Enterasys Networks DFE-Gold Series Configuring LACP

clear port mirroring Configuring LACP

Enterasys Matrix DFE-Gold Series Configuration Guide 4-55

Configuring LACP

Usingmultiplelinkssimultaneouslytoincreasebandwidthisadesirableswitchfeature,which

canbeaccomplishedifbothsidesagreeonasetofportsthatarebeingusedasaLinkAggregation

Group(LAG).OnceaLAGisformedfromselectedports,problemswithloopingcanbeavoided

sincetheSpanningTreecantreatthisLAGasasingleport.

EnabledbydefaultonMatrixdevices,theLinkAggregationControlProtocol(LACP)logically

groupsinterfacestogethertocreateagreaterbandwidthuplink,orlinkaggregation,accordingto

theIEEE802.3adstandard.ThisstandardallowstheswitchtodeterminewhichportsareinLAGs

andconfigurethemdynamically.SincetheprotocolisbasedontheIEEE802.3adspecification,any

switchfromanyvendorthatsupportsthisstandardcanaggregatelinksautomatically.

802.3adLACPaggregationscanalsoberuntoend‐users(i.e.,aserver)ortoarouter.

Foreachaggregatableportinthedevice,LACP:

• Maintainsconfigurationinformation(reflectingtheinherentpropertiesoftheindividuallinks

aswellasthoseestablishedbymanagement)tocontrolaggregation.

•ExchangesconfigurationinformationwithotherdevicestoallocatethelinktoaLink

AggregationGroup(LAG).

• AttachestheporttotheaggregatorusedbytheLAG,anddetachestheportfromthe

aggregatorwhenitisnolongerusedbytheLAG.

•Usesinformationfromthepartnerdevice’slinkaggregationcontrolentitytodecidewhether

toaggregateports.

TheoperationofLACPinvolvesthefollowingactivities:

•Checkingthatcandidatelinkscanactuallybeaggregated.

• ControllingtheadditionofalinktoaLAG,andthecreationofthegroupifnecessary.

• Monitoringthestatusofaggregatedlinkstoensurethattheaggregationisstillvalid.

•RemovingalinkfromaLAGifitsmembershipisnolongervalid,andremovingthegroupifit

nolongerhasanymemberlinks.

InordertoallowLACPtodeterminewhetherasetoflinksconnecttothesamedevice,andto

determinewhetherthoselinksarecompatiblefromthepointofviewofaggregation,itis

necessarytobeabletoestablish

•Agloballyuniqueidentifierforeachdevicethatparticipatesinlinkaggregation.

Caution: Link aggregation configuration should only be performed by personnel who are

knowledgeable about Spanning Tree and Link Aggregation, and fully understand the ramifications

of modifications beyond device defaults. Otherwise, the proper operation of the network could be at

risk.

Note: Earlier (proprietary) implementations of port aggregation referred to groups of aggregated

ports as “trunks”.

Note: A given link is allocated to, at most, one Link Aggregation Group (LAG) at a time. The

allocation mechanism attempts to maximize aggregation, subject to management controls.