互聯(lián)網(wǎng)協(xié)議英文

InternetProtocol互聯(lián)網(wǎng)協(xié)議英文第1頁(yè)Overview1.0 TCP/IPandtheDoDModel2.0 IPAddressing3.0 Subnetting互聯(lián)網(wǎng)協(xié)議英文第2頁(yè)1.0 TCP/IPandtheDoDModel1.1 ComparisonofDodandOSIModel1.2 TheTCP/IPprotocolsuite1.3 TheProcess/ApplicationlayerProtocols1.4 TheHost-to-HostLayerProtocols1.5 TheInternetLayerProtocols互聯(lián)網(wǎng)協(xié)議英文第3頁(yè)1.1 ComparisonofDoDandOSIModel(1)TheTCP/IPsuitewascreatedbytheDoDTheDoDmodelisacondensedversionoftheOSImodelApplicationPresentationSessionTransportNetworkDataLinkPhysicalProcess/ApplicationHost-to-HostInternetNetworkAccessDoDModelOSIModelNode-to-nodeapplicationcommunicationControlsuser-interfacespecificationsSettinguptheleveloftransmissionserviceforapplicationsTakescareIPaddressanddesignateprotocolsforlogicaltransmissionofpacketsovertheentirenetworkOverseeshardwareaddressinganddefinesprotocolsforthephysicaltransmissionofdata互聯(lián)網(wǎng)協(xié)議英文第4頁(yè)1.1 ComparisonofDoDandOSIModel(2)TCP/IPModelOSIModel互聯(lián)網(wǎng)協(xié)議英文第5頁(yè)1.2 TheTCP/IPProtocolSuiteProcess/ApplicationTelnetTCPUDPIPICMPARPLANTechnologies:Ethernet,FastEthernet,TokenRing,FDDIWANTechnologies:SerialLines,FrameRelay,ATMRARPHost-to-HostInternetNetworkAccessFTPTFTPSMTPLPDSNMPNFSXWindowBootP/DHCPDNSIGMP互聯(lián)網(wǎng)協(xié)議英文第6頁(yè)1.3 TheProcess/ApplicationLayerProtocolsTelnet–TelephoneNetworkFTP–FileTransferProtocolTFTP–TrivialFileTransferProtocolNFS–NetworkFileSystemSMTP–SimpleMailTransferProtocolLPD–LinePrinterDaemonXWindow–writingaGUI-basedclient/serverapplicationsDNS–DomainNameService(DNS)BootP–BootstrapProtocolDHCP–DynamicHostConfigurationProtocol互聯(lián)網(wǎng)協(xié)議英文第7頁(yè)1.4 TheHost-to-HostLayerProtocolsToshieldtheupper-layerapplicationsfromthecomplexitiesofthenetworkTCP(TransmissionControlProtocol)BreakdowndatafromupperlayersintoSegmentNumbersandsequenceseachsegmentConnection-oriented–virtualcircuitrequiredUserDatagramProtocol(UDP)BreakdowndatabutnotsequencethesegmentThinprotocolwhichdoesn’ttakeupmuchbandwidthonanetworkConnectionless–novirtualcircuitrequired,thusunreliableForsendinglittlemessageandreliabilityaccomplishedattheupperlayers互聯(lián)網(wǎng)協(xié)議英文第8頁(yè)1.4a TransmissionControlProtocol(TCP)Connection-orientedSessionisestablishedbeforeexchangingdataVirtualcircuitrequiredReliableDeliverySequencenumbersAcknowledgments(ACKs)Doesn’ttrustthelowerlayersandrunsitsownCRCUsesPortNumbersasEndpointstoCommunicate互聯(lián)網(wǎng)協(xié)議英文第9頁(yè)1.4b TCPThree-WayHandshakeApplicationTransportInternetNetworkDataApplicationTransportInternetNetworkData,ACK(+startbyte)ACK互聯(lián)網(wǎng)協(xié)議英文第10頁(yè)1.4c TCPSegmentFormat互聯(lián)網(wǎng)協(xié)議英文第11頁(yè)1.4d UserDatagramProtocol(UDP)ConnectionlessNosessionisestablishedDoesNotGuaranteeDeliveryNosequencenumbersNoacknowledgmentsLowoverheadReliabilityIstheResponsibilityoftheApplicationDoesn’ttrustthelowerlayersandrunsitsownCRCUsesPortNumbersasEndpointstoCommunicate互聯(lián)網(wǎng)協(xié)議英文第12頁(yè)1.4e