IPv6 Transition Strategies. Philip Smith APNIC 44 Taichung, Taiwan 7 th 14 th September 2017

Transcription

1 IPv6 Trasitio Strategies Philip Smith APNIC 44 Taichug, Taiwa 7 th 14 th September 2017 Last updated 12 th September

2 Presetatio Slides p Will be available o Ad o the APNIC44 website p Feel free to ask questios ay time

3 Ackowledgemets p This material origiated from the Cisco ISP/IXP Workshop Programme developed by Philip Smith & Barry Greee These slides were origially developed by Cisco s CTO Cosultig Egieerig Group p Use of these materials is ecouraged as log as the source is fully ackowledged ad this otice remais i place p Bug fixes ad improvemets are welcomed Please workshop (at) bgp4all.com Philip Smith 3

4 Itroductio Why should we care? 4

5 The times, They are a chagi IPv4 All Goe! Source: ipv4.potaroo.et (September 2017) 5

6 Is IPv4 really ruig out? p Yes! IANA IPv4 free pool ra out o 3 rd February 2011 RIR IPv4 free pool is startig to ru out ow p p (depeds o RIR soft-ladig policies) p The ruout gadgets ad widgets are ow watchig whe the RIR pools will ru out: ietcore.com/project/ipv4ec/idex_e.html p (shows 1 RIR with o IPv4 left, ad 3 out of 4 RIRs i ru out austerity phase) ipv6.he.et/statistics/ 6

7 Strategies available for Service Providers p Do othig Wait ad see what competitors do Busiess ot growig, so do t care what happes p Exted life of IPv4 Force customers to NAT Buy IPv4 address space o the marketplace p Deploy IPv6 Dual-stack ifrastructure IPv6 ad NATed IPv4 for customers 6rd (Rapid Deploy) with ative or NATed IPv4 for customers DS-Lite or 464XLAT with ative IPv6 ad NATed IPv4 for customers Or other combiatios of IPv6, IPv4 ad NAT 7

8 Defiitio of Terms 8

9 Dual-Stack Networks p p p Both IPv4 ad IPv6 have bee fully deployed across all the ifrastructure Routig protocols hadle IPv4 ad IPv6 Cotet, applicatio, ad services available o IPv4 ad IPv6 Ed-users use dual-stack etwork trasparetly: If DNS returs IPv6 address for domai ame query, IPv6 trasport is used If o IPv6 address retured, DNS is queried for IPv4 address, ad IPv4 trasport is used istead Recet improvemets itroduce happy eye-balls (RFC6555) It is evisaged that the Iteret will operate dual-stack for may years to come 9

10 IP i IP Tuels p A mechaism whereby a IP packet from oe address family is ecapsulated i a IP packet from aother address family Eables the origial packet to be trasported over etwork of aother address family p Allows ISP to provide dual-stack service prior to completig ifrastructure deploymet p Tuellig techiques iclude: IPiIP, GRE, 6to4, Teredo, ISATAP, 6rd, MPLS 10

11 Address Family Traslatio (AFT) p Refers to traslatio of a IP address from oe address family ito aother address family e.g. IPv6 to IPv4 traslatio p Usually called NAT64 Or IPv4 to IPv6 traslatio p Usually called NAT46, usually usig SIIT 11

12 Network Address Traslatio (NAT) p NAT is traslatio of oe IP address ito aother IP address p NAPT (Network Address & Port Traslatio) traslates multiple IP addresses ito oe other IP address TCP/UDP port distiguishes differet packet flows p NAT-PT (NAT Protocol Traslatio) is a particular techology which does protocol traslatio i additio to address traslatio NAT-PT is has ow bee made obsolete by the IETF 12

13 Carrier Grade NAT (CGN) p ISP versio of subscriber NAT Subscriber NAT ca hadle oly hudreds of traslatios ISP NAT ca hadle millios of traslatios Expesive high performace hardware p Not limited to just traslatio withi oe address family, but does address family traslatio as well p Sometimes referred to as Large Scale NAT (LSN) 13

14 Happy Eyeballs RFC6555 p The device or applicatio chooses the protocol which will give the user the best experiece p Desiged to work aroud shortcomigs i either IPv4 or IPv6 ifrastructure, or miscofigured IPv4 or IPv6 destiatio devices p Short summary for dual stack device: Applicatio asks for IPv4 ad IPv6 address If both are retured, applicatio opes coectio usig IPv6 ad IPv4 simultaeously (or IPv6 first, the IPv4 after a short (few ms) delay) Applicatio uses the trasport which respods with a coectio first 14

