思科網(wǎng)絡(luò)技術(shù)培訓(xùn)之2基本概念匯總課件

1、Chapter 2Internetworking Concepts OverviewChapter 2ObjectivesOn completion of this chapter, you will be able to perform the following tasks:Describe how data traffic is exchanged between source and destination devicesIdentify the roles and functions of a hub, switch, and router, and where they best

2、fit in the networkSelect the appropriate Cisco equipment for a given set of network requirementsObjectivesOn completion of thiDefining Components of the NetworkMain OfficeBranch Office Home Office Mobile UsersInternetredundencyDefining Components of the NetFloor 2Floor 1Server FarmDefining the Compo

3、nents of a Network (cont.)Branch OfficeTelecommuterISDNRemoteCampusFloor 2Floor 1Server FarmDefinNetwork Structure Defined by Hierarchy Distribution LayerCore LayerAccessLayerNetwork Structure Defined by HAccess Layer CharacteristicsEnd station entry point to the networkAccess LayerAccess Layer Char

4、acteristicsEnDistribution Layer CharacteristicsAccess Layer Aggregation PointRoutes traffic Broadcast/Multicast DomainsMedia TranslationSecurityPossible point for remote accessDistribution LayerDistribution Layer CharacterisCore Layer Characteristics Fast transport to enterprise servicesNo packet ma

5、nipulationCore LayerCore Layer Characteristics FasOSI Model OverviewData Flow LayersTransport LayerData Link Network LayerPhysicalApplication (Upper) LayersSessionPresentationApplication注意OSI模型與網(wǎng)絡(luò)三個(gè)層次的區(qū)別OSI Model OverviewData Flow TrKeeping different applications data separateUser InterfaceHow data

6、is presentedSpecial processing such as encryptionTelnetHTTPASCIIEBCDICJPEGOperating System/Application Access SchedulingTransport LayerData Link Network LayerPhysicalEXAMPLESSessionPresentationApplicationRole of Application LayersKeeping different applicationsTCPUDPSPX802.3 / 802.2HDLCEIA/TIA-232V.3

7、5IPIPXPresentationApplicationSessionEXAMPLESRole of Data Flow LayersReliable or unreliable deliveryError correction before retransmitCombines bits into bytes and bytes into framesAccess to media using MAC addressError detection not correctionMove bits between devicesSpecifies voltage, wire speed and

8、 pin-out cablesTransport Data LinkPhysical Network Provide logical addressing which routers use for path determinationTCP802.3 / 802.2EIA/TIA-232V.Encapsulating DataTransport Data LinkPhysical Network Upper Layer DataUpper Layer DataTCP HeaderDataIP HeaderDataLLC Header0101110101001000010DataMAC Hea

9、derPresentationApplicationSessionSegmentPacketBitsFramePDUFCSFCSProtocol data unitsEncapsulating DataTransport DaUpper Layer DataDe-encapsulating DataLLC Hdr + IP + TCP + Upper Layer DataMAC HeaderIP + TCP + Upper Layer DataLLC HeaderTCP+ Upper Layer DataIP HeaderUpper Layer DataTCP Header0101110101

10、001000010Transport Data LinkPhysical Network PresentationApplicationSessionUpper Layer DataDe-encapsulatiApplicationPresentationSessionTransportNetworkData LinkPhysicalOSI ModelPDUFunctional ResponsibilitiesExamplesWritten Exercise: OSI Model ApplicationPresentationSessionPhysical Layer FunctionsDef

11、inesMedia type Connector type Signaling typeEthernet802.3V.35PhysicalEIA/TIA-232Physical Layer FunctionsDefinPhysical Layer: Ethernet/802.3HubHostsHost10Base2Thick Ethernet10Base5Thick Ethernet10BaseTTwisted PairPhysical Layer: Ethernet/802.3Hubs Operate at Physical layerABCDPhysical All devices in

12、the same collision domainAll devices in the same broadcast domainDevices share the same bandwidthHubs Operate at Physical layerHubs: One Collision DomainMore end stations means more collisionsCSMA/CD is usedHubs: One Collision DomainMoreData Link layer FunctionsDefinesPhysical source and destination

13、 addressesHigher layer protocol (Service Access Point)associated with frame Network topology Frame sequencingFlow controlConnection-oriented or connectionlessData LinkPhysicalEIA/TIA-232v.35EthernetFrame RelayHDLC802.2802.3Data Link layer FunctionsDefinDataSource addFCSLengthDest addVariable26640000

