IPv6

INTRODUCTION

INTRODUCTION

Internet Protocol version 6 (IPv6) =Internetworking Protocol next generation (IPng)

enabling a wider range of Internet-connected devices

to replace IPv4 designed by IETF

(Internet Engineering Task Force ) recommended by IPng Area Directors of IETF at

Toronto IETF meeting on 25 July 1994.

INTRO (Cont…)

IPv6 was adopted because:– The use of address space is inefficient.– The Internet must accommodate real-time

audio and video transmission.– IPv4 provided no security mechanism.

IPv6 offers automatic addressing.

INTRO (Cont…)

3 types of address:– Unicast addressing– Multicast addressing– Anycast addressing

Additional fields included in IPv6 header– priority field, flow field.

IPv6 is a natural increment to IPv4.

IPv6

NEW CHANGES IN IPv6

New changes in IPv6

simplified header format- The IPv6 header format is simpler than IPv4

• longer address fields- The length of address field is extended the bits. The

address structure also provides more levers of hierarchy.

• Flexible support for opinion- The length of address field is extended the bits. The

address structure also provides more levers of hierarchy.

Flow label capability- The options in appear in optional extension headers that are encoded in more efficient and flexible fashion than

they were in IPv4.

• Security- IPv6 supports built-in authentication and confidentiality.

• Large packets- IPv6 supports built-in authentication and confidentiality.

• Fragmentation at source only- IPv6 supports payloads that are longer than 64 kilo bytes, call jumbo payloads.

  

  

No checksum field - The checksum field has been removed to reduce

packet processing time in a router. Packets carried by the physical network such as Ethernet, ATM are typically already checked.

IPv6

TRANSITION FROM IPv4 TO IPv6

Transition from IPv4 to IPv6

Dual-Stack- Strategies, which allow IPv4 and IPv6 to communicate

in the same devices and networks. Tunneling - Techniques, to avoid order dependencies when upgrading

hosts, routers or regions. Translation- Techniques, to allow IPv6 only devices to communicate

with IPv4-only devices.

IPv6

IPv6 HEADER

Introduction

more simpler efficient reduce process cost

Base Header

Version- Specifies the version number- 4 bits

Priority- Priority of the packet with respect to traffic congestion- Congestion-controlled (0-7)- Noncongestion-controlled (8-15)- 4 bits

Traffic Class- Class of service desired for the datagram- 8 bits

Flow Label- Provide special handling for a particular flow of data- 20 bits

Payload Length- Length of the data field (excluding the base header) in the datagram- 16 bits

Next Header- Defining the header that follows the base header in datagram- 8 bits

Hop Limit- Specifies the maximum number of hops a packet may travel before reaching the destination- 8 bits

Source Address- Identifies the original source of the datagram- 128 bits

Destination Address- Identifies the final destination of the datagram- 128 bits

IPv6

IPv6 EXTENSION HEADER

IPv6 EXTENSION HEADER

Extension headers- support extra functionalities.- placed between the basic header and the

payload.- each of them contains its own Next Header

Field. (daisy chained )- are placed in order.

DAISY-CHAIN EXTENSION HEADER

Basic headerNext header= TCP

TCP segment

Basic headerNext header= routing

Routing headerNext header= fragment

FragmentheaderNext header=authentication

Authentication HeaderNext header=TCP

TCP segment

TYPES OF EXTENSION HEADERS

Hop-by-hop options header (header code:0) Routing header (header code:43) Fragment header (header code:44) Authentication header (header code: 51) Encapsulating security payload header

(header code:52) Destination options header (header code:60)

HOP-BY-HOP OPTIONS HEADER

Implement an efficient method to alert routers of a packet that requires special processing.

ROUTING HEADER

used by the source to control the routing of packet.

explicitly dictate the route from the source to the destination.

contains a list of one or more intermediate nodes to be visited on the way to a packet’s destination.

FRAGMENT HEADER

allows fragmented packets to traverse the IPv6 network.

Performing by source nodes, not by routers along a packet’s delivery path.

- simplifies the routers’ work and makes routing go faster.

will discards the packet that is too big

send an ICMP packet back to the source

use a path MTU discovery technique to find the smallest MTU supported by any network on the path

Source then fragments by using this knowledge

Otherwise, the source must limit all packets to 1280 octets(the minimum MTU that must be supported by each network).

AUTHENTICATION HEADER

uses an algorithm to ensure that the IPv6 packet has not been altered along its path.

Ensures that the IPv6 packet has arrived from the sourced listed in the IP Header.

Provides a mechanism by which the receiver of a packet can be sure of who sent it.

Use cryptographic techniques to encrypt the contents of a packet so that only the intendend recipient can read it.

ENCAPSULATING SECURITY PAYLOAD HEADER

For packets that must be sent secretly. Provide confidentiality and privacy.

DESTINATION OPTION HEADER

optional information to be examined by the destination node.

