IPv6

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IPv6

• AL-MAJRASHI, FAHAD 208192
• AL-MUQAIREN, FAHAD 215721

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TOPICS

• Why IPv6
• How IPv6 Developed
• Basic functions Offerings of IPv6
• Changes From IPv4 to IPv6
• Header Format
• Network Addressing
• Special IPv6 addresses
• Extension Headers

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Why IPv6

• IPv6 is the next generation of the Internet
  Protocol.
• It will eventually replace IPv4.
• The development and the expand in using the
  internet created heavy demand for new IP address.
• The 32 bits of IPv4 will be exhausted so there
  will be need for larger one.
• 75 of IPv4 space allocated to US, only 25 for
  the rest of the world.

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How IPv6 Developed

• The current version (IPv4) is running out of
  addresses
• and become too complex to manage .
• It is designed to interoperate with IPv4 because
  it need many years for this transition
• The Internet Engineering Task Force (IETF) began
  to solve the problem of exhaustion for IPv4.
• By 1994, the new version of IPv6 was invented.

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Basic functions of IPv6

• It retain the most basic service provided by
  IPv4.
• It is connectionless delivery service.
• IPv6 has the ability to support the functions do
  not work will with IPv4 and the new emerging
  applications such as
• - real-time video conferencing.
• IPv6 leaps from 32 to 128-bit addressing.

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IPv6 Offerings

• Increased address space.
• Improved efficiency in routing and packet
  handling.
• Support for auto configuration and plug and play.
• Support for embedded IPSec.
• Enhanced support for Mobile IP and mobile
  computing devices.
• Elimination of the need for network address
  translation (NAT).
• Support for widely deployed routing protocols.
• Increased number of multicast addresses, and
  improved support for multicast.

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Changes From IPv4 to IPv6 (1/3)

• Longer address field
• Length of IPv4 is 32bits while it is 128 bits for
  IPv6.
• Provides more level of hierarchy.
• It can support up to 3.4 x 10 hosts.
• Simplified header format
• - Some of the headers like checksum and IHL do
  not appear in IPv6.

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Changes From IPv4 to IPv6 (2/3)

• Flexible Support for Options
• Options in IPv6 appear in optional extension
  headers.
• More efficient and flexible.
• Flow label capability
• To identify a certain packet flow

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Changes From IPv4 to IPv6 (3/3)

• Security confidentiality.
• Large Packets longer than 64K bytes
• called jumbo payloads.
• Fragmentation at source only check the minimum
  MTU along the path.
• No checksum field to reduce packet processing
  time in a router.

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IPv6 Value Proposition Engineered to Perform
IPv4
IPv6
Uses a 32-bit address Running out of internet
addresses System management is complex and
slow Incredibly successful 20 years old
Uses 128-bit addressing Enough address space to
give every human on the planet a unique IP
address Less Infrastructure Maintenance and
complexity required More efficient Mobile IP
seamless service availability Architecture of the
future Next Generation internet
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Header Format

• Consist of a required basic header and optional
  extension header.
• Packets transmitted in network byte order.
• The IPV6 address are four times as large as the
  IPV4 address.
• The header length is only twice as big.

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The IPv4 header
0 bits
31
4
8
24
16
Ver
IHL
Total Length
Service Type
Identifier
Flags
Fragment Offset
Header Checksum
Protocol
Time to Live
32 bit Source Address
32 bit Destination Address
Options and Padding
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The IPv6 header
0
31
4
12
24
16
Version
Class
Flow Label
Payload Length
Next Header
Hop Limit
128 bit Source Address
128 bit Destination Address
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Header Format ( 1/2)

• The header consist of the following field
• Version at the beginning stays un changed.
• The traffic class specifies the priority of the
  packet.
• Flow label defined as a sequence of packets
  sent to a particular destination.
• ex packet video system must delivered within
  a certain time constraint. Hosts dont support
  this field ( set to 0).

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Header Format ( 2/2)

• Payload length the length of the data.
• Next header identifies the type of the extension
  header, similar to options in IPv4 that follow
  the basic header.
• Hop limit the number of hops that packet can
  travel.
• Source and destination address.

