Zte ZXR10 ZSR V2 - Page 24

ZXR10ZSRV2CongurationGuide(IPv6)
Thisisan8-biteldandreservedforfutureuse.Itislikelytobeusedforextending
thetop-ornext-levelaggregationidentiereld.
àNLAIDeld
Thisisthenext-levelaggregationidentierwith24bits.Thisidentierisused
bysomeinstitutions(includinglarge-sizeISPsandotherinstitutionsthatprovide
publicnetworkaccess)tocontrolthetop-levelaggregationforaddressspace
arrangement.
Suchinstitutionscandividethis24-biteldforuseinaccordancewiththeirown
addressinghierarchicalstructures.Inthisway,anentitycandividetwobitsof
addressspaceintofourinternaltop-levelroutes,andallocatetheother22bitsof
addressspacetootherentities(forexample,asmalllocalISP).
Whentheseentitiesobtainenoughaddressspace,theycansubdividetheobtained
spaceinthesamewayasmentionedabove.
àSLAIDeld
Thisisthesiteaggregationidentierandisusedbysomeinstitutionstoarrange
theirinternalnetworkstructures.Eachinstitutioncancreateitsowninternal
hierarchicalnetworkstructureinthesamewayasthatofIPv4.
Whenthe16-biteldisdedicatedtotheplaneaddressspace,thereareatmost
65,535differentsubnetsavailable.Ifthersteightbitsareusedfortheinternal
advancedroutingofthisinstitution,thentherewillbe255advancedsubnets
available,andeachadvancedsubnetcanhaveupto255sub-subnets.
àInterfaceidentiereld
Thisisa64-biteld,containing64-bitvaluesoftheIEEEEUI-64interface
identier.
lSpecialAddress&ReservedAddress
Intherst1/256IPv6addressspace,therst8bits00000000ofalltheaddresses
arereserved.Mostofthevacantaddressspacesareusedforspecialaddresses,
including:
àUndesignatedaddress
Thisisanall-zeroaddressandisusedifnovalidaddressisavailable.For
example,ifahostdoesnotobtainanIPv6addressuponitsinitialstartupfrom
thenetwork,itcanusethisaddress.Thatis,itcanspecifythisaddressforthe
sourceaddressoftheIPv6packetwhenitsendsoutarequestforconguration
information.Thisaddresscanbeexpressedas0:0:0:0:0:0:0:0,orexpressedas
::.
àLoopbackaddress
InIPv4,theloopbackaddressisdenedas127.0.0.1.Anypacketthatsendsa
loopbackaddressmustbesenttoanetworkinterfacethroughaprotocolstack,
insteadofbeingsenttothenetworklink.Thenetworkinterfaceitselfshould
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SJ-20140504150128-018|2014-05-10(R1.0)ZTEProprietaryandCondential