1 what’s happening with ipv6? october, 2001 steve deering [email protected]

1

What’s Happening with IPv6?

October, 2001

Steve [email protected]

2

IP Scaling Problems —the View from Late 1991

• running out of Class B addresses (near-term)solution: CIDR (Classless Interdomain Routing) to allow addresses

to be allocated and routed as blocks of anypower-of-two size, not just Class A, B, and C

• running out of routing table space (near-term)solution: provider-based delegation of address blocks, i.e.,

address hierarchy changed from organization:subnet:host to provider:subscriber:subnet:host

• running out of all IP addresses (long-term)solution: a new version of IP with bigger addresses,

dubbed IP Next Generation, of IPng

note: this was before the Web!

3

IPng Candidates

“IPv7” (Ullman)

TUBA (Callon)

ENCAPS (Hinden)

SIP (Deering)

Pip (Francis)

TP/IX

SIPPIPv6

CATNIP

Jan 92

IPAE

Jan 93 Jul 94Jan 94Jul 92 Jul 93

4

What’s Been Happening Since Mid 1994?

• writing protocol specs, arguing about every detail, and progressing through the IETF Standards process– scores of documents, on IPv6 address formats and routing

protocols (unicast & multicast), L2 encapsulations, auto-configuration, DNS changes, header compression, security extensions, IPv4/IPv6 co-existence & transition, MIBS,…(see playground.sun.com/ipv6 for list of documents)

• implementation by vendors, and interoperability testing

• building deployment testbeds

• shipping products

• deploying production services

5

Why IPv6?(Theoretical Reasons)

only compelling reason: more IP addresses!• for billions of new users (Japan, China, India,…)

• for billions of new devices (mobile phones, cars, appliances,…)

• for always-on access (cable, xDSL, ethernet-to-the-home,…)

• for applications that are difficult, expensive, or impossible to operate through NATs (IP telephony, peer-to-peer gaming, home servers,…)

• to phase out NATs to improve the robustness, security, performance, and manageability of the Internet

6

IP Address Allocation History

1981 - IPv4 protocol published

1985 ~ 1/16 of total space




• this despite increasingly intense conservation efforts– PPP / DHCP address sharing– CIDR (classless inter-domain routing)– NAT (network address translation)– plus some address reclamation

• theoretical limit of 32-bit space: ~4 billion devicespractical limit of 32-bit space: ~250 million devices(see draft-durand-huitema-h-density-ratio)

7

Other Benefits of IPv6

• server-less plug-and-play possible

• end-to-end, IP-layer authentication & encryption possible

• elimination of “triangle routing” for mobile IP

• other minor improvements

NON-benefits:

• quality of service (same QoS capabilities as IPv4)– flow label field in IPv6 header may enable more efficient flow

classification by routers, but does not add any new capability

• routing (same routing protocols as IPv4)– except larger address allows more levels of hierarchy

• except customer multihoming is defeating hierarchy

8

Why IPv6?(Current Business Reasons)

• demand from particular regions– Asia, EU– technical, geo-political, and business reasons– demand is now

• demand for particular services– cellular wireless (especially 3GPP[2] standards)– Internet gaming (e.g., Sony Playstation 2)– use is >= 1.5 years away (but testbeds needed now)

• potential move to IPv6 by Microsoft?– IPv6 included in Windows XP, but not enabled by default– to be enabled by default in next major release of Windows– use is >= 1.5 years away

9

IPv6 Header compared to IPv4 Header

Ver.

Time toLive

Source Address

Total LengthType ofService

HdrLen

Identification FragmentOffsetFlg

Protocol HeaderChecksum

Destination Address

Options...

Ver. TrafficClass

Source Address

Payload Length NextHeader

HopLimit

Destination Address

HdrLen

Identification FragmentOffsetFlg

HeaderChecksum

Options...

shaded fields have no equivalent in theother version

IPv6 header is twice as long (40 bytes) asIPv4 header without options (20 bytes)

Flow LabelFlow Label

10

How Was IPv6 Address Size Chosen?

