Presentation on theme: "1 What’s Happening with IPv6? October, 2001 Steve Deering"— Presentation transcript:
1 What’s Happening with IPv6? October, 2001 Steve Deering email@example.com
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 any power-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!
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 1990 ~ 1/8 of total space 1995 ~ 1/4 of total space 2000 ~ 1/2 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 devices practical 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 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 to Live Source Address Total Length Type of Service Hdr Len Identification Fragment Offset Flg Protocol Header Checksum Destination Address Options... Ver. Traffic Class Source Address Payload Length Next Header Hop Limit Destination Address Hdr Len Identification Fragment Offset Flg Header Checksum Options... shaded fields have no equivalent in the other version IPv6 header is twice as long (40 bytes) as IPv4 header without options (20 bytes) Flow Label
10 How Was IPv6 Address Size Chosen? some wanted fixed-length, 64-bit addresses –easily good for 10 12 sites, 10 15 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
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 / interoperability with 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
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