Specifications

Configuring MAC Locking
19-50 Authentication and Authorization Configuration
Configuring MAC Locking
ThisfeaturelocksaMACaddresstooneormoreports,preventingconnectionofunauthorized
devicesthroughtheport(s).WhensourceMACaddressesarereceivedonspecifiedports,the
switchdiscardsallsubsequentframes notcontainingtheconfiguredsourceaddresses.Theonly
framesforwardedona“locked”portarethosewith
the“locked”MACaddress(es)forthatport.
TherearetwomethodsoflockingaMACtoaport:firstarrivalandstatic.Thefirstarrivalmethod
isdefinedtobelockingthefirstnnumberofMACswhicharriveonaportconfiguredwithMAC
lockingenabled.Thevaluenis
configuredwiththesetmaclockfirstarrivalcommand.
ThestaticmethodisdefinedtobestaticallyprovisioningaMAC‐portlockusingthesetmaclock
command.ThemaximumnumberofstaticMACaddressesallowedforMAClockingonaport
canbeconfiguredwiththesetmaclockstaticcommand.
Youcanconfigure
theswitchtoissueaviolationtrapifapacketarriveswithasourceMAC
addressdifferentfromanyofthecurrentlylockedMACaddressesforthatport.
MACsareunlockedasaresultof:
•Alinkdownevent
•WhenMAClock ing isdisabledonaport
•WhenaMACisaged
outoftheforwardingdatabasewhenFirstArrivalagingisenabled
Whenproperlyconfigured,MAClockingisanexcellentsecuritytoolasitpreventsMACspoofing
onconfiguredports.AlsoifaMACweretobesecuredbysomethinglikeDragonDynamic
IntrusionDetection,MAClockingwouldmakeitmoredifficultfor 
ahackertosendpacketsinto
thenetworkbecausethehackerwouldhavetochangetheir MACaddressandmovetoanother
port.Inthemeantimethesystemadministratorwouldbereceivingamaclocktrapnotification.
Purpose
Toreview,disable,enable,andconfigureMAClocking.
Commands
authenticated mac
address
If authentication has succeeded, displays the MAC address assigned for egress.
vlan id If authentication has succeeded, displays the assigned VLAN id for ingress.
Table 19-5 show vlanauthorization Output Details (Continued)
Output Field What It Displays...
For information about... Refer to page...
show maclock 19-51
show maclock stations 19-52
set maclock enable 19-53
set maclock disable 19-54
set maclock 19-54
clear maclock 19-55