Specifications

December 02, 2010 Page 1 of 23
Configuring Link Aggregation
ThisdocumentdescribesthelinkaggregationfeatureanditsconfigurationonEnterasysMatrix
®

N‐Series,S‐Series
®
,stackableandstandaloneswitchdevices.
What is Link Aggregation
IEEE802.3adlinkaggregationprovidesastandardizedmeansofgroupingmultipleparallel
EthernetinterfacesintoasinglelogicalLayer2link.TheformedgroupofEthernetinterfacesis
referredtoasaLinkAggregationGroup(LAG).DynamicLAGformationand activationis
providedbytheLinkAggregationControlProtocol(LACP).
Each
pairofLAGphysicalportsismadeupofalocalportonthedeviceresponsibleforLACP
negotiation,referredtoastheactor,anditsdirectlylinkedremoteportonthedeviceparticipating
intheLACPnegotiation,referredtoasthepartner.LAGsformautomaticallybaseduponaset
of
criteria(seeHowaLAGFormsonpage 3).
OnlyLAGmembersintheattachedstatecarryusertraffic.OncetheLAGisformed,thesystem
ID,madeupofasystempriorityandthedeviceMACaddress,determineswhichdevicewillbein
chargeofchoosingtheLAGportmembers
thatwillbemovedtotheattachedstate.Whileport
speedisnotacriteriaforjoiningaLAG,theportspeedmustmatchforallportsthatareplacedin
theLACPattachedstate.AggregatableportsnotselectedtocarrytrafficforthisLAGareavailable
tothenextLAG
aslongasLAGresourcesarenotdepleted.ShouldLAGresourcesbecome
depleted,aggregatableportsareplacedinLACPstandbystate.
802.3adLACPaggregationscanberunbetweencombinationsofswitches,routers,andedge
devices,suchasaserver,thatsupportLACP.
Note: See the Enterasys Matrix X Router Configuration Guide for X Router link aggregation
configuration information.
For information about... Refer to page...
What is Link Aggregation 1
Why Would I Use Link Aggregation in My Network 2
How Can I Implement Link Aggregation 2
Link Aggregation Overview 3
Configuring Link Aggregation 10
Link Aggregation Configuration Example 12
Terms and Definitions 21
Note: Earlier (proprietary) implementations of port aggregation referred to groups of aggregated
ports as “trunks”.