15 Aside: NAT Issues (1) p How to scale NAT performace for large etworks? Limitig tcp/udp ports per user harms user experiece p CGN deploymet usually requires redesig of SP etwork Deploy i core, or access edge, or border,? p Breaks the ed-to-ed model of IP p Breaks ed-to-ed etwork security p Breaks o-nat friedly applicatios Or NAT has to be upgraded (if possible) 15

16 Aside: NAT Issues (2) p Makes fast reroutig ad multihomig more difficult Movig IPv4 address pools betwee CGNs for exteral traffic egieerig p Address sharig has reputatio, reliability ad security issues for ed-users p Layered NAT devices (double or eve triple NAT) p Madates that the etwork keeps the state of the coectios p Makes the NAT device a target for miscreats due to possible impact o large umbers of users p Makes cotet hostig impossible 16

17 Aside: NAT Issues (3) p Limited ports for NAPT: Typical user device TCP/UDP ports per IPv4 address Implies /400 users Oe IPv4 /22 has: Oe IPv4 /22 could support: 400 sessios 130k 320 users 1024 addresses 320k users p Sizig a NAT device has to be cosidered quite seriously 17

18 Aside: NAT Issues (4) p Cosumer NAT device: 3000 sessios meas oly 7 coected devices! NAT table FULL error messages Broke Googlemaps Stuck Iteret p Carrier Grade NAT device: 20 millio sessios (Cisco ASR9001 ISM) Which realistically is 50k users (400 sessios per user) APNIC fial /22 oly allows 320k users L p How to support LTE etworks?! Number of users? Public IPv4 addresses for CGN? Maitaiig LTE performace? Throughput of CGN? 18

19 Strategy Oe Do Nothig 19

20 IPv4 oly Network IPv6 host Customer Router IPv6 Iteret IPv4+IPv6 host IPv4 Iteret IPv4 host IPv4 IPv6 Subscriber Network IPv4-oly SP Network Iteret p The situatio for may SPs today: No IPv6 for cosumer IPv4 scalig lasts as log as IPv4 addresses are available 20

21 IPv4 oly: Issues p Advatages Easiest ad most cost effective short term strategy p Disadvatages Limited to IPv4 address availability (RIRs or marketplace) No access to IPv6 Negative public perceptio of SP as a laggard Strategy will have to be recosidered oce IPv4 address space is o loger available 21

22 IPv4 oly: Applicability p For Network Operators who: Have sufficiet IPv4 address space for foreseeable future busiess eeds Do t udertake log term plaig Are ot heedig customer requests regardig IPv6 access Have sufficiet fuds to purchase IPv4 address space via the marketplace 22

23 Strategy Two Exted life of IPv4 etwork 23

24 Extedig life of IPv4 Network p Two ways of extedig IPv4 etwork Next step alog from Strategy Oe: Do othig 1. Force customers to use NAT Customers moved to RFC1918 address space SP ifrastructure moved to RFC6598 address space (as public IPv4 eeded for CGN pools) 2. Acquire IPv4 address space from aother orgaisatio IPv4 subet tradig 24

25 SP NAT i IPv4-oly etwork IPv6 host Customer Router IPv6 Iteret IPv4+IPv6 host IPv4 host SP NAT Sharig IPv4 address(es) IPv4 Iteret IPv4 p Subscriber Network Next step o from doig othig : SP IPv4-oly Network usig RFC6598 addresses Iteret IPv6 SP itroduces NAT i core whe IPv4 addresses ru out No access to IPv6 Iteret for IPv6 eabled hosts 25

26 SP NAT i IPv4-oly etwork: Issues p p Advatages ISPs ca reclaim global IPv4 addresses from their customers, replacig with o-routable private addresses ad NAT Allows cotiued IPv4 subscriber growth Disadvatages SP eeds a large NAT device i the aggregatio or core layers Has every well kow techical drawback of NAT, icludig prevetio of service deploymet by customers Double NAT highly likely (customer NAT as well as SP NAT) Sharig IPv4 addresses could have behavioural, security ad liability implicatios Trackig associatio of port/address ad subscriber, ot to metio Lawful Itercept issues, are still uder study May postpoe IPv6 deploymet for a couple of years Prevets subscribers from usig IPv6 cotet, services ad applicatios 26

