Switch User Manual

Link Aggregation Control Protocol (LACP)
7-44 Port Configuration
is,willblockredundantpaths).Forinformationaboutbuildingstaticaggregations, refertoset
lacpstatic(page 7‐48).
EachSecureStackC3moduleprovidessixvirtuallinkaggregatorports,whicharedesignatedin
theCLIaslag.0.1throughlag.0.6.EachLAGcanhaveuptoeightassociatedphysicalports.Once
underlying
physicalports(forexample,fe.x.x,orge.x.x)areassociatedwithanaggregatorport,
theresultingaggregationwillberepresentedasoneLAGwithalag.0.xportdesignation.LACP
determineswhichunderlyingphysicalportsarecapableofaggregatingbycomparingoperational
keys.AggregatorportsallowonlyunderlyingportswithkeysmatchingtheirstojointheirLAG.
LACPuses
asystempriorityvaluetobuildaLAGID,whichdeterminesaggregationprecedence.
Iftherearetwopartnerdevicescompetingforthesameaggregator,LACPcomparestheLAGIDs
foreachgroupingofports.TheLAGwiththelowerLAGIDisgivenprecedenceandwillbe
allowedtouse
theaggregator.
Thereareafewcasesinwhichportswillnotaggregate:
•Anunderlyingphysicalportisattachedtoanotherportonthissameswitch(loopback).
•ThereisnoavailableaggregatorfortwoormoreportswiththesameLAGID.Thiscan
happeniftherearesimplynoavailableaggregators,
orifnoneoftheaggregatorshavea
matchingadminkeyandsystempriority.
• 802.1xauthenti cationisenabledusingtheseteapolcommand(page 16‐18)andportsthat
wouldotherwiseaggregatearenot802.1Xauthorized.
TheLACPimplementationontheSecureStackC3devicewillallowuptoeightphysicalports
into
aLAG.ThedevicewiththelowestLAGIDdetermineswhichunderlyingphysicalportsare
allowedintoaLAGbasedontheports’LAGportpriority.PortswiththelowestLAGportpriority
valuesare allowedintotheLAGandallotherspeedgroupingsgointoastandbystate.
Multi‐
portLAGswillcontinuetooperateaslongasthereisatleastoneactiveportintheLAG.
Therefore,thereisnoneedtocreatebackupsingleportLAGsortospecificallyassigntheLAGand
allitsphysicalportstotheegresslistoftheLAG’sVLAN.
Typically,two
ormoreportsarerequiredtoformaLAG.However,youcanenablethecreationof
singleportLAGsasdescribedin“setlacpsingleportlag”onpage7‐50.IfasingleportLAGgoes
downandtheswitchstaysup,theswitchwillreconfiguretheLAGtothe
sameLAGnumberifthe
portcomesbackup.
Commands
Note: To aggregate, underlying physical ports must be running in full duplex mode and must be of
the same operating speed.
For information about... Refer to page...
show lacp 7-45
set lacp 7-46
set lacp asyspri 7-47
set lacp aadminkey 7-47
clear lacp 7-48
set lacp static 7-48
clear lacp static 7-49