ZyXEL Communications 202 Manuale Utente

Pagina di 81
ZyXEL M-202 User’s Guide
32
Chapter 2 Wireless LAN Network
The AP derives and distributes keys to the wireless clients.
The AP and wireless clients use the TKIP or AES encryption process to encrypt data 
exchanged between them.
Figure 11   WPA(2)-PSK Authentication
2.2.5  WPA(2) 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(2)-RADIUS 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.
Figure 12   WPA(2) with RADIUS Application Example