MasterclockGMRUserManualv2–2016.12
17
DHCPAuto‐Configuration
DHCP(DynamicHostConfigurationProtocol)isamechanismforautomatingtheconfigurationofnetworked
devicesthatuseTCP/IP.WhenDHCPisenabled,DHCPconfigurationacquisitionwilloverwriteanymanual
configurationitems.
TheGMRcanobtainitsnetworkconfigurationautomaticallyfromDHCP,whenoneortheotherisavailableonthe
network.UtilizingDHCP,theGMRwillautomaticallybeassigneditsnetworkconfiguration.ThisincludesanIP
addressandadditionalfunctions,suchasDNSserverandRouter/Gatewaysettings.Thisfeatureisenabledby
default.AGMRnetworkdevicewillnotfunctionproperlyifconfiguredtouseDHCPserviceswhennoDHCPserver
ispresentonthenetwork.IfnoDHCPserverispresent,thedevicewilluseafallbackIPaddress:169.254.xxx.yyy
wherexxxandyyyarethelasttwobytesoftheMACaddress.
TheGMRcanautomaticallyobtainTimeZoneOffsetconfigurationandtheNTPserveraddresses(primaryand
secondary).
ToutilizethesefeaturestheDHCPserverofthenetworkmustbepre‐configuredwiththeappropriate
checklistitems.Factorydefault:DHCPenabled.
LongDHCPnamesarenotsupported.Onlythefirst14charactersofthedevicenamewillberegisteredbythe
DHCPserver.
TheIPaddressofthe
unitisrequiredtoconfiguretheGMRwithSSHorTelnet.TheDHCPservercanbeutilizedto
providetheIPaddressoftheassociateddevicenamethatisregistered.
ThefollowingRFC2132‐definedoptionalconfigurationitemsare,whenavailable,usedbytheGMRfor
configuration:
Option No.
Comments
Router 3
ThefirstIPaddressprovidedwillbeusedforrouter/gateway
configuration.
DomainName
Server
6
UptotwoserverIPaddressesmaybespecified.GMRdevicewilltreat
addressesasprimaryandsecondaryDNSservers.
NTPServer 42
SpecifiesanNTPserveravailabletotheclient.Ifmorethanoneislisted,
onlythefirstwillbeused.