Internet Protocol version 6 IPv6

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Internet Protocol version 6 (IPv6)
Úna Logan Broadcom Eireann Research
Ltd. http//www.broadcom.ie
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Topics

• EURESCOM Project P803
• Why IPv6?
• Key IPv6 Features
• IPv6 Header
• Benefits of IPv6 over IPv4
• IPv6 Transition Mechanisms
• IPv6 Implementations Deployment
• Conclusions

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EURESCOM Project P803

• Development of European IP Testbed between
  partners to
• Investigate IPv6
• Investigate techniques for differentiated QoS in
  IP networks
• Investigate different network architectures
• Promote creation of European agreement, build
  relationships with Internet standards bodies
  industry
• IPv6
• Migration scenarios and Interworking
• Dual IP Layer, Tunneling, DNS, Compatibility
• Protocol related IPv6 issues
• Mobility, Addressing, Security and
  Authentication, Routing, Traffic Flows and
  Multicast and Anycast

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P803 IPv6 Network
H1 R1 H2 R2

6Bone
6Bone
R
R
R
R
H3 R3 H4 R4
H3 R3 H4 R4
H Host R Router
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Why IPv6 (1)?

• New version of the Internet Protocol
• Developed in the early 90s in the IETF
• Designed as an evolutionary step from IPv4
• Lack of Address Space was the driving force
  behind the new Internet Protocol

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Why IPv6 (2)?

• Other kinds of markets will develop
• Nomadic Personal Computing Devices
• Networked Entertainment
• Device Control
• IPv6 can provide the management and control
  needed
• Common protocol that can work over a variety of
  networks
• Large scale routing and addressing
• Communicates with current generation of computers
• Meets today's requirements and the requirements
  of these emerging markets

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Key IPv6 Features(1)

• Expanded Addressing Capabilities / Efficient
  Routing
• IPv6 increases the IPv4s address size from 32
  bits to 128 bits
• Address Autoconfiguration
• Unicast, Anycast and Multicast Addresses
• Hierarchical Addressing Structure
• Header Format Simplification
• New streamlined header
• Improved Support for Options / Extensions
• Allows efficient forwarding
• Ability to add new options in the future

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Key IPv6 Features(2)

• Flow Labeling Capability
• Labeling of packets belonging to particular
  traffic "flows" for which the sender requests
  special handling
• Mobility
• Built in Route Optimisation
• Security
• Authentication and Encryption.

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IPv6 Packet Header Format
32 bits

• Ver Version number
• TC (Traffic Class)Identify different classes or
  priority
• Flow Label Request for special handling by
  routers within a network
• Payload Length Length of the remainder of the
  packet following the IPv6 header
• Next Header Type of header following the IPv6
  header
• Hop Limit Limitation for the impact of routing
  loops

Ver TC Flow Label
Payload Length Next Header Hop
Limit
Source Address Destination Address
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IPv6 Flow Label

• Differentiated Services Flow Label Field
• Used by hosts to label packets that
• require special handling by routers
• Handling can be conveyed to routers
• By a control protocol, e.g... RSVP
• By information within the flow's packets
  themselves
• Integrated Services Traffic Class
• Enables a source to identify the desired delivery
  priority of its packets, relative to other
  packets from the same source
• The Priority values are divided into two ranges
• Traffic that "backs off" in response to
  congestion, such as TCP traffic
• Traffic that does not back off in response to
  congestion, e.g..., "real-time" traffic

TC Flow Label
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Specialised Extension Headers
Destination Options

• Location
• Between the IPv6 header and before the upper
  layer headers in a packet
• Efficient
• Most not examined or processed until the packet
  reaches its destination
• Optional

Encapsulating Sec Payload
Authen -tication
Fragment
Routing
Destination Options
Hop-by-Hop Options
IPv6 Header Extension Headers
Upper Layers
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Packet Size and Fragmentation

• High packet latency hinders audio and video
  streams
• Fragmentation is a major source of high latency
  under IPv4
• IPv4 provides fragmentation at any point in the
  path
• Routers along the path a packet travels perform
  fragmentation by so that fragments are at most
  the size of next-hop link MTU
• IPv6 provides end-to end fragmentation
• A source alone performs fragmentation by using a
  path MTU discovery algorithm
• Fragmentation field has moved to an extension
  header

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Voice over IPv6

• Problems with voice over IP today
• Limited bandwidth
• Also, in an Internet connection, the bandwidth
  can be very inconsistent
• Latency
• Unpredictable latency times
• Improvements for voice over IPv6
• Limited bandwidth is not a protocol issue
• More efficient routing system
• More Efficient End-to-End fragmentation will
  improve latency
• Still unpredictable latency times!

