User`s guide

Link Aggregation Control Protocol (LACP) Overview
4-2 Configuring Link Aggregation
LACP Operation
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grou p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thefollowing:
•Agloballyuniqueidentifierforeachdevice
thatparticipatesinlinkaggregation
•Ameansofidentifyingthesetofcapabilitiesassociatedwitheachportandwitheach
aggregator,asunderstoodbyagivendevice
•AmeansofidentifyingaLAGanditsassociatedaggregator
LACP Terminology
Table 4‐1defineskeyterminologyusedinLACPconfiguration.
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.
Table 4-1 LACP Terms and Definitions
Term Definition
Aggregator Virtual port that controls link aggregation for underlying physical ports. Each
Matrix DFE-Platinum Series module or N-SA device provides 48 aggregator
ports, which are designated in the CLI as lag.0.1 through lag.0.48. Each
Matrix DFE-Gold Series module provides 4 aggregator ports, which are
designated in the CLI as lag.0.1 through lag.0.4.
LAG Link Aggregation Group. Once underlying physical ports (such as, 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.x.x port designation.