• some wanted fixed-length, 64-bit addresses– easily good for 1012 sites, 1015 nodes, at .0001 allocation

efficiency (3 orders of magnitude more than IPv6 requirement)– minimizes growth of per-packet header overhead– efficient for software processing

• some wanted variable-length, up to 160 bits– compatible with OSI NSAP addressing plans– big enough for auto-configuration using IEEE 802 addresses– could start with addresses shorter than 64 bits & grow later

• settled on fixed-length, 128-bit addresses(340,282,366,920,938,463,463,374,607,431,768,211,456 in all!)

11

IPv4-IPv6 Transition / Co-Existence Techniques

a wide range of techniques have been identified and implemented, basically falling into three categories:

(1)dual-stack techniques, to allow IPv4 and IPv6 to co-exist in the same devices and networks

(2)tunneling techniques, to avoid order dependencies when upgrading hosts, routers, or regions

(3)translation techniques, to allow IPv6-only devices to communicate with IPv4-only devices

expect all of these to be used, in combination

12

Standards

• core IPv6 specifications are IETF Draft Standards=> well-tested & stable– IPv6 base spec, ICMPv6, Neighbor Discovery, PMTU

Discovery, IPv6-over-Ethernet, IPv6-over-PPP,...

• other important specs are further behind on the standards track, but in good shape– mobile IPv6, header compression,...– for up-to-date status: playground.sun.com/ipv6

• 3GPP UMTS Release 5 cellular wireless standards mandate IPv6; also being considered by 3GPP2

13

Implementations

• most IP stack vendors have an implementation at some stage of completeness– some are shipping supported product today,

e.g., 3Com, *BSD(KAME), Cisco, Compaq, Epilogue, Ericsson/Telebit, IBM, Hitachi, Nortel, Sun, Trumpet, …

– others have beta releases now, supported products “soon”,e.g., HP, Juniper, Linux community, Microsoft, …

– others rumored to be implementing, but status unkown (to me),e.g., Apple, Bull, Mentat, Novell, SGI, …

(see playground.sun.com/ipv6 for most recent status reports)

• good attendance at frequent testing events

14

Deployment

• experimental infrastructure: the 6bone– for testing and debugging IPv6 protocols and operations

(see www.6bone.net)

• production infrastructure in support of education and research: the 6ren– CAIRN, Canarie, CERNET, Chunahwa Telecom, Dante, ESnet,

Internet 2, IPFNET, NTT, Renater, Singren, Sprint, SURFnet, vBNS, WIDE,…(see www.6ren.net, www.6tap.net)

• commercial infrastructure– a few ISPs (IIJ, NTT, Telia…) have started or announced

commercial IPv6 service

15

Deployment (cont.)

• IPv6 address allocation– 6bone procedure for test address space– regional IP address registries (APNIC, ARIN, RIPE-NCC)

for production address space

• deployment advocacy (a.k.a. marketing)– IPv6 Forum: www.ipv6forum.com

16

Much Still To Do

though IPv6 today has all the functional capability of IPv4,

• implementations are not as advanced(e.g., with respect to performance, multicast support, compactness, instrumentation, etc.)

• deployment has only just begun

• much work to be done moving application, middleware, and management software to IPv6

• much training work to be done(application developers, network administrators, sales staff,…)

• many of the advanced features of IPv6 still need specification, implementation, and deployment work

17

IPv6 Timeline(A pragmatic projection)

