks in corporate offices means network security teams must now address a growing and diverse threat surface, especially if BYOD policies are in use. 802.1X allows these teams to now be able to enforce strict access control policies for their highly mobile workforces and maintain compliance with confidence.

What Can 802.1X Security Do?

The 802.1X security protocol is currently used for network access control in a number of ways:

  • Pre-admission control: Blocks unauthenticated messages
  • Device and user detection: Identifies users and devices with pre-defined credentials or MAC addresses
  • Authentication and authorization: Verifies and provides access.
  • Onboarding: Provisions a device with security, management, or host-checking software.
  • Profiling: Scans endpoint devices.
  • Policy enforcement: Applies role and permission-based access.
  • Post-admission control: Enforces session termination and cleanup.

Additionally, 802.1X can deliver L2 control as it validates users and devices attempting to connect to physical ports in the office.

How Secure is 802.1X?

Today, the 802.1X security protocol is the golden standard when it comes to network authentication. The protocol prevents over-the-air credential theft attacks like Man-in-the-Middle attacks and Evil Twin proxies. This authentication is significantly more secure than PKI networks. There is some variation when it comes to 802.1X protocol security, however. First, if end users are left to manually configure their devices, there’s a much higher potential for credential theft. In a perfect world, configuration would be conducted by knowledgeable IT staff.

Another variation in security effectiveness relies on whether an organization is using credential-based authentication or certificate-based authentication. Certificate-based EAP-TLS is know to significantly reduce organizational risk when it comes to credential theft. This the most effective way to utilize 802.1X security in a corporate networking environment. Not only can 802.1X stop credentials from being sent over the air where they can be easily stolen, but it forces users to go through an enrollment/on-boarding process that ensures proper device configuration.

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