Static Wep Keys; Eap (With Dynamic Wep Keys) - Cisco Aironet CB21AG Installation And Configuration Manual

Chapter 5 Configuring the Client Adapter
The WEP keys used to encrypt and decrypt transmitted data can be statically associated with your
adapter or dynamically created as part of the EAP authentication process. The information in the
WEP Keys"
of WEP keys you want to use. Dynamic WEP keys with EAP offer a higher degree of security than static
WEP keys.
WEP keys, whether static or dynamic, are either 40 or 128 bits in length. 128-bit WEP keys offer a
greater level of security than 40-bit WEP keys.
Refer to the
Note
features that can make your WEP keys even more secure.

Static WEP Keys

Each device (or profile) within your wireless network can be assigned up to four static WEP keys. If a
device receives a packet that is not encrypted with the appropriate key (as the WEP keys of all devices
that are to communicate with each other must match), the device discards the packet and never delivers
it to the intended receiver.
You do not need to re-enter static WEP keys each time the client adapter is inserted or the Windows
device is rebooted because the keys are stored (in an encrypted format for security reasons) in the
registry of the Windows device. When the driver loads and reads the client adapter's registry parameters,
it also finds the static WEP keys, unencrypts them, and stores them in volatile memory on the adapter.
The Define Pre-Shared Keys window enables you to view the WEP key settings for a particular profile
and to assign new WEP keys or overwrite existing WEP keys. Refer to the
page 5-26

EAP (with Dynamic WEP Keys)

The standard for wireless LAN security, as defined by IEEE, is called 802.1X for 802.11, or simply
802.1X. An access point that supports 802.1X and its protocol, Extensible Authentication Protocol
(EAP), acts as the interface between a wireless client and an authentication server, such as a RADIUS
server, to which the access point communicates over the wired network.
Five 802.1X authentication types are available in ADU for use with Windows 2000 or XP:
•
Cisco Aironet 802.11a/b/g Wireless LAN Client Adapters (CB21AG and PI21AG) Installation and Configuration Guide
OL-4211-05
and "EAP (with Dynamic WEP Keys)"
"Additional WEP Key Security Features" on page 5-21
for instructions.
EAP-Cisco Wireless (or LEAP)—This authentication type leverages Cisco Key Integrity Protocol
(CKIP) and MMH message integrity check (MIC) for data protection. ADU offers a variety of LEAP
configuration options, including how a username and password are entered to begin the
authentication process.
The username and password are used by the client adapter to perform mutual authentication with the
RADIUS server through the access point. The username and password need to be re-entered each
time the client adapter is inserted or the Windows device is rebooted unless you configure your
adapter to use saved LEAP credentials.
RADIUS servers that support LEAP include Cisco Secure ACS release 2.6 or later, Cisco Access
Registrar release 1.7 or later, Funk Software's Steel-Belted RADIUS release 4.1 or later, and
Meetinghouse Data Communications' AEGIS release 1.1 or later.
Setting Security Parameters
sections below can help you to decide which type
for information on three security
"Enabling Static WEP" on
"Static
5-15