台湾宜兰大学互联网交换技术课程 03_spanning tree_print

《台湾宜兰大学互联网交换技术课程 03_spanning tree_print》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、BridgesandSpanningTreeSpeaker:Dr.Whai-EnChenAssistantProfessorInstituteofComputerScienceandInformationEngineeringNationalIlanUniversity(NIU)Email:wechen@niu.edu.twThesourceisobtainedfromProf.Nen-FuHuang.1Bridges©Allrightsreserved.Nopartofthispublicationandfilemaybereproduced,

2、storedinaretrievalsystem,ortransmittedinanyformorbyanymeans,electronic,mechanicalphotocopyingrecordingorotherwisewithoutpriorwrittenmechanical,photocopying,recordingorotherwise,withoutpriorwrittenpermissionofProfessorNen-FuHuang(E-mail:nfhuang@cs.nthu.edu.tw).2FunctionsofaBri

3、dge∑MAClayerdevicewhichrelaysframesamongphysicallyseparatedLANsandmakesthephysiilLANcalLANsappearasonelogiilLANtthcalLANtotheendstations∑BasicFunctions:òFrameForwardingòLearningandFilteringòResolvingPossibleLoopsintheTopology∑AdditionalFunctions:òCiCongestionClControl(E(Ehnou

4、ghBBuffffer))òStaticFiltering(Security)òTranslation(Multi-Bridgg)e)òRouting(Multi-Bridge)òSegmentation3ASimpleBridgeExample區域網路A1234橋接器工作站區域網路B5674DesignConsiderations∑Nomodificationstothecontentorformatoftheframes∑Containenoughbufferspacetomeetpeakdemands∑Containaddressingan

5、droutingintelligence∑Abridgemayconnectmorethantwonetworks∑WhyBridgedLANs(BLAN)?òReliabilityòPerformanceòSecurityòGeography5BridgeRouting∑TheBridgesmustbeequippedwitharoutingcapability∑Theroutingdecisionmaynotalwaysbeasimpleone(loop)∑Topologychangeshavetobeconsidered∑Abridgekn

6、owsallthestationaddresses(FilteringDatabase)6BLANExample(Withoutloop)橋接器1ID=10埠1埠2AB區域網路3區域網路1埠1埠1橋接器4埠1橋接器3ID=40橋接器2ID=30埠2埠3ID=20埠2埠2區域網路4區域網路2區域網路5區域網路6CDFE7BridggpedLAN(BLAN)ExamplewithLoop1工作站區域網路1橋接器1橋接器223區域網路2橋接器3區域網路3橋接器4橋接器5橋接器6橋接器7區域網路6區域網路4區域網路54568RemoteBridge•Pr

7、edldominantlyusedddtoextendeddLANsoverthhewiddearea•Leadstounstablenetworkswhenmorethan7bridgesareinterconnectedbetweenLANs區域網路C遠距橋接器遠距遠距區域網路區域網路廣域網路橋接器橋接器橋接器BA9BridgeProtocolArchitecture工作站A工作站DUSERUSERt1LLC橋接器t8LLCt2MACMACMACt7MACt3tt5PHYBPHYPHYCt6PHY4區域網路1區域網路2t1,t8UserDat

8、at2,t7LLC-HUserDatat3t4t5t6t3,t4,t5,t6MAC-HLLC-HUserDataMAC-T10Spann