Not use during routing.

IPv6

IPv6 ADDRESSING

Brief Introduction

Provides 128 bit address space allows for 2128 ≈ 1040 different addresses can address 3.4 x 1038 nodes if address

assignment efficiency is 100%. 3 basic types:

– Unicast– Anycast– Multicast

Unicast Address

Corresponds to a single computer The format is:

010 Registry Provider Subscriber Subnet Interface

Unicast Address

3 types of Unicast Address– Global unicast

– Site-local unicast it is designed to used for addressing inside of a site

without the need for a glocal prefix

n bits m bits 128 – n – m – bits

Global Routing Prefix Subnet Id Interface ID

10 bits 54 bits 64 bits

1111111011 Subnet ID Interface ID

Unicast Address

– Link - local unicast it is used on a single link. The addresses are designed

on a single link for purposes such as automatic address configuration, neighbor discovery, or when no routers are present

10 bits 54 bits 64 bits

1111111010 0 Interface ID

Anycast Address

assigned to more than one interface, with the property that a packet sent to an anycast address is routed to the “nearest” interface having that address, according to the routing protocols’ measurement.

allocated from the unicast address space by using any of the defined unicast address formats

Anycast Address

A longest prefix P identifies the topological region in which all interfaces belonging to that anycast address reside.

Within the region identified by P, the anycast address must be maintained as a separate entry in the routing system

Outside the region identified by P, the anycast address may be aggregated into the routing entry for prefix P.

Multicast Address

Pre-defined Multicast addresses– defined for explicit scope values

The following slide shows the reserved Multicast Addresses. This reserved addresses shall never be assigned to any multicast group.

Multicast Address

FF00:0:0:0:0:0:0:0FF01:0:0:0:0:0:0:0FF02:0:0:0:0:0:0:0FF03:0:0:0:0:0:0:0FF04:0:0:0:0:0:0:0FF05:0:0:0:0:0:0:0FF06:0:0:0:0:0:0:0FF07:0:0:0:0:0:0:0FF08:0:0:0:0:0:0:0FF09:0:0:0:0:0:0:0FF0A:0:0:0:0:0:0:0FF0B:0:0:0:0:0:0:0FF0C:0:0:0:0:0:0:0FF0D:0:0:0:0:0:0:0FF0E:0:0:0:0:0:0:0FF0F:0:0:0:0:0:0:0

Multicast Address

All nodes addresses – identify the group of all IPv6 nodes within 1 scope

1 (interface-local) or 2 (link-local).

FF01:0:0:0:0:0:0:1

FF02:0:0:0:0:0:0:1

Multicast Address

All routers addresses – identify the group of all IPv6 routers within scope

1 (interface-local), 2 (link-local), or 5 (site-local).

FF01:0:0:0:0:0:0:2

FF02:0:0:0:0:0:0:2

FF05:0:0:0:0:0:0:2

Multicast Address

Solicited-Nodes Address: – Computed as a function of a node’s unicast and anycast

addresses – formed by taking the low-order 24 bits of an address

(unicast or anycast) and appending those bits to the prefix FF02:0:0:0:0:1:FF00::/104 resulting in a multicast address in the range FF02:0:0:0:0:1:FF00:0000 to FF02:0:0:0:0:1:FFFF:FFFF.

– Format:

FF02:0:0:0:0:1:FFXX:XXXX

Address Notation

Normally, a 128-bit number written in dotted decimal notation:

105.220.136.100.255.255.255.255.0.0.18.128.140.10.255.255

Address Notation

Colon Hexadecimal Notation– Reduced the number of characters used to write

an address– each group of 16 bits is written in hexadecimal

with a colon separating groups

105.220.136.100.255.255.255.255.0.0.18.128.140.10.255.25

69DC:8864: FFFF: FFFF: 0:1280:8C0A: FFFF

Address Notation

Zero Compression– replaces sequences of zeros with double

semicolons – can only once per address – Example:

FDEC: 0:0:0:0: BBFF: 0: FFFF can be written as

FDEC:: BBFF:0:FFFF

Address Notation

If the 0 string begins the address, the notation starts with the double colon.

Example:

0000:0000:0000:0000:0AFF:1BDF:000F:0077

can be written as

:: 0AFF:1BDF:F:0077

Address Notation

CIDR Notation. – The example below show how can we define a

prefix of 60 bits using CIDR.

FDEC: 0:0:0:0: BBFF: 0: FFFF/60

IPv6

CONCLUSION

CONCLUSION

IPv6 come at the right time- Internet growing so rapidly.

Solution of the new disruptive applications. IPv4 IPv6 -larger task for some company or

industry, but the rate of IPv4 address consumption is rapidly increasing.

IPv6 has a bright future.– allow us to build a more robust and reliable

Internet.– simplify the implementation and deployment

of emergency response networks.– making our lives safer & more secure.