Eap Authentication Overview - ZyXEL Communications ZyWALL 5 User Manual

ZyWALL 5 User's Guide
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.
• 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.

6.5.2 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.
Your ZyWALL supports EAP-MD5 (Message-Digest Algorithm 5) with the local user
database.
The following figure shows an overview of authentication when you specify a RADIUS server
on your access point.
104 Chapter 6 Wireless LAN