深圳职业技术学院计算机系网络专业

2006, Shenzhen Polytechnic. All rights reserved. 1IP寻址IP Address深圳职业技术学院计算机系网络专业 2006, Shenzhen Polytechnic. All rights reserved. 2教学目标（ Objectives ）1. IP地址概念（ Concept of IP Address ）2. IP地址分类 （ Class of IP Address）3. 保留和私有地址（ Reserved and Private IP Address）4. 网络掩码和子网划分（ Network Mask and Subnetting ） 5. 可变长度子网掩码（ VLSM ）6. 汇总和 CIDR（ Summarization and CIDR） 2006, Shenzhen Polytechnic. All rights reserved. 3IP地址（ IP Address）IP地址唯一的标识网络上计算机， IP地址就是由 0和 1组成的 32位字符串。Each computer in a TCP/IP network must be given a unique identifier, or IP address. An IP address is a 32-bit sequence of 1s and 0s. 2006, Shenzhen Polytechnic. All rights reserved. 4IP地址表示（ Representation of IP Address）为了容易使用，采用点分十进制格式来表示 IP地址To make the IP address easier to use, the address is usually written as four decimal numbers separated by periods192 . 168 . 123 . 2 2006, Shenzhen Polytechnic. All rights reserved. 5IP地址结构（ Structure of IP Address） 2006, Shenzhen Polytechnic. All rights reserved. 6IP地址的类别（ Class of IP Address） 2006, Shenzhen Polytechnic. All rights reserved. 7A类地址（ Class A）地址范围： 1126(127保留 )Address Range:1-126(127 Reserved) 2006, Shenzhen Polytechnic. All rights reserved. 8B类地址（ Class B）地址范围： 128191Address Range:128-191 2006, Shenzhen Polytechnic. All rights reserved. 9C类地址（ Class C）地址范围： 192223Address Range:192-223 2006, Shenzhen Polytechnic. All rights reserved. 10地址分配（ Address Allocating）分配 A类 IP： 国际网络信息中心 NIC分配 B类 IP： InterNIC、 APNIC、 ENIC分配 C类 IP： 国家或地区的 NIC 2006, Shenzhen Polytechnic. All rights reserved. 11保留地址（ Reserved Address）保留地址 指某些地址不能分配网络上的设备使用Certain host addresses are reserved and cannot be assigned todevices on a network. 1.主机部分全 0表示网络地址An IP address that has binary 0s in all host bit positions is reservedfor the network address. 2.主机部分全 1表示广播地址An IP address that has binary 1s in all host bit positions is reservedfor the broadcast address. 3.全 0的 IP地址，即 0.0.0.0。设置缺省路由时使用。An IP address that has binary 0s in all bit positions is reserved for defaultroute4.全 1地址 255.255.255.255，表示泛洪广播An IP address that has binary 0s in all bit positions is reserved for flood broadcast 2006, Shenzhen Polytechnic. All rights reserved. 12私有地址 （ Private IP Address）1. 私有地址可以节省 IP地址Private IP addresses are another solution to the problem of the impending exhaustion of public IP addresses. 2. 私有地址不能在 Internet上被路由Private IP addresses are not routed on the Internet backbone. 2006, Shenzhen Polytechnic. All rights reserved. 13Exercise: IP Address ClassesAddress Class Network Host10.2.1.1128.63.2.100201.222.5.64192.6.141.2130.113.64.16256.241.201.10 2006, Shenzhen Polytechnic. All rights reserved. 14IP Address Classes Exercise AnswersAddress Class Network Host10.2.1.1128.63.2.100201.222.5.64192.6.141.2130.113.64.16256.241.201.10ABCCBNonexistent10.0.0.0128.63.0.0201.222.5.0192.6.141.0130.113.0.00.2.1.10.0.2.1000.0.0.640.0.0.20.0.64.16 2006, Shenzhen Polytechnic. All rights reserved. 15网络掩码（ Network Mask）A类： 255.0.0.0B类： 255.255.0.0C类： 255.255.255.0 2006, Shenzhen Polytechnic. All rights reserved. 