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Explore IPv6, its advantages, header formats, extension headers, and transition strategies from IPv4 to IPv6. Learn how IPv6 solves addressing limitations and enhances security in the digital world.
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IntroductiontoIPv6 Compiled By: Ashish Kr. Jha
2 • Introduction • ThehugegrowthinInternetusehasnotonlyledtoincreaseddemandforbetter,fastertechnology,buthasalsoincreasedthedemandforaddressesfromwhichtosendandreceiveinformation. • ThisisespeciallytruefordevelopingcountrieswherepeopleareonlyreallystartingtousetheInternet. • IPv6deploymentcansolvetheproblem. Compiled By: Ashish Kr. Jha
3 • UnforeseenlimitationsofIPv4 • AddressSpace • Variousunnecessaryheaderfields • Variableheaderfields • FragmentationinRouter • AddressingModel • NAT • BroadcastVersusMulticast • QualityofService Compiled By: Ashish Kr. Jha
4 • AdvantagesofIPv6 • Verylargeaddressspace • ▫ 128-bitaddress=>2^128~3Trilliontrilliontrillion • Every grainofsandonearthcangetUniqueIPv6addressರ • Reduceend-to-enddelay • ▫ Processingdelayreducesduetofixedheadersizeandnoheader • checksum • Astreamlined40bytesheader • ▫ AllowsfasterprocessingoftheIPdatagram • Flowlabelingandpriority • ▫ Hasandelusivedefinitionofflow(accordingtoqualityofserviceorrealtimeservicee.g.audioandvideotransfer) • Higherlevelofsecurity • ▫ MandatoryIPsec • Mobility-KeepsameIPaddressregardlessofthenetwork • Nofragmentationbyrouters • ▫ reducesfragmentation/reassemblyoverhead • Aidmulticastingbyallowingscopestobespecified. Compiled By: Ashish Kr. Jha
5 IPv6HeaderFormat Compiled By: Ashish Kr. Jha
6 • IPv6HeaderFormat • Version(4bits)-4bitsareusedtoindicatetheversionofIP • andissetto6 • TrafficClass(8bits)-SamefunctionastheTypeofService • fieldintheIPv4, • requirement • FlowLabel(20bits) distinguishdifferentreal-timedelivery • ▫ Identifiesaflowanditisintendedtoenabletheroutertoidentifypacketsthatshouldbetreatedinasimilarwaywithouttheneedfordeeplookupswithinthosepackets. • ▫ Setbythesourceandshouldnotbechangedbyroutersalongthepathtodestination. • PayloadLength(16bits)–Onlythelengthofthepayload • (Headerlengthisfixedto40bytes) Compiled By: Ashish Kr. Jha
7 • IPv6HeaderFormat • NextHeader(8bits)-Indicateseitherthefirstextensionheader(ifpresent)ortheprotocolintheupperlayerPDU(suchasTCP,UDP,orICMPv6). • HopLimit(8bits)-IPv4TTLwasappropriatelyrenamedHopLimitbecauseitisavariablethatisdecrementedateachhop,anditdoesnothaveatemporaldimension. • SourceAddress(128bits)-StorestheIPv6addressoftheoriginatinghost. • DestinationAddress(128bits)-StorestheIPv6addressofthecurrentdestinationhost. Compiled By: Ashish Kr. Jha
8 HeaderComparison 1516 31 0 Removed(6) • ID,flags,flagoffset • TOS,hlen • headerchecksum 20 bytes • Changed(3) • totallength=>payload • protocol=>nextheader • TTL=>hoplimit IPv4 Added(2) • trafficclass • flowlabel • Expanded • address32to128bits 40 bytes IPv6 Compiled By: Ashish Kr. Jha
9 • ExtensionHeaders • Thelengthofbaseheaderis40bytes. • HoweverinIPv6headercanbefollowedbyheader upto6extension • ThisistogivemorefunctionalitytoIPdatagram • ExtensionheadersofvariablesizecontainaHeaderExtensionLengthfieldandmustusepaddingasneededtoensurethattheirsizeisamultipleof8bytes. • NextHeaderfieldintheIPv6headerandzeroormore • extensionheadersformachainofpointers. • Eachpointerindicatesthetypeofheaderthatcomesaftertheimmediateheaderuntiltheupperlayerprotocolisultimatelyidentified. • Extensionheadersmustbeprocessedstrictlyintheordertheyappearinthepacket. Compiled By: Ashish Kr. Jha
10 IPv6ExtensionHeaders Compiled By: Ashish Kr. Jha
