CISCO中生成樹協(xié)議的配置

1、實驗一生成樹（STP）一、實驗目的1）：本實驗的目的是通過配置以下三種拓樸圖，讓我們對生成樹的工作原理有更 深的認識。2）:掌握生成樹在交換機上的配置方法，對生成樹在網(wǎng)絡上的應用有更深的了解二、實驗要求：1）：簡述生成樹協(xié)議的三個前提。2）:簡述根橋、根端口、指定端口的選舉原則。三、實驗內(nèi)容：1、通過三種拓樸圖來研究根橋、根端口、指定端口選舉方法；2、根橋、根端口、指定端口查看方法四、實驗步驟：第一種：實驗拓樸：VLAN1Spanning tree enabled protocol ieeeRoot IDPriority32768Addresscc00t 0a30. 0000This brid

2、ge is the rootHello Time 2 sec Max Age 20 sec1）查看三臺交換機那個臺是根橋在交換機上使用命令show spanning-tree vlan 1或 show spanning-tree brif可以查看當前網(wǎng)絡中的根橋、根端口、指定端口。如下：Sfflttsh spanning-tree briRridge ID Priority32768AddressccOO. Da30. 0000Hello Time2 sec Max Age 20 sec Forward Delay 15 secAging Time300Forward Delay 15 sec

3、I.r I. ) I- i j 匚 h LDesignatedInterfaceNameSts Cost Bridge IDPort IDFastEthernetO/1Fas tE theme tO/2128,2128128.312819 FWD19 FWD0 32768 ccOO. 0a30. 0000 128.20 32768 ccOO. Da3D. 0000 128.3SW2ttsh spanning-tree briVLAN1Spanning Root IDtree enabled protocol ieeeForward Delay 15 secPriorityAddressCost

4、PortHello Time32768CCOO. 0a30. 0000192 (FastEthernetO/1)2 sec Max Age 20 secBridge IDPriori ty32768AddressccOO. 0f90. 0000Hello Time2 sec Max Age 20 secForward Delay 15 aecAging Time300InterfaceDesignatedNamePort IDFrioCostS LsCostBridgeIDPortFastEthernetO/1123. 212819FWD032768ccOO. 0a30+ 0000128. 2

5、HastEthernetO/2128. 312819BLK1932768ccOO. 0c24. 0000128. 3可以看出SW為根橋，SW2為非根橋，用同樣的命令查看第三臺交換機。2)現(xiàn)在修改SW2的優(yōu)先級讓它成為根橋在交換機上使用此命令spa nnin g-tree vlan 1 priority 4096SW2(co nfig)# spa nnin g-tree vlan 1 priority 4096SW2#sh spanning-tree bri查看 spanning-treeSff2fish spanning-tree briVLAN1Spanning tree enabled p

6、rotocol ieeeRoot IDPriority4096AddressccOO. Of 90.0000This bridgeis th巳 rootHello Time2 sec Man Age 20 secForward Delay 15 secBridge IDPriority4096AddressccOO. 0f90. 0000Hello Time2 sec Max Age 20 secForward Delay 15 secAging Time300InterfaceDesignatedNamePo譏 ID Prio Cost Sts Cost Bridge IDPort IDFa

7、stEthernetO/1128.212819 FW04096 ccOO. 0f90. 0000 128.2F/tEth陸netQ/2128/12819 F刖04096 cMO. Qf90.0000 128.3第二種：實驗拓樸1 ）查看二臺交換機那個臺是根橋在交換機上使用命令show spanning-treevlan 1 或 show spanning-treebrif可以查看當前網(wǎng)絡中的根橋、根端口、指定端口。SI2ltsh spanning一tree briInterfacelameDesignaPort ID Prio Cost Sts Cost Bridge IDPort IDVLA

8、N1Spanning tree enabled protocol ieeeRoot IDPriorityAddressCostPoriHello Time32768bccOO, 0380. OOOdf192 (FastEthernetO/1)2 sec May Age 20 secFonrard Delay 15 secBridge IDPriority32768AddressccOO. 10e8, 0000Hello Time2 sec May Age 20 secForward Delay 15 secAging Time300FastEthernetO/1128.212819 FVD0

9、32766 ccOO. 0380,0000128.2FastEthernetO/2128.312819 BLK0 32768 ccOO. 0380.0000128.3可以看到交換機 SW2上的FO/1是轉發(fā)狀態(tài)，F(xiàn)0/2是阻斷狀態(tài)。2 )指定為根端口方法有：a:改變接口上的cost值(在本端修改)命令為 spanning-tree vlan 1 cost 20b:改變發(fā)送者接口上ID值(在對端修改)命令為 spanning-tree vlan 1 port-priority 96注：port-priority 后的值是16倍數(shù)c:在物理上改變在這就不作詳解了。3 )步聚如下：第一種方法：在本端

10、修改接口cost值SW2(co nfig)# int fa0/1SW2(co nfig-if)# spa nnin g-tree vlan 1 cost 20SW2#sh spa nnin g-tree briSV2#sh spanningstree briVLAN1Spanning tree enabled protocol ieeeRoot IDPriorityAddressCostPortHello Time32768ccDO. laic. 0000193 (FastEthernetO/2)2 sec Mas Age 20 secBridge IDPriority32768Address

11、ccDO. la4B. DODOHello Time2 sec Max Age 20 secAging Time300Forward Delay 15 secForward Delay 15 secInterfaceNameDesignatedPort IDPort ID Prio Cost Sts Cost Bridge IDFastEthernetO/1128.212820 BLK0 32768 ccOO. laic. 0000 128.2FastEthernetO/2128.312819 FWD0 32768 ccOO. laic. 0000 128.3第二種方法：在對端修改發(fā)送者接口ID值SW1(config ) #int faO/2SW1 (con fig-if)#spa nnin g-tree vla n 1 priority 96SW2#sh spanning-tree bri (在對端查看)第三種：實驗拓樸1)在一臺