UDPSegmentFormatLowoverheadNosequencenumberNoAcknowledgementnumberNowindowssize互聯(lián)網(wǎng)協(xié)議英文第13頁(yè)TransportApplicationInternetNetwork1.4f PortsNumbers(1)TCPandUDPmustuseportnumberstocommunicatewiththeupperlayers.Portnumberskeeptrackofdifferentconversationscrossingthenetworksimultaneously.TFTPServerWebServer0...655350...65535TCPPorts20,21UDPPort69TCPPort80WindowsSocketsInterfaceTCPProtocolNo.6UDPProtocolNo.17IPFTPServerSMTPTCPPort25DNSUDPPort53POP3UDPPort110SNMPUDPPort161互聯(lián)網(wǎng)協(xié)議英文第14頁(yè)1.4g PortNumbers(2)No.below1024Well-knownportno.definedinRFC1700UsuallyindestinationporttotellthereceivinghostthepurposeoftheintendedconnectionNo.1024andaboveusedbyupperlayers(randomlychosen)tosetupsessionswithotherhostsUsedbyTCPtouseassourceanddestinationaddressesintheTCPsegmentUsuallyinSourceporttodifferentiatebetweensessionswithdifferentsourcehosts互聯(lián)網(wǎng)協(xié)議英文第15頁(yè)1.5 TheInternetLayerProtocolsForroutingandprovidingasinglenetworkinterfacetotheupperlayerlayers.AllnetworkpathsthroughthemodelgothroughIP.ProtocolsworksattheInternetLayer:InternetProtocol(IP)–essentiallyistheInternetLayer,andotherprotocolsfoundheremerelyexisttosupportit.InternetControlMessageProtocol(ICMP)AddressResolutionProtocol(ARP)ReverseAddressResolutionProtocol(RARP)互聯(lián)網(wǎng)協(xié)議英文第16頁(yè)1.5a InternetProtocol(IP)AddressesandRoutesPacketsaccordingtotheRoutingTableFragmentsandReassemblesDatagrams/PacketsConnectionlessNosessionisestablishedNonguaranteed“BestEffort”DeliveryReliabilityIstheResponsibilityofHigher-LayerProtocolsandApplications互聯(lián)網(wǎng)協(xié)議英文第17頁(yè)1.5b IPheader*Protocolnumber:01–ICMP,06–TCP,17–UDP,etc.互聯(lián)網(wǎng)協(xié)議英文第18頁(yè)1.5c InternetControlMessageProtocol(ICMP)ManagementProtocolandmessagingserviceproviderforIP.Inroutersolicitation,ICMPisusedtosendthefollowingeventsandmessages(intheDataarea):DestinationUnreachableBufferFullHopsPingTraceroute互聯(lián)網(wǎng)協(xié)議英文第19頁(yè)1.5d AddressResolutionProtocol(ARP)SuccessfulMappingofanIPAddresstoaHardwareAddressARPUsesaLocalBroadcasttoObtainaHardwareAddressAddressMappingsAreStoredinaCacheforFutureReference互聯(lián)網(wǎng)協(xié)議英文第20頁(yè)1.5e ResolvingalocalIPAddressARPCache808004...ARPCache808004...4IPAddress=8HardwareAddress=08004...IPAddress=9HardwareAddress=08007...3HardwareAddress=08007...21ping9ARPBroadcast互聯(lián)網(wǎng)協(xié)議英文第21頁(yè)1.5f ResolvingaRemoteIPAddressARouterBIPAddress=4HardwareAddress=08004...IPAddress=9HardwareAddress=08009...ARPCache08009...08006...ARPCache08004...4108005...08006...25ping9ARPCache3Network1Network2321ARPBroadcastforRouterInterfaceAARPBroadcastforRouterInterfaceBAB45互聯(lián)網(wǎng)協(xié)議英文第22頁(yè)1.5g ReverseAddressResolutionProtocol(RARP)TodiscovertheidentityoftheIPaddressfordisklessmachineswithaRARPbroadcastFordisklessworkstationaskingforitsIPaddress互聯(lián)網(wǎng)協(xié)議英文第23頁(yè)2.0 IPAddressing2.1 IPTerminology2.2 TheHierarchicalIPAddressingScheme2.3 NetworkAddressing2.4 AddressClassSummary2.5 Networkaddresses:SpecialPurposeandGuidelines2.6 AssigningNetworkAddresses2.7 AssigningHostAddressesIPAddressingwasdesignedtoallowahostononenetworktocommunicatewithahostonadifferentnetwork,regardlessofthetypeofLANsthehostareparticipatingin.