Q1Q1

Q2Q2

Q3Q3

Q4Q4

20072007Q1Q1

Q2Q2

Q3Q3

Q4Q4

20042004Q1Q1

Q2Q2

Q3Q3

Q4Q4

20032003Q1Q1

Q2Q2

Q3Q3

Q4Q4

20002000Q1Q1

Q2Q2

Q3Q3

Q4Q4

20012001Q1Q1

Q2Q2

Q3Q3

Q4Q4

20022002Q1Q1

Q2Q2

Q3Q3

Q4Q4

20052005Q1Q1

Q2Q2

Q3Q3

Q4Q4

20062006

Consumer adoption <= Dur. 5+ yrs.Consumer adoption <= Dur. 5+ yrs. =>=>

Early adopterEarly adopter

Appl. Porting <= Duration 3+ yrs.Appl. Porting <= Duration 3+ yrs. =>=>

Enterprise adopt.Enterprise adopt.<= 3+ yrs. => <= 3+ yrs. =>

adoption <= Dur. 3+ yrs.adoption <= Dur. 3+ yrs. ISPISP =>=>

18

Q1Q1

Q2Q2

Q3Q3

Q4Q4

20072007Q1Q1

Q2Q2

Q3Q3

Q4Q4

20042004Q1Q1

Q2Q2

Q3Q3

Q4Q4

20032003Q1Q1

Q2Q2

Q3Q3

Q4Q4

20002000Q1Q1

Q2Q2

Q3Q3

Q4Q4

20012001Q1Q1

Q2Q2

Q3Q3

Q4Q4

20022002Q1Q1

Q2Q2

Q3Q3

Q4Q4

20052005Q1Q1

Q2Q2

Q3Q3

Q4Q4

20062006

IPv6 Timeline(A pragmatic projection)IPv6 Timeline

(A pragmatic projection)






AsiaAsia

19

Q1Q1

Q2Q2

Q3Q3

Q4Q4

20072007Q1Q1

Q2Q2

Q3Q3

Q4Q4

20042004Q1Q1

Q2Q2

Q3Q3

Q4Q4

20032003Q1Q1

Q2Q2

Q3Q3

Q4Q4

20002000Q1Q1

Q2Q2

Q3Q3

Q4Q4

20012001Q1Q1

Q2Q2

Q3Q3

Q4Q4

20022002Q1Q1

Q2Q2

Q3Q3

Q4Q4

20052005Q1Q1

Q2Q2

Q3Q3

Q4Q4

20062006








EuropeEuropeAsiaAsia

20

Q1Q1

Q2Q2

Q3Q3

Q4Q4

20072007Q1Q1

Q2Q2

Q3Q3

Q4Q4

20042004Q1Q1

Q2Q2

Q3Q3

Q4Q4

20032003Q1Q1

Q2Q2

Q3Q3

Q4Q4

20002000Q1Q1

Q2Q2

Q3Q3

Q4Q4

20012001Q1Q1

Q2Q2

Q3Q3

Q4Q4

20022002Q1Q1

Q2Q2

Q3Q3

Q4Q4

20052005Q1Q1

Q2Q2

Q3Q3

Q4Q4

20062006

AmericasAmericas



EuropeEuropeAsiaAsia




Enterprise adopt.Enterprise adopt.<= 3+ yrs. <= 3+ yrs. => =>


21

Recent IPv6 “Hot Topics” in the IETF

• multihoming

• address selection

• address allocation

• DNS discovery

• 3GPP usage of IPv6

• anycast addressing

• scoped address architecture

• flow-label semantics

• API issues(flow label, traffic class, PMTU

discovery, scoping,…)

• enhanced router-to-host info

• site renumbering procedures

• inter-domain multicast routing

• address propagation and AAA issues of different access scenarios

• end-to-end security vs. firewalls

• and, of course, transition /co-existence / interoperabilitywith IPv4(a bewildering array of transition tools and techniques)

Note: this indicates vitality, not incompleteness, of IPv6!

22

Conclusions?

• if I knew it was going to take so long, I would have let one of the other IPng candidates “win”!

• one shouldn’t expect it to have taken less time, given the nature of the undertaking

• the IETF was unusually far-sighted (lucky?) in starting this work when it did, instead of waiting till the Internet falls apart

• the Internet is now falling apart

• IPv6 is ready to put it back together again

1 what’s happening with ipv6? october, 2001 steve deering [email protected]

Documents

ipv6 address formats

address hierarchy

mobile ip

total space

hierarchy slide

ipv6 header

internet slide

ip address allocation