ZyXEL Communications Corporation G-220F Manuel D’Utilisation
ZyXEL G-220F User’s Guide
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Chapter 2 Wireless LAN Network
The encryption mechanisms used for WPA(2) and WPA(2)-PSK are the same. The only
difference between the two is that WPA(2)-PSK uses a simple common password, instead of
user-specific credentials. The common-password approach makes WPA(2)-PSK susceptible to
brute-force password-guessing attacks but it's still an improvement over WEP as it employs an
easier-to-use, consistent, single, alphanumeric password.
difference between the two is that WPA(2)-PSK uses a simple common password, instead of
user-specific credentials. The common-password approach makes WPA(2)-PSK susceptible to
brute-force password-guessing attacks but it's still an improvement over WEP as it employs an
easier-to-use, consistent, single, alphanumeric password.
2.2.4 WPA(2)-PSK Application Example
A WPA(2)s-PSK application looks as follows.
1 First enter identical passwords into the AP and all wireless clients. The Pre-Shared Key
(PSK) must consist of between 8 and 63 ASCII characters (including spaces and
symbols).
symbols).
2 The AP checks each client's password and (only) allows it to join the network if it
matches its password.
3 The AP derives and distributes keys to the wireless clients.
4 The AP and wireless clients use the TKIP encryption process to encrypt data exchanged
between them.
Figure 11 WPA-PSK Authentication
2.2.5 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.
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.
1 The AP passes the wireless client's authentication request to the RADIUS server.
2 The RADIUS server then checks the user's identification against its database and grants
or denies network access accordingly.
3 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.
generate unique data encryption keys to encrypt every data packet that is wirelessly
communicated between the AP and the wireless clients.