分类：
2012-02-07 20:46:53
以下是Services 1交换机的MST实例配置：
Services 1(config)#spanning-tree mst configuration
Services 1(config-mst)#name region1
Services 1(config-mst)#revision 10
Services 1(config-mst)#instance 1 vlan 10, 30, 100
Services 1(config-mst)#instance 2 vlan 20, 40, 200
Services 1(config-mst)#exit
以下是Services 2交换机的MST实例配置：
Services 2(config)#spanning-tree mst configuration
Services 2(config-mst)#name region1
Services 2(config-mst)#revision 10
Services 2(config-mst)#instance 1 vlan 10, 30, 100
Services 2(config-mst)#instance 2 vlan 20, 40, 200
Services 2(config-mst)#exit
以下是配置两汇聚层交换机中的所有中继链路上可以承载所有VLAN通信。
Services 1(config)#interface FastEthernet0/5
Services 1(config-if)#switchport trunk allowed vlan 10,20,30,40,100,200
!
Services 1(config)#interface FastEthernet0/47
Services 1(config-if)#switchport trunk allowed vlan 10,20,30,40,100,200
!
Services 1(config)#interface FastEthernet0/48
Services 1(config-if)#switchport trunk allowed vlan 10,20,30,40,100,200
!
Services 2(config)#interface FastEthernet0/6
Services 2(config-if)#switchport trunk allowed vlan 10,20,30,40,100,200
!
Services 2(config)#interface FastEthernet0/47
Services 2(config-if)#switchport trunk allowed vlan 10,20,30,40,100,200
!
Services 2(config)#interface FastEthernet0/48
Services 2(config-if)#switchport trunk allowed vlan 10,20,30,40,100,200
以下是把两汇聚层交换机上当前的PVST+模式迁移到MSTP模式。
Services 1(config)#spanning-tree mode mst
Services 2(config)#spanning-tree mode mst
下面是配置两汇聚层交换机间的中继链路上的VLAN通信流负载均衡。这是通过配置Services 1交换机Fa 0/47端口对于MST2实例具有比Fa 0/46端口更低的端口开销值，使在Fa 0/47端口只传输MST2实例中的VLAN通信。注意，这里也只需要在中继链路的一端配置即可。然后在Services 2交换机配置Fa 0/6端口对于MST1实例中VLAN的路径开销值更高，从而禁止从Fa 0/46端口传输MST1实例中的VLAN通信，只允许传输MST2中的VLAN通信。
Services 1(config)#interface fastEthernet 0/46
Services 1(config-if)#spanning-tree mst 2 cost 200000 !--
Services 1(config-if)#exit
Services 1(config)#interface fastEthernet 0/47
Services 1(config-if)#spanning-tree mst 2 cost 100000
Services 1(config-if)#exit
Services 2(config)#interface FastEthernet 0/6
Services 2(config-if)#spanning-tree mst 1 cost 500000
Services 2(config-if)#exit
以下是清除两汇聚层交换机上的PVST+ 的UplinkFast和BackboneFast特性配置，恢复Services 1交换机Fa0/5端口对于VLAN 100的路径开销值为默认值，恢复Services 2交换机Fa0/6端口对于VLAN 200的路径开销值为默认值，恢复Services 2交换机Fa0/48端口对于VLAN 200的端口优先级值为默认值。
Services 1(config)#no spanning-tree uplinkfast
Services 1(config)#no spanning-tree backbonefast
Services 1(config)#interface FastEthernet0/5
Services 1(config-if)#no spanning-tree vlan 100 cost 18
Services 1(config-if)#exit
Services 2(config)#no spanning-tree uplinkfast
Services 2(config)#no spanning-tree backbonefast
Services 2(config)#interface FastEthernet0/6
Services 2(config-if)#no spanning-tree vlan 200 cost 18
Services 2(config-if)#exit
Services 2(config)#interface FastEthernet0/48
Services 2(config-if)#no spanning-tree vlan 200 port-priority 64
Services 2(config-if)#exit
