Apple AirPort Networks - Manual (Page 11)

Chapter 2 AirPort Security 11
RADIUS Support
The Remote Authentication Dial-In User Service (RADIUS) makes securing a large
network easy. RADIUS is an access control protocol that allows a system administrator
to create a central list of the user names and passwords of computers that can access
the network. Placing this list on a centralized server allows many wireless devices to
access the list and makes it easy to update. If the MAC address of a user’s computer
(which is unique to each 802.11 wireless card) is not on your approved MAC address list,
the user cannot join your network.
Wi-Fi Protected Access (WPA) and WPA2
There has been increasing concern about the vulnerabilities of WEP. In response, the
Wi-Fi Alliance, in conjunction with the IEEE, has developed enhanced, interoperable
security standards called Wi-Fi Protected Access (WPA) and WPA2.
WPA and WPA2 use specifications that bring together standards-based, interoperable
security mechanisms that significantly increase the level of data protection and access
control for wireless LANs. WPA and WPA2 provide wireless LAN users with a high-level
assurance that their data remains protected and that only authorized network users
can access the network. A wireless network that uses WPA or WPA2 requires all
computers that access the wireless network to have WPA or WPA2 support. WPA
provides a high level of data protection and (when used in Enterprise mode) requires
user authentication.
The main standards-based technologies that constitute WPA include Temporal Key
Integrity Protocol (TKIP), 802.1X, Message Integrity Check (MIC), and Extensible
Authentication Protocol (EAP).
TKIP provides enhanced data encryption by addressing the WEP encryption
vulnerabilities, including the frequency with which keys are used to encrypt the
wireless connection. 802.1X and EAP provide the ability to authenticate a user on
the wireless network.
802.1X is a port-based network access control method for wired as well as wireless
networks. The IEEE adopted 802.1X as a standard in August 2001.
The Message Integrity Check (MIC) is designed to prevent an attacker from capturing
data packets, altering them, and resending them. The MIC provides a strong
mathematical function in which the receiver and the transmitter each compute and
then compare the MIC. If they do not match, the data is assumed to have been
tampered with and the packet is dropped. If multiple MIC failures occur, the network
may initiate countermeasures.