1 / 25

IPv6 The New Internet Protocol

IPv6 The New Internet Protocol. Integrated Network Services Almerindo Graziano. Introduction. Justification for IPv6 IPv6 goals IPv6 Addressing The new Header Extension Headers Recap. Justification for IPv6: What is wrong with IPv4?. Wasteful of address space

celine
Download Presentation

IPv6 The New Internet Protocol

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. IPv6The New Internet Protocol Integrated Network Services Almerindo Graziano

  2. Introduction • Justification for IPv6 • IPv6 goals • IPv6 Addressing • The new Header • Extension Headers • Recap

  3. Justification for IPv6: What is wrong with IPv4? • Wasteful of address space • Not built-in support for hierarchical addressing • Subnetting • CIDR • Large routing tables • Large administrative workload: • Changing ISP • Merger or acquisition Renumbering or NAT

  4. What is wrong with IPv4? • Routers perform a lot of operations • Table lookup • Options • Checksum • Fragmentation • Lack of authentication • IP spoofing • Lack of encryption

  5. IPv6 goals • Support for a larger number of addresses • Reduce the size of routing tables • Simplify the protocol (easier to process) • Provide better security • Better support for Quality of Service • Provide support for mobile users • Allow the protocol to be extensible • Be compatible

  6. IPv6 Addressing scheme • Designed to be highly scalable and hierarchical • 16-byte long • 7x1023 IP addresses per square meter!!! • It “eliminates” the need for private address space • IPv6 notation 8000:0000:0000:0000:0123:8219:E42A:DF3E 8000::123:8219:E42A:DF3E • IPv4 addresses can be written as ::192.31.20.46

  7. Address Allocation • IPv6 could support a number of diverse addressing schemes • Provider Allocation hierarchy is based on large service providers, regardless of their location • Geographic Allocation hierarchy is based on the location of subscribers (similar to the telephony system) • Both approaches have drawbacks Large networks do not often conform to provider and/or geographical boundaries!!

  8. Aggregation Based Allocation • Combines provider and geographic allocation approaches • Based on the existence of limited number of high-level exchange points • Large providers are represented at one or more exchange points (provider orientation) • Exchanges are distributed around the globe (geographic orientation) • Favoured by the IETF

  9. Long-Haul Provider Long-Haul Provider Interexchange (TLA) Long-Haul Provider Long-Haul Provider Provider Provider Subscriber Subscriber Subscriber Subscriber Subscriber IPv6 Address Hierarchy To other TLA TLA: Top Level Aggregator

  10. 3 13 8 24 bits 16 bits 64 bits 001 TLA RES NLA SLA Interface ID Public Topology Local Interface Site Topology IEEE EUI-64 Address 24 bits - Company ID 40 bits - interface ID Aggregation-based Allocation • First 3 bits identify the type of address • unicast, multicast, anycast etc.. • International registries assign block to TLA • TLA allocate block of addresses to NLA • NLA can be large providers or global corporate networks • NLA can create their own hierarchy

  11. 32 bits NLA 1 Site SLA Interface ID NLA 2 Site SLA Interface ID NLA 3 Site SLA Interface ID Aggregation-based Allocation

  12. 128 bits 1111111010 00 . …. 00 Interface ID 10 bits 54 bits 64 bits Other Address Types • Site-Local Addresses • Similar to IPv4 private addresses • Link-Local Addresses • A router doesn’t exist • Operate over a single link • Used for temporary bootstrapping Not propagated outside organizational boundaries Not allocated by public registry authorities

  13. Other Address Types • Multicast Addresses • Logical addresses to communicate to multiple nodes • Anycast Addresses • Used to communicate to the closest of a class of nodes (closest DNS, closest router) • Allocated from the same address space as Unicast addresses

  14. Address Autoconfiguration • A node combines its MAC address with a network prefix it learns from a neighbouring router • The autoconfiguration doesn’t need a manually configured server: stateless address autoconfiguration • It differs from IPv4’s DHCP (stateful address configuration). DHCPv6 has been developed • Great advantage when an enterprise is forced to renumber because of an ISP change or M&A • Great support for mobile users and dynamic workgroups

  15. Type of Service Priority Flow Label Version IHL Total Length Version Next Header Hop Limit Fragment Offset Flag Payload Length Identification TTL Protocol Header Checksum Source Address Source Address Destination Address Options Padding 32 bits Destination Address 32 bits Header Comparison IPv4 Header IPv6 Header IPv4 Header = 14 fields IPv6 Header = 8 fields

  16. The new Header • Fixed size • Fewer fields • No Checksum • Already performed by other layers • Reliable networks • Extension Headers replace Options • Routers can skip over some extension headers Faster processing Extensible

  17. QoS Support • Priority field (4 bits) • Congestion-Controlled traffic (0-7) • Traffic where the source backs off in case of congestion (e.g. TCP) • Non-Congestion-Controlled traffic (8-15) • Traffic where constant data rate and delay are desirable (real-time audio/video) • Flow label field (20 bits) • A sequence of packets sent from a particular source to a particular destination for which the source desires special handling by intervening routers

  18. Extension Headers • Hop-by-Hop options header • Destination options header-1 • Source Routing header • Fragmentation header • Authentication header • IPv6 Encryption header • Destination options header-2

  19. Extention Headers • Hop-by-Hop • Carries information for all intermediate nodes • Used for management and debugging • Destination • Carries information to be read just by destination nodes • Source Routing • Allows to specify a list of router to traverse

  20. Fragmentation Header • Each source is responsible for sending packets of the right size • MTU path discovery process • Packet fragmentation is not permitted by intermediate nodes (routers) • Faster processing • If fragmentation is required, the fragmentation header is used

  21. Authentication Header • It gives network applications a guarantee that a packet did in fact come from an authentic source • A checksum is created based on the key and the content of the packet • The checksum is re-run at the destination and validated

  22. IPv6 Encryption Header • Encapsulation Security Payload (ESP) • It provides encryption at the network layer • Two encryption modes are supported • Transport mode • Tunnel mode (steel pipe)

  23. Unencrypted Encrypted Transport Header and Payload IPv6 Header Extention Headers ESP Header Unencrypted Encrypted Transport Header and Payload ESP Header IPv6 Header IPv6 Header Extention Headers Extention Headers Original IP packet Encryption modes Transport Mode Tunnel Mode

  24. The Transition to IPv6 • IPv6 offers a robust future-oriented solution to integrate physical networks • Possibly use NAT but • can be a bottleneck • prevents the use of IP-level security • breaks Domain Name Servers • 6Bone • Experimental world-wide network for testing IPv6

  25. IPv6 Resources • Main IPv6 page http://ipv6.com/ • 6Bone home page http://6bone.net/ • The case for IPv6 (Internet Draft) http://www.6bone.net/misc/case-for-ipv6.html

More Related