第一步：配置Vlans1(config)#vlan 1s1(config-vlan)#vlan 2s1(config-vlan)#vlan 3s1(config-vlan)#vlan 4第二步：为了同
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第一步：配置Vlan
s1(config)#vlan 1
s1(config-vlan)#vlan 2
s1(config-vlan)#vlan 3
s1(config-vlan)#vlan 4
第二步：为了同步vlan信息，我们配置vtp
s1(config)#int r f0/19 ,f0/24
s1(config-if-range)#sw trunk encapsulation dot1q
s1(config-if-range)#sw mo trunk
s2(config)#vtp domain libo
s2(config)#int f0/21
s2(config-if-range)#sw tr en d
s2(config-if-range)#sw mo tr
SW3上同理
第三步：配置MST
s1(config)#sp
s1(config)#spanning-tree mode mst
s1(config)#spanning-tree mst configuration
s1(config-mst)#name libo
s1(config-mst)#revision 1
s1(config-mst)#instance 1 vlan 1-2
s1(config-mst)#instance 2 vlan 3-4
s1(config)#spanning-tree mst 1 priority 12288
s1(config)#spanning-tree mst 2 priority 8192
s2(config)#spanning-tree mode mst
s2(config)#spanning-tree mst configuration
s2(config-mst)#name libo
s2(config-mst)#revision 1
s2(config-mst)#instance 1 vlan 1-2
s2(config-mst)#instance 2 vlan 3-4
s2(config-mst)#exi
s2(config)#spanning-tree mst 1 priority 8192
s2(config)#spanning-tree mst 2 priority 12288
//以上的配置说明了，让s1成为实例2的根桥，让s2成为实例1的根桥
在SW3上做相同的配置，不过不做优先级的更改，我们会想到，sw3的一个接口在一个实例中为转发状态，而在另一个实验中处于阻塞状态
第四步：show 相关
s3#sh spanning-tree
MST0
Spanning tree enabled protocol mstp
Root ID Priority 4096
Address 000b.be3d.4e00
Cost 0
Port 19 (FastEthernet0/19)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 4096 (priority 4096 sys-id-ext 0)
Address 0011.209a.cf80
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Interface Role Sts Cost Prio.Nbr Type
Fa0/19 Root FWD 200000 128.19 P2p
Fa0/21 Desg FWD 200000 128.21 P2p
MST1
Spanning tree enabled protocol mstp
Root ID Priority 8193
Address 0011.20a2.2880
Cost 200000
Port 21 (FastEthernet0/21)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32769 (priority 32768 sys-id-ext 1)
Address 0011.209a.cf80
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Interface Role Sts Cost Prio.Nbr Type
Fa0/19 Altn BLK 200000 128.19 P2p
Fa0/21 Root FWD 200000 128.21 P2p
MST2
Spanning tree enabled protocol mstp
Root ID Priority 8194
Address 000b.be3d.4e00
Cost 200000
Port 19 (FastEthernet0/19)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32770 (priority 32768 sys-id-ext 2)
Address 0011.209a.cf80
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Interface Role Sts Cost Prio.Nbr Type
Fa0/19 Root FWD 200000 128.19 P2p
Fa0/21 Altn BLK 200000 128.21 P2p