16网络掩码的作用（ Function of Network Mask）10101100 00010000 00000010 10100000 172.16.2.160 11111111 11111111 00000000 00000000 255.255.0.010101100 00010000 00000000 00000000 172.16.0.0Network ID 2006, Shenzhen Polytechnic. All rights reserved. 17子网划分（ Subnetting）为了克服有限的 IP地址，所有类别网络可以被划分为更小的子网。To efficiently manage a limited supply of IP addresses, all classes can be subdivided into smaller subnetworks. 2006, Shenzhen Polytechnic. All rights reserved. 18划分子网原因（ Reasons for Subnetting）1. 提供灵活的编址Provides addressing flexibility Provides2. 提供广播抑制Broadcast Containment 3. 为 LAN提供低水平的安全Low-level security on the LAN. 2006, Shenzhen Polytechnic. All rights reserved. 19介绍子网划分（ Introduction to Subnetting）划分 子网要从主机位借位Host bits must are reassigned (or “borrowed”) as network bits. 3 bits borrowed allows 23-2 or 6 subnets5 bits borrowed allows 25-2 or 30 subnets12 bits borrowed allows 212-2 or 4094 subnets 2006, Shenzhen Polytechnic. All rights reserved. 20介绍子网划分（ Introduction toSubnetting）网络号码 主机号码网络号码 主机号码网络号码 主机号码子网号码不考虑子网网络掩码子网掩码扩充的网络号码考虑子网化 2006, Shenzhen Polytechnic. All rights reserved. 21Comparison between decimal and binary 2006, Shenzhen Polytechnic. All rights reserved. 22实例 1： C类地址 2位子网化（ E.g1 Two Bits Subnetting for Class C ）子网号（ Subnet） 地址范围（ range）00 000000 0 0000000100111111 162 其中 :0为网络地址， 63为广播地址01 000000 64 0100000101111111 65127其中 :64为网络地址， 127为广播地址10 000000 128 1000000110111111 129191其中 :128为网络地址， 191为广播地址11 000000 192 1100000111111111 193255其中 :192为网络地址， 255为广播地址 2006, Shenzhen Polytechnic. All rights reserved. 23实例 2： C类地址 4位子网化（ E.g2 4 Bits Subnetting for Class C ）组合 子网号 地址范围0000 0000 0 0000000100001111 115 其中： 15为广播地址0001 0000 16 0001000100011111 1731 其中： 31为广播地址0010 0000 32 0010000100101111 3347 其中： 47为广播地址0011 0000 48 0011000100111111 4963 其中： 63为广播地址0100 0000 64 0100000101001111 6579 其中： 79为广播地址0101 0000 80 0101000101011111 8195 其中： 95为广播地址0110 0000 96 0110000101101111 97111 其中： 111为广播地址0111 0000 112 0111000101111111 113127 其中： 127为广播地址1000 0000 128 1000000110001111 129143 其中： 143为广播地址1001 0000 144 1001000110011111 145159 其中： 159为广播地址1010 0000 160 1010000110101111 161175 其中： 175为广播地址1011 0000 176 1011000110111111 177191 其中： 191为广播地址1100 0000 192 1100000111001111 193207 其中： 207为广播地址1101 0000 208 1101000111011111 209223 其中： 223为广播地址1110 0000 224 1110000111101111 225239 其中： 239为广播地址1111 0000 240 1111000111111111 241255 其中： 255为广播地址 2006, Shenzhen Polytechnic. All rights reserved. 24可用的子网和主机数（ Number of Usable Subnets and Hosts ）usable subnets(2 power of borrowed bits)2usable hosts=(2 power of remaining host bits)2 2006, Shenzhen Polytechnic. All rights reserved. 25C类地址划分子网情况汇总（ Summary of Class C Subnetting） 2006, Shenzhen Polytechnic. All rights reserved. 26Written Exercise: Subnet MasksAddress Subnet Mask Class Subnet172.16.2.1010.6.24.20172.30.36.12255.255.255.0255.255.0.0255.255.255.0202.30.36.82 255.255.255.192 2006, Shenzhen Polytechnic. All rights reserved. 27Subnet Mask Exercise AnswersAddress Subnet Mask Class Subnet172.16.2.1010.6.24.2010.30.36.12255.255.255.0255.255.240.0255.255.255.0BAA172.16.2.010.6.16.010.30.36.0 2006, Shenzhen Polytechnic. All rights rese