ADM389 IPv6

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ADM389 IPv6

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Make a (brief) case for IPv6 (level 200) Give you a crash-course on the main aspects of the protocol (level 300) Explain the available technology support including migration strategies (level 300)

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Nội dung Text: ADM389 IPv6

  1. ADM389 IPv6 in association with Rafal Lukawiecki www.ip426.com rafal@projectbotticelli.co.uk www.projectbotticelli.co.uk Strategic Consultant Project Botticelli Ltd
  2. 2 Objectives Make a (brief) case for IPv6 (level 200) Give you a crash-course on the main aspects of the protocol (level 300) Explain the available technology support including migration strategies (level 300)
  3. 3 Why IPv6?
  4. 4 IP Address Allocation History 1981 - IPv4 protocol published 1985 ~ 1/16 of total space 1990 ~ 1/8 of total space 1995 ~ 1/3 of total space 2000 ~ 1/2 of total space 2002.5 ~ 2/3 of total space This despite increasingly intense conservation efforts: PPP / DHCP address sharing NAT (network address translation) CIDR (classless inter-domain routing) plus some address reclamation Theoretical limit of 32-bit space: ~4 billion devices Practical limit of 32-bit space: ~250 million devices (RFC 3194)
  5. 5 Running Out of Addresses Even if every company used only 1 address by fully utilising NATs (Network Address Translation)… …we would be out of addresses in the next 3-5 years “Slower that Y2K problem, but a surer one”
  6. 6 More IPv4 Pain Argh, NATs  Peer-to-peer is difficult NAT security record is dubious Management is a pain Security is an optional add-on QoS (Quality of Service) is rare and not real-time Routing tables too large and process slow Mobility is a pain But peer-to-peer mobility is the future of Internet Device autoconfiguration is rare DHCP & address ownership does not work across organisational boundaries Using external agents for autoconfiguration is a non-starter
  7. 7 US versus ROW US accounts for 90% of address allocation Some universities in US have more allocated addresses than the whole of Asia The so-called, in US, “Rest of the World” is hardly an even partner Reliance on American organisations may be politically difficult, at times, for large or governmental Internet projects Gives US an unwelcome monopoly power
  8. 8 6 Benefits of IPv6 Address depletion solved International misallocation solved End-to-end communication restored Scoped addresses & address selection More efficient forwarding Built-in security and mobility
  9. 9 Who’s Doing IPv6? More places than you would think! Japanese city of Kyoto (now) JANET (Joint Academic Network) in UK US Deparment of Defence June 13th 2003 decision made by Pentagon ( http://story.news.yahoo.com/news?tmpl=story&cid=1509&ncid=738& ) Planning and preparation in 2003-4 Transition in 2005 Completion in 2008
  10. 10 Crash Course on IPv6
  11. 11 Features of IPv6 New header format Large address space Efficient and hierarchical addressing and routing infrastructure Stateless and stateful address configuration Built-in security Better support for QoS New protocol for neighboring node interaction Extensibility
  12. 12 Differences Between IPv4 & IPv6 Feature IPv4 IPv6 Address length 32 bits 128 bits IPSec support Optional Required QoS support Some Better Fragmentation Hosts and routers Hosts only Packet size 576 bytes 1280 bytes Checksum in header Yes No Options in header Yes No Link-layer address resolution ARP (broadcast) Multicast Neighbor Discovery Messages Multicast membership IGMP Multicast Listener Discovery (MLD) Router Discovery Optional Required Uses broadcasts Yes No Configuration Manual, DHCP Automatic, DHCP DNS name queries Uses A records Uses AAAA records DNS reverse queries Uses IN-ADDR.ARPA Uses IP6.INT
  13. 13 IPv6 Terminology Neighbors Host Host Host Bridge Intra-subnet router Router LAN segment Link Subnet Additional subnets Network
  14. 14 The IPv6 Address Space 128-bit address space 2128 possible addresses 340,282,366,920,938,463,463,374,607,431,768,211,456 addresses (3.4 x 1038) 6.65 x 1023 addresses per square metre of Earth’s surface 128 bits were chosen to allow multiple levels of hierarchy and flexibility in designing hierarchical addressing and routing Typical unicast IPv6 address: 64 bits for subnet ID, 64 bits for interface ID
  15. 15 IPv6 Address Syntax IPv6 address in binary form: 0010000111011010000000001101001100000000000000000010111100111011 0000001010101010000000001111111111111110001010001001110001011010 Divided along 16-bit boundaries: 0010000111011010 0000000011010011 0000000000000000 0010111100111011 0000001010101010 0000000011111111 1111111000101000 1001110001011010 Each 16-bit block is converted to hexadecimal and delimited with colons: 21DA:00D3:0000:2F3B:02AA:00FF:FE28:9 C5A Suppress leading zeros within each 16-bit block:
  16. 16 Compressing Zeros Some IPv6 addresses contain long sequences of zeros A single contiguous sequence of 16-bit blocks set to 0 can be compressed to “::” (double-colon) Example: FE80:0:0:0:2AA:FF:FE9A:4CA2 becomes FE80::2AA:FF:FE9A:4CA2 FF02:0:0:0:0:0:0:2 becomes FF02::2 Cannot use zero compression to include part of a 16-bit block FF02:30:0:0:0:0:0:5 does not become FF02:3::5.
  17. 17 IPv6 Prefixes Prefix is the part of the address where the bits have fixed values or are the bits of a route or subnet identifier IPv6 subnets or routes always uses address/prefix-length notation CIDR notation Examples: 21DA:D3::/48 for a route 21DA:D3:0:2F3B::/64 for a subnet No more dotted decimal subnet masks! 
  18. 18 Types of IPv6 Addresses Unicast Address of a single interface One-to-one delivery to single interface Multicast Address of a set of interfaces One-to-many delivery to all interfaces in the set Anycast Address of a set of interfaces One-to-one-of-many delivery to a single interface in the set that is closest No more broadcast addresses
  19. 19 Unicast IPv6 Addresses Aggregatable global unicast addresses Link-local addresses Site-local addresses Special addresses Compatibility addresses NSAP addresses
  20. 20 Aggregatable Global Unicast Addresses Top-Level Aggregation ID (TLA ID) Next-Level Aggregation ID (NLA ID) Site-Level Aggregation ID (SLA ID) Interface ID 13 bits 8 bits 24 bits 16 bits 64 bits 001 TLA ID Res NLA ID SLA ID Interface ID
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