互聯(lián)網(wǎng)協(xié)議英文第24頁(yè)2.1 IPTerminologyBit/ByteOctetNetworkAddress/SubnetAddress/HostAddressBroadcastAddressSendinginformationtoallnodesonanetworklocal/limitedbroadcast–55–allnetworks,allnodesDirectedbroadcast–allthebitsofhostaddressturnedon–allsubnetsandhostsonnetworkBroadcastdomain–agroupofdevicesreceivingbroadcastframesinitiatingfromanydevicewithinthegroup.Becausetheydonotforwardbroadcastframes,broadcastdomainsaregenerallysurroundedbyrouters.互聯(lián)網(wǎng)協(xié)議英文第25頁(yè)2.2 TheHierarchicalIPAddressingSchemeNetworkIDHostID32Bitsw.x.

y.z.172.16.30.56Example:ClassBTheIPaddressisastructureorhierarchicaladdresswhichconsistsofa32-bitbinarynumberof4octetsandisusuallydisplayedinthedecimalformat6(dotteddecimalnotation).互聯(lián)網(wǎng)協(xié)議英文第26頁(yè)2.3 NetworkAddressing*TheclassoftheNetworkisdeterminedbythehighorderbits*ClassDisforMulticastandClassEisreservedforResearch.ClassCClassANetworkAddressHostAddress0ClassBNetworkAddressHostAddress10NetworkAddressHostAddress11000000000 00000001 1..01111110 12601111111 12710000000 12810111111 19111000000 19211011111 223互聯(lián)網(wǎng)協(xié)議英文第27頁(yè)2.4 AddressClassSummaryNumberofNetworks12616,3842,097,152NumberofHostsperNetwork16,777,21465,534254ClassAClassBClassCRangeofNetworkIDs

(FirstOctet)1–126128–191192–223互聯(lián)網(wǎng)協(xié)議英文第28頁(yè)2.5 NetworkAddresses:SpecialPurposeandGuidelinesNetworkAddressCannotBe127127isreservedforloopbackfunctionsandself-diagnosticisreservedasaloopbackaddressNetworkIDand/orHostIDCannotBeAllBitsSetto1All1smeans“Allnetworks”,or“allnodes”255isabroadcastaddress;amessagesenttothisaddressisbroadcasttoeachmachineonthesubnet.E.g.55–sendto“allnodes”onnetwork128.255 LimitedBroadcastNetworkIDand/orHostIDCannotBeAllBitsSetto0-usedbyCiscorouterstodesignatethedefaultroute0means“thisnetworkorsegment”,or“thisnode”HostIDMustBeUniquetotheNetwork互聯(lián)網(wǎng)協(xié)議英文第29頁(yè)2.6 AssigningNetworkAddressesRouter123124.x.y.z192.121.73.z131.107.y.zRouter互聯(lián)網(wǎng)協(xié)議英文第30頁(yè)2.7 AssigningHostAddressesRouterRouter124.0.0.27124.0.0.28124.0.0.29131.107.0.27131.107.0.28131.107.0.29192.121.73.1124.0.0.1192.121.73.2131.107.0.1124.x.y.z192.121.73.z131.107.0.z123互聯(lián)網(wǎng)協(xié)議英文第31頁(yè)3.0 Subnetting3.1 WhatisaSubnet?3.2 WhySubnetting?3.3 ImplementingSubnetting3.4 SubnetMasks3.5 DefaultSubnetMasks3.6 PossibleSubnetMasksforClassA,B&C3.7 DefiningaSubnetMask3.8 DefiningaSubnetIDs3.9 DefiningaHostIds3.10 Example互聯(lián)網(wǎng)協(xié)議英文第32頁(yè)3.1 WhatisaSubnet?