2018年7月31日ccna ccnav3.0修改版課件15-0實(shí)現(xiàn)vlan和trunk

1、Implementing VLANs and Trunks實(shí)現(xiàn)VLAN和TrunkBuilding a Medium-Sized Network erconnecting Cisco Networking Devi, Part 1 (ICND1) v3.0204426777IThese ies in a Poorly Designed Networkes are often found in poorly desidnetworks:s一個(gè)超大的廣播域，極其浪費(fèi)帶寬Large broadcastManagement and support challenges帶來(lái)管理和支持上的sible se

2、curity vulnerabilities安全性幾乎為0204426777VLANroductionA VLAN is a virtual LAN.VLAN = broadcastVLAN = logical network (subnet)VLANs address these needs:SegmenSecurityionNetwork flexibility靈活性204426777Trunking with 802.1QRunning many VLANs betn switches would require thesamber oferconnecting links.204426

3、777Trunking with 802.1Q (Cont.)Combining many VLANs on the same port is called trunking-trunk允許多個(gè)vlan流量在同一鏈路轉(zhuǎn)發(fā)A trunk allows the transporion of frames from different VLANs.t specifies the VLANt it belongs to通過(guò)幀中的tag指定vlan流量的歸屬Each frame has a tagFrames are forwarded to the corresponding VLAN based o

4、n the tag information.基于幀把相應(yīng)vlan的信息轉(zhuǎn)發(fā)到端口204CCNAv3.0課程Trunking with 802.1Q (Cont.)204426777Trunking with 802.1Q (Cont.)204426777Trunking with 802.1Q (Cont.)204426777Creating a VLANAdds VLAN 2 and names it Sales204426777SwitchX#configure terminal SwitchX(config)#vlan 2 SwitchX(config-vlan)SalesCreatin

5、g a VLAN (Cont.)Verifies VLAN2204426777SwitchX# show vlan id 2VLAN NameSusPorts2SalesactiveFa0/2, Fa0/12VLAN Type SAIDMTUParent RingNo BridgeNo StpBrdgMode Trans1 Trans22enet 100002 1500 -00Assigning a Port to a VLANAssigns port FastEthernet0/3 to VLAN 2204426777SwitchX#configure terminal SwitchX(co

6、nfig)#erface FastEthernet 0/3 SwitchX(config-iswitchport acs vlan 2Assigning a Port to a VLAN (Cont.)Verifiest port FastEthernet0/3 was assigned to VLAN 2204426777SwitchX#show vlan briefVLAN NameSusPortsdefaultactiveFa0/1SalesactiveFa0/3vlan3activevlan4activeAssigning a Port to a VLAN (Cont.)Verifie

7、s VLAN membership on the Fa0/3erface204426777SwitchX#showerface FastEthernet0/3 switchportName: Fa0/3 Switchport: EnabledAdministrative Mode: dynamic auto Operational Mode: sic acs Administrative Trunking Encapsulation: dot1q Operational Trunking Encapsulation: native Negotiation of Trunking: OnAcs

8、Mode VLAN: 2 (Sales)Configuring an 802.1Q TrunkEnter theerface configuration mode.Configure the Fa0/11erface as a VLAN trunk.Change the native VLAN from 1 to 99.SwitchX#configure SwitchX(config)# SwitchX(config-iterminalerface FastEthernet 0/11#switchport mode trunkSwitchX(config-if)#switchport trun

9、k native vlan99Native VLAN 的幀在Trunk鏈不帶標(biāo)記交換機(jī)收到不打標(biāo)記的幀將會(huì)轉(zhuǎn)發(fā)到Native vlan。vlan d204426777Configuring an 802.1Q Trunk (Cont.)o Verifies a trunk on the Fa0/11erface204426777SwitchX#showerfaFastEthernet0/11 trunkPortModeEncapsulation SusNative vlan Fa0/11 on802.1qtrunking99PortVlans allowed on trunk Fa0/111-

10、4094PortVlans allowed and activeanagementFa0/111-13SwitchX#showerfaFastEthernet0/11 switchportName: Fa0/11 Switchport: EnabledAdministrative Mode: trunkOperational Mode: trunkAdministrative Trunking Encapsulation: dot1q Negotiation of Trunking: OnAcs Mode VLAN: 99 Trunking Native Mode VLAN: 99VLAN D

11、esign Considerationsum number of VLANs is switch-dependent考慮VLAN數(shù)目以及The交換機(jī)可以承載的vlanVLAN 1 is the factory-default Ethernet VLAN.A use-dedicated VLAN is for the Cisco swit一個(gè)專門(mén)的vlan進(jìn)行交換機(jī)的管理Keep management traffic in a separate VLAN.Change the native VLAN to something other native vlan更改到一個(gè)不用的vlananagem

12、ent IP address.用n VLAN 1為了安全期間把204426777VLAN Design Considerations (Cont.)When configuring a trunk link, consider the following:Make suret the native VLAN for an 802.1Q trunk is the same on bothends of the trunk link.確保native vlan在trunk的兩端相同n Cisco switches.用DTP協(xié)議管DTP manages trunk negotiations bet理

