生成树的详细配置及试验1分析解析

1、实验拓扑图：STP 及其优化实验步骤：1. 设置 SW1，SW2， SW3主机名分别为 Core1,Core2, ED-SW2. 把 Core1与 Core2 间的两条链路绑定成 etherchannel2 ，并设置成 Trunk modeCore1:支持 ISL 及 dot1Q 的交换机必须设置 trunk 的封装interface range fa0/23 - 24switchport trunk encapsulation dot1q /协议。低端的 C2950，C2960，C2918 只支持 dot1Q，无此命令。switch mode trunk / channel-group 2

2、mode on /Creating a port-channel interface Port-channel 2/interface Port-channel2 /接口设置为 Trunk 模式。接口加入 Etherchannel2 。系统提示自动创建 port-channel2 。Port-channel2 接口配置必须同物理接口一致。switchport trunk encapsulation dot1q switchport mode trunkCore2:interface range fa0/23 - 24 switchport trunk encapsulation dot1q s

3、witch mode trunk channel-group 2 mode onCreating a port-channel interface Port-channel 2 interface Port-channel2switchport trunk encapsulation dot1q switchport mode trunk3. 验证 etherchannel 设置显示 etherchannel 的详细信息Core1#sh etherchannel summary / Flags: D - downP - in port-channelI - stand-alone s - su

4、spended H - Hot-standby (LACP only)R - Layer3 S - Layer2U - in use f - failed to allocate aggregator u - unsuitable for bundlingw - waiting to be aggregatedd - default port目前已经建好 1 个 etherchannel 。Number of channel-groups in use: 1/Number of aggregators:1Group Port-channel Protocol Ports+2 Po2(SU)fa

5、0/23(P) fa0/24(P) /S - Layer2 U - in use P - in port-channel4. Core1 ，Core2，ED-SW间的所有链路均设置成 TrunkED-SW:int range f0/23 24no shutdownswitchport mode trunkCore1: int f0/21 switch trunk encap dot1q switch mode trunkCore2: int f0/21 switch trunk encap dot1q switch mode trunk5. 验证 etherchannel 设置Core2#sh

6、ow interface trunkPort Mode Encapsulation Status Native vlanFa0/21 on 802.1q trunking 1 / 式为 ON，封装为 802.1q ，目前已经形成 Po2on802.1q trunking 1F0/21 ，Trunk 模Trunking ，native vlan 为 vlan 1 。PortVlans allowed on trunkFa0/211-4094/此 Trunk 允许所有的 vlan 流量通过。Po21-4094PortFa0/21/此交换域只有vlan 1 是活动的 vlan 。因为现在无其他 vl

7、anPo2PortFa0/21Vlans in spanning tree forwarding state and not prunedVlan 没有被 vtp 修剪/Po2Vlans allowed and active in management domain6. 添加 vlan1-10, 奇数 vlan 生成树根选择 Core1，偶数 vlan 生成树根选择 Core2Core1 ， Core2， ED-SW:vlan 2 / 添加 vlan 2name testvlan2/ 命名 vlan 2 为 testvlan2vlan 3name testvlan3vlan 4name tes

8、tvlan4 vlan 5name testvlan5vlan 6name testvlan6vlan 7name testvlan7vlan 8name testvlan8 vlan 9name testvlan9vlan 10name testvlan107. 验证新添加的 vlanCore1#sh vlan brief/ Vlan 标号列， vlan 名字，状态，及对应端口VLAN Name Status Ports1 defaultactive Fa0/1, Fa0/2, Fa0/3, Fa0/4 Fa0/5, Fa0/6, Fa0/7, Fa0/8 Fa0/9, Fa0/10, Fa

9、0/11, Fa0/12Fa0/13, Fa0/14, Fa0/15, Fa0/16Fa0/17, Fa0/18, Fa0/19, Fa0/20Fa0/22, Gi0/1, Gi0/2/ 这些端口默认划分到vlan1 ，注意 Fa0/21,23,24不在这里，因为这 3 个端口做成了 Trunk2 testvlan2 部分输出忽略9 testvlan910 testvlan101002 fddi-defaultactiveactiveactive act/unsup /这些为特殊 vlan ，现在基本不用1003 token-ring-defaultact/unsup8. 验证新添加的 vla

