802.1X

Port-based network access control, the standard for authenticating users and devices onto wired and wireless networks. Articles tagged 802.1X cover supplicant and authenticator behavior, RADIUS, EAP methods, Cisco ISE, dynamic VLANs, dACLs, host modes, and phased deployment.

36 posts

802.1X

EAPOL Explained: How 802.1X Traffic Moves Over the Wire

EAPOL carries EAP between the supplicant and switch at Layer 2. It never leaves the segment, which is why captures and debug have to happen on or at the port.

Mar 24, 2026 8 min read

802.1X

How EAP Works in 802.1X: EAP Methods Compared

EAP is a framework, not a protocol. Compare EAP-TLS, PEAP-MSCHAPv2, EAP-FAST, and EAP-TTLS by credential type, tunnel, and where each belongs in enterprise 802.1X.

Mar 24, 2026 9 min read

802.1X

802.1X Components Explained: Supplicant, Authenticator, and Authentication Server

802.1X splits work across three roles: supplicant, authenticator, and authentication server. Understanding the boundaries explains both the config and the failure points.

Mar 24, 2026 9 min read

802.1X

What Is 802.1X? Port-Based Network Access Control Explained

802.1X is port-based network access control. It forces a device to authenticate before the switch forwards traffic, closing the wall-jack gap in modern enterprise networks.

Mar 24, 2026 8 min read

802.1X

MAC Authentication Bypass (MAB) Configuration on Cisco IOS XE and ISE

MAB authenticates printers, cameras, and legacy gear that cannot run a supplicant by using their MAC as the RADIUS username. Here is the Cisco IOS XE and ISE config.

Mar 24, 2026 11 min read

802.1X

Configuring EAP-TLS with Certificates on Cisco ISE and IOS XE

EAP-TLS replaces 802.1X passwords with mutual certificate auth. Here is the PKI prep, ISE policy, and IOS XE config you need for a production certificate-based rollout.

Mar 24, 2026 10 min read