11 • TypesofExtensionHeaders • Hop-by-HopOptionsHeader: • ▫ Specialoptionsthatrequirehop-by-hopprocessing • DestinationOptionsHeader: • ▫ Usedtocarryoptionalinformationfordestinationnode • RoutingOptionsHeader: • ▫ ListsoneormoreIPv6nodetobe ಯvisitedರonthewaytoa packet • destination. • FragmentationOptionsHeader: • ▫ Fragmentationandreassembly • ▫ OnlysourcenodecanfragmentapacketinIPv6 • AuthenticationOptionsHeader: • ▫ ProvideIntegrityandauthentication,security • EncapsulatingSecurityPayload: • ▫ ProvidesEncryptionSecurity,Confidentiality Compiled By: Ashish Kr. Jha
12 ExtensionHeaderCodes Fig.NextHeaderCode Compiled By: Ashish Kr. Jha
13 • IPv4toIPv6Transition • BecauseofthehugenumberofsystemsontheInternet,the • transitionfromIPv4toIPv6cannothappensuddenly. • FlagDayisnotPossible • Thetransitionmustbesmoothtoprevent • betweenIPv4andIPv6systems. • Threestrategiestohelpthetransition: anyproblems Compiled By: Ashish Kr. Jha
14 • DualStack • StationsrunbothIPv6andIPv4simultaneouslyuntilallthe • InternetusesIPv6 • Forreceivedpackets,usesversionfieldtodecidewhich • stack(v4orv6)touse • Whensendingpacketstodestination,sourcehostqueriesDNSandstackisselectedaccordingtotheIPaddressreturnedbyDNSserver. Compiled By: Ashish Kr. Jha
15 • DualStack • Dual-stackIPv6/IPv4implementationsrecognizeaspecial • classofaddresses • ▫ v4compatiblev6address • Add960’s(zero-extending)toa32-bitv4addresseg.::10.0.0.1 • EnablesIPv6devicestocommunicatethroughIPv4connectednetworksbyembeddingIPv4addressinitsIPv6addresswhichcanlaterbeextractedbyIPv4routerstoroutethroughIPv4networks. • DeprecatedinfavourofIPv4-mappedIPv6addresses. • ▫ v4mappedv6address • Add2bytesof1’s tov4addressthenzero-extendtherest– • eg.::ffff:10.0.0.1 • UsedtorepresenttheaddressesofIPv4nodesasIPv6addressestoapplicationsthatareenabledforIPv6 Compiled By: Ashish Kr. Jha
16 DualStack Compiled By: Ashish Kr. Jha
17 • Tunneling • Tunnelingisusedtodealwithnetworkswherev4router(s)sit • betweentwov6routers • Simplyencapsulatev6packetsandalloftheirinformationin • v4packetsuntilyouhitthenextv6router • ▫ [ಯDualStackWhereYoucan,TunnelWhereYouMustರ] Compiled By: Ashish Kr. Jha
18 • HeaderTranslation • ConvertingIPv6HeadertoIPv4andviceversa • UsedtolinkIPv6andIPv4Networks • Someheaderfieldsmaylostduringtranslation • ▫ Eg.WhenconvertingIPv6PackettoIPv4,theheaderinformation • likeFlow-labelgetslost IPv6header Payload Compiled By: Ashish Kr. Jha
19 • IPv6AddressRepresentation • 16bitfieldsincaseinsensitivecolonhexadecimal • representation • ▫ 2031:0000:130F:0000:0000:09C0:876A:130B • Leadingzerosinafieldareoptional(ZeroSuppression): • ▫ 2031:0:130F:0:0:9C0:876A:130B • Successivefieldsof0representedas::(ZeroCompression),butonlyonceinanaddress: Compiled By: Ashish Kr. Jha
20 IPv6AddressRepresentation Compiled By: Ashish Kr. Jha
21 IPv6AddressRepresentation Compiled By: Ashish Kr. Jha
22 • IPv6Addressing • IPv6AddressingrulesarecoveredbymultipleRFCs • ▫ ArchitecturedefinedbyRFC4291 • AddressTypesare: • ▫ Unicast:OnetoOne(Global,UniqueLocal,Linklocal) • ▫ Anycast:OnetoNearest(AllocatedfromUnicast) • ▫ Multicast:OnetoMany • AsingleinterfacemaybeassignedmultipleIPv6addresses • ofanytype(unicast,anycast,multicast) • ▫ NoBroadcastAddress→UseMulticast Compiled By: Ashish Kr. Jha
23 IPv6Addressing Compiled By: Ashish Kr. Jha
24 RelationofMACaddresswithIPv6Address Compiled By: Ashish Kr. Jha
25 • IPv6Multicasting • IPmulticastaddresshasaprefixFF00::/8 • Thesecondoctetdefinesthelifetimeandscopeofthemulticastaddress. Compiled By: Ashish Kr. Jha
26 IPv6MulticastingExamples Compiled By: Ashish Kr. Jha
27 ThankYou! Compiled By: Ashish Kr. Jha