10、nCore1#sh spanning-treeVLAN0001Spanning tree enabled protocol ieee/ Spanning-tree 为 ieee 标准Root ID Priority 32769 / 此交换机 vlan 1 的优先级默认 32728 vlan 的标号，则 vlan2 为 327682，其他 vlan 类似。Address 000d.65dc.8800 / 交换机 MACThis bridge is the root/ 此交换机已经成为 valn1 的 root ，默认情况一台交换机成为所有 vlan 的 rootHello Time 2 sec

11、Max Age 20 sec Forward Delay 15 secBridge ID Priority 32769 (priority 32768 sys-id-ext 1)Address 000d.65dc.8800Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Aging Time 300InterfaceRoleStsCostPrio.Nbr TypeFa0/4DesgFWD19128.4P2pFa0/21DesgFWD19128.21P2p /状态，STP Cost 为 19Po2DesgFWD12128.65P2pF0/2

12、1 为指定端口， 处于转发VLAN0002Spanning tree enabled protocol ieeeRoot ID Priority 32770Address 000d.65dc.8800This bridge is the rootHello Time 2 sec Max Age 20 sec Forward Delay 15 secBridge ID Priority 32770 (priority 32768 sys-id-ext 2)Address 000d.65dc.8800Hello Time 2 sec Max Age 20 sec Forward Delay 15

13、secAging Time 300InterfaceRole Sts Cost Prio.Nbr TypeFa0/21 Desg FWD 19 128.21 P2pPo2Desg FWD 12 128.65 P2p9. 设置 Core1 为 vlan 1 ，3，5，7，9 的主根 作为 vlan2 ，4，6，8，10 的次根 设置 Core2 为 vlan2 ，4，6，8，10 的主根 作为 vlan1 ，3，5，7，9 的次根Core1 ：spanning-tree vlan 1,3,5,7,9 root primary spanning-tree vlan 2,4,6,8,10 root

14、secondaryCore2 ：spanning-tree vlan 1,3,5,7,9 root secondaryspanning-tree vlan 2,4,6,8,10 root primary10. 验证根配置Core1#sh spanning-treeVLAN0001Spanning tree enabled protocol ieee Root ID Priority 24577Address 000d.65dc.8800 This bridge is the rootHello Time 2 sec Max Age 20 sec Forward Delay 15 secBrid

15、ge ID Priority 24577 (priority 24576 sys-id-ext 1) Address 000d.65dc.8800Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Aging Time 300InterfaceRole Sts CostPrio.Nbr TypeFa0/4Desg FWD 19128.4P2pFa0/21Desg FWD 19128.21P2pPo2Desg FWD 12128.65P2pVLAN0002Spanning tree enabled protocol ieeeRoot ID P

16、riority 24578 / 根网桥优先级及 MAC，vlan2 的根已经变成了 Core2 Address 0013.80e2.4880Cost 12Port 65 (Port-channel2)本网桥优先级及 MAC地址Hello Time 2 sec Max Age 20 sec Forward Delay 15 secBridge ID Priority 28674 (priority 28672 sys-id-ext 2)Address 000d.65dc.8800Hello Time 2 sec Max Age 20 sec Forward Delay 15 secAging T

17、ime 300InterfaceRole Sts CostPrio.Nbr TypeFa0/21Desg FWD 19128.21 P2pPo2Root FWD 12128.65 P2p /指定端口变成了根端口Core1#sh runspanning-tree mode pvst / 生成树模式，默认为 PVST spanning-tree vlan 1,3,5,9 priority 24576spanning-tree vlan 2,4,6,8,10 priority 28672 /命令被自动转换，也可以直接使用此命令11. 把 PC接入到 ED-SW的 Fa0/2 ，并记录端口指示灯转换到

18、绿色的时间 _S 为了解决交换机端口转发延迟问题，启用 Fa0/2 的 portfast 功能ED-SW: ed-sw(config-if)# spanning-tree portfast %Warning: portfast should only be enabled on ports connected to a single host. Connecting hubs, concentrators, switches, bridges, etc. to this interface when portfast is enabled, can cause temporary bridgi