27 SP NAT i IPv4-oly etwork: Applicability p For Network Operators who: Are happy to purchase ad operate CGN devices withi their core etwork Are aware of the operatioal ad performace pitfalls of CGN devices Are aware that their IPv4 etwork will eed to be redesiged to accommodate CGN devices Are aware of suboptimal routig ad extra badwidth requiremets Are able to reclaim public addresses from their customers for redeploymet i their backboe Are ot heedig requests from customers for IPv6 access 27

28 IPv4 Subet Tradig p Today the cost of gettig IPv4 address space is low: Service Provider: p RIR membership fee p Registratio service fee (varies accordig to RIR service regio) Ed-sites usually receive IPv4 address block from SP as part of service May SPs already charge ed-site for privilege of public IPv4 address p I future whe RIRs have o more IPv4 address space to distribute: Cost of IPv4 addresses will be higher (today it s close to 0) SPs may purchase IPv4 address space from other orgaisatios 28

29 IPv4 Subet Tradig: Issues p Advatages Valuatio of IPv4 addresses may haste IPv6 adoptio by ecouragig sellers, perhaps more tha offsettig costs to move some or all of their etwork to v6 Receivers of trasferred IPv4 address space ca prolog their IPv4 etworks p Disadvatages Market may ot materialise, so orgaisatios hopig to beefit may ot Depedig o regio, if RIR does t register trasfer, there may be o routability Risk to itegrity of routig system, as RIRs o loger authoritative for address records Eve more rapid growth of routig system Fiacial pressure o ISPs to dispose of IPv4 addresses 29 they still eed

30 IPv4 Subet Tradig: Applicability p For Network Operators who: Are have sufficiet fuds to purchase IPv4 address space o the marketplace Are aware of the operatioal ad performace pitfalls of purchased address space p Routability (legacy SP filters) p Registratio (RIR vs ot) p Reputatio (previous user) Are ot heedig requests from customers for IPv6 access 30

31 Strategy Three IPv4/v6 Coexistece/Trasitio techiques 31

32 IPv4/IPv6 coexistece & trasitio p Three strategies for IPv6 trasitio: Dual Stack Network p The origial strategy p Depeds o sufficiet IPv4 beig available 6rd (Rapid Deploy) p Special case of & improvemet o 6to4 for SP customer deploymet p Documeted i RFC XLAT or DS-Lite or NAT64 with CGN p SP deploys large NAT boxes to do address ad/or protocol traslatio 32

33 IPv4/IPv6 coexistece & trasitio p Carrier Grade NAT (CGN) Dual-Stack Lite p IPv4 to IPv4 over IPv6 p Documeted i RFC XLAT p IPv4 to IPv4 over IPv6 p Documeted i RFC6877 NAT64 p Traslatio betwee IPv6 ad IPv4 p Documeted i RFC

34 Dual-Stack Network IPv4 IPv6 IPv6 host Customer Router IPv6 Iteret IPv4+IPv6 host IPv4 Iteret IPv4 host p Subscriber Network Dual-Stack SP Network Iteret The origial trasitio sceario, but depedet o: IPv6 beig available all the way to the cosumer Sufficiet IPv4 address space for the cosumer ad SP core 34

35 Dual-Stack Network: Issues p Advatages Most cost effective log term model Oce services are o IPv6, IPv4 ca simply be discotiued p Disadvatages IPv4 growth limited to available IPv4 address space Ruig dual-stack etwork requires extra staff traiig IPv6 o existig IPv4 ifrastructure might cost extra i terms of hardware chages (RIB ad FIB memories) IPv6-oly ed-poits caot access IPv4, but give most IPv6 ed-poits are dual-stack, require IPv4 address too 35

36 Dual-Stack Network: Applicability p For Network Operators who: Have sufficiet IPv4 address space for foreseeable future Also may cosider purchasig IPv4 address space o the ope market Have o legacy equipmet or ifrastructure which does ot support IPv6 Do ot wish to deploy CGN (NAT44) Are willig to support dual-stack CPE p Note: this is cosidered the ideal optio p Example: Typical traditioal Iteret Service Provider deploymet 36

37 Dual-Stack with SP NAT IPv4 IPv6 IPv6 host Customer Router IPv6 Iteret IPv4+IPv6 host SP NAT Sharig IPv4 address(es) IPv4 Iteret IPv4 host p Subscriber Network More likely sceario: Dual-Stack SP Network usig RFC6598 addresses Iteret IPv6 beig available all the way to the cosumer SP core ad customer has to use IPv4 NAT due to v4 depletio 37