14、.0C xx.xxxxVendor assignedIEEE assignedMAC Layer - 802.3Data Link Layer Functions (cont.)PreambleEthernet II uses “Type” here and does not use 802.2.MAC Address8# BytesDataSource addFCSLengthDest adDataDest SAPSource SAPDataSource addFCSLengthDest addVariable11802.2 (SAP)MAC Layer - 802.3Data Link L

15、ayer Functions (cont.)Ctrl1 or 232PreambleDataDest SAPAASource SAPAAVariable11802.2 (SNAP)Ctrl031 or 2OROUI IDType為高層協(xié)議使用DataDest SAPSource SAPDataSoEach segment has its own collision domainAll segments are in the same broadcast domainData LinkSwitches and Bridges Operate at Data Link LayerOR123124E

16、ach segment has its own colliSwitchesEach segment has its own collision domainBroadcasts are forwarded to all segmentsMemorySwitchSwitchesEach segment has its oNetwork Layer FunctionsDefines logical source and destination addresses associated with a specific protocolDefines paths through networkInte

17、rconnects multiple data linksNetworkIP, IPXData LinkPhysicalEIA/TIA-232v.35EthernetFrame RelayHDLC802.2802.3Network Layer FunctionsNetworkDataSourceaddressDestination addressIPNetwork Layer Functions (cont.)HeaderNodeNetworkLogical AddressNetwork Layer End Station PacketDataSourceaddressDestination

18、Network Layer Functions (cont.) 11111111 11111111 00000000 00000000 10101100 00010000 01111010 11001100BinaryMaskBinaryAddress04 17216122204255AddressMask25500NetworkHostNetwork Layer Functions (cont.Routing TableNETINTMetric124S0S0E01001.04.01.3E04.3S02.2E02.1S01.2Routing TableNETINTMetric

19、124E0S0S0001Logical addressing allows for hierarchical networkConfiguration requiredUses configured information to identify paths to networksNetwork Layer Functions (cont.)Routing TableNETINTMetric124S0Routers: Operate at the Network LayerBroadcast controlMulticast controlOptimal path determinationT

20、raffic managementLogical addressingConnects to WAN servicesRouters: Operate at the NetwoUsing Routers to Provide Remote AccessInternetTelecommuterBranch OfficeModem or ISDN TAMobile UserMain OfficeUsing Routers to Provide RemotTransport Layer FunctionsDistinguishes between upper layer applicationsEs

21、tablishes end-to-end connectivity between applicationsDefines flow control Provides reliable or unreliable services for data transferNetworkIPXIPTransportSPXTCPUDPTransport Layer FunctionsDistiReliable Transport Layer FunctionsSynchronizeAcknowledge, SynchronizeAcknowledgeData Transfer(Send Segments

22、)SenderReceiverConnection EstablishedReliable Transport Layer FunctNetwork Device DomainsHubBridgeSwitchRouterCollision Domains:1 4 4 4 Broadcast Domains:1 1 1 4 Network Device DomainsHubBridgChoosing a Cisco Product Distribution LayerCore LayerAccessLayerChoosing a Cisco Product DistrProduct Select

23、ion ConsiderationsProvides functionality and features you need todayCapacity and performance Easy installation and centralized managementProvides network resiliency Investment protection in existing infrastructureMigration path for change and growthSeamless access for mobile users and branch offices

24、Product Selection ConsideratioFirst select WAN technology solutions based on the following:Availability of serviceBandwidth requirementCostSecond, choose products that support selected WAN solutionsProduct Selection Considerations (cont.)Cost per MonthUsageLeased Line, T1Modem/ISDNFrame Relay0First

25、select WAN technology sProduct Selection Considerations (cont.)15441286456Determine applications that you want to runISDN, Frame RelayOld ModemTelnetNew ModemWeb BrowsingVoiceVideo, MultimediaE-Mail, File TransferLeased Line,Frame Relay,XDSLkbpsProduct Selection ConsideratioSelection Issue

26、s: Need for 10 Mbps or 100 Mbps on media Port density Need for management console Easy OperationsCisco 1500Micro HubCiscoFastHub300Cisco 1528Micro Hub 10/100CiscoFastHub400CiscoFastHub200CiscoFastHub100Cisco Hub ProductsSelection Issues:Cisco 1500MiSelection Issues:Need for 10 Mbps, 100 Mbps, or 100

27、0 Mbps on mediaNeed for trunking and inter-switch linksWorkgroup segmentation (VLANs)Port density needsDifferent user interfaces Desktop/Workgroup SolutionsWiring Closet/Backbone SolutionsCisco 1548 Micro Switch 10/100Catalyst 3000 seriesCatalyst 2900series XLCatalyst 1900/2820 seriesCatalyst 2900 seriesCatalyst 500