MSTP环路避免实验

思科设备参考：

一，技术简介

MSTP（多生成树协议），MSTP解决了STP和RSTP没有考虑vlan的问题，STP和RSTP将所有的vlan共享为一个生成树实例，无法实现负载分担，这样就导致了网络中一些设备出现闲置状态，没有流量通过。MSTP将这个交换网络分成多个生成树，每一棵树对应一个实例，每一个实例之间对应多个vlan，实例与实例之间互不影响。

二，实验目的

要求

① 所有交换机都在 "A" 这个域上，修订级别为1。

② vlan10对应实例10，根网桥在Switch1上。vlan20对应实例20，根网桥在Switch2上。

③ PC1能够走Switch3---->Switch1----->Router成功访问PC2，最短路径优先，PC2也如此

三，配置命令

1，基础配置

Router

<Huawei>system-view

[Huawei]int g0/0/0

[Huawei-GigabitEthernet0/0/0]ip address 192.168.10.10 24

[Huawei-GigabitEthernet0/0/0]quit

[Huawei]int g0/0/1

[Huawei-GigabitEthernet0/0/1]ip address 192.168.20.20 24

[Huawei-GigabitEthernet0/0/1]quit

[Huawei]display current-configuration

Switch1

<Huawei>system-view

[Huawei]undo info-center enable

[Huawei]vlan batch 10 20

[Huawei]int g0/0/1

[Huawei-GigabitEthernet0/0/1]port link-type trunk

[Huawei-GigabitEthernet0/0/1]port trunk allow-pass vlan 10 20

[Huawei-GigabitEthernet0/0/1]quit

[Huawei]int g0/0/3

[Huawei-GigabitEthernet0/0/3]port link-type trunk

[Huawei-GigabitEthernet0/0/3]port trunk allow-pass vlan 10 20

[Huawei-GigabitEthernet0/0/3]quit

[Huawei]int g0/0/2

[Huawei-GigabitEthernet0/0/2]port link-type hybrid

[Huawei-GigabitEthernet0/0/2]port hybrid untagged vlan 10

[Huawei-GigabitEthernet0/0/2]port hybrid pvid vlan 10

[Huawei-GigabitEthernet0/0/2]quit

[Huawei]display current-configuration

Switch2

<Huawei>system-view

[Huawei]undo info-center enable

[Huawei]vlan batch 10 20

[Huawei]int g0/0/1

[Huawei-GigabitEthernet0/0/1]port link-type trunk

[Huawei-GigabitEthernet0/0/1]port trunk allow-pass vlan 10 20

[Huawei-GigabitEthernet0/0/1]quit

[Huawei]int g0/0/3

[Huawei-GigabitEthernet0/0/3]port link-type trunk

[Huawei-GigabitEthernet0/0/3]port trunk allow-pass vlan 10 20

[Huawei-GigabitEthernet0/0/3]quit

[Huawei]int g0/0/2

[Huawei-GigabitEthernet0/0/2]port link-type hybrid

[Huawei-GigabitEthernet0/0/2]port hybrid untagged vlan 10

[Huawei-GigabitEthernet0/0/2]port hybrid pvid vlan 10

[Huawei-GigabitEthernet0/0/2]quit

[Huawei]display current-configuration

Switch3

<Huawei>system-view

[Huawei]undo info-center enable

[Huawei]vlan batch 10 20

[Huawei]int g0/0/1

[Huawei-GigabitEthernet0/0/1]port link-type access

[Huawei-GigabitEthernet0/0/1]port default vlan 10

[Huawei-GigabitEthernet0/0/1]quit

[Huawei]int g0/0/2

[Huawei-GigabitEthernet0/0/2]port link-type access

[Huawei-GigabitEthernet0/0/2]port default vlan 20

[Huawei-GigabitEthernet0/0/2]quit

[Huawei]int g0/0/3

[Huawei-GigabitEthernet0/0/3]port link-type trunk

[Huawei-GigabitEthernet0/0/3]port trunk allow-pass vlan 10 20

[Huawei-GigabitEthernet0/0/3]quit

[Huawei]int g0/0/4

[Huawei-GigabitEthernet0/0/4]port link-type trunk

[Huawei-GigabitEthernet0/0/4]port trunk allow-pass vlan 10 20

[Huawei-GigabitEthernet0/0/4]quit

[Huawei]display current-configuration

以上配置好了以后，其实PC1和PC2是可以ping通的，因为整个网络就只存在一个生成树，且无环路，但是走的路可能不是最优的，有一些链路也存在闲置状态，完全没有达到负载分担的效果。

2，MSTP配置

所有的交换机都要配置MSTP

Switch1

[Huawei]stp mode mstp

[Huawei]stp region-configuration

[Huawei-mst-region]region-name myRegion

[Huawei-mst-region]revision-level 1

[Huawei-mst-region]instance 10 vlan 10

[Huawei-mst-region]instance 20 vlan 20

[Huawei-mst-region]active region-configuration

[Huawei-mst-region]quit

[Huawei]stp instance 10 root primary

[Huawei]stp instance 20 root secondary

[Huawei]display current-configuration

Switch2

[Huawei]stp mode mstp

[Huawei]stp region-configuration

[Huawei-mst-region]region-name myRegion

[Huawei-mst-region]revision-level 1

[Huawei-mst-region]instance 10 vlan 10

[Huawei-mst-region]instance 20 vlan 20

[Huawei-mst-region]active region-configuration

[Huawei-mst-region]quit

[Huawei]stp instance 10 root secondary

[Huawei]stp instance 20 root primary

[Huawei]display current-configuration

Switch3

[Huawei]stp mode mstp

[Huawei]stp region-configuration

[Huawei-mst-region]region-name myRegion

[Huawei-mst-region]revision-level 1

[Huawei-mst-region]instance 10 vlan 10

[Huawei-mst-region]instance 20 vlan 20

[Huawei-mst-region]active region-configuration

[Huawei-mst-region]quit

[Huawei]display stp brief

对于实例10 g0/0/4为阻塞端口，对于实例20 g0/0/3为阻塞端口，这样，就确保了vlan10 的数据只能够经过Switch3--->Switch1--->Router，效果达到。