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Network Addressing

• IPv6 address is 128 bits long.
• Sufficient for many years.
• More flexibility in terms of address allocation.
• It is divided into three categories
• Unicast addresses single network interface.
• Multicast addresses group of network
  interfaces, at different locations.
• packet will be sent to all network interfaces
  in the group.

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Network Addressing

• 3 Anycast addresses group of network
  interfaces packet will be sent only to one
  network interface in the group (nearest one).
• The broadcast address supported with a multicast
  address.
• IPv6 uses hexadecimal digits for every for bits
  and separates every 16 bits with a colon.

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Network Addressing

• Example of an IPv6
• 4BF5AA120216FEBCBAF5039ABE9A2176
• Often IPv6 can be shortened to more compact form
• 1 when the 16-bits field has some leading zeros
• 4BF5000000000000BAF5039A000A2176
• 4BF5000BAF539AA2176

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Network Addressing

• 2 when consecutive zero-valued fields appear
• 4BF5000BAF539AA2176
• can be shortened by double colon ()
• 4BF5BAF539AA2176
• - To recover the original address from one
  containing a double colon
• you take the non-zero value that appear to the
  left of the double colons and align them to the
  left and the number to the right align them to
  the right
• and set zeros between them.

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Network Addressing

• The dotted-decimal notation of IPv4 can be mixed
  with the new hexadecimal notation
• e.g. FFFF128.155.12.198
• Less than 30 percent of the address space has
  been assigned and the remaining saved for the
  future.
• Most types are assigned for unicast addresses.
• Address allocations are organized by types,
  which are in turn classified according to
  prefixes
• ( leading bits of the address).

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Network Addressing

• Address types based on prefixes

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Special IPv6 addresses

• 1 The address 00 is called unspecified
  address and is never used as a destination
  address. It is used as a source address when
  station wants to learn its address.
• 2 The address 1 is used for loopback.
• 3 IP mapped addresses used to indicateIPv4
  hosts and routers that dont support IPv6. It
  consists of 80 bits of zeros, followed by 16 bits
  of 1s, and then by 32 bits of IPv4 address.
  

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Special IPv6 addresses

• 4 IPv4 compatible addresses needed during
  the transition period where an IPv6 packet needs
  to be tunneled across an IPv4 network. They
  are used by IPv6 routers and hosts that directly
  connected to an IPv4 network. It consists of
  96 bits of zeros followed by 32 bits of IPv4
  address. Example
• IPv4 address 135.150.10.247
• can be converted to an IPv4 compatible IPv6
• 135.150.10.247

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Special IPv6 addresses

• Provider based unicast addresses are identified
  by the prefix 010.
• It appears that these addresses will be
  mainly used by the internet service providers to
  assign addresses to their subscribers.

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Extension Headers

• To support extra functionalities that are not
  provides by the basic header.
• IPv6 allows number of extension headers between
  the basic header and the payload.
• Extension headers act like options in IPv4.
• More efficiently and flexibility.
• There are six extension headers has been defined.
  

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Extension Headers

• The extension header are daisy chained by the
  next header field.
• The following figure illustrates of the next
  header field.
• A consequence of the daisy-chain formation is
  that the extension headers must be processed in
  the order which they appear in the packet.

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Extension Headers

• Daisy-chain extension headers.

TCP segment
Basic header Next header TCP
Routing header Next header fragment
TCP segment
Authentication Header Next header TCP
Fragment header Next header Authentication
Basic header Next header TCP
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Extension Headers

• header code
  header type
• 0
  hop-by-hop options header
  
  
• 43
  Routing header
  
• 44
  Fragment header
• 51
  Authentication header
• 52
  Encapsulating security payload header
• 60
  Destination options header

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Some Uses of Extension Headers

• LARGE BACKET
• - IPv6 allows a payload size of more than 64K by
  using an extension header.
• - used by super computers.
• FRAGMENTATION
• - fragmentation performed by the source only
  which make the routers process packets faster.

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Some Uses of Extension Headers

• SOURCE ROUTING
• Allows the source host to specify the sequence of
  routers to be visited by a packet to reach the
  destination.
• It is defined by routing extension header.

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Links

• IPv6 information
• http//ipv6.internet2.edu
• 90-minute talk about IPv6
• http//www.nanog.org/mtg-0306/doyle.html
• Recent IPv6 news
• http//www.hs247.com/

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• Thank You