38 Dual-Stack with SP NAT: Issues p p Advatages ISPs ca reclaim global IPv4 addresses from their customers, replacig with o-routable private addresses ad NAT Allows cotiued IPv4 subscriber growth SP ca offer IPv6 coectivity too Does ot postpoe IPv6 deploymet SP NAT off-load (compared with IPv4-oly etwork) Disadvatages SP eeds a large NAT device i the aggregatio or core layers Has every well kow techical drawback of NAT, icludig prevetio of service deploymet by customers Double NAT highly likely (customer NAT as well as SP NAT) Sharig IPv4 addresses could have behavioural, security ad liability implicatios Trackig associatio of port/address ad subscriber, ot to metio Lawful Itercept issues, are still uder study SP icurs additioal ivestmet ad operatioal expediture by deployig a IPv6 ifrastructure 38

39 Dual-Stack with SP-NAT: Applicability p For Network Operators who: Have do ot sufficiet IPv4 address space ad are cotet deployig CGN (NAT44) i the core Are able to reclaim public IPv4 address space from customers for redeploymet o their backboe ifrastructure Have o legacy equipmet or ifrastructure which does ot support IPv6 Are willig to support dual-stack CPE p Note: this is cosidered the realistic best practice p Example: Typical traditioal Iteret Service Provider deploymet 39

40 Aside: SP-NAT Offload p p p If 50% of ed user traffic is IPv6, the this meas 50% less IPv4 traffic which has to be mapped ad traslated via the SP s CGN istallatio The greater the proportio of IPv6 traffic (compared with IPv4), the less the load is o the CGN devices, ad reduced demad o the public IPv4 address pool CGN is used simply for accessig legacy IPv4 sites Operators with high data volumes realise that by deployig IPv6: Ed users have better Iteret experiece whe traffic is ot NAT ed They have reduced CapEx deployig fewer CGN devices Savigs from reduced CGN CapEx are ofte greater tha the additioal costs to deploy IPv6 to ed-users This is called SP-NAT Offload 40

41 6rd IPv4 IPv6 IPv6 host Customer Router Dual-Stack SP Network 6rd BR IPv6 Iteret IPv4+IPv6 host IPv4 Iteret IPv4 host IPv4-oly SP Network SP NAT Subscriber Network Iteret p 6rd (Rapid Deploy) used where ISP ifrastructure to customer is ot IPv6 capable (eg IPv4-oly BRAS) Customer has IPv4 Iteret access either atively or via NAT Customer IPv6 address space based o ISP IPv4 block 41

42 6rd: Issues p p Advatages The service provider has a relatively quick way of providig IPv6 to their customer without deployig IPv6 across their ifrastructure Subscribers ca readily get access to IPv6 SP NAT off-load (compared with IPv4-oly etwork) 6rd relay ad CPE are becomig available from vedors 6rd operatio is completely stateless, does ot have the operatioal drawbacks of 6to4, ad does ot postpoe IPv6 deploymet Disadvatages 6rd is ot a log-term solutio for trasitioig to IPv6 oe further trasitio step to remove the tuels CPE eeds to be upgraded to support 6rd The ISP has to deploy oe or several 6rd termiatio devices If customer or SP uses NAT for IPv4, all NAT disadvatages are iherited 42

43 6rd: Applicability p For Network Operators who: Have do ot sufficiet IPv4 address space ad are cotet deployig CGN (NAT44) i the core Are able to reclaim public IPv4 address space from customers for redeploymet o their backboe ifrastructure Have legacy equipmet or ifrastructure which does ot support IPv6 p Ad realise that it will evetually have to be upgraded Are willig to ru a 6rd Border Router Are willig to support dual-stack CPE (with 6rd) p Example: Broadbad operators who have legacy DSLAMs or lease a third party s L2 etwork 43

44 Dual-Stack Lite IPv4 IPv6 IPv6 host Customer Router IPv6 Iteret IPv4+IPv6 host Tuel SP NAT Sharig IPv4 address(es) IPv4 Iteret IPv4 host p Subscriber Network IPv6-oly SP Network Iteret Service Provider deploys IPv6-oly ifrastructure: IPv6 beig available all the way to the cosumer IPv4 is tuelled through IPv6 core to Iteret via SP NAT device 44

