STP configuration and routing rules

1. Use four S3700 switch, 2 PC, set up the network topology

2. Set mengyu-S1

　　(1) Enable Spanning Tree switch (MSTP Huawei switches enabled by default), change the STP mode switch to normal spanning tree STP;

　　(2) configuration, the wait time is 30s by default spanning tree is recalculated, using the commands "display stp" See spanning tree state mengyu-S1

　　(3) You can also use the command "display stp brief", view summary information

3. Set mengyu-S2

　　(1) Enable Spanning Tree switch (MSTP Huawei switches enabled by default), change the STP mode switch to normal spanning tree STP;

　　(2) is configured, by default wait time is 30s spanning tree recalculation, then the command "display stp" View mengyu-S2 spanning tree state

　　(3) You can also use the command "display stp brief", view summary information

4. Set mengyu-S3

　　(1) Enable Spanning Tree switch (MSTP Huawei switches enabled by default), change the STP mode switch to normal spanning tree STP;

　　(2) configuration, the wait time is 30s by default spanning tree is recalculated, using the commands "display stp" See spanning tree state mengyu-S3

　　(3) You can also use the command "display stp brief", view summary information

5. mengyu-S4 set

　　(1) Enable Spanning Tree switch (MSTP Huawei switches enabled by default), change the STP mode switch to normal spanning tree STP;

　　(2) is configured, by default wait time is 30s spanning tree recalculation, then the command "display stp" View mengyu-S4 spanning tree state

　　(3) You can also use the command "display stp brief", view summary information

Currently we can see, mengyu-S2 root switch

4. Now we have to manually set the root switch

　　(1) Manually Set mengyu-S1 is the root switch, mengyu-S2 is a standby switch, we mengyu-S1 priority is set to 0, menyu-S2 priority is set to 4096 (4096 is a multiple of the priority of the default The priority is 32768);

　　　　① 设置 mengyu-S1

　　　　② Set mengyu-S2

　　　　③ After configuration view mengyu-S1 and status information mengyu-2

　　　　④ we can find a priority mengyu-S1 becomes 0, is the root switch; mengyu-S2 becomes the priority of 4096, for the root switch;

　　(2) in another way to the root switch mengyu-S1, mengyu-S2 to the backup exchange

　　　　①先用命令“undo stp priority”，删除在mengyu-S1配置的优先级（让它回到默认值32768）；然后用命令“stp root primary”，把mengyu-S1交换机设为根交换机

　　　　②先用命令“undo stp priority”，删除在mengyu-S2配置的优先级（让它回到默认值32768）；然后用命令“stp root secondary”，把mengyu-S2交换机设为备份根交换机

　　　　③查看交换机状态，发现mengyu-S1的优先级还是0，mengyu-S2的优先级为4096

5.根端口的选举

　　（1）在mengyu-S1为根交换机，mengyu-S2为备份交换机是用命令“display stp brief”查看生成树信息，发现E0/0/2为根端口，状态为转发状态

　　　　①由于拓扑中所有的链路都是百兆以太网链路，mengyu-S4经过mengyu-S3到mengyu-S1与mengyu-S2到mengyu-S1的开销值相同；接下来比较交换机标识， mengyu-S2的优先级是4096，而mengyu-S3默认是32768，所以与mengyu-S2连接的E0/0/2接口为根端口。

　　　　 ②使用命令 display stp interface Ethernet 0/0/2 的开销值