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Next Generation IP < IPv6 >

Next Generation IP < IPv6 >. 下一代網際網路協定. National Dong Hwa University Director of Computer Center Han-Chieh Chao 趙涵捷. Overview. Limitations of current Internet Protocol (IP) IPv6 addressing IPv4/IPv6 Transition IPv6 features Autoconfiguration IPSec QoS IPv6 Mobility Support Summary.

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Next Generation IP < IPv6 >

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  1. Next Generation IP< IPv6 > 下一代網際網路協定 National Dong Hwa University Director of Computer Center Han-Chieh Chao 趙涵捷

  2. Overview • Limitations of current Internet Protocol (IP) • IPv6 addressing • IPv4/IPv6 Transition • IPv6 features • Autoconfiguration • IPSec • QoS • IPv6 Mobility Support • Summary

  3. Internet Growth

  4. Internet Growth

  5. Growing Pains Depletion of IP address ( between 2005 and 2001 ) Explosion of Routing Tables ( routing table explosion will condemn the internet even sooner than the exhaustion of network addresses )

  6. IPv4 Addresses • Example: 203.64.105.100 =1100 1011:0100 0000:0110 1001:0110 0100 (32 bits) = CB:40:69:64 • Maximum = 232 = 4 Billion • Class A Network: 15 Million nodes • Class B Network: 64,000 nodes or less • Class C Network: 250 nodes or less

  7. IPv4 Address (cont.) • 127 Class A + 16,381 Class B + 2,097,151 Class C Network = 2,113,659 networks total • Class B is most popular • 20% of Class B were assigned by 7/90 and doubling every 14 months => Will exhaust by 3/94 • Question: Estimate how big will you become? Answer: more than 256! Class C is too small. Class B is just right.

  8. How many address? • Some believe 26 to 28 address per host • Safety margin => 1015 addresses • IPng Requirements => 1012 end systems and 109 networks. Desirable 1012 to 1015 networks

  9. Address Size • H Ratio = log10(number of objects)/available bits • 2n objects with n bits: H Ratio = log102 = 0.30103 • French telephone moved from 8 to 9 digits at 107 households => H = 0.26 (assuming 3.3 bits/digit) • US telephone expanded area codes with 108 subscribers => H = 0.24 • SITA expanded 7-character address at 64k nodes => H = 0.14 (assuming 5 bits/char)

  10. Address Size (cont.) • Physics/space science net stopped at 15000 nodes using 16-bit addresses => H = 0.26 • 3 Million Internet hosts currently using 32-bit addresses => H = 0.20 => A few more years to go

  11. IPv6 motivation • The enormous growth of Internet. • The Address space is running out in IPv4 (32 bits). • Routing tables are exploding. • The lack of security at the network layer • Device Control – Smart Homes • High Performance Networks • IP Based Cellular Systems • Connect everything over IP • Several years of networking with TCP/IP had brought lessons and knowledge • Lack of Mobility support • New Applications such as Real Time Multimedia. • Networked Entertainment - your TV will be an Internet host • More Scalable Solution is needed

  12. Internet Draft Proposed Standard (RFC) Yes Technically complete and stable? Draft Standard (RFC) Yes Multiple Interoperable Implemen- tations Internet Standard (RFC) Significant Operational Experience? Yes IPv6 Standardization Where in the standardization process is IPv6? 6ren, vBNS etc. GPRS, UMTS?

  13. Ipng long term solution 1991: Work starts on next generation Internet protocols -- More than 6 different proposals were developed 1993: IETF forms IPng Directorate --To select the new protocol by consensus 1995: IPv6 selected -- Evolutionary (not revolutionary) step from IPv4 1996: 6Bone started 1998: IPv6 standardized Today: Initial products and deployments

  14. IPv6 Main Features/Functionality expanded addressing and routing capabilities support for extension headers and options Simplified header format quality of service capabilities Auto-configuration Multi-Homing Class of Service/Multimedia support support for authentication and privacy Multicast (No more broadcast ) IPv4 , IPv6 Transition Strategy

  15. Revised Renamed Suppressed IPv4 Header20 Octets+Options : 13 fields, include 3 flag bits 24 31 0 bits 4 8 16 Ver IHL Service Type Total Length Identifier Flags Fragment Offset Time to Live Protocol Header Checksum 32 bit Source Address 32 bit Destination Address Options and Padding

  16. New IPv6 Header40 Octets, 8 fields Version Class Flow Label Payload Length Next Header Hop Limit 128 bit Source Address 128 bit Destination Address

  17. Major Simplifications Assign a fixed format to all headers (40 bytes) Remove the header checksum Remove the hop-by-hop segmentation procedure Built-in security