45 Dual-Stack Lite: Issues p Advatages The SP is usig IPv6 across their etire ifrastructure, avoidig the IPv4 address pool depletio issue totally The SP ca scale their ifrastructure without ay IPv4 depedecies Cosumers ca trasitio from IPv4 to IPv6 without beig aware of ay differeces i the protocols IPv6 packets routed atively SP NAT off-load (compared with IPv4-oly etwork) p Disadvatages SP requires NAT device i core supportig DS-Lite Subscriber router eeds to be IPv6 capable Model has all drawbacks of SP NAT model for IPv4 traffic 45

46 Dual-Stack Lite: Applicability p For Network Operators who: Are cosiderig gree-field deploymets Are cotet ruig a IPv6-oly backboe Are willig to deploy CGN (DS-Lite) i the core Are willig to support dual-stack CPE (with DS-Lite) p Example: Mobile operators rollig out a brad ew etwork, with hadsets which have dual-stack radios 46

47 Stateful AFT (NAT64) IPv4 IPv6 IPv6 host SP DNS64 Customer Router IPv6 Iteret IPv4+IPv6 host IPv4 host NAT64 IPv6 SP NAT64 Sharig IPv4 address(es) IPv4 Iteret Subscriber Network IPv6-oly SP Network Iteret p Service Provider deploys IPv6-oly ifrastructure: Oly IPv6 is available to the cosumer IPv4 Iteret available via Address Family Traslatio o SP 47 NAT device

48 Stateful AFT (NAT64) Details IPv6 IPv4 SP DNS64 IPv6 host 1. AAAA RR? 2. A RR? 4. Sythetic AAAA RR 3. A RR DNS IPv4+IPv6 host Customer Router IPv4 Iteret SP NAT64 Sharig IPv4 address(es) IPv4 host Subscriber Network IPv6-oly SP Network Iteret 48

49 Stateful AFT: Issues p Advatages Allows IPv6 oly cosumers access to IPv4 based cotet without givig them IPv4 address resources IPv6 services ad applicatios offered atively to cosumers SP etwork rus IPv6 oly, avoidig IPv4 depedecies p Disadvatages SP requires NAT device i core SP s DNS ifrastructure eeds to be modified to support NAT64 Subscriber router eeds to be IPv6 capable Subscriber devices eed to be IPv6 capable (o legacy support) Model has all drawbacks of SP NAT model for IPv4 traffic 49

50 Stateful AFT: Applicability p For Network Operators who: Are cosiderig gree-field deploymets Are cotet ruig a IPv6-oly backboe Are willig to deploy CGN (NAT64) i the core Are willig to support IPv6-oly CPE p Example: Mobile operators rollig out a brad ew etwork, with hadsets which have sigle-stack (IPv6-oly) radios 50

51 464XLAT IPv4 IPv6 IPv6 host Customer Router (CLAT) IPv6 Iteret IPv4+IPv6 host SIIT ecaps SP NAT (PLAT) Sharig IPv4 address(es) IPv4 Iteret IPv4 host Subscriber Network IPv6-oly SP Network Iteret p Service Provider deploys IPv6-oly ifrastructure: IPv6 beig available all the way to the cosumer IPv4 is trasported through IPv6 core to Iteret via SIIT o 51 customer router, ad NAT64 o SP NAT device

52 464XLAT: Issues p p Advatages The SP is usig IPv6 across their etire ifrastructure, avoidig the IPv4 address pool depletio issue totally The SP ca scale their ifrastructure without ay IPv4 depedecies Cosumers ca trasitio from IPv4 to IPv6 without beig aware of ay differeces i the protocols Devices ot supportig IPv6 ca access IPv6-oly etworks IPv6 packets routed atively SP NAT off-load (compared with IPv4-oly etwork) Disadvatages SP requires NAT device i core (PLAT & NAT64) Subscriber router eeds to be IPv6 capable ad support IPv4/IPv6 header traslatio (CLAT SIIT) Model has all drawbacks of SP NAT model for IPv4 traffic 52

53 464XLAT: Applicability p For Network Operators who: Are cosiderig gree-field deploymets Are cotet ruig a IPv6-oly backboe Are willig to deploy CGN (PLAT) i the core Are willig to support dual-stack CPE (CLAT) p Example: Mobile operators rollig out a brad ew etwork, with hadsets which have dual-stack radios 53

