Enterasys G3G170-24 - Chapter 13: DHCP Server Configuration; DHCP Overview; DHCP Server

Enterasys G-Series CLI Reference 13-1
13
DHCP Server Configuration
ThischapterdescribesthecommandstoconfiguretheIPv4DHCPserverfunctionalityonaG‐
Seriesswitch.
DHCP Overview
DynamicHostConfigurationProtocol(DHCP)forIPv4isanetworklayerprotocolthat
implementsautomaticormanualassignmentofIPaddressesandotherconfigurationinformation
toclientdevicesbyservers.ADHCPservermanagesauser‐configuredpoolofIPaddressesfrom
whichitcanmakeassignmentsuponclientrequests.A
relayagentpassesDHCPmessages
betweenclientsandserverswhichareondifferentphysicalsubnets.
DHCP Server
DHCPserverfunctionalityallowstheG‐SeriesswitchtoprovidebasicIPconfiguration
informationtoaclientonthenetworkwhorequestssuchinformationusingtheDHCPprotocol.
DHCPprovidesthefollowingmechanismsforIPaddressallocationbyaDHCPserver:
• Automatic—DHCPserverassignsanIPaddresstoaclientfor
alimitedperiodoftime(or
untiltheclientexplicitlyrelinquishestheaddress)fromadefinedpoolofIPaddresses
configuredontheserver.
•Manual—Aclient’sIPaddressisassignedbythenetworkadministrator,andDHCPisused
simplytoconveytheassignedaddresstotheclient.Thisismanagedby
meansof“static”
addresspoolsconfiguredontheserver.
TheamountoftimethataparticularIPaddressisvalidforasystemiscalledalease.TheG‐Series
maintainsaleasedatabasewhichcontainsinformationabouteachassigned IPaddress,theMAC
addresstowhichitisassigned,the
leaseexpiration,andwhethertheaddressassignmentis
dynamic(automatic)orstatic(manual).TheDHCPleasedatabaseisstoredinflashmemory.
InadditiontoassigningIPaddresses,theDHCPservercanalsobeconfiguredtoassignthe
followingtorequestingclients:
•Defaultrouter(s)
•DNSserver(s)anddomainname
•NetBIOSWINSserver(s)
andnodename
For information about... Refer to page...
DHCP Overview 13-1
Configuring General DHCP Server Parameters 13-3
Configuring IP Address Pools 13-10