19、ng loops. Use with CAUTION/ 告警信息， 建议启用了 portfast 功能的接口只连接单台主机， 接其他设备可 能会发生环路%Portfast has been configured on FastEthernet0/2 but will only have effect when the interface is in a non-trunking mode./ Portfast 功能只在非 Trunk 模式下生效注：也可以在全局模式下输入 spanning-tree portfast default 启用所有的端口 portfast 功能12. 重新插拔 PC与

20、 ED-SW的网线，再次记录端口指示灯转换到绿色的时间 _S 验证 portfast 已经在 Fa0/2 口上启用ed-sw#sh spanning-tree interface f0/2 portfastVLAN0001 enabled13. 配置 PC IP 地址： 192.168.88.203/24配置 Core1 Vlan1 IP 地址： 192.168.88.201/24配置 Core2 Vlan1 IP 地址： 192.168.88.202/24Core1 ：interface Vlan1ip address 192.168.88.201 255.255.255.0no shut

21、endCore2 ：interface Vlan1ip address 192.168.88.202 255.255.255.0no shutend14. 在 PC的 DOS命令行下：ping 192.168.88.201 -t /不停的 Ping 192.168.88.201断掉 ED-SW到 Core1 的连接，记录 ping 包丢失了 _个15. 在 ED-SW上配置 uplinkfasted-sw(config)#spanning-tree uplinkfast16. 验证 uplinkfasted-sw#sh spanning-tree uplinkfastUplinkFast is

22、 enabled17. 在 PC的 DOS命令行下：ping 192.168.88.201 -t /不停的 Ping 192.168.88.201断掉 ED-SW到 Core1 的连接，记录 ping 包丢失了 _个18. 取消 ED-SW的 uplinkfast 功能ed-sw(config)#no spanning-tree uplinkfast19. 启用 Core1，Core2，ED-SW的 RSTP功能Core1，Core2，ED-SW：(Config)# spanning-tree mode rapid-pvst20. 验证 RSTP是否启用ed-sw#sh spanning-tr

23、eeVLAN0001Spanning tree enabled protocol rstp / 生成树模式Root ID Priority 24577Address 000d.65dc.8800Cost 19Port 23 (FastEthernet0/23)Hello Time 2 sec Max Age 20 sec Forward Delay 15 secBridge ID Priority 32769 (priority 32768 sys-id-ext 1)Address 000d.bdbb.7480Hello Time 2 sec Max Age 20 sec Forward De

24、lay 15 secAging Time 300InterfaceRole Sts CostPrio.Nbr TypeFa0/2Desg FWD 19128.2 Edge P2p /边缘端口Fa0/4Desg BLK 19128.4 P2pFa0/23Root FWD 19128.23 P2pFa0/24Altn BLK 19128.24 P2p /被阻塞的端口VLAN0002Spanning tree enabled protocol rstpRoot ID Priority 24578Address 0013.80e2.4880Cost 19Port 24 (FastEthernet0/2

25、4)Hello Time 2 sec Max Age 20 sec Forward Delay 15 secBridge ID Priority 32770 (priority 32768 sys-id-ext 2)Address 000d.bdbb.7480Hello Time 2 sec Max Age 20 sec Forward Delay 15 secAging Time 300InterfaceRole Sts CostPrio.Nbr TypeFa0/23Altn BLK 19128.23 P2pFa0/24 Root FWD 19 128.24 P2p在 PC 的 DOS命令行

26、下：ping 192.168.88.201 -t /不停的 Ping 192.168.88.201断掉 ED-SW到 Core1 的连接，记录 ping 包丢失了 _个21. 配置 MST，2Core1，Core2，ED-SW上启用两个 MST Instance 1Vlan1，3，5，7，Vlan2 ，4，6，8，Core1 instance 19 映射到 Instance 110映射到 Instance 2优先级设为 4096Instacen 2 优先级设置 16384 spanning-tree mst 1 priority 16384 spanning-tree mst 2 priori

27、ty 8192Core2 instance 1Instacen 2优先级设为 16384优先级设置 4096Core1:spanning-tree mode mst spanning-tree mst configuration instance 1 vlan 1, 3, 5, 7, 9 instance 2 vlan 2, 4, 6, 8, 10spanning-tree mst 1 priority 16384 spanning-tree mst 2 priority 8192Core2 ：spanning-tree mode mst spanning-tree mst configura

28、tion instance 1 vlan 1, 3, 5, 7, 9 instance 2 vlan 2, 4, 6, 8, 10ED-SW： spanning-tree mode mst spanning-tree mst configuration instance 1 vlan 1, 3, 5, 7, 9 instance 2 vlan 2, 4, 6, 8, 1022. 验证 MST配置Core2#sh spanning-treeMST0Spanning tree enabled protocol mstpRoot ID Priority 32768Address 000d.65dc.

