Appendix D Wireless LANs
NWA1100-N User’s Guide
187
WPA(2) with RADIUS Application Example
To set up WPA(2), 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
A 256-bit Pairwise Master Key (PMK) is derived from the authentication process by the RADIUS
server and the client.
4
The RADIUS server distributes the PMK to the AP. The AP then sets up a key hierarchy and
management system, using the PMK to dynamically generate unique data encryption keys. The
keys are used to encrypt every data packet that is wirelessly communicated between the AP and
the wireless clients.
Figure 101
WPA(2) with RADIUS Application Example
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 or 64 hexadecimal characters (including spaces and
symbols).
2
The AP checks each wireless client's password and allows it to join the network only if the password
matches.
3
The AP and wireless clients generate a common PMK (Pairwise Master Key). The key itself is not
sent over the network, but is derived from the PSK and the SSID.
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