Enterasys b5

Enterasys B5 CLI Reference 24-1
24
sFlow Configuration
ThischapterprovidesinformationaboutthecommandsusedtoconfigureandmonitorthesFlow
system.
Overview
sFlowisamethodformonitoringhigh‐speedswitchedandroutednetworks.sFlowtechnologyis
builtintonetworkequipmentandgivesvisibilityintonetworkactivity,enablingeffective
managementandcontrolofnetworkresources.
AnsFlowsolutionconsistsofansFlowAgent,embeddedinthenetworkdevicesuchasaswitch
or
router,andansFlowCollector.ThesFlowAgentusessamplingtechnologytocapturetraffic
statisticsfromthedeviceitismonitoringandimmediatelyforwardsthesampledtrafficstatistics
toansFlowCollectorforanalysisinsFlowdatagrams.
ThesFlowAgentusestwoformsofsampling—statisticalpacket‐basedsamplingofswitched
or
routedPacketFlows,andtime‐basedsamplingofcounters.
Version5ofsFlowisdescribedindetailinthedocumententitled“sFlowVersion5”availablefrom
sFlow. org(http://www.sflow.org).
Using sFlow in Your Network
TheadvantagesofusingsFlowinclude:
•sFlowmakesitpossibletomonitorportsofaswitch,withnoimpactonthedistributed
switchingperformance.(See“UsageNotes”onpage 24‐3formoreinformation.)
•sFlowrequiresverylittlememoryorCPUusage.Samplesarenotaggregatedintoaflow‐
tableonthe
switch—theyareforwardedimmediatelyoverthenetworktothesFlow
Collector.
•Thesystemistoleranttopacketlossinthenetwork.(Thestatisticalmodelmeanslossis
equivalenttoaslightchangeinthesamplingrate.)
•ThesFlowCollectorcanreceivedatafrommultipleswitches,providingareal‐time
synchronizedviewofthewholenetwork.
•ThesFlowCollectorcananalyzetrafficpatternsforwhateverprotocolsarefoundinthe
packetheaders(forexample,TCP/IP,IPX,Ethernet,AppleTalk).Thereisnoneedforthelayer
2switchtodecodeandunderstandallprotocols.
For information about... Refer to page...
Overview 24-1
Commands 24-4