29、8800Cost 0Port 65 (Port-channel2)Hello Time 2 sec Max Age 20 sec Forward Delay 15 secBridge ID Priority 32768 (priority 32768 sys-id-ext 0)Address 0013.80e2.4880Hello Time 2 sec Max Age 20 sec Forward Delay 15 secInterfaceRole Sts Cost Prio.Nbr TypeFa0/4Desg FWD 200000 128.4 P2pFa0/21Desg FWD 200000

30、 128.21 P2p Pre-STD-RxPo2Root FWD 100000 128.65 P2pMST1Spanning tree enabled protocol mstpRoot ID Priority 16385Address 0013.80e2.4880This bridge is the rootHello Time 2 sec Max Age 20 sec Forward Delay 15 secBridge ID Priority 16385 (priority 16384 sys-id-ext 1)Address 0013.80e2.4880Hello Time 2 se

31、c Max Age 20 sec Forward Delay 15 secFa0/4InterfaceRole Sts Cost Prio.Nbr TypeDesg FWD 200000 128.4 P2pFa0/21Desg FWD 200000 128.21 P2p Pre-STD-RxPo2 Desg FWD 100000 128.65 P2pMST2Spanning tree enabled protocol mstpRoot ID Priority 8194Address 0013.80e2.4880This bridge is the rootHello Time 2 sec Ma

32、x Age 20 sec Forward Delay 15 secBridge ID Priority 8194 (priority 8192 sys-id-ext 2)Address 0013.80e2.4880Hello Time 2 sec Max Age 20 sec Forward Delay 15 secInterface Role Sts Cost Prio.Nbr TypeFa0/21 Desg FWD 200000 128.21 P2p Pre-STD-RxPo2Desg FWD 100000 128.65 P2p23. 配置 ED-SW BPDU Guarded-sw(co

33、nfig-if)#int f0/24ed-sw(config-if)# spanning-tree bpduguard enableed-sw(config-if)#02:51:16: %SPANTREE-2-BLOCK_BPDUGUARD: Received BPDU on port FastEthernet0/24 with BPDU Guard enabled. Disabling port. /端口启用此功能后，收到任何BPDU信息，则此端口进入err-disable 状态02:51:16: %PM-4-ERR_DISABLE: bpduguard error detected on

34、Fa0/24, putting Fa0/24 in err-disable state02:51:17: %LINEPROTO-5-UPDOWLNin: e protocol on Interface FastEthernet0/24, changed state to down24. 配置 ED-SW F0/24端口，启用 Guard Root 功能ed-sw(config-if)# spanning-tree guard root02:54:56: %SPANTREE-2-ROOTGUARD_CONFIG_CHANGE: Root guard enabled on port FastEth

35、ernet0/24.02:54:56: %SPANTREE-2-ROOTGUARD_BLOCK: Root guard blocking port FastEthernet0/24 on MST00./ 启用此功能后， 如果 F0/24 端口接入了 =目前根交换机生成树优先级的交换 机，则 Block 此端口25. 验证 ED-SW的 STP状态ed-sw#sh spanning-treeMST00Spanning tree enabled protocol mstpRoot ID Priority 32768Address 000d.65dc.8800CostPort 23 (FastEth

36、ernet0/23)Hello Time 2 sec Max Age 20 sec Forward Delay 15 secBridge ID Priority 32768 (priority 32768 sys-id-ext 0)Address 000d.bdbb.7480Hello Time 2 sec Max Age 20 sec Forward Delay 15 secInterfaceRole Sts CostPrio.Nbr TypeFa0/2Desg FWD 200000128.2Edge P2pFa0/4Desg FWD 200000128.4P2pFa0/23Root FWD 200000128.23P2pFa0/24Desg BKN*2