Authentication
4-14 Advanced Configuration
Authentication
WirelessclientscanbeauthenticatedfornetworkaccessbycheckingtheirMACaddressagainst
thelocaldatabaseconfiguredontheaccesspoint,orbyusingadatabaseconfiguredonacentral
RADIUSserver.Alternatively,authenticationcanbeimplement edusingtheIEEE802.1Xnetwork
accesscontrolprotocol.
ClientstationMACauthenticationoccurs
priortotheIEEE802.1Xauthenticationprocedure
configuredfortheaccesspoint.However,aclient’sMACaddressprovidesrelativelyweakuser
authentication,sinceMACaddressescanbeeasilycapturedandusedbyanotherstationtobreak
intothenetwork.Using802.1Xprovidesmorerobustuserauthenticationusingusernamesand
passwordsordigitalcertificates.So,althoughyoucanconfiguretheaccesspointtouseMAC
addressand802.1Xauthenticationtogether,itisbettertochooseoneortheother,asappropriate.
UseMACaddressauthenticationforasmallnetworkwithalimitednumberofusers.MAC
addressescanbemanuallyconfigured
ontheaccesspointitselfwithouttheneedtosetupa
RADIUSserver.UseIEEE802.1Xauthenticationfornetworkswithalargernumberofusersand
wheresecurityisthemostimportantissue.For802.1XauthenticationaRADIUSserverisrequired
inthewirednetworktocontroltheuser
credentialsofthewirelessclients.
Theaccesspointcanalsooperateinan802.1Xsupplicantmode.Thisenables theaccesspointitself
tobeauthenticatedwithaRADIUSserverusingaconfiguredMD5usernameandpassword.This
preventsrogueaccesspointsfromgainingaccesstothenetwork.