Enterasys Matrix DFE-Gold Series Configuration Guide 15-1
15

NetFlow Configuration

ThischapterdescribesNetFlowcommandsandhowtousethem.

Configuring NetFlow

NetFlowisaprotocoldevelopedforcollectingIPtrafficinformation.Networkdevices(switches
androuters)withNetFlowenabledgenerateNetFlowflowrecords,whichareexportedfromthe
deviceinUDPpacketsandcollectedbyaNetFlowcollector.

Enterasys Matrix DFE Implementation

TheEnterasysMatrixDFEflowbasedarchitectureprovidesapowerfulmechanismforcollecting
networkflowstatistics,withreportingcapacitythatscaleswiththeadditionofeachDFEblade.
Foreachflow,packetandbytecountstatisticsarecollectbytheDFEforwardinghardware.The
flowreportgenerationlogicisdistributed,permittingeachbladetoreportflowsonitsownports.
TheEnterasysMatrixDFEimplementationenablesthecollectionofNetFlowdataonboth
switchedandroutedframes,allowingDFEbladesinallareasofanetworkinfrastructuretocollect
andreportflowdata.RoutingdoesnotneedtobeenabledtoutilizeNetFlowdatacollection.Flow
detaildependsonthecontentoftheframeandthepaththeframetakesthroughtheswitch.

Operation

NetFlowcanbeenabledonallportsonaEnterasysMatrixsystem,includingfixedfrontpanel
ports,LAGports,NEMports,andFTM1backplaneports.RouterinterfaceswhichmaptoVLANs
maynotbeenableddirectly.
NetFlowrecordsaregeneratedonlyforflowsforwhichahardwareconnectionhasbeen
established.Aslongasthenetworkconnectionexists(andNetFlowisenabled),NetFlowrecords
willbegenerated.Flowsthatareswitchedinfirmware(softforwarded)willnothaveNetFlow
recordsreported.Forflowsthatarerouted,theDFEfirmwarereportsthesourceanddestination
ifIndexesasthephysicalports,notroutedinterfaces.
InthecaseofaLAGport,theblade(s)thatthephysicalportsareonwillgenerateNetFlowrecords
independently.Theywillhowever,reportthesourceifIndexastheLAGport.TheFlowSequence
CounterfieldintheNetFlowHeaderisuniqueperblade.TheEngineIDfieldoftheNetFlow
Headerisusedtoidentifyeachuniqueblade.EachbladefunctionsasaseparateNetflowengine.
WhenNetFlowisenabled,eachDFEbladeintheEnterasysMatrixsystemwilltransmitaNetFlow
packetwhen:
Note: An Enterasys Feature Guide document that contains a complete discussion on NetFlow
configuration exists at the following Enterasys web site: http://www.enterasys.com/support/
manuals/