9-理解IP地址和子网.pdfVIP免费

Ender204426777乾颐堂CCNAv3.0课程Part1(ICND1)v3.0EstablishingInternetConnectivityUnderstandingIPAddressingandSubnets理解IP地址和子网乾颐堂CCNAv3.0Ender204426777SubnetsTherecanbeproblemswithinasinglebroadcastdomain:•ThedomainreliesonMACaddressesforpacketdelivery.•Largeramountsofbroadcasttrafficconsumeresources.大量广播消耗资源和带宽•Alldevicessharethesamebroadcastdomain.所有设备共享一个广播域EnderICND1—2-17乾颐堂CCNAv3.0Ender204426777Subnets(Cont.)Solution:SubnetworksSmallernetworksareeasiertomanage.小的网络易于管理Overalltrafficisreduced.整体的流量将会减少Youcanapplynetworksecuritypoliciesmoreeasily.能够更加容易运用网络安全策略EnderICND1—2-18乾颐堂CCNAv3.0Ender204426777SubnetMasksAsubnetmask:•Definesthenumberofbitsthatrepresentthenetworkandsubnetpartoftheaddress-表示网络•UsedbyendsystemstoidentifythedestinationIPaddressaseitherlocalorremote-以此判定终端系统在本地或者远端的另外一个网络•UsedbyLayer3devicestodeterminenetworkpathEnderICND1—2-19乾颐堂CCNAv3.0Ender204426777OctetValuesofaSubnetMaskSubnetmasks,likeIPaddresses,arerepresentedinthedotteddecimalformat,suchas255.255.255.0.子网掩码，表现为点分十进制Thebinary1reflectsthenetworkandsubnetworkpartoftheIPaddress.1反映了网络和子网的IP地址（换句话说，没有反映主机位）EnderICND1—2-20乾颐堂CCNAv3.0Ender204426777OctetValuesofaSubnetMask(Cont.)128643216842100000000=010000000=12811000000=19211100000=22411110000=24011111000=24811111100=25211111110=25411111111=255EnderICND1—2-211的数目代表子网；0的数目代表主机数目乾颐堂CCNAv3.0Ender204426777OctetValuesofaSubnetMask(Cont.)DefaultSubnetMasks,ClassAExampleClassAaddress(decimal):10.0.0.0ExampleClassAaddress(binary):00001010.00000000.00000000.00000000DefaultClassAmask(binary):11111111.00000000.00000000.00000000DefaultClassAmask(decimal):255.0.0.0Defaultclassfulprefixlength:/8EnderICND1—2-22乾颐堂CCNAv3.0Ender204426777OctetValuesofaSubnetMask(Cont.)DefaultSubnetMasks,ClassB，B类地址的默认子网掩码/16ExampleClassBaddress(decimal):172.16.0.0ExampleClassBaddress(b...