Internet Protocol Version 6 in computer Networks

TCP/IP Protocol Suite 1
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Chapter 27
IPv6
Protocol

OBJECTIVES:
OBJECTIVES:
 To give the format of an IPv6 datagram composed of a base
header and a payload.
 To discuss different fields used in an IPv6 datagram based
header and compare them with the fields in IPv4 datagram.
 To show how the options in IPv4 header are implemented using
the extension header in IPv6.
 To show how security is implemented in IPv6.
 To discuss three strategies used to handle the transition from
IPv4 to IPv6: dual stack, tunneling, and header translation.

Chapter
Chapter
Outline
Outline
27.1 Introduction
27.1 Introduction
27.2 Packet Format
27.2 Packet Format
27.3 Transition to IPv6
27.3 Transition to IPv6

27-1 INTRODUCTION
In this introductory section, we discuss two topics:
rationale for a new protocol and the reasons for
delayed adoption.

Topics Discussed in the Section
 Rationale for Change
 Reason for Delay in Adoption

27-2 PACKET FORMAT
The IPv6 packet is shown in Figure 27.1. Each
packet is composed of a mandatory base header
followed by the payload. The payload consists of two
parts: optional extension headers and data from an
upper layer. The base header occupies 40 bytes,
whereas the extension headers and data from the
upper layer contain up to 65,535 bytes of
information.

 Base Header
 Flow Label
 Comparison between IPv4 and IPv6 Headers
 Extension Headers
 Comparison between IPv4 and IPv6 Options

Figure 27.1 IPv6 datagram

Figure 27.2 Format of the base header

Figure 27.3 Extension header format

Figure 27.4 Extension header types

Figure 27.5 Hop-by-hop option header format

Figure 27.6 The format of the option in a hop-by-hop option header
Action C Type
1 bit
2 bits 5 bits
Action: if the option not recognized
00 Skip this option
01 Discard datagram, no more action
10 Discard datagram and send ICMP message
11 Discard datagram send ICMP message if not multicast
C: Change in option value
0 Does not change in transit
1 May be changed in transit
Type
00000 Pad1
00001 PadN
00010 Jumbo payload

Figure 27.7 Pad1

Figure 27.8 PadN

Figure 27.9 Jumbo payload

Figure 27.10 Source routing

Figure 27.11 Source routing example
Source: A
Destination: R1
Left: 3
R2
R3
B
Source: A
Destination: R2
Left: 2
R1
R3
B
Source: A
Destination: R3
Left: 1
R1
R2
B
Source: A
Destination: B
Left: 0
R1
R2
R3

Figure 27.12 Fragmentation

Figure 27.13 Authentication

Figure 27.14 Calculation of authentication data

Figure 27.15 Encrypted security payload

27-3 TRANSITION FROM IPv4 TO IPv6
Because of the huge number of systems on the
Internet, the transition from IPv4 to IPv6 cannot
happen suddenly. It will take a considerable amount
of time before every system in the Internet can move
from IPv4 to IPv6. The transition must be smooth to
prevent any problems between IPv4 and IPv6
systems. Three strategies have been devised by the
IETF to help the transition (see Figure 27.16).

 Dual Stack
 Tunneling
 Header Translation

Figure 27.16 Three transition strategies

Figure 27.17 Dual stack

Figure 27.18 Tunneling strategy
Payload
IPv6 header
IPv4 header

Figure 27.19 Header translation strategy
Payload
IPv6 header
Payload
IPv4 header

Internet Protocol Version 6 in computer Networks

More Related Content

Similar to Internet Protocol Version 6 in computer Networks (20)

Recently uploaded (20)

Internet Protocol Version 6 in computer Networks