Specifications

Configuring Link Flap Detection
January 29, 2009 Page 3 of 4
Example Link Flap Detection Configuration
PoEdevices(forexample,VoIPphonesorwirelessaccesspoints)connectedtoaMatrixNdevice
areexperiencingintermittentpowerlosses,thoughtheMatrixNdeviceitselfhasnotexperienced
anycorrespondingpowerlosses.Thenetworkadministratorenableslinkflapdetectiononarange
ofPoEportstowhichthePoE
devicesareconnected.
Matrix(rw)->set linkflap portstate enable ge.1.1-12
Thenetworkadministratoralsosetsvaluesfortheinterval,threshold,anddowntimeontheports.
Matrix(rw)->set linkflap interval ge.1.1-12 20
Matrix(rw)->set linkflap threshold ge.1.1-12 8
Matrix(rw)->set linkflap downtime ge.1.1-12 600
Ifthelinkflapthresholdisexceededwithinthelinkflapinterval(eightlinkflapconditionswithin
20seconds,asconfiguredabove),theMatrixNdevicewill,bydefault,disabletheport(for600
seconds,asconfiguredabove)andgeneratebothasyslogentryandanSNMPt r ap. Thesedefault
actions
canbechangedbyusingtheset linkflap actioncommand.
TheMatrixNdevicedisablesportsge.1.1andge.1.2whenexcessivelinkflappingoccursonthe
ports.Thenetworkadministratorcancheckthestatusoftheportsandthenumberoflinkflap
conditionsthatoccurredbyusingthe
show linkflap metricscommand.
Whiletheportsaredisabled,thenetworkadministratorreplacesthepotentiallyfaultyEthernet
cablesconnectingtheportstothePoEdevices.Thenetworkadministratorthenenablestheports.
Matrix(rw)->clear linkflap down ge.1.1-2
IfnoadditionalpowerlossesoccuronthePoEdevicesandnoadditionallinkflappingconditions
occur,thenetworkadministra tordisableslinkflapdetectiononthePoEports.
Matrix(rw)->set linkflap portstate disable ge.1.1-12
Link Flap Detection Display Commands
Table 1listslinkflapdetectionshowcommandsforMatrixN‐Series,SecureStack,D‐Series,
G‐Series,andI‐Seriesdevices.
Refertothedevice’sCLIReferenceGuideorConfigurationGuide foradescriptionoftheoutputof
eachcommand.
Table 1 Link Flap Detection Show Commands
Task Command
Display whether the port is enabled for generating
an SNMP trap message if its link state changes.
show port trap [port-string]
Display link flap detection state and configuration
information.
The show linkflap parameters and show
linkflap metrics commands provide summary
views of your current link flap detection
configuration.
show linkflap {globalstate | portstate
| parameters | metrics | portsupported
| actsupported | maximum | downports |
action | operstatus | threshold |
interval] | downtime | currentcount |
totalcount | timelapsed | violations
[port-string]}