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Benefits of IPv6 over IPv4 (1)

• Addressing scheme
• IPv4s workarounds (e.g.. DHCP and NAT, CIDR)
  only delay the inevitable!
• Address Autoconfiguration reduces set up costs
  and provides easy renumbering of sites
• Efficient Routing
• Lack of uniformity in IPv4s hierarchical system,
  limited addresses
• gt reduces performance, increases routing
  complexity and requires more routing information
  in backbone routers
• IPv6s large hierarchical address space allows
  efficient routing.
• Simplified Reworked Packet Structure
• Extension headers can be worked in as needed
• With IPv6, most options are stored in the
  Extension headers, reducing processing time at
  each hop.

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Benefits of IPv6 over IPv4 (2)

• Improved Support for Mobility
• Built in Route Optimisation
• Direct routing to a mobile node
• QoS
• Improved Flow Handling efficiency
• Security
• Built-in, Mandatory Security

Home Node
IPv4 IPv4
IPv6
Sender
Mobile Node
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P803 Mobility
Correspondent Router
Home Agent Router Node
6Bone
Home Agent Router
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IPv6 Implementations

• Over 50 IPv6 implementations completed or
  underway worldwide
• Host Implementations
• Apple, Digital UNIX, FreeBSD, Linux, Microsoft,
  Solaris 2 (Sun), VMS (DEC)
• Router Implementations
• 3Com, Bay Networks, Cisco Systems, Digital, IBM,
  Ipsilon, Telebit...

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The Transition to IPv6 (1)
IPv4 Header

• The Transition Features
• Incremental upgrade and deployment
• Minimal upgrade dependencies
• Low start-up costs
• Easy Addressing
• The Transition Mechanisms
• Dual IP layer technique
• Addressing structures that embed IPv4 addresses
  within IPv6 addresses
• Tunnelling IPv6 packets over IPv4 routing
  infrastructures
• Encapsulates IPv6 packets in IPv4 packets

IPv6 IPv6 Header encaps.
Header
Transport Layer Transport
Layer
Header decaps. Header
Data Data
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The Transition to IPv6 (2)

• Network Address Translation-Protocol Translation
  (NAT-PT)
• Allows IPv6-only nodes to interoperate with
  IPv4-only nodes
• IPv6 DNS
• IETF designers have defined DNS Extensions to
  Support IPv6
• Creates a new 128-bit DNS record type that will
  map domain names to an IPv6 address
• Reverse lookups based on 128-bit addresses are
  also defined
• Application Modification for IPv6
• No direct access to the network stack - requires
  no updating to run in the dual-stack environment
• Directly interfacing with IP and related
  components - requires updating
• Directly interfacing with both IPv4 and IPv6 -
  requires more extensive updating

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The 6Bone

• Launched in July 1996
• Virtual network
• Layered on top of portions of the physical
  IPv4-based Internet to support routing of IPv6
  packets
• Test network
• Allows the IPv6 protocol features and
  interoperability to be fully tested
• Currently, there 41 countries on the 6Bone
• Other similar initiatives
• Internet2 (http//www.Internet2.edu/)
• The Wide Project (http//www.v6.wide.ad.jp/)

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Conclusions

• Sooner or later the address space will run out!
• IPv6 Deployment
• Only experimental
• Vendors appear committed to the development of
  IPv6
• The core set of IPv6 protocols due to be fully
  standardised this year
• Most IPv6 functionality has been retro-fitted
  into IPv4
• No substitute to a protocol designed from the
  ground up with scaleable addressing, advanced
  routing, security, QoS and related features
• IPv6 provides the platform for new Internet
  functionality needed in the near future

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Additional Information

• http//www.playground.sun.com/pub/html/ipng-main.h
  tml
• Pointers to current Specifications and
  implementations updated on a regular basis
• http//www.ietf.org/
• Information on the IETF organisation, Internet
  Standards, Drafts and RFC s
• http//www.eurescom.de/
• Information on the P803 European IP Testbed
• http//www.6bone.net/
• Information about the 6Bone and what you need to
  know in order to participate