  18. IPv6 Address • 128 bits long. Fixed size • 2128 = 3.4×1038 addresses => 6.65×1023 addresses per m2 of earth surface • If assigned at the rate of 106/s, it would take 20 years • Expected to support 8×1017 to 2×1033 addresses 8×1017 => 1,564 address per m2 • Allows multiple interfaces per host • Allows multiple addresses per interface

  19. The "::" can only appear once in an address • The "::" can also be used to compress the leading and/or trailing zeros • in an address 1080 :: 8 : 800 : 200C : 417A :: 203.64.105.100 Text Representation of ddresses Colon-Hex: 1080 : 0 : 0 : 0 : 8 : 800 : 200C : 417A “::” indicates multiple groups of 16-bits of zeros Dot-Decimal : 203.64.105.100 Can leave the last 32 bits in dot-decimal,

  20. Hierachy 3+5+16+16+8+32=80 The remaining 48 bits define the particular system on the subnetwork.

  21. Global Site-Local Link-Local IPv6 Address Models • Allows unicast, multicast, anycast • Allows provider based, site-local, link-local • 85% of the space is unassigned • Addresses have lifetime • Valid and Preferred lifetime

  22. 10 54 64 bits 1111 1110 10 0 Interface ID 10 38 16 64 bits 1111 1110 11 0 Subnet ID Interface ID Local-Use Address • Link Local: Not forwarded outside the link, FE80::xxx • Site Local: Not forwarded outside the site, FEC0::xxx

  23. 8bits 4bits 4bits 112bits 1111 1111 Flags Scope Group ID 0 0 0 T Multicast Address • T=0 => Permanent (well-known) multicast address, T=1 => Transient • Scope: 1 Node-local, 2 Link-local, 5 Site-local, 8 Organization-local, E Global, F Reserved • Predefined: 1 => All nodes, 2 => Routers,

  24. Multicast Address (cont.) • Link-local scope limits multicast to single Ethernet

  25. Multicast Address (cont.) • Organization-local scope limits multicast to organization boundary

  26. “Can any local router help me ” Destination address : 5A01: 203 : 405 :607 : 809 : 0 : 0 : 0 Subnetwork Prefix : 5A01: 203 : 405 :607 : 809 :: /80 Anycast Address (the subnet-router address) • Workstation uses an anycast address to ask for help from any router.

  27. Address Prefixes • Can specify a prefix by /length

  28. IPv6 Address Allocation Allocation Prefix Fraction of (binary) Address Space ------------------------------- -------- ------------- Reserved 0000 0000 1/256 (0::/8) Unassigned 0000 0001 1/256 (100::/8) Reserved for NSAP Allocation 0000 001 1/128 (200::/7) Reserved for IPX Allocation 0000 010 1/128 (400::/7) Unassigned 0000 011 1/128 (600::/7) Unassigned 0000 1 1/32 (800::/5) Unassigned 0001 1/16 (1000:/4)

  29. IPv6 Address Allocation (cont.) Allocation Prefix Fraction of (binary) Address Space ------------------------------- -------- ------------- Aggregatable Global Unicast Addresses 001 1/8 (2000::3) Unassigned 1111 0 1/32 (F000::/5) Unassigned 1111 10 1/64 (F800::/6) Unassigned 1111 110 1/128 (FC00::/7) Unassigned 1111 1110 0 1/512 (FE00::/9) Link Local Unicast Addresses 1111 1110 10 1/1024 (FE80::/10) Site Local Unicast Addresses 1111 1110 11 1/1024 (FEC0::/10) Multicast Addresses 1111 1111 1/256 (FF00::/8)

  30. IPv6 Header Next Header=TCP TCP Header IPv6 Header Next Header= Routing Routing Header Next Header= TCP TCP Header IPv6 Header Next Header= Routing Routing Header Next Header= Fragment Fragment Header Next Header= TCP TCP Header IPv6 Extension Headers • IP options have been moved to a set of optional Extension Headers • Extension Headers are chained together Next Header

  31. Routing Header Next Header Routing Type Num. Address Next Address Reserved Strict/Loose bit mask Address 1 Address 2 ….. Address n

  32. Routing Header (cont.) • Strict => Discard if Address[Next-Address]  neighbor • Type = 0 => Current source routing • Type > 0 => Policy based routing (later) • New Functionality: Provider selection, Host mobility, Auto-readdressing (route to new address)

  33. Address Autoconfiguration • Allow plug and play • BOOTP and DHCP are used in IPv4 • DHCPng will be used with IPv6 • Two Methods: Stateless and Stateful • Stateless: • A system uses link-local address as source and multicasts to "All routers on this link" • Router replies and provides all the needed prefix info • All prefixes have a associated lifetime • System can use link-local address permanently if no router

