35
Managing Dependencies
Dependenciesaccountfortopologicalconstraintsonyournetwork.These
constraintsmaybeeithertheresultofthedesignofaspecificdevice,suchas
interfacesonaswitchorrouter,ortheresultofthephysicalarchitectureofthe
networkitself.TheUnreachablestatusaccountsforcaseswhereadevicemay
appeartobedown,butitsstatusisactuallyindeterminateduetoanotherdevice
beingdownorunresponsive.
Interfacesareuniquebecausetheycannotbedefinedaschildobjectsinthe
product.SolarWindsproductsdeterminetheinterfacestatusbypollingtheparent
node.Iftheparentnodeisphysicallydownorunresponsivetotheselected
pollingmethod,allinterfacesontheparentnodearereportedasUnreachable.
Forexample,whenaswitchgoesdownorbecomesunresponsive,allinterfaces
ontheswitcharealsounresponsive,eventhoughtheymayworking.Thechild
interfacesdisplayasUnreachablebecausetheirparentnodereportsasdown.
Youcanalsodefinedependenciesamongdistinctdevices,suchasasubnetof
devicesonyournetworkthatdependsonasingleWANlinktoconnectwiththe
restofyournetwork.Ifyoudefineagroupconsistingofthedevicesinthis
dependentsubnet,youcandefineadependencywherethedependentsubnetis
achildgrouptotheparentrouterthatservesastheWANlinktotherestofyour
network.Formoreinformationaboutgroups,seeManaging
Groups
.
YourSolarWindsproductcancreate1:1parent/childnode
dependenciesautomaticallywhenyouenableAutoDependenciesin
thePollingSettingspage.
Dependenciesaremostusefulwhendesigningalerts.Ifyouhaveanalert
configuredtotriggerwhenthestatusofamonitoredobjectisdown,youonlywant
thatalerttotriggerifamonitoredobjectisactuallydown.Withoutdependencies,
allmonitoredobjectsonanunresponsive,monitorednodereportasdown.By
establishingdependenciesthesechildobjectsdisplayasUnreachableinsteadof
down,whichpreventsfalsedownobjectalerts.
Note:Thestatusofobjectsinchildgroupsisdeterminedseparatelyfromthe
relatedparentobject'sstatus.
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ManagingDependencies