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Irish IPv6 Task Force

Irish IPv6 Task Force. Introduction to IPv6 Fundamentals. Irish IPv6 Task Force IPv6 Training Slide-sets. The Bigger Picture: Why is IPv6 so Important? Introduction to IPv6 Fundamentals (technical) <- This slide set is second in a series IPv6 Deployment & Strategy (technical)

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Irish IPv6 Task Force

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  1. Irish IPv6 Task Force Introduction to IPv6 Fundamentals Irish IPv6 Task Force - http://www.ipv6.ie/

  2. Irish IPv6 Task ForceIPv6 Training Slide-sets • The Bigger Picture: Why is IPv6 so Important? • Introduction to IPv6 Fundamentals (technical)<- This slide set is second in a series • IPv6 Deployment & Strategy (technical) • The Business Case for IPv6 • Mobile IPv6 (technical) • IPv6 Quality of Service (technical) • IPv6 Security (technical)

  3. Presentation Structure • Introduction • Why IPv6 was designed. • IPv6 Addressing (format, types and policy). • How IPv6 interacts with other layers • Transition mechanisms. • The current state of IPv6.

  4. Introduction

  5. Introduction • Introduction to IPv6 technical details. • Only overview, not comprehensive. • Further information in complementary sources. • Will also touch on policy/history where it influences technical matters.

  6. Why IPv6 was designed.

  7. IPv4: Late 80s/Early 90s • Hosts went from 10,000 to 100,000 between 1987 to 1989. • IP space was classful: • 126 class A of 16M hosts, • 16K class B of 64K, • 2M class C of 253. • Concern about routing and addressing. • By 1993, people reckoned there was < 1year worth of address space left. • Lead to CIDR: Classless Interdomain Routing.

  8. CIDR • Class A, B and C had network/host boundary. • CIDR puts the boundary on any bit.

  9. NAT • Connection from private block is made. • Allocate public address/ports, record in rules. • Outgoing packets have private address and port replaced. • Incoming packets have public address and port replaced. Network Address Translationmade it possible to use fewer addresses. Idea: rewrite addresses using rules. Allows use of private address space.

  10. IPv4 Today • NAT/CIDR have bought IPv4 (too much?) time. • IPv4 has developed new problems since. • Security (spam, viruses, botnets, exploits, …) • Routing (scalability, stability, multihoming) • NAT (inhibitor, robustness, performance, cost) • Politics/Market (scarce resources, must be (seen to be?) distributed fairly)

  11. IPv6 • OSI 7 Layer Model. • TCP/IP spans many layers. • IP is layer 3. • IPv6 is a new layer 3. • So we keep TCP, UDP, HTTP, … • Need to update the glue between layers too.

  12. Major Changes • Bigger addresses (128 bit up from 32 bit). • Better extensibility (extension headers). • Built in autoconfiguration (DHCP/PPP still possible). • Mandatory IPsec. • More integrated multicast. • ARP replaced with Neighbour Discovery.

  13. IPv6 Addressing (format, types and policy)

  14. Addresses • Compromise between variable and 64 bit. • 128 bit addresses: 340282366920938463463374607431768211456. • In practice you loose space to structure. • 64 bits for hosts: enough for biggest subnets? • 64 bits for networks: enough to make aggregation easier ? • Long, so written in 8 hex quads. • Shortcuts permitted.

  15. Example Address • 2001:0db8:0010:0300:0000:0000:0ae2:510b • Long version. • 2001:db8:10:300:0:0:ae2:510b • Omit leading zeros. • 2001:db8:10:300::ae2:510b • Replace run of zeros with :: • 2001:db8:10:300::10.226.81.11 • Can write end as IPv4 address.

  16. Structured Addressing • 2001::/16 Chunk of production address space • 2001:770::/32 = HEAnet (ISP prefix) • 2001:770:10::/48 = TCD (organisation prefix) • 2001:770:64:300::/56 = Maths (dept prefix) • 2001:770:64:301::/64 = Wireless (subnet) This structure is dictated by policy at various levels, rather than being hardwired Into the protocol. This allows the policy to be adjusted to balance the needs of various stakeholders (users, network administrators, ISPs, governments, hardware/software vendors, …)

  17. Special Addresses • :: the unspecified address. • ::1 localhost/loopback. • fe80::/10 link-local addresses. • ff00::/8 multicast addresses. • Multiple addresses on each network card on each machine now normal!

  18. How IPv6 interacts with other layers.

  19. Communication Modes • Unicast: Destined to a single machine (normal). • Broadcast: Destined to all machines (ARP). • Multicast: Destined to all in a particular group (IP TV, ND). • Anycast: Destined to any one of a particular group (DNS Root Servers, 6to4).

  20. Autoconfiguration • Generate host-id and form link-local. • Check link-local is unique. • Now we can talk IPv6. • Multicast router solicitation to get prefix(es). • Global address(es) = prefix(es) + host-id. • Do duplicate address detection. • Doesn’t have to be used: manual, DHCPv6, PPP and privacy addressing also possible.

