Chapter 6 Wireless Security Configuration
ZyXEL NWA-3100 User’s Guide
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The encryption mechanisms used for WPA and WPA-PSK are the same. The only difference
between the two is that WPA-PSK uses a simple common password, instead of user-specific
credentials. The common-password approach makes WPA-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.
6.4.3 WPA(2)-PSK Application Example
A WPA(2)-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).
2 The AP checks each wireless client's password and (only) allows it to join the network if
the password matches.
3 The AP derives and distributes keys to the wireless clients.
4 The AP and wireless clients use the TKIP or AES encryption process to encrypt data
exchanged between them.
Figure 45 WPA(2)-PSK Authentication
6.5 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) 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.
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