链路聚合多生成树域

多生成树（MST）使用修正的快速生成树（RSTP）协议，叫做多生成树协议（MSTP）

　　MSTP（Multiple Spanning Tree Protocol，多生成树协议）

　　将环路网络修剪成为一个无环的树型网络，避免报文在环路网络中的增生和无限循环，同时还提供了数据转发的多个冗余路径，在数据转发过程中实现VLAN 数据的负载均衡。MSTP 兼容STP 和RSTP，并且可以弥补STP 和RSTP 的缺陷。它既可以快速收敛，也能使不同VLAN 的流量沿各自的路径分发，从而为冗余链路提供了更好的负载分担机制。

实验环境：ensp模拟器

Sw1配置：

[sw1]vlan 10

[sw1-vlan10]vlan 20

[sw1-vlan20]vlan 30

[sw1]stp enable #启动生成树，默认启动mstp

[sw1]dis stp

-------[CIST Global Info][Mode MSTP]-------

CIST Bridge :32768.4c1f-cc73-940e

Config Times :Hello 2s MaxAge 20s FwDly 15s MaxHop 20

Active Times :Hello 2s MaxAge 20s FwDly 15s MaxHop 20

CIST Root/ERPC :32768.4c1f-cc6c-00b5 / 1

CIST RegRoot/IRPC :32768.4c1f-cc73-940e / 0

CIST RootPortId :128.3

BPDU-Protection :Disabled

TC or TCN received:6

[sw1]stp region-configuration

[sw1-mst-region]region-name liufan #建立域名

[sw1-mst-region]instance 1 vlan 10 20 #建立树1

[sw1-mst-region]instance 2 vlan 30 40 #建立树2

[sw1-mst-region]check region-configuration #查看域

Admin configuration

Format selector :0

Region name :liufan

Revision level :0

Instance VLANs Mapped

0 1 to 9,11 to 19,21 to 29,31 to 39,41 to 4094

1 10,20

2 30,40

[sw1-mst-region]revision-level 1

[sw1-mst-region]active region-configuration #启动域

Info: This operation may take a few seconds. Please wait for a moment...done.

[sw1]inter gig0/0/1

[sw1-GigabitEthernet0/0/1]port link-type trunk

[sw1-GigabitEthernet0/0/1]port trunk allow vlan all

[sw1]inter gig0/0/3

[sw1-GigabitEthernet0/0/3]port link-type trunk

[sw1-GigabitEthernet0/0/3]port trunk allow vlan all

[sw1]inter gig0/0/2

[sw1-GigabitEthernet0/0/2]port link-type trunk

[sw1-GigabitEthernet0/0/2]port trunk allow vlan all

[sw1]inter gig0/0/4

[sw1-GigabitEthernet0/0/4]port link-type trunk

[sw1-GigabitEthernet0/0/4]port trunk allow vlan all

Sw2配置：

[sw2]vlan 10

[sw2-vlan10]vlan 20

[sw2-vlan20]vlan 30

[sw2-vlan30]vlan 40

[sw2]stp region-configuration

[sw2-mst-region]region-name liufan

[sw2-mst-region]instance 1 vlan 10 20

[sw2-mst-region]instance 2 vlan 30 40

[sw2-mst-region]revision-level 1

[sw2-mst-region]active region-configuration

Info: This operation may take a few seconds. Please wait for a moment...done.

[sw2-mst-region]

Nov 28 2012 17:34:52-08:00 sw2 DS/4/DATASYNC_CFGCHANGE:OID 1.3.6.1.4.1.2011.5.25

.191.3.1 configurations have been changed. The current change number is 9,the c

hange loop count is 0,and the maximum number of records is 4095.

[sw2-mst-region]check region

Admin configuration

Format selector :0

Region name :liufan

Revision level :1

Instance VLANs Mapped

0 1 to 9,40

[sw2-GigabitEthernet0/0/4]inter gig0/0/2

[sw2-GigabitEthernet0/0/2]port link-type trunk

[sw2-GigabitEthernet0/0/2]port trunk allow vlan all

[sw2-GigabitEthernet0/0/2]inter gig0/0/4

[sw2-GigabitEthernet0/0/4]port link-type trunk

[sw2-GigabitEthernet0/0/4]port trunk allow vlan all

[sw2-GigabitEthernet0/0/4]inter gig0/0/1

[sw2-GigabitEthernet0/0/1]port link-type trunk

[sw2-GigabitEthernet0/0/1]port trunk allow vlan all

配置sw3：

[sw3]vlan 10

[sw3-vlan10]vlan 20

[sw3-vlan20]vlan 30

[sw3-vlan30]vlan 40

[sw3]stp region-configuration

[sw3-mst-region]region-name liufan

[sw3-mst-region]instance 1 vlan 10 20

[sw3-mst-region]instance 2 vlan 30 40

[sw3-mst-region]revision-level 1

[sw3-mst-region]active region-configuration

[sw3]inter gig0/0/1

[sw3-GigabitEthernet0/0/1]port link-type trunk

[sw3-GigabitEthernet0/0/1]port trunk allow vlan all

[sw3]inter gig0/0/3

[sw3-GigabitEthernet0/0/3]port link-type trunk

[sw3-GigabitEthernet0/0/3]port trunk allow vlan all

配置sw4：

[sw4]vlan 10

[sw4-vlan10]vlan 20

[sw4-vlan20]vlan 30

[sw4-vlan30]vlan 40

[sw4]stp region-configuration

[sw4-mst-region]region-name liufan

[sw4-mst-region]instance 1 vlan 10 20

[sw4-mst-region]instance 2 vlan 30 40

[sw4-mst-region]revision-level 1

[sw4-mst-region]active region-configuration

[sw4]inter gig0/0/1

[sw4-GigabitEthernet0/0/1]port link-type trunk

[sw4-GigabitEthernet0/0/1]port trunk allow vlan all

[sw4]inter gig0/0/3

[sw4-GigabitEthernet0/0/3]port link-type trunk

[sw4-GigabitEthernet0/0/3]port trunk allow vlan all

在sw1和sw2上做链路聚合：

[sw1]port-group 1

[sw1-port-group-1]group-member gig0/0/2

[sw1-port-group-1]group-member gig0/0/4

[sw1-port-group-1]dis port-group all

Portgroup: 1

GigabitEthernet0/0/2

GigabitEthernet0/0/4

[sw2]port-group 1

[sw2-port-group-1]group-member gig0/0/2

[sw2-port-group-1]group-member gig0/0/4

Sw3设置为树2的根：

[sw3]stp instance 2 root primary

[sw3]stp instance 1 root second

Sw4设置为树1的根：

[sw4]stp instance 1 root primary

[sw4]stp instance 2 root second

测试：

[sw2]dis stp instance 1 brief