(1)7Subnet12Subnet21MainNetworkAsubnetisasubsectionofannetwork,definedforadministrativepurposeortocutdownonbroadcasttraffic,asallmessagesonanetworkare“heard”byallhostswhetherthemessageisforthathostornot.Messagesentfromonehosttoanotherwithinthesamesubnetdonotneedtoberouted,butmessagessentbetweenhostsindifferentsubnetsmustberouted.Subnetsareconnectedbyrouters,ordefaultgateways.互聯(lián)網(wǎng)協(xié)議英文第33頁(yè)3.1 WhatisaSubnet?(2)NetworkIDHostID10ExampleNetworkIDFROMISPNo.ofNetwork=1SUBNETMASKNo.ofHosts=65534(2^16-2)NetworkIDHostID10WeneedmorenetworksSubnetIDBorrowfromHostID互聯(lián)網(wǎng)協(xié)議英文第34頁(yè)3.1 WhatisaSubnet?(3)AfterSubnetNetworkIDbecome -Subnetmaskbecome

No.ofSubnets 254HostforperSubnet 254(2^8-2)NetworkIDHostID10SubnetIDUseall8bit11111111forSubnet254combinations(2^8-2)*Only8bitforHost*However,accordingtoRFC1812,255combinationscanbeachieved.互聯(lián)網(wǎng)協(xié)議英文第35頁(yè)3.1 WhatisaSubnet?(4)AfterSubnetNetworkID SubnetMask HostRange -54 -54 -54 -54……………………. -54 -54 -54TOTAL254SUBNETS254HOSTSPERSUBNET互聯(lián)網(wǎng)協(xié)議英文第36頁(yè)3.2 WhySubnetting?Reducednetworktraffic–smallerthenetworksmallerthebroadcastdomainsandlessnetworktrafficonthatnetworksegmentOptimizednetworkperformance–resultofreducednetworktrafficSimplifiedmanagement–easiertoidentifyandisolatenetworkproblemsinasmallergroupFacilitatedspanningoflargegeographicaldistances–sinceWANlinksareconsiderablyslowerandmoreexpensive;connectingmultiplesmallernetworksmakesthesystemmoreefficient互聯(lián)網(wǎng)協(xié)議英文第37頁(yè)3.3 ImplementingSubnettingDeterminetheNumberofRequiredNetworkIDsOneforeachsubnetOneforeachwide-areanetworkconnectionDeterminetheNumberofRequiredHostIDsperSubnetOneforeachTCP/IPhostOneforeachrouterinterfaceBasedontheaboverequirement,createthefollowing:DefineOneSubnetMaskBasedonRequirementsDefineaUniqueSubnetIDforEachPhysicalSegmentBasedontheSubnetMaskDefineValidHostIDsforEachSubnetBasedontheSubnetID互聯(lián)網(wǎng)協(xié)議英文第38頁(yè)3.4 SubnetMasksA32-bitvaluecomposedof1sand0s.The1sinthesubnetmaskrepresentthepositionsthatrefertothenetworkorsubnetaddresses.DistinguishestheNetworkIDfromtheHostIDUsedtoSpecifyWhethertheDestinationHostisLocalorRemoteIfANDedresultsofsourceanddestinationhostsmatch,thedestinationislocal互聯(lián)網(wǎng)協(xié)議英文第39頁(yè)3.5 DefaultSubnetMasksBitsUsedforSubnetMaskAddressClassDottedDecimalNotationClassAClassBClassC11111111 00000000 00000000 0000000011111111 11111111 00000000 0000000011111111 11111111 11111111 0000000016.200131.107.0.0255.255.131.107.w.x.IPAddressSubnetMaskNetworkIDHostID16.200y.z互聯(lián)網(wǎng)協(xié)議英文第40頁(yè)3.6 PossibleSubnetMasksforClassA,B&CClassC28922440485254ClassB28922440485254ClassA28922440485254互聯(lián)網(wǎng)協(xié)議英文第41頁(yè)3.7 DefiningaSubnetMaskConverttheNumberofSegmentstoBinaryCounttheNumberofRequiredBitsConverttheRequiredNumberofBitstoDecimal

(HighOrder)123ExampleofClassBAddressNumberofSubnetsBinaryValueConverttoDecimal