802.1x in a Windows Environment

Recent Windows versions can provide both client-side support and authentication service for 802.1x. 802.1x systems involve three types of components: supplicants (clients), authenticators, and authentication servers.

Supplicants. Supplicants in a Windows environment include devices running Windows XP, Windows CE .NET 4.x, or some earlier versions of Windows running add-on software. Before a supplicant can use a wireless access point (AP) or an Ethernet switch to access the network, it must request a port from an authenticator.

Authenticators. The supplicants connect to the network via the authenticators, which could be 802.11(a, b, or g) APs or managed Ethernet switches. With 802.1x, the authenticator does not handle authentication itself but instead hands off the task to an authentication server, which is typically running the Remote Authentication Dial-In User Service (RADIUS). The authenticator passes authentication requests to the authentication server using a lower-level protocol called the Extensible Authentication Protocol Over LAN (EAPOL) to secure the communication.