CISCO中生成樹協(xié)議的配置

1、實(shí)驗(yàn)一生成樹（STP）一、實(shí)驗(yàn)?zāi)康?）：本實(shí)驗(yàn)的目的是通過配置以下三種拓樸圖，讓我們對(duì)生成樹的工作原理有更 深的認(rèn)識(shí)。2）:掌握生成樹在交換機(jī)上的配置方法，對(duì)生成樹在網(wǎng)絡(luò)上的應(yīng)用有更深的了解二、實(shí)驗(yàn)要求：1）：簡(jiǎn)述生成樹協(xié)議的三個(gè)前提。2）:簡(jiǎn)述根橋、根端口、指定端口的選舉原則。三、實(shí)驗(yàn)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(shí)驗(yàn)步驟：第一種：實(shí)驗(yàn)拓樸：1）查看三臺(tái)交換機(jī)那個(gè)臺(tái)是根橋在交換機(jī)上使用命令show spanning-tree vlan 1或 show spanning-tree brif可以查看當(dāng)前網(wǎng)絡(luò)中的根橋、根端口、指

2、定端口。如下：Sfflttsh spanning-tree briRoot IDPriori ty Address This bridge Hello Time32768ccOO. Oa30. 0000 is the root2 sec Max Age 20 secForward Delay 15Bridge IDPriori ty32768AddressccOO. Da3D. 0000Hello Time2 sec Max Age 20 secForward Delay 15Aging Time300InterfaceDesignatedNameFort ID Prio Cost Sts C

3、ostBridge IDtree enabled protocol ieeesecsecVLAN1SpanningPort IDFastEthernetO/1Fas tE theme tO/2128,2128128.312819 FWD19 FWD0 32768 ccOO. 0a30. 0000 128.20 32768 ccOO. Da3D. 0000 128.3Spanning Root IDtree enabled protocol ieeeForward Delay 15 secPriorityAddressCostPortHello Time32768CCOO. 0a30. 0000

4、192 (FastEthernetO/1)2 sec Max Age 20 secBridge IDPriori ty32768AddressccOO. 0f90. 0000Hello Time2 sec Max Age 20 secForward Delay 15 aecAging Time300SW2ttsh spanning-tree briVLAN1J.nt erfaceNameDes ignaPort ID Prio CostSts Cost Bridge IDPort ID精選資料，歡迎下載FastEthernetO/1HastEthernetO/2128. 212819 FWD0

5、 32768 ccOO. 0a30+ 0000 128. 2128.312819 BLK19 32768 ccOO. 0c24. 0000 128. 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(tái)交換機(jī)。2)現(xiàn)在修改SW2的優(yōu)先級(jí)讓它成為根橋在交換機(jī)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 briVLAN1Spann

6、ing tree enabled protocol ieeeRoot IDPriority4096AddressccOO. 0f9D. 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 Time 300InterfaceDesignatedNamePo譏 ID Prio Cost Sts Cost

7、Bridge IDPort IDFastEthernetO/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(shí)驗(yàn)拓樸InterfacelameDesignaPort ID Prio Cost Sts Cost Bridge IDPort ID1）查看二臺(tái)交換機(jī)那個(gè)臺(tái)是根橋在交換機(jī)上使用命令show spanning-treevlan 1 或 show spanning-treebrif可以查看當(dāng)前網(wǎng)絡(luò)中的根橋、根端口、指定端口。SI2ltsh spa

8、nning一tree briVLAN1Spanning 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/

9、1128.212819 FVD0 32766 ccOO. 0380,0000128.2FastEthernetO/2128.312819 BLK0 32768 ccOO. 0380.0000128.3可以看到交換機(jī) SW2上的FO/1是轉(zhuǎn)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(duì)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?cè)谶@就不作詳解了。

10、3 )步聚如下：第一種方法：在本端修改接口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 IDPriority32768AddressccOO. laic. 0000Cost19Port3 (FastEthernetO/2)Hello Time2 sec Mas Age 20 secForward Dela

11、y15 secBridge IDPriority32768AddressccOO. la4B. DODOHello Time2 sec Max Age 20 secForward Delay15 secAging Time 300InterfaceDesignatedPort ID128.2128.3NamePort ID Prio Cost Sts Cost Bridge IDFastEthernetO/1128*212820 BLK0 32768 ccOO. laic* 0000FastEthernetO/2128.312819 FWD0 32768 ccOO. laic. 0000第二種方法：在對(duì)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(duì)端查看)第三種：實(shí)