Chapter 27 IPv 6 Protocol TCPIP Protocol Suite

Chapter 27 IPv 6 Protocol TCP/IP Protocol Suite Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. 1

OBJECTIVES: q To give the format of an IPv 6 datagram composed of a base header and a payload. q To discuss different fields used in an IPv 6 datagram based header and compare them with the fields in IPv 4 datagram. q To show the options in IPv 4 header are implemented using the extension header in IPv 6. q To show security is implemented in IPv 6. q To discuss three strategies used to handle the transition from IPv 4 to IPv 6: dual stack, tunneling, and header translation. TCP/IP Protocol Suite 2

Chapter Outline TCP/IP Protocol Suite 27. 1 Introduction 27. 2 Packet Format 27. 3 Transition to IPv 6 3

27 -1 INTRODUCTION In this introductory section, we discuss two topics: rationale for a new protocol and the reasons for delayed adoption. TCP/IP Protocol Suite 4

Topics Discussed in the Section ü Rationale for Change ü Reason for Delay in Adoption TCP/IP Protocol Suite 5

27 -2 PACKET FORMAT The IPv 6 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. TCP/IP Protocol Suite 6

Topics Discussed in the Section ü Base Header ü Flow Label ü Comparison between IPv 4 and IPv 6 Headers ü Extension Headers ü Comparison between IPv 4 and IPv 6 Options TCP/IP Protocol Suite 7

Figure 27. 1 TCP/IP Protocol Suite IPv 6 datagram 8

Figure 27. 2 TCP/IP Protocol Suite Format of the base header 9

TCP/IP Protocol Suite 10

Figure 27. 3 TCP/IP Protocol Suite Extension header format 11

Figure 27. 4 TCP/IP Protocol Suite Extension header types 12

Figure 27. 5 TCP/IP Protocol Suite Hop-by-hop option header format 13

Figure 27. 6 TCP/IP Protocol Suite The format of the option in a hop-by-hop option header 14

Figure 27. 7 Pad 1 TCP/IP Protocol Suite 15

Figure 27. 8 TCP/IP Protocol Suite Pad. N 16

Figure 27. 9 TCP/IP Protocol Suite Jumbo payload 17

Figure 27. 10 TCP/IP Protocol Suite Source routing 18

Figure 27. 11 TCP/IP Protocol Suite Source routing example 19

Figure 27. 12 TCP/IP Protocol Suite Fragmentation 20

Figure 27. 13 TCP/IP Protocol Suite Authentication 21

Figure 27. 14 TCP/IP Protocol Suite Calculation of authentication data 22

Figure 27. 15 TCP/IP Protocol Suite Encrypted security payload 23

27 -3 TRANSITION FROM IPv 4 TO IPv 6 Because of the huge number of systems on the Internet, the transition from IPv 4 to IPv 6 cannot happen suddenly. It will take a considerable amount of time before every system in the Internet can move from IPv 4 to IPv 6. The transition must be smooth to prevent any problems between IPv 4 and IPv 6 systems. Three strategies have been devised by the IETF to help the transition (see Figure 27. 16). TCP/IP Protocol Suite 24

Topics Discussed in the Section ü Dual Stack ü Tunneling ü Header Translation TCP/IP Protocol Suite 25

Figure 27. 16 TCP/IP Protocol Suite Three transition strategies 26

Figure 27. 17 TCP/IP Protocol Suite Dual stack 27

Figure 27. 18 TCP/IP Protocol Suite Tunneling strategy 28

Figure 27. 19 TCP/IP Protocol Suite Header translation strategy 29