About this interactive
From the lesson:
- **Supplicant:** the device trying to connect, with a certificate or a username and password.
- **Authenticator:** the switch port or wireless access point it connects to. It passes only authentication traffic until the server answers, then opens the port or keeps it closed.
- **Authentication server:** usually a RADIUS server, holding the accounts or certificates. It gives the yes or no.
- **EAP** runs between supplicant and authenticator; the authenticator carries it to the server inside **RADIUS**.
802.1X checks who is connecting; port security only checks MAC addresses. (The video mentions a captive portal as an example; a captive portal is web-based sign-in, not 802.1X.)
What you'll learn
- Identify the 802.1X roles: the supplicant that asks to connect, the authenticator (switch or access point) that controls the port, and the authentication server that decides
- Trace how EAP runs between supplicant and authenticator, and RADIUS between authenticator and server
Aligned to
Cisco CCNA
5.8
Compare authentication, authorization, and accounting concepts
5.7
Configure and verify Layer 2 security features
Key terms
- 802.1X
- An IEEE standard for port-based network access control that requires devices to authenticate before gaining access to a wired or wireless network, using a supplicant, authenticator, and authentication server (typically RADIUS). It is the foundation of enterprise Wi-Fi security and wired port security using EAP methods.
- Supplicant
- In the IEEE 802.1X authentication framework, the device or user requesting network access that must prove its identity to the authenticator before being granted access. The supplicant runs an EAP method such as EAP-TLS or PEAP and communicates with the authenticator using EAPoL.
- Authenticator
- In the IEEE 802.1X framework, the network device (typically a switch or wireless access point) that sits between the supplicant and the authentication server, relaying EAP messages and enforcing whether the port is opened or blocked based on the authentication result. The authenticator does not verify credentials itself; it passes that responsibility to the RADIUS server.
- Authentication Server
- The server in a network access control framework (such as 802.1X) that validates supplicant credentials and grants or denies network access based on authentication policy. RADIUS is the most common authentication server protocol.
- Extensible Authentication Protocol
EAP
- Extensible Authentication Protocol is a flexible authentication framework used in wireless networks and PPP connections that supports multiple authentication methods including certificates, tokens, and passwords.
- Remote Authentication Dial In User Service
RADIUS
- A network protocol that provides centralized authentication, authorization, and accounting (AAA) for users and devices connecting to a network, commonly used with 802.1X and VPN deployments. RADIUS uses UDP and encrypts only the password field in its messages.
Topics
802 1x
Supplicant
Authenticator
Authentication Server
Radius
Eap
Interactive
Categorize
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