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

Cisco TrustSec and SGTs: How They Integrate with 802.1X

TrustSec attaches a Security Group Tag to an 802.1X session, so segmentation policy follows identity through the network. Here is how SGT assignment integrates with ISE.

Mar 24, 2026 10 min read

802.1X

RADIUS Redundancy and Failover in 802.1X Deployments

Running Closed Mode 802.1X without RADIUS redundancy is asking for an outage. Here are the failure modes, the IOS XE config for multiple PSNs, and the verification.

Mar 24, 2026 11 min read

802.1X

Phased 802.1X Deployment Strategy for Enterprise Networks

Phased 802.1X deployments succeed when each phase is data collection first, enforcement second. Here is Phase 0 through Phase 4 with real endpoint discovery tactics.

Mar 24, 2026 11 min read

802.1X

Monitor Mode vs Low-Impact Mode vs Closed Mode: Choosing Your 802.1X Deployment Strategy

Monitor Mode, Low-Impact Mode, and Closed Mode each trade visibility for enforcement. Here are the IOS XE configs, show output, and honest gaps for each mode.

Mar 24, 2026 11 min read

802.1X

802.1X Scalability and High Availability Design for Large Enterprise Networks

Scaling 802.1X to thousands of ports means distributing ISE PSNs, templating switch configs, and planning for re-auth storms. Here is the large-enterprise HA design.

Mar 24, 2026 12 min read

802.1X

802.1X on Cisco Switches: Step-by-Step Configuration Guide

Learn to configure 802.1X port-based network access control on Cisco switches — includes RADIUS setup, switch commands, troubleshooting, and best practices.

Dec 21, 2024 3 min read