步驟：
1.關閉連接主機的端口的生成樹協議: sw1,sw2,sw3
int e0/0/3
stp disable
int e0/0/4
stp disable
2.創建vlan : sw1,sw2,sw3
vlan batch 10 20
3.把端口加入vlan:sw1,sw2,sw3
int e0/0/3
port link-type access
port default vlan 10
int e0/0/4
port link-type access
port default vlan 20
4.設置trunk端口:sw1,sw2,sw3
port-group 1
group-member e0/0/1 e0/0/2
port link-type trunk
port trunk allow-pass vlan all
5.創建stp域和創建兩個實例:sw1,sw2,sw3
stp region-configuration
region-name ABC
instance 1 vlan 10
instance 2 vlan 20
active region-configuration
6.設置每條路的拓撲，爲每個實例確定根網橋
[sw2]stp instance 1 priority 4096
[sw3]stp instance 2 priority 4096
7.分別測試vlan10和vlan20中各主機通聯