Understanding 802.1X Authentication in Enterprise Networks

????What is 802.1X?

802.1X is a network access control (NAC) protocol that enforces authentication before allowing a device to connect to a LAN.

It usesEAP (Extensible Authentication Protocol)overRADIUSfor user verification.

Typically deployed incorporate and campus networksforsecure wired and wireless access.

????How Does 802.1X Work?

1️⃣Client (Supplicant) → Requests network access.

2️⃣Switch (Authenticator) → Forwards request to RADIUS server.

3️⃣RADIUS Server → Verifies credentials & grants access.

Mandatory Steps to Enable 802.1X on SW3

✅A. Configure an AAA Scheme

Defines authentication, authorization, and accounting (AAA) methods.

Links802.1X authentication to the RADIUS server.

✅B. Configure an Authentication Profile

Specifies how authentication is handled on the switch.

Associates802.1X authentication with an AAA scheme.

✅C. Configure an Authentication Domain

Groups authentication policies for different user types.

MapsAAA scheme to user login requests.

✅D. Configure an 802.1X Access Profile

Applies 802.1X authentication to specific switch ports (GE0/0/2 & GE0/0/3).

Ensures thatonly authenticated users can pass traffic.

Why Are All Four Steps Necessary?

✅Each step plays a critical role in enabling 802.1X authentication and linking it to the RADIUS server.

✅Without any one of these configurations, the 802.1X authentication process would fail.

Real-World Application:

Enterprise Wired Security:Ensures thatonly authenticated devicesaccess corporate networks.

University Campuses & Public Wi-Fi:Prevents unauthorized access tosecure LAN environments.

✅Reference:Huawei HCIE-Datacom Guide – 802.1X Authentication & RADIUS Server Configuration