台北科技大学：《计算机网络》（英文版） NP04 4 CONTENTS

IP Addresses Classful Addressing Chuan-Ming liu CSIE NTUT Spring 04, TAIWAN CS旧E.NTUT. TAWAN

CSIE, NTUT, TAIWAN 1 IP Addresses: Classful Addressing Chuan-Ming Liu CSIE, NTUT Spring ’04, TAIWAN

CONTENTS INTRODUCTION CLASSFULADDRESSING OTHER ISSUES A SAMIPLE INTERNET CSIE NTUT TANAN

CSIE, NTUT, TAIWAN 2 CONTENTS • INTRODUCTION • CLASSFUL ADDRESSING • OTHER ISSUES • A SAMPLE INTERNET

INTRODUCTION CSIE NTUT TANAN

CSIE, NTUT, TAIWAN 3 INTRODUCTION 4.1

Note an p address is a 32b address CSIE NTUT TANAN

CSIE, NTUT, TAIWAN 4 An IP address is a 32-bit address

Note wre CSIE NTUT TANAN

CSIE, NTUT, TAIWAN 5 The IP addresses are unique

Address Space Total number of addresses used by the protocol If a protocol uses m bit to define an address the address space is 2N IPv4 uses 32 bit addresses CSIE NTUT TANAN

CSIE, NTUT, TAIWAN 6 addr15 addr1 addr2 addr41 addr31 addr226 ………….. ………….. ………….. ………….. ………….. ………….. ………….. Address Space • Total number of addresses used by the protocol • If a protocol uses N bit to define an address, the address space is 2 N. • IPv4 uses 32 bit addresses

Note The address space of Ipy4 is 22 or 4,294967296 CSIE NTUT TANAN

CSIE, NTUT, TAIWAN 7 The address space of IPv4 is 2 32 or 4,294,967,296

Address notations Three common notations to show an ip Binary notation Dotted-Decimal notation Hexadecimal Notation CSIE NTUT TANAN

CSIE, NTUT, TAIWAN 8 Address Notations Three common notations to show an IP – Binary Notation – Dotted-Decimal Notation – Hexadecimal Notation

Binary notation 01110101100101010001110111101010 CSIE NTUT TANAN

CSIE, NTUT, TAIWAN 9 01110101 10010101 00011101 11101010 Binary Notation

Dotted-decimal notation 10000000 00001011 00000011 00011111 128.11.3.31 CSIE NTUT TANAN Figure 4-1

CSIE, NTUT, TAIWAN 10 Figure 4-1 Dotted-decimal notation