Authentication is a means of verifying information transmitted from a secure source. If information
is authentic, you know who created it and you know it has not been altered in any way since it was
originated. Authentication entails a network administrator employing a software “supplicant” on
their computer or wireless device.

Authentication is critical for the security of any wireless LAN device. Traditional authentication
methods are not suitable for use in wireless networks where an unauthorized user can monitor
network traffic and intercept passwords. The use of strong authentication methods that do not
disclose passwords is necessary. The access point uses the Kerberos authentication service
protocol (specified in RFC 1510) to authenticate users/clients in a wireless network environment
and to securely distribute the encryption keys used for both encrypting and decrypting.

A basic understanding of RFC 1510 Kerberos Network Authentication Service (V5) is helpful in
understanding how Kerberos works. By default, WLAN devices operate in an open system network
where any wireless device can associate with an AP without authorization. Kerberos requires
device authentication before access to the wired network is permitted.

For detailed information on Kerbeors configurations, see Configuring Kerberos Authentication on
page 6-194.

EAP Authentication

The Extensible Authentication Protocol (EAP) feature provides access points and their associated
MUs an additional measure of security for data transmitted over the wireless network. Using EAP,
authentication between devices is achieved through the exchange and verification of certificates.

EAP is a mutual authentication method whereby both the MU and AP are required to prove their
identities. Like Kerberos, the user loses device authentication if the server cannot provide proof of
device identification.

Using EAP, a user requests connection to a WLAN through the access point Mobility 7131 Access
Point. The access point Mobility 7131 Access Point then requests the identity of the user and
transmits that identity to an authentication server. The server prompts the AP for proof of identity
(supplied to the Mobility 7131 Access Point by the user) and then transmits the user data back to
the server to complete the authentication process.

An MU is not able to access the network if not authenticated. When configured for EAP support, the
access point displays the MU as an EAP station.