6Mutual Authentication
6.1. 802.1x mechanism
The 802.1x access control mechanism is deployed in the Local Area Network (LAN) implementing the following technologies:
- – Ethernet technology in the case of access to a switch;
- – Wireless Fidelity (Wi-Fi) in the case of a connection to an access point (AP).

Figure 6.1. Components of 802.1x mechanism
The authentication uses the 802.1x access control mechanism that defines the following three components (Figure 6.1):
- – the supplicant is the device (network host) wishing to access the Ethernet or Wi-Fi network;
- – the authenticator is the device (Ethernet switch or Wi-Fi access point) that controls the supplicant’s access to the LAN;
- – the authentication server is the device that authenticates the supplicant and authorizes access to the LAN.
The 802.1x mechanism relies on the following set of protocols (Figure 6.2):
- – the extensible authentication protocol (EAP) over LAN (EAPOL), exchanged between the supplicant and the authenticator;
- – the EAP exchanged between the supplicant, on the one hand, and the authenticator or authentication server, on the other hand:
- - the EAP is carried by the EAPOL protocol on the interface between the supplicant and the authenticator;
- - the EAP carries EAP-Method messages exchanged between the supplicant and the authentication server;
- – the remote authentication dial-in user service (RADIUS) protocol, ...
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