802.1X

/ˌeɪt oʊ tuː pɔɪnt wʌn ɛks/ · Noun · Security & Infosec

Definitions

  1. 802.1X is an IEEE standard for port-based network access control that provides an authentication framework for devices connecting to a local area network (LAN) or wireless network (WLAN). When a device attempts to connect to an 802.1X-enabled network, it must authenticate through an authentication server (typically a RADIUS server) before being granted access to network resources. The standard defines three roles: the supplicant (the device requesting access), the authenticator (the network switch or wireless access point that controls access), and the authentication server (which verifies credentials). The Extensible Authentication Protocol (EAP) provides the framework for different authentication methods, including EAP-TLS (certificate-based, considered most secure), PEAP (protected EAP, using server certificates), and EAP-TTLS. 802.1X is widely deployed in enterprise networks to prevent unauthorized devices from accessing the network, enforce security policies, and assign users to appropriate VLANs based on their identity. It is a cornerstone of Zero Trust network architecture.

    In plain English: A standard that checks identity before letting a device onto a network.

    Example: "The campus Wi-Fi requires 802.1X, so unmanaged devices cannot just connect anonymously."

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