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

Configuring PEAP Authentication with Cisco ISE and IOS XE

PEAP-MSCHAPv2 protects the credential exchange inside a TLS tunnel against an ISE server certificate. Here is the full Cisco ISE and IOS XE config for AD users.

Mar 24, 2026 10 min read

802.1X

Configuring Cisco ISE as a RADIUS Server for 802.1X

The ISE side of 802.1X: network devices, identity sources, authentication and authorization policies, and the Policy Set that ties it all together for a Catalyst 9300.

Mar 24, 2026 9 min read

802.1X

Basic 802.1X Port Configuration on Cisco IOS XE Switches

A complete 802.1X switchport config on IOS XE 17.9: AAA, RADIUS servers, dot1x system-auth-control, interface policy-map, and the voice VLAN gotchas to avoid.

Mar 24, 2026 11 min read

802.1X

802.1X Authentication Flow Step by Step: From EAPOL Start to RADIUS Accept

The 802.1X authentication flow, step by step, from EAPOL-Start through RADIUS Access-Accept and port authorization. Three conversations, one timeline, no magic.

Mar 24, 2026 7 min read

802.1X

Introduction to Cisco ISE: What It Is and Why It Matters for 802.1X

Cisco ISE is more than a RADIUS server. It is the policy decision point for 802.1X, layering device type, posture, and context on top of pass/fail authentication.

Mar 24, 2026 10 min read

802.1X

Change of Authorization (CoA) in 802.1X: How It Works and How to Configure It

RADIUS CoA lets ISE push policy updates to the switch mid-session, no re-auth required. Here is the IOS XE and ISE config, plus the posture remediation use case.

Mar 24, 2026 11 min read