  34. Address Autoconfiguration (cont.) • Stateful: • Problem w stateless: Anyone can connect • Routers ask the new system to go DHCP server (by setting managed configuration bit) • System multicasts to "All DHCP servers" • DHCP server assigns an address

  35. Automatic Renumbering • Renumbering IPv6 Hosts is easy • Add a new Prefix to the Router • Reduce the Lifetime of the old prefix • As nodes depreciate the old prefix the new Prefix will start to be used for new connections • Renumbering in IPv6 is designed to happen! • An end of ISP “lock in”! • Improved competition

  36. APPLICATION TCP/UDP IPv4 IPv6 DRIVER Transition Mechanism • Dual Stack :Providing complete support for both IPv4 and IPv6 in hosts and routers. IPv6 host IPv4 host Dual IP host • This allows indefinite co-existence of IPv4 and IPv6, and gradual, app-by-app upgrades to IPv6 usage

  37. Transition Mechanism (cont.) • IPv6 over IPv4 tunneling : Encapsulating IPv6 packets within • IPv4 headers to carry them over IPv4 routing infrastructures. Entry Router IPv4 Infrastructure Leaving Router IPv4 header Protocol number=41 IPv6 packet IPv6 packet IPv6 packet

  38. Transition Mechanism (cont.) Encapsulate IPv6 packets inside IPv4 packets(or MPLS frames) any methods exist for establishing tunnels: -- configured tunnels - manual -- automatic tunnels - IPv4 compatible addresses ::<ipv4> • IPv6-to-IPv4 (inter-domain, using IPv4 addr as IPv6 site prefix)

  39. Dest. :: 0102:0304 Dest. :: 0102:0304 Dest. 1.2.3.4 Transition Mechanism (cont.) • IPv4-compatible IPv6 Addresses 96 bits 32 bits |0000..............................00000000| IPv4 address |

  40. Dest. ::FFFF: 0102:0304 Transition Mechanism (cont.) • IPv4-mapped IPv6 address 80 bits 16 bits | 000………000 : 11….11: IPv4 | Dest. ::FFFF: 0102:0304 Dest. 1.2.3.4

  41. QoS • Class Field • Diff Serv Code Point will be used • Can be used for distinguish between different traffic classes • Flow label • Identifies streams that needs special handling • Used by RSVP today • Not fully defined yet • Could be used for a deterministic hashkey to classify on L2-L7 -> Would make it easier to implement in Hardware

  42. IPv6 Security • Two headers in IPv6 that provides security - AH, ESP • AH - Authentication Header • Provides source authentication • Integrity • ESP - Encrypted Security Payload • Integrity • Authentication • Confidentiality • Note: IPSec is exactly the same for IPv4 and IPv6 only that it was Taylor-made for IPv6. • Advantages with IPsec • Network level security • Transparent to End-user • Open Standard

  43. Mobile IPv6 • IPv6 Mobility is based on core features of IPv6 • The base IPv6 was designed to support Mobility • Mobility is not an “Add-on” features • All IPv6 Networks are IPv6-Mobile Ready • All IPv6 nodes are IPv6-Mobile Ready • All IPv6 LANs / Subnets are IPv6 Mobile Ready • IPv6 Neighbor Discovery and Address Autoconfiguration allow hosts to operate in any location without any special support

  44. Mobile IPv6 (cont.) • No Foreign Agent • In a Mobile IP, an MN registers to a foreign node and borrows its’ address to build an IP tunnel so that the HA can deliver the packets to the MN. But in Mobile IPv6, the MN can get a new IPv6 address, which can be only used by the MN and thus the FA no longer exists. • More Scalable : Better Performance • Less traffic through Home Link • Less redirection / re-routing (Traffic Optimisation)

  45. IPv6 Mobility Support No FA’s, ND, always Co-located Co addresses for mn.ndhu.tw at agent.mit.us mn.ndhu.tw Router Home Agent Correspondend Node Gets an address trough ND for mn.ndhu.tw mit.us INTERNET ndhu.tw

  46. Improved Performance • Faster processing time per IPv6 packet • Align on 64 bits boundary • Fewer Optional Headers (from 12 to 8) • Removed checksum • Better designed for HW support • Scalable hierarchical address architecture • Faster routing lookups • Smaller routing tables due to Hierarchical address architecture -> which make ip_forwarding faster and more efficient use of the memory • Less routing traffic in the backbone -> which mean less load on the network

  47. Summary Streamlined Header Format Flow Label 128-bit Network Addresses Elimination of Header Checksum Fragmentation only by source Host Extension Headers Built-in-security

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