User's Manual

6 IPConfiguration
6.1 IPOverview
InthePMP320system,therearethreeinterfacesthatneedtohaveIPaddresses
intelligentlyassignedtotheminorderforthesystemtooperateproperly.Thethree
interfacesare:1)TheAPswired(GMAC)and2)wireless(WMAC)interfaces,and3)the
CPEswireless(WLAN)interfaces.ThetwoAPinterfacescaneitherbestaticallyassigned
viatheGUIorSNMP,ortheycanbesetviaanexternalDHCPserver.TheCPEWAN
interfacesmustbeassignedviaDHCPinorderfortheAPtoproperlyrouteusertrafficto
thecorrectCPE.

TherecommendedconfigurationistosetupstaticreservationsfortheAP’stwo
interfacesonanexternalDHCPserversothatallAPIPaddressescanbecentrally
controlledandchangedifnecessary.AlthoughtheseaddressesarebeingsetviaaDHCP
server,itisimportanttonotethattheAPwillnotattempttorenewtheseaddresses
unlesstheAPisrebooted.Ingeneral,thereshouldnotbeaneedforanAPsGMACand
WMACinterfacestochangeoncethenetworkdesignhasbeencompleted.

InordertosettheCPEWANIPaddresses,eithertheAP’sinternalDHCPservercanused,
or,theAPcanactasaDHCPrelayagentandrelayDHCPrequeststotheexternalDHCP
server.

IftheinternalDHCPserverisused,theAPcaneitherhandoutaddressesfromageneral
pool,ortheAPcanbeconfiguredtousestaticreservationsbasedontheMACaddress
oftherequestingCPE.

When the external DHCP server is used, the server should be setup so that an unique
address pool is allocated for each AP.As previously mentioned, one address in each
poolshouldbe staticallyreservedforeachAP’sWMACinterface.WhentheAPforwards
the CPE’s DHCP request to the DHCP server, it will set the gateway address in the
request message to it’s WMAC IP address.The DHCP server will use the gateway
address to determine which of it’s configured IP pools to use in order to service this
request.The end result is that the CPEs will  receive DHCP IP addresses on the same
subnetastheWMACIPaddressoftheAPthattheyareregisteredto.
6.2 KeyIPguidelines
• TheAP’sWiredandWirelessinterfacemustbeondifferentsubnets.
• StaticreservationsmustbemadefortheAP’swireless(WMAC)and
wired(GMAC)interface
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