ZyXEL p-662h-61 Guia Do Utilizador

Prestige 662HW Series User’s Guide

Chapter 8 Wireless LAN Setup

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• Access-Reject

Sent by a RADIUS server rejecting access.

• Access-Accept

Sent by a RADIUS server allowing access. 

• 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:

• Accounting-Request

Sent by the access point requesting accounting.

• 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 
network from unauthorized access. 

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.

Figure 28   EAP Authentication 

The details below provide a general description of how IEEE 802.1x EAP authentication 
works. For an example list of EAP-MD5 authentication steps, see the appendix about IEEE 
802.1x. 

1 The wireless station sends a "start" message to the Prestige. 

2 The Prestige sends a "request identity" message to the wireless station for identity 

information.