802.1X: Ensuring Authorized Access in Wired and Wireless Networks

 802.1x

802.1X is a network authentication protocol that provides a secure method for controlling access to wired and wireless networks. It's part of the IEEE 802 family of networking standards and is primarily used for port-based network access control (PNAC).

How 802.1X Works

802.1X operates using three key components:

• Supplicant (Client Device) – This is the device that wants to connect to the network, such as a laptop, phone, or IoT device.
• Authenticator (Network Access Device) – This is the network device controlling access, such as a switch for wired connections or an access point (AP) for wireless networks.
• Authentication Server (RADIUS Server) – The backend server verifies the credentials and allows or denies access.

Authentication Process

1. Initial Connection – The supplicant attempts to connect to the authenticator.

2. EAP (Extensible Authentication Protocol) Exchange – The authenticator requests authentication, and the supplicant sends its credentials.

3. Credential Validation – The authentication server verifies the credentials using a configured authentication method, such as EAP-TLS, PEAP, or EAP-MD5.

4. Access Granted or Denied—If the authenticator is successful, it allows network access. If authentication fails, the device is denied access or placed into a guest network.

Security Benefits

• Prevents Unauthorized Access – Only authenticated devices can join the network.
• Centralized Authentication – Using RADIUS servers allows for better control over user access.
• Encryption Support – When combined with WPA2-Enterprise, 802.1X offers strong encryption for Wi-Fi security.

Common Use Cases

• Enterprise Networks – Large organizations use 802.1X to secure wired and wireless networks.
• Public Wi-Fi Security – Many institutions, like universities, implement 802.1X for secure Wi-Fi access.
• IoT Device Authentication – Ensures that only trusted devices connect to sensitive networks.