ZyXEL Communications 70 Series User Manual

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ZyWALL 5/35/70 Series User’s Guide
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Chapter 9 Wireless LAN
Figure 78   WPA-PSK Authentication
9.13  Introduction to RADIUS
The ZyWALL can use an external RADIUS server to authenticate an unlimited number of 
users. 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.
• 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 ZyWALL acts as a message relay 
between the wireless station and the network RADIUS server.
9.14  WPA with RADIUS Application Example
You need the IP address of the RADIUS server, its port number (default is 1812), and the 
RADIUS shared secret. A WPA application example with an external RADIUS server looks as 
follows. "A" is the RADIUS server. "DS" is the distribution system.
The AP passes the wireless client's authentication request to the RADIUS server.
The RADIUS server then checks the user's identification against its database and grants 
or denies network access accordingly.
The RADIUS server distributes a Pairwise Master Key (PMK) key to the AP that then 
sets up a key hierarchy and management system, using the pair-wise key to dynamically 
generate unique data encryption keys to encrypt every data packet that is wirelessly 
communicated between the AP and the wireless clients.