Link Aggregation Control Protocol (LACP)
5-36 Port Configuration
protocol,nodynamiclinkaggregationswillbeformedandtheswitchwillfunctionnormally(that
is,willblockredundantpaths).Forinformationaboutbuildingstaticaggregations,refertoset
lacpstatic(page 5‐40).
EachSecureStackB3moduleprovidessixvirtuallinkaggregatorports,whicharedesignatedin
theCLIas
lag.0.1throughlag.0.6.EachLAGcanhaveuptoassociatedphysicalports.Once
underlyingphysicalports(forexample,
ge.x.x,orge.x.x)areassociatedwithanaggregatorport,
theresultingaggrega tionwillberepresentedasoneLAGwithalag.x.xportdesignation.LACP
determineswhichunderlyingphysicalportsarecapableofaggregatingbycomparingoperational
keys.AggregatorportsallowonlyunderlyingportswithkeysmatchingtheirstojointheirLAG.
LACPuses
asystempriorityvaluetobuildaLAGID,whichdeterminesaggregationprecedence.
Iftherearetwopartnerdevicescompetingforthesameaggregator,LACPcomparestheLAGIDs
foreachgroupingofports.TheLAGwiththelowerLAGIDisgivenprecedenceandwillbe
allowedtouse
theaggregator.
Thereareafewcasesinwhichportswillnotaggregate:
•Anunderlyingphysicalportisattachedtoanotherportonthissameswitch(loopback).
•ThereisnoavailableaggregatorfortwoormoreportswiththesameLAGID.Thiscan
happeniftherearesimplynoavailableaggregators,
orifnoneoftheaggregatorshavea
matchingadminkeyandsystempriority.
• 802.1xauthenti cationisenabledusingtheseteapolcommand(page 20‐17)andportsthat
wouldotherwiseaggregatearenot802.1Xauthorized.
TheLACPimplementationontheSecureStackB3devicewillallowuptophysicalportsinto
a
LAG.ThedevicewiththelowestLAGIDdetermineswhichunderlyingphysicalportsareallowed
intoaLAGbasedontheports’LAGportpriority.PortswiththelowestLAGportpriorityvalues
areallowedintotheLAGandallotherspeedgroupingsgointoastandbystate.
Whenan
existingdynamicallycreatedLAGisreducedtooneport,theSecureStackB3removes
theLAGfromitsVLANandaddstheremainingunderlyingporttotheVLAN.Forthisreason,
youshouldensurethattheLAGandalltheportsintheLAGareassignedtotheegresslistofthe
desiredVLAN.Otherwise,whentheLAGisremoved,theremainingportmaybeassignedtothe
wrongVLAN.Theotheroptionistoenablethesingleportlagfeatureasdescribedin“setlacp
singleportlag”onpage5‐41.
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 5-37
set lacp 5-38
set lacp asyspri 5-38
set lacp aadminkey 5-39
clear lacp 5-40
set lacp static 5-40
clear lacp static 5-41
set lacp singleportlag 5-41