Neighbor Discovery Protocol

TechnicalInformation

TheNeighborDiscoveryProtocoldefinesfiveICMPv6types

1. RouteRequest

2. RouteAnnouncement

3. NeighborSolicitation

4. NeighborAnnouncement

5. Redirect

TCP/IPprotocolfamily

Internetprotocolfamily(English:InternetProtocolSuite,abbreviatedIPS)isanetworkcommunicationmodelandanentirenetworktransmissionprotocolfamily,whichisthebasiccommunicationarchitectureoftheInternet.ItisoftenreferredtoastheTCP/IPProtocolSuite(English:TCP/IPProtocolSuite,orTCP/IPProtocols),abbreviatedasTCP/IP.Becausethetwocoreprotocolsoftheprotocolfamily:TCP(TransmissionControlProtocol)andIP(InternetProtocol)aretheearlieststandardsadoptedinthefamily.Becausethenetworkcommunicationprotocolgenerallyadoptsalayeredstructure,whenmultiplelayersofprotocolsworktogether,itissimilartothestackincomputerscience,soitisalsocalledtheTCP/IPprotocolstack(English:TCP/IPProtocolStack).TheseagreementsoriginatedfromtheARPAnetworkprojectoftheU.S.DepartmentofDefense(abbreviatedasDoD),sotheyarealsocalledDoDModel(DoDModel).ThisprotocolfamilyismaintainedbytheInternetEngineeringTaskForce.

TCP/IPprovidesapoint-to-pointlinkmechanismtostandardizehowdatashouldbeencapsulated,addressed,transmitted,routed,andreceivedatthedestination.Itabstractsthesoftwarecommunicationprocessintofourabstractlayers,andadoptsaprotocolstacktorealizedifferentcommunicationprotocols.Thevariousprotocolsundertheprotocolfamilyareclassifiedintothesefourhierarchicalstructuresaccordingtotheirdifferentfunctions,andareoftenregardedasasimplifiedseven-layerOSImodel.

IPv6

InternetProtocolVersion6(English:InternetProtocolversion6,abbreviation:IPv6)isthelatestversionoftheInternetProtocol(IP),whichisusedasthenetworklayerprotocoloftheInternet.ItisusedtoreplaceIPv4mainlytosolvetheexhaustionofIPv4addresses.Problem,butitalsoimprovesIPv4inmanyotherways.

IPv6isdesignedtoreplaceIPv4.However,IPv4hasstilloccupiedadominantpositioninInternettrafficforalongtime,andtheuseofIPv6hasgrownslowly.InJuly2017,thepercentageofusersusingGoogleservicesviaIPv6exceeded20%forthefirsttime.

TheIPv6planistocreatethefoundationforfutureInternetexpansion.ItsgoalistoreplaceIPv4.AlthoughIPv6wasdesignatedbytheIETFin1994asthenext-generationstandardforIPv4,duetoearlyrouters,firewalls,andcorporateTheenterpriseresourceplanningsystemandrelatedapplicationsmustberewritten.Therefore,comparedwithIPv4,thereareveryfewpublicnetworksdeployedusingIPv6intheworld,andthedualarchitecturestillcoexistsinthemajorityoftechnologies.ItisexpectedthatIPv4willstillbesupportedbefore2025inordertoleaveenoughtimefortheamendmentofthenewagreement.

ThereisacleardeviationbetweenthecoreproblemsthatIPv6cansolveandthekeyproblemsfacingtheInternet,anditisdifficulttobringrevolutionaryinfluencetothedevelopmentoftheInternet.ComparedwithvariousIPv4addressreusesolutions,IPv6canreducecomplexityandcost,butonlymanufacturerscanfeelthisadvantage,usersandoperatorscannotdirectlyfeelit,resultinginthelackofmotivationintheindustrychaintopromoteIPv6.

ICMPv6

InternetControlMessageProtocolVersion6whichisICMPv6(InternetControlMessageProtocolVersion6b>orICMPforIPv6)isthenewversionoftheInternetControlMessageProtocol(ICMP)undertheIPv6protocol.ItisdefinedinRFC4443,anditsprotocolnumber(NextHeaderfieldofIPv6)is58.

TheICMPv6protocolisdefinedintheInternetLayeroftheTCP/IPreferencemodel,whichisusedtoreporterrormessagesintheprocessofIPv6nodedatapacketprocessingandcompletesomenetworkdiagnosticfunctions(suchaspingandTraceroute,etc.)).ItisanintegralpartoftheIPv6system,anditsbasicprotocolmustbefullysupportedbyallIPv6implementationsandIPv6nodes.