User's Manual

USER GUIDE
Appendix
ireless network security is challenging for several reasons. First, the problem is very
different from the wired network security because the boundaries have changed. In
addition, initial attempts at wireless security (e.g., 802.11b) were seriously flawed, but
commercially successful. Solutions that hope to capitalize on these markets must
compensate for their flaws while remaining compatible. Finally, securing network access and
communication poses tradeoffs with network performance and convenience. Security measures
must be provided in a way that is flexible so that it works correctly in environments that have
varying requirements.
5: Security Overview
W
The ability to establish boundaries is essential to realizing reliable network security. With wireless
networks the physical boundaries have moved. With a wired LAN, you must be physically
connected to the network to send or receive messages on the network. A building’s physical
security, its walls, ceilings, doors, and alarms play a role in the security of the network by
preventing unintended recipients from gaining access to the network.
In a wireless network, any client within the coverage area of an Access Point can receive data
transmitted to or from it. Radio waves travel through walls and ceilings, so intruders and
eavesdroppers don’t have to be in the same room, on the same floor, or even inside the
building. So, a secure connection must be forged only with legitimate users over this open
communication channel.
Security for a generic Access Point is comprised of two distinct parts: authentication and
encryption. Authentication is the process used to verify that the device attempting to attach to
an access point has the correct credentials to access the wired network. Encryption protects
subsequent data exchanges so that transmissions between the device and the access point
cannot be intercepted and deciphered. Data encryption generally does not extend to the wired
network unless a Virtual Private Network (VPN) is utilized.
Security Process
Authentication  Association  Remote Authentication  Key Exchange Network Access
 Periodic Validation/Key Exchange
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