54 Coclusios & Recommedatios 54

55 Fuctioalities ad Operatioal Issues IPv4-oly etwork IPv4-oly etwork with IPv4 NAT Dual-Stack, o IPv4 NAT Dual-Stack with IPv4 NAT 6rd, o IPv4 NAT 6rd with IPv4 NAT DS-Lite 464XLAT Stateful AFT Prologs IPv4 No Yes No Yes No Yes Yes Yes Yes Allows Busiess Growth No Yes (scalig issues if cotet is mostly IPv6) Limited to IP v4 address availability Yes (traffic to IPv4-oly servers) Limited to IPv4 address availability Yes Yes Yes Yes Requires IPv6 Deploymet Coexists with IPv6 Deploymet Complexity of Operatio Complexity of Troubleshootig Breaks Ed-to-Ed IPv4 NAT Scalability issues to IPv4 services NAT Scalability issues to IPv6 services No No Yes Yes Yes Yes Yes Yes Yes No No Yes Yes Yes Yes Yes Yes Yes Low Low Low Moderate Moderate Moderate Moderate Moderate Moderate Low Moderate Low High Moderate High High High Moderate No Yes No Yes No Yes Yes Yes N/A No Yes No Yes No Yes Yes Yes Yes N/A Yes No No No No No No No DNSSEC issues No Yes No Lawful Itercept issues Yes for IPv4 No for IPv6 No Yes for IPv6 No for IPv4 Yes for IPv4 No for IPv6 Yes for IPv4 No for IPv6 Yes for IPv4 No for IPv6 55 No Yes No Yes for IPv4 No Yes for IPv4 Yes for IPv4 Yes for IPv4 Yes for IPv4

56 Fuctioalities ad Operatioal Issues p Complexity of operatio: Moderate i the case of a sigle etwork with two address families p Complexity of troubleshootig: Ruig two address families ad/or tuels is assumed to be more complex p Breaks ed-to-ed coectivity i IPv4: Subscribers sharig a CGN will have little to o hurdles i their commuicatio Subscribers separated by oe or several CGN will experiece some applicatio issues 56

57 Comparig where chages will occur IPv4-oly etwork IPv4-oly etwork with IPv4 NAT Dual-Stack, o IPv4 NAT Dual-Stack with IPv4 NAT 6rd, o IPv4 NAT 6rd with IPv4 NAT DS-Lite 464XLAT Stateful AFT Chage CPE No No Oly if customer wats IPv6 Oly if customer wats IPv6 Yes Yes Yes Yes Yes CPE to do AFT to access IPv6 IPv4 NAT i core/edge AFT i core/edge to access IPv6 No No No No No No No No No No Yes No Yes No Yes Yes Yes No Yes Yes No No No No No No Yes 57

58 Coclusios Potetial Scearios 1. Most of the cotet ad applicatios move to IPv6 oly; 2. Most of the cotet ad applicatios are offered for IPv4 ad IPv6; 3. Most of the users move to IPv6 oly Especially mobile operators offerig LTE hadsets i emergig coutries 4. No chage (the cotets/applicatios stay IPv4 ad absece of pro-ipv6 regulatio), SP customer expectatios devolve to double-nat; 5. No chage (the cotets/applicatios stay IPv4) but SP customer expectatios do ot devolve to double-nat (or they are ready to pay for peer-to-peer coectivity). Perhaps well established broadbad markets like US or Europe 58

59 Coclusios Potetial Techiques Sceario Cotet ad Applicatios move to IPv6 Cotet ad Applicatios o IPv4 ad IPv6 Potetial Techiques IPv6 oly etwork; Dual-Stack, 6rd, 464XLAT or DS-lite as migratio techiques Dual-Stack (if eough IPv4) or 6rd; SP IPv4- NAT; DS-lite or 464XLAT (for greefield) * Users are IPv6 oly Stateful AFT to get to IPv4 cotet * No chage (double NAT) SP IPv4-NAT * No chage (o double NAT) Do othig * * Trasfer Market applicable 59

60 Recommedatios 1. Start deployig IPv6 as log term strategy 2. Evaluate curret addressig usage to uderstad if IPv4 to IPv4 NAT is sufficiet for trasitio period 3. Prepare a traslatio mechaism from the IPv4 Iteret to the IPv6 Iteret 4. Educate your user base o IPv6 itroductio, the use cases ad troubleshootig 60

61 Recommedatios p Mobile operator: 464XLAT (support IPv4 ad IPv6) NAT64 (IPv6 oly) p Access provider: Dual stack core ad access (if supported to ed-user) 6rd (if legacy IPv4 ifrastructure or legacy 3 rd party L2) p Eterprise service provider: Dual stack access ad core p Cotet provider: Dual stack access ad core 61

62 IPv6 Trasitio Plaig A Review of IPv4-IPv6 Co- Existece Techiques 62