IPv6AL-MAJRASHI, FAHAD 208192

AL-MUQAIREN, FAHAD 215721

TOPICSTOPICS Why IPv6Why IPv6 How IPv6 DevelopedHow IPv6 Developed Basic functions &Basic functions & Offerings of IPv6 of IPv6 Changes From IPv4 to IPv6Changes From IPv4 to IPv6 Header FormatHeader Format Network AddressingNetwork Addressing Special IPv6 addressesSpecial IPv6 addresses Extension Headers

Why IPv6Why 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.

How IPv6 DevelopedHow IPv6 DevelopedThe 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.

Basic functions of IPv6Basic 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.

IPv6 OfferingsIncreased 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.

Changes From IPv4 to IPv6 (1/3)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.

Changes From IPv4 to IPv6 (2/3)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”

Changes From IPv4 to IPv6 (3/3)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.

IPv6 Value Proposition Engineered to Perform

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

IPv4 IPv6

Header FormatHeader 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.

The IPv4 header

0 bits 31

Ver IHL Total Length

Identifier Flags Fragment Offset

32 bit Source Address

32 bit Destination Address

4 8 2416

Service Type

Options and Padding

Header ChecksumProtocol

RemovedChanged

Time to Live

The IPv6 header0 31

Version Class Flow Label

Payload Length Next Header Hop Limit

128 bit Source Address

128 bit Destination Address

4 12 2416

Header Format ( 1/2)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 don’t support this field ( set to 0).

Header Format ( 2/2)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.

Network AddressingNetwork 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 AddressingNetwork Addressing3 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 AddressingNetwork Addressing Example of an IPv6:

4BF5:AA12:0216:FEBC:BAF5:039A:BE9A:2176

Often IPv6 can be shortened to more compact form:

1 when the 16-bits field has some leading zeros

4BF5:0000:0000:0000:BAF5:039A:000A:2176

4BF5:0:0:0:BAF5:39A:A:2176

1

Network AddressingNetwork Addressing2 when consecutive zero-valued fields appear 4BF5:0:0:0:BAF5:39A:A:2176

can be shortened by [double colon (::)] 4BF5::BAF5:39A:A:2176

- 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 AddressingNetwork Addressing The dotted-decimal notation of IPv4 can be mixed

with the new hexadecimal notation:

e.g. ::FFFF:128.155.12.198 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).

Network AddressingNetwork Addressing Address types based on prefixes Address types based on prefixes

Special IPv6 addressesSpecial IPv6 addresses 1 The address 0::0 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 don’t support IPv6. It consists of 80 bits of zeros, followed by 16 bits of 1s, and then by 32 bits of IPv4 address.

1

2

3

Special IPv6 addressesSpecial IPv6 addresses4 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 addressesSpecial IPv6 addresses

5 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.

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.

Extension Headers

Daisy-chain extension headers.

TCP segment

Routing header Next header= fragment

TCP segment

Authentication Header

Next header =TCP

Fragment headerNext header=

Authentication

Basic header Next header=

TCP

Basic header Next header=

TCP

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

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.

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.

Links

IPv6 information:http://ipv6.internet2.edu

90-minute talk about IPv6:http://www.nanog.org/mtg-0306/doyle.html

Recent IPv6 newshttp://www.hs247.com/

Thank You