網(wǎng)絡(luò)基礎(chǔ)中國IT認(rèn)證實驗室網(wǎng)絡(luò)概念網(wǎng)絡(luò)局域網(wǎng)LAN（LocalAreaNetwork）廣域網(wǎng)WAN（WideAreaNetwork）LAN特點地域有限傳輸速率高傳輸可靠拓?fù)浣Y(jié)構(gòu)靈活局域網(wǎng)中常用的設(shè)備HubBridge/SwitchRouterWAN特點地域廣LAN–LAN拓?fù)浣Y(jié)構(gòu)不靈活廣域網(wǎng)中常用的設(shè)備Modem/CSU/DSURouterWANSwitchAccessServerATMSwitch網(wǎng)絡(luò)拓?fù)浣Y(jié)構(gòu)網(wǎng)絡(luò)拓?fù)浣Y(jié)構(gòu)總線型星型樹型環(huán)型網(wǎng)狀型標(biāo)準(zhǔn)化組織ISO InternationalStandardsOrganizationIEEE 電子電器工程師協(xié)會ANSI AmericanNationalStandardsInstituteEIA/TIA 電子工業(yè)協(xié)會ITU InternationalTelecommunicationsUnionIAB InternetArchitectureBoardIETF InternetEngineeringTaskForceOSI參考模型OpenSystemsInterconnectionISOOSI參考模型歷史分層的目的工作過程OSI模型Application 應(yīng)用層Presentation 表示層Session 會話層Transport 傳輸層Network 網(wǎng)絡(luò)層DataLink 數(shù)據(jù)鏈路層Physical 物理層OSI模型ApplicationTransport SegmentNetwork PacketDataLink FramePhysical Flow物理層電壓水平數(shù)據(jù)傳輸速率最大傳輸距離物理接口設(shè)備：Hub(集線器)數(shù)據(jù)鏈路層物理地址定義Mac地址差錯驗證物理介質(zhì)訪問設(shè)備：網(wǎng)卡，交換機IEEE802ApplicationTransportNetworkDataLink Physical LLC LogicalLinkControlMAC MediaAccessControl網(wǎng)絡(luò)層將數(shù)據(jù)發(fā)送到目的網(wǎng)絡(luò)尋址和路由網(wǎng)絡(luò)協(xié)議地址IP地址IPX地址設(shè)備：路由器傳輸層建立端到端的連接保證數(shù)據(jù)正確傳輸TCP協(xié)議提供可靠的傳輸流量控制思考網(wǎng)線是否屬于物理層Modem，網(wǎng)卡衛(wèi)星，無線網(wǎng)絡(luò)NT網(wǎng)vsIP網(wǎng)vs以太網(wǎng)局域網(wǎng)以太網(wǎng)令牌環(huán)網(wǎng)以太網(wǎng)以太網(wǎng)以太網(wǎng)簡史訪問機制什么是以太網(wǎng)一種共享介質(zhì)技術(shù)以太網(wǎng)訪問機制以什么樣的方式訪問網(wǎng)絡(luò)CSMA/CDCarrier-SenseMultipleAccesswithCollisionDetection帶沖突檢測的載波偵聽和多路訪問工作過程以太網(wǎng)訪問機制任何時刻，只能有一臺主機在共享介質(zhì)上發(fā)送數(shù)據(jù)以太網(wǎng)尋址MAC地址MAC地址物理地址硬件設(shè)備的唯一標(biāo)識被固化在網(wǎng)絡(luò)接口卡的ROMMAC地址12個十六進(jìn)制的數(shù)組成（6bytes）Vendercode+Serialcode00-E0-FC-XX-XX-XX00-E0-FC-02-37-a2以太網(wǎng)尋址數(shù)據(jù)幀形式Unicast

00-E0-FC-12-34-56Broadcast FF-FF-FF-FF-FF-FFMulticast 01-00-5E-XX-XX-XX以太網(wǎng)幀格式幀大小64byte~1518byteIEEE802局域網(wǎng)標(biāo)準(zhǔn)802.1802.2802.3 以太網(wǎng)802.4 令牌總線802.5 令牌環(huán)802.11以太網(wǎng)標(biāo)準(zhǔn)標(biāo)準(zhǔn)以太網(wǎng)10Ba