Zte ZXR10 ZSR V2 - Figure 2-1 Ipv4 Header Format; Figure 2-2 Ipv6 Header Format

ZXR10ZSRV2CongurationGuide(IPv6)
IPv4andIPv6HeaderFormat
ThefollowingaredifferencesbetweenIPv4andIPv6inheaderformat.
TheheaderformatsofIPv4andIPv6asshowninFigure2-1andFigure2-2respectively.
(Numbersintheguresrefertobitnumbers.)
Figure2-1IPv4HeaderFormat
Figure2-2IPv6HeaderFormat
IPv6headerissimplerthanIPv4headerinstructurebecausemanyeldsinIPv4header
thatarenotfrequentlyusedaredeletedfromIPv6header,andareputintoitsoptionsand
headerextension,whicharedenedmorestrictly.
lIPv4containsteneldswithxedlength,twoaddressspacesandsomeoptions,while
IPv6containsonlysixeldsandtwoaddressspaces.
lAlthoughIPv6headeroccupies40bytes,whichis1.6timesofIPv4headerwith
24-bytes,itdoesnotconsumetoomuchmemorycapacityduetoitsxedlength(the
lengthoftheIPv4headerisvariable).
lThefollowingsixeldsaredeletedfromIPv4header:headerlength,typeofservice,
identier,ags,fragmentedoffsetsandheaderchecksum.Namesandsomefunctions
ofthethreeeldsoftotallength,protocolandTimetoLive(TTL)arechanged,and
itsoptionalfunctionsarecompletelychanged.Apartfromthis,twoeldsareadded:
trafctypeandowlabel.
lIPv6headerformatisgreatlysimplied,whicheffectivelyparesdownoverheadof
processingheadersbyarouterorswitch.Atthesametime,IPv6enhancesthe
2-2
SJ-20140504150128-018|2014-05-10(R1.0)ZTEProprietaryandCondential