[SW1-mst-region]int g0/0/1
[SW1-GigabitEthernet0/0/1]dis this
port link-type trunk
port trunk allow-pass vlan 2 to 4094
[SW1-GigabitEthernet0/0/1]int g0/0/2
interface GigabitEthernet0/0/2
port link-type trunk
port trunk allow-pass vlan 2 to 4094
[SW2-mst-region]int g0/0/1
[SW2-GigabitEthernet0/0/1]dis this
port link-type trunk
port trunk allow-pass vlan 2 to 4094
[SW2-GigabitEthernet0/0/1]int g0/0/2
interface GigabitEthernet0/0/2
port link-type trunk
port trunk allow-pass vlan 2 to 4094
[SW3-mst-region]int g0/0/1
[SW3-GigabitEthernet0/0/1]dis this
port link-type trunk
port trunk allow-pass vlan 2 to 4094
[SW3-GigabitEthernet0/0/1]int g0/0/2
interface GigabitEthernet0/0/2
port link-type trunk
port trunk allow-pass vlan 2 to 4094
[SW1-mst-region]dis this
stp region-configuration
region-name GOK
revision-level 12
instance 1 vlan 10
instance 2 vlan 20
active region-configuration
[SW2-mst-region]dis this
stp region-configuration
region-name GOK
revision-level 12
instance 1 vlan 10
instance 2 vlan 20
active region-configuration
[SW3-mst-region]dis this
stp region-configuration
region-name GOK
revision-level 12
instance 1 vlan 10
instance 2 vlan 20
active region-configuration
多了实例1和2
[SW1]dis this
vlan batch 10 20
stp instance 1 root primary //实例1 中交换机1为根桥
[SW2]dis this
vlan batch 10 20
stp instance 2 root primary //实例2中交换机2为根桥
以交换机1为例，在实例1中交换机1位根桥，所以实例一中交换机的两个端口都为指定端口
SW2，在实例2中交换机1位根桥，所以实例2中交换机2的两个端口都为指定端口
实现了负载分担