Introduction To Radius - ZyXEL Communications P-330W - V1.90 User Manual

Chapter 6 Wireless

6.7.7 Introduction to RADIUS

RADIUS is based on a client-sever model that supports authentication and accounting, where
access point is the client and the server is the RADIUS server. The RADIUS server handles the
following tasks among others:
• Authentication
Determines the identity of the users.
• Accounting
Keeps track of the client's network activity.
RADIUS user is a simple package exchange in which your P-330W acts as a message relay
between the wireless station and the network RADIUS server.
6.7.7.1 Types of RADIUS Messages
The following types of RADIUS messages are exchanged between the access point and the
RADIUS server for user authentication:
• Access-Request
Sent by an access point requesting authentication.
• Access-Reject
Sent by a RADIUS server rejecting access.
• Access-Accept
Sent by a RADIUS server allowing access.
6.7.7.2 Access-Challenge
Sent by a RADIUS server requesting more information in order to allow access. The access
point sends a proper response from the user and then sends another Access-Request message.
The following types of RADIUS messages are exchanged between the access point and the
RADIUS server for user accounting:
6.7.7.3 Accounting-Request
Sent by the access point requesting accounting.
6.7.7.4 Accounting-Response
Sent by the RADIUS server to indicate that it has started or stopped accounting.
In order to ensure network security, the access point and the RADIUS server use a shared
secret key, which is a password, they both know. The key is not sent over the network. In
addition to the shared key, password information exchanged is also encrypted to protect the
wired network from unauthorized access.
6.7.7.5 EAP Authentication Overview
EAP (Extensible Authentication Protocol) is an authentication protocol that runs on top of the
IEEE802.1x transport mechanism in order to support multiple types of user authentication. By
using EAP to interact with an EAP-compatible RADIUS server, the access point helps a
wireless station and a RADIUS server perform authentication.
The type of authentication you use depends on the RADIUS server or the AP. The P-330W
supports EAP-TLS, EAP-TTLS and PEAP with RADIUS. Refer to the Types of EAP
Authentication appendix for descriptions on the four common types.
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P-330W User's Guide