  21. Address Scope • Might have same link-local address on each interface. • How do we know which one? • Addresses can have scope. • E.g. two interfaces eth0 and eth1 • fe80::2b0:d0ff:fef4:c6c5%eth0 • fe80::2b0:d0ff:fef4:c6c5%eth1 • No need for scope on global addresses.

  22. Header Differences • Bigger addresses. • Drop uncommonly used features (fragments, IP options). • Drop fields that are redundant (header length, checksum). • Rename some fields to better represent modern usage. • 64 bit alignment to help hardware guys. • Add a new flow label.

  23. Header Flexibility • Main header is for forwarding packet. • Minimum necessary fields included. • New types of header may be chained together leading to TCP, UDP or ICMP. • Used for mobility, security, tunnels, and other advanced features.

  24. Glue • ICMP closely linked with IP, so new ICMPv6. • ICMPv6 includes Neighbour Discovery to replace ARP. • Most layer 2 glue is included in details of neighbour discovery. • Changes to higher layers relatively small. • TCP/UDP “pseudo-header” for checksums. • Update protocols that embed IPv4 addresses.

  25. Transition Mechanisms

  26. Transition Mechanisms • We have a large IPv4 network. • We want a large IPv6 network. • IPv4 only hardware, software and people. • How to get IPv6 working around this? • A lot of effort on Transition Mechanisms.

  27. Transition Mechanisms • Several broad strategies. • Dual stack: run both IPv4 and IPv6. • Tunnelling: hide IPv6 inside IPv4/UDP/… • Translation: convert IPv6 into IPv4. • Proxies: Someone speaks IPv6 on your behalf. • Too many to discuss all.

  28. Transition Examples • Vista/OS X/Linux/BSD all run dual-stack. • Point-to-point tunnels to get around legacy equipment. • Automagic tunnelling (6to4, Teredo) for end users in IPv4 only networks. • Proxies already common (web proxy, DNS server, SMTP server, …) • Translation uncommon, maybe for legacy apps?

  29. The current state of IPv6.

  30. Potted Local History • 1999-2001: Small scale academic experiments. • 2002: Native gigabit IPv6 from HEAnet to TCD. • 2003: IPv6 addresses in .ie zone. • 2004: IPv6 server for .ie zone. • 2005: National IPv6 centre established. • 2006: 6bone retired in favour of full IPv6 net. • 2007: ???

  31. IPv6 Today • The basics are done. • Deployment underway, not yet widespread. • Core/edge ready, corporate/ISP waiting. • Policy/standards continuing to evolve. • Considering IPv6 in lifetime of current planning, projects & purchases considered prudent.

  32. Summary • IPv6 just replaces IP layer in TCP/IP. • Fixes problems, particularly addressing. • Eases features such as mobility, security, … • Transition mechanisms to help deployment. • Standards, policy and network in place. • Someway to go before full deployment. • Continuing to evolve as living protocol.

  33. Acknowledgements This presentation includes some material originally developed for presentations at Doolin Tech Talks, RIPE, HEAnet and TCD.

  34. Contact Mícheál Ó Foghlú Research Director Telecommunications Software & Systems Group Waterford Institute of Technology Cork Road Waterford Ireland +353 51 302963 (w) mofoghlu@tssg.org http://www.tssg.org http://www.ofoghlu.net/log (Personal Blog)

  35. Further Information Web Sites: • National Irish IPv6 Centre http://www.ipv6-ireland.org • Irish IPv6 Task Force http://www.ipv6.ie • IPv6 ePrints Server (Public Documents) http://www.6journal.org/ • IPv6 Dissemination (Public Training) http://www.6diss.org/tutorials/ Individual Documents/Presentations: • http://arstechnica.com/articles/paedia/IPv6.ars/1 (Iljitsch van Beijnum, 7th March 2007) • http://bgp.potaroo.net/ipv4/ (Geoff Huston APNIC, 2006) • http://www.6journal.org/archive/00000261/02/WWC_IPv6_Forum_Roadmap__Vision_2010_v6.pdf (IPv6 Forum Roadmap & Vision, 2006) • http://colab.cim3.net/file/work/Expedition_Workshop/2005-12-06_Advancing_Information_Sharing_And_Data_Architecture/IPV6/NIST%20ipv6-doc-eai-v4%2012062005.ppt (Doug Montgomery NIST, 2005)

  36. Further Information Individual Documents/Presentations Contd: • MIPv6 Linux Software ( MIPL ) • www.mobile-ipv6.org • MIPv6 IETF charter • http://www.ietf.org/html.charters/mip6-charter.html

  37. Thank you!This presentation has been shared under the Creative Commons Attribution 2.0 UK: England & Wales Licence(http://creativecommons.org/licenses/by/2.0/uk)by the Irish IPv6 Task Force(http://www.ipv6.ie)Please acknowledge this source if you use it for free or for profit Irish IPv6 Task Force - http://www.ipv6.ie/

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