PLEASE:
STP-Spanning Tree Protocol (Spanning Tree Protocol)
1. Logically disconnect the loop to prevent broadcast storms.
2. When the line fails, the blocking interface is activated to restore communication and play a backup role
The generation of switching network loops:
The formation of broadcast storm
Multi-frame replication
MAC address disorder
Spanning Tree Algorithm
The spanning tree algorithm is divided into three steps:
1. Select the root bridge (switch)
2. Select the root port
3. Select the designated port
Excluding the root port and designated ports, the rest is blocked ports
MSTP：
Multiple Spanning Tree Protocol—A spanning tree can be constructed for each VLAN or multiple VLANs as a group to achieve network load sharing (balance)
-----------将SW1、SW2分别做vlan10、vlan20的根网桥----------
[SW1]stp mode mstp ###将交换机配置成MSTP模式，MSTP兼容STP/RSTP。
[SW1]stp region-configuration ###进入MSTP域视图MSTP配置模式
[SW1-mst-region]region-name huawei1 ###配置MSTP域的域名为huawei1，缺省为交换设备主控板上管理网口的MAC地址。
[SW1-mst-region]revision-level 1 ###配置MST域的MSTP修订级别为1，缺省情况下MSTP域的MSTP修订级别为0，需要将各设备的MSTP修订级别修改为一致
####配置多生成树实例和VLAN的映射关系，同一vlan的数据只能对应一个实例，而一个实例可以对应多个vlan（instance 1 vlan 2 to 10）
[SW1-mst-region]instance 1 vlan 10 ###将vlan 10加入实例1中
[SW1-mst-region]instance 2 vlan 20 ###将vlan 20加入实例2中
[SW1-mst-region]check region-configuration ###查看MSTP域配置参数
[SW1-mst-region]active region-configuration ###激活MSTP域的配置（必须配置）
[SW1-mst-region]quit ###退出配置模式
[SW1]stp instance 1 root primary ###配置此交换机为实例1的主根桥
[SW1]stp instance 2 root secondary ###配置此交换机为实例2的备份根桥
------------------------------
[SW2]stp mode mstp
[SW2]stp region-configuration
[SW2-mst-region]region-name huawei1
[SW2-mst-region]revision-level 1
[SW2-mst-region]instance 1 vlan 10
[SW2-mst-region]instance 2 vlan 20
[SW2-mst-region]active region-configuration
[SW2-mst-region]quit
[SW2]stp instance 1 root secondary ###配置SW1交换机为实例1的备份根桥
[SW2]stp instance 2 root primary ###配置SW2交换机为实例2的主根桥
-----------------------------------
[SW3]stp mode mstp
[SW3]stp region-configuration
[SW3-mst-region]region-name huawei1
[SW3-mst-region]revision-level 1
[SW3-mst-region]instance 1 vlan 10
[SW3-mst-region]instance 2 vlan 20
[SW3-mst-region]active region-configuration
[SW1]stp enable ###在所有交换机上启用MSTP
[SW2]stp enable
[SW3]stp enable
[SW3]dis stp brief ###查看STP接口角色及状态信息
--------修改交换机优先级值----------------
[SW1]stp priority 0 ###数值要为4096的倍数
[SW1]stp root primary ###优先级变为0
[SW1]dis stp ###查看stp信息，可以确定哪个是根网桥
Practice questions
