Appendix F Wireless Lan With Ieee 802.1X - ZyXEL Communications ZyWALL 5 User Manual

As wireless networks become popular for both portable computing and corporate networks, security is
now a priority.
Security Flaws with IEEE 802.11
Wireless networks based on the original IEEE 802.11 have a poor reputation for safety. The IEEE
802.11b wireless access standard, first published in 1999, was based on the MAC address. As the
MAC address is sent across the wireless link in clear text, it is easy to spoof and fake. Even the WEP
(Wire Equivalent Privacy) data encryption is unreliable as it can be easily decrypted with current
computer speed
Deployment Issues with IEEE 802.11
User account management has become a network administrator's nightmare in a corporate
environment, as the IEEE 802.11b standard does not provide any central user account management.
User access control is done through manual modification of the MAC address table on the access
point. Although WEP data encryption offers a form of data security, you have to reset the WEP key on
the clients each time you change your WEP key on the access point.
IEEE 802.1x
In June 2001, the IEEE 802.1x standard was designed to extend the features of IEEE 802.11 to support
extended authentication as well as providing additional accounting and control features. It is supported
by Windows XP and a number of network devices.
Advantages of the IEEE 802.1x
•
User based identification that allows for roaming.
•
Support for RADIUS (Remote Authentication Dial In User Service, RFC 2138, 2139) for centralized
user profile and accounting management on a network RADIUS server.
•
Support for EAP (Extensible Authentication Protocol, RFC 2486) that allows additional authentication
methods to be deployed with no changes to the access point or the wireless clients.
RADIUS Server Authentication Sequence
The following figure depicts a typical wireless network with a remote RADIUS server for user
authentication using EAPOL (EAP Over LAN).
Wireless LAN With IEEE 802.1x
Wireless LAN With IEEE 802.1x
ZyWALL 5 Internet Security Appliance
Appendix F
F-1