Ender204426777乾颐堂CCNAv3.0课程BuildingaMedium-SizedNetworkInterconnectingCiscoNetworkingDevices,Part1(ICND1)v3.0ImplementingVLANsandTrunks实现VLAN和TrunkEnder204426777乾颐堂CCNAv3.0课程IssuesinaPoorlyDesignedNetworkTheseissuesareoftenfoundinpoorlydesignednetworks:•Largebroadcastdomains一个超大的广播域，极其浪费带宽•Managementandsupportchallenges带来管理和支持上的挑战•Possiblesecurityvulnerabilities安全性几乎为0EnderICND1—4-3Ender204426777乾颐堂CCNAv3.0课程VLANIntroduction•AVLANisavirtualLAN.•VLAN=broadcastdomain•VLAN=logicalnetwork(subnet)•VLANsaddresstheseneeds:–Segmentation–Security–Networkflexibility灵活性EnderICND1—4-4Ender204426777乾颐堂CCNAv3.0课程Trunkingwith802.1QRunningmanyVLANsbetweenswitcheswouldrequirethesamenumberofinterconnectinglinks.EnderICND1—4-5Ender204426777乾颐堂CCNAv3.0课程Trunkingwith802.1Q(Cont.)•CombiningmanyVLANsonthesameportiscalledtrunking-trunk允许多个vlan流量在同一链路转发•AtrunkallowsthetransportationofframesfromdifferentVLANs.•EachframehasatagthatspecifiestheVLANthatitbelongsto通过帧中的tag指定vlan流量的归属•FramesareforwardedtothecorrespondingVLANbasedonthetaginformation.基于帧把相应vlan的信息转发到端口EnderICND1—4-6Ender204426777乾颐堂CCNAv3.0课程Trunkingwith802.1Q(Cont.)EnderICND1—4-7Ender204426777乾颐堂CCNAv3.0课程Trunkingwith802.1Q(Cont.)EnderICND1—4-8Ender204426777乾颐堂CCNAv3.0课程Trunkingwith802.1Q(Cont.)EnderICND1—4-9Ender204426777乾颐堂CCNAv3.0课程CreatingaVLANSwitchX#configureterminalSwitchX(config)#vlan2SwitchX(config-vlan)#nameSales•AddsVLAN2andnamesit"Sales"EnderICND1—4-10Ender204426777乾颐堂CCNAv3.0课程CreatingaVLAN(Cont.)•VerifiesVLAN2SwitchX#showvlanid2VLANNameStatusPorts----------------------------------------------------2SalesactiveFa0/2,Fa0/12VLANTypeSAIDMTUParentRingNoBridgeNoStpBrdgModeTrans1Trans2----------------------------------------------------------------2enet1000021500-----00EnderICND1—4-11Ender204426777乾颐堂CCNAv3.0课程AssigningaPorttoaVLANSwitchX#configureterm...