13、思科設(shè)備trunk的協(xié)商204426777Physical Redundancy in a LANLoops may occurhe network as part of a design strategy forredundancy.物理環(huán)路在有冗余的同時(shí)也會(huì)造成環(huán)路的產(chǎn)生204426777Physical Redundancy in a LAN (Cont.)通過(guò)Spanning-tree避免環(huán)路的產(chǎn)生204426777實(shí)施DTP協(xié)議204426777Trunking ConfigurationdsTrunks can be configured s或者DTP默認(rèn)配置trunkically

14、 or via DTP.可以通過(guò)靜態(tài)DTP provides the ability to negotiate the trunkingConmfigeutrhinogda.DTrTuPnk協(xié)議提供協(xié)商trunk的方式switchport trunkswitchport modeswitchport nonegotiate204426777DTPDTP - Dynamic Trunking protocol它的前身是DISL - Dynamic ISL它們都是思科私有的協(xié)議，用于協(xié)商Trunk鏈路（類型為0X2004的組播MAC：01-00-讓回顧0C-CC-CC-CC,每間隔一秒發(fā)送一次，形

15、成干道之后間隔30秒發(fā)送）TrunkON 默認(rèn)發(fā)送DTP（ switchport mode trunk ）OFF 用命令“switchport nonegotiate”關(guān)掉DTPDynamic一下青蔥歲月的“戀愛(ài)故事”Auto 默認(rèn)不發(fā)送DTP，但是收到DTP后可以回復(fù)，協(xié)商switchport mode dynamic autoDesirable 默認(rèn)主動(dòng)發(fā)送DTP，主動(dòng)協(xié)商switchport mode dynamic desirable-IOU不支持該命令A(yù)cs 不發(fā)送DTP,不協(xié)商Trunk204426777Trunk工作模式204426777鏈路trunk模式描述開(kāi)啟將端口強(qiáng)制設(shè)定為

16、Trunk即使對(duì)端不成為T(mén)runk，本端也成為T(mén)runk關(guān)閉將端口強(qiáng)制設(shè)定為非Trunk期望（desirable）端口主動(dòng)與鄰接端口協(xié)商為T(mén)runk自動(dòng)（Auto）如果鄰接端口嘗試協(xié)商為T(mén)runk，則成為T(mén)runk非協(xié)商將端口強(qiáng)制設(shè)定為T(mén)runk，并且不在發(fā)送DTP報(bào)文Switchport 模式交互Note: Table ashow dtpmes DTP is enabled at both ends.erface 看當(dāng)前配置Debug dtp event-驗(yàn)證DTP事件204426777Dynamic AutoDynamicDesirableTrunkAcsDynamic AutoAcsTr

17、unkTrunkAcsDynamic DesirableTrunkTrunkTrunkAcsTrunkTrunkTrunkTrunkNotmendedAcsAcsAcsNotmendedAcs實(shí)施VTP協(xié)議204426777VTP-VLAN Trunking ProtocolVTP is a Layer 2 messaging protocolt maains VLAN configuration consistencyby managing the addition, deletion, and renaming of VLANs on a network-wide basisVTP是一種為

18、了保持VLAN配置的連續(xù)性，方便管理增加、刪除、重命名VLAN等行為設(shè)計(jì)的二層協(xié)議VTP 應(yīng)用場(chǎng)景，在交換網(wǎng)絡(luò)中減少配置量，在一臺(tái)VTP server上配置vlan，該信息會(huì)分發(fā)到該域內(nèi)的所有設(shè)備。VTP是思科私有協(xié)議，在絕大多數(shù)交換機(jī)上都支持目前存在三個(gè)版本V1、V2和V3（版本兼容性存在一些問(wèn)題）VTP Ver1 and VTPVer2 are noteroperable on switcheshe same VTP. Every switchhe VTPmust use the same VTP ver.204426777VTP 協(xié)議公告 VLAN 配置信息在整個(gè)公共管理域內(nèi)保持VLAN

19、配置一致只在Trunk端口發(fā)送公告/空時(shí)接收域信息并同步不同設(shè)備不同版本的IOS默認(rèn)的VTP版本號(hào)不一204426777VTP 域交換 VLAN 信息的一組交換機(jī)交換機(jī)上管理VLANs在204426777VTP 模式Server (服務(wù)器模式，默認(rèn)的模式)創(chuàng)建、修改和刪除 VLANs發(fā)送和轉(zhuǎn)發(fā)公告同步 VLAN 配置VLAN 配置信息保存在 Flash 的 vlan.dat 里面Cnt（客戶模式）不能創(chuàng)建、修改和刪除 VLANs發(fā)送、續(xù)傳公告同步 VLAN 配置VLAN 配置信息保存在 Flash 的vlan.dat里面Transparent（透明模式）創(chuàng)建、修改和刪除 VLANs不發(fā)送公告，轉(zhuǎn)發(fā)公告不同步 VLAN 配置VLAN 配置信息保存在 Config 里面204426777nt同步ServerVTP C現(xiàn)在VTP Cnt配置版本號(hào)為5（已經(jīng)被同步過(guò)）服務(wù)器端vtp為0NULL（會(huì)清空配置版本號(hào)），此時(shí)服務(wù)器端配置版本號(hào)QYT（修改，與客戶端相同），那么此時(shí)客戶端會(huì)同步服務(wù)vtp器端