Zte ZXR10 ZSR V2 - Chapter 12 MLD Configuration

Chapter12
MLDConguration
TableofContents
MLDOverview..........................................................................................................12-1
ConguringMLD......................................................................................................12-2
MLDCongurationInstances...................................................................................12-6
12.1MLDOverview
MLDoriginatesfromIGMP.MLDv1correspondstoIGMPv2,andMLDv2correspondsto
IGMPv3.DifferentfromIGMPwhichusesthemessagetypeofIPprotocolnumber2,MLD
usesthemessagetypeofICMPv6(theIPprotocolnumberis58),includingMLDQuery
message(typevalueis130,MLDv1Reportmessage(typevalueis131),MLDv1Leaving
message(typevalueis132)andMLDv2Reportmessage(typevalueis143).MLDacts
completelythesameasIGMPdoesexceptforthemessagestructure.
MLDprovidestheinformationthatisneededinthelaststatetoforwardamulticastpacket
tothedestination.Themulticastrouterexchangesinformationwiththehostreceivingthe
multicastdata.Theinformationiscollectedfromthegroupmembersofhoststhatconnect
tothemulticastrouterdirectly.
MLDmainlyusestwotypesofmessages,groupmemberquerymessageandgroup
memberreportmessage.
lThemulticastroutersendsgroupmemberquerymessagestoallhostsperiodicallyto
determinethegroupmembersontheinterconnectedsubnets.
lEachhostreplieswithamemberreportmessagetoreportthemulticastgroupwhich
itbelongsto.
Whenahostjoinsanewgroup,itsendsajoinmessageimmediatelyinsteadofwaiting
foraqueryincaseitistherstmemberofthegroup.
Whenahostbeginstoreceiveinformationasamemberofagroup,themulticastrouter
willquerythegroupperiodicallytocheckwhetherthereisanymemberinthegroup.As
longasthereisonehost,themulticastroutercontinuesforwardingdata.
Whenahostleavesagroup,themulticastrouterreceivesaleavingmessage,andthen
itquerieswhetherthereisanyotheractivememberinthegroupimmediately.Ifthereis
any,themulticastroutercontinuesforwardingdata.Otherwise,itwillnotforwarddataany
longer.
Atpresent,therearetwoversionsofMLD.MLDv1correspondstoIGMPv2,anditprovides
thefastleavingmechanismofgroupmembers.MLDv2correspondstoIGMPv3,and
12-1
SJ-20140504150128-018|2014-05-10(R1.0)ZTEProprietaryandCondential