Zte ZXR10 ZSR V2 - Page 186

ZXR10ZSRV2CongurationGuide(IPv6)
allthePIMroutersinthePIMdomaininauniedway.EachPIMrouter,accordingtothe
similarHashrules,electstheonewiththehighestpriorityastheformalRPfromthesame
candidateRPset.CandidateRPsareconguredmanually.
MessagesTypes
InPIM-SM,therearethefollowingtypesofmessages.
lHellomessage:TherouterinterfacesonwhichPIM-SMrunssendHellomessages
periodicallytotheneighborinterfacesinthesamesegmenttoestablishaneighbor
relationship.HellomessagesarealsousedforroutersrunningMLDtoelecttheDR.
lRegistermessage:Whenreceivingamulticastpacketsentbyahostinthelocal
network,theDRencapsulatesthepacketinaRegistermessageandsendsittothe
RPthroughunicast.ThesourceaddressintheIPheaderoftheRegistermessageis
theaddressoftheDR,andthedestinationaddressistheaddressoftheRP .
lRegister-Stopmessage:TheRPunicastsaRegister-Stopmessagetothesenderof
theRegistermessagetoinformitstopsendingRegistermessages.
lJoin/Prunemessage:Thismessageisforwardedinthedirectiontothesourceor
theRP.AJoinmessageisusedtoconstructasourcetreeorashardtree.Whena
receiverleavesagroup,itsendsaPrunemessagetoprunethesourcetreeorthe
shardtree.Thismessagecontainsthejoininginformationandpruninginformation
aboutthemulticastrouteentities.TheJoinmessageandthePrunemessagearein
thesamepacket.Eithermessagecanbenull.
lBootstrapmessage:ArouteneedstosendBootstrapmessagesonallinterfaces
excepttheinterfaceonwhichtheBootstrapmessageisreceived.Thismessageis
generatedontheBSRandforwardedbyallrouters.
lAssertmessage:Whenthereareseveralroutersonamulti-accessnetworkanda
multicastgrouppacketisreceivedonanegressinterfaceofarouter,itisnecessary
tousetheAssertmessagetodesignateaforwarder.
lCandidate-RP-Advertisement:AcandidateRPunicasts
Candidate-RP-AdvertisementtotheBSRperiodicallytoadvertisethesetofgroup
addressesservedbytheCandidateRP .
PIM-SMFeatures
TheroutersrunningPIM-SMdiscovereachotherandmaintaintheneighborrelationshipby
exchangingHellomessages.Inthemulti-accessnetwork,theHellomessagesalsocontain
thepriorityinformationaboutrouters.TheDRiselectedaccordingtothisparameter.
Themulticastsourceorthersthoprouter(theDRconnectingtothesourcedirectly)
encapsulatesapacketinaRegistermessage,andthensendsittotheRPthroughaunicast
router.WhenreceivingtheRegistermessage,theRPde-encapsulatesthemessagesto
takeoutthepacket,andthensendsthepackettothereceiversofthegroupalongthe
sharedmulticasttree.
EachhostactingasareceiverjoinsthemulticastgroupthroughtheIGMPmemberreport
message.Thelasthoprouter(ortheDPinthemulti-accessnetwork)sendsthereceived
JoinmessagetotheRPlevelbylevel.AfterreceivingtheJoinmessage,theintermediate
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SJ-20140504150128-018|2014-05-10(R1.0)ZTEProprietaryandCondential