Enterasys SecureStack B3

SecureStack B3 Configuration Guide 15-1
15
DHCP Server Configuration
ThischapterdescribesthecommandstoconfiguretheIPv4DHCPserverfunctionalityona
SecureStackB3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SecureStackB3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leas e. The
SecureStackB3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
For information about... Refer to page...
DHCP Overview 15-1
Configuring General DHCP Server Parameters 15-2
Configuring IP Address Pools 15-10