MasterclockGMRUserManualv2–2016.12
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SNMP–SimpleNetworkManagementProtocol
SNMP
SNMPisastandardwaytomonitoradeviceonanEthernet
network.Itisusedtomonitorthehealthandnetworkstatus
ofadeviceonanEthernetLAN.SNMP'spurposeisonlyto
conveystatus,notforcontrollingthedevice.
TheGMRrunsfirmwarecalledtheSNMPAgent.The
user
runssoftwarecalledanSNMPManager(orMIBBrowser)on
aPC.THEUSERMUSTACQUIRETHEMANAGERSOFTWARE;
Masterclockdoesnotofferone.
OurAgentsupportsversions1and2ofSNMP.ThePCon
whichtheManagerisrunningmustalsohaveSNMPabilities
forManagerand
Agenttocommunicate.Windows7andXP
supportSNMPv1and2.TheuserrunstheManagertoget
thedata,issuingrequeststotheAgent.Ifsomesecuritytests
arepassed,thentheAgentrespondswiththedata.
TheSNMPControlwindowinWinDiscoveryprovidesSTART
andSTOPbuttonsfor
theusertoturntheSNMPAgenton
andoff,andoffersafewoptions,likeName,Locationand
Contact.
Thusadevicecouldbenamed"GPSRef",withthelocation
"Bldg1‐A",andthecontact"636‐724‐3666".
ACustomCommunitynamecanbecreated(community#2)
andputtousebymakingittheCurrentCommunity,
providingsomesecurityifthenameiskeptsecret.
TrapReceiversaretheIPaddressesofPCstowhichtrapsare
sent.TrapsaremessagesthattheAgentcansendtothe
Managerwithoutbeingasked.Theytellofevents
like:
1.DeviceRestart
2.EthernetLinkUp
3.AuthenticationFailure(Communitymismatch)
InadditiontothatstandardSNMPdata,Masterclockhas
createdacustomset,calledacustomMIB,whichcanbe
importedintoanMIBBrowser(Manager).Itisavailablefor
downloadfromoursite.Totheleftis
adisplayfromaMIB
BrowserofthetypeofdatathisMIBenablestheuserto
receivefromtheGMR.Whentheuserdouble‐clicksonan
entrytheAgentisaskedforthedata,andifreturneditis
displayed,alongwithdescriptivetextfromtheimportedMIB.