Conf t
Interface f0/0
Switchport mode trunk
Switchport trunk encapsulation dot1q/isl
Switchport trunk allowed vlan 1,4
Switchport trunk allowed vlan 1-4
Switchport trunk allowed except vlan 1-2
生成树(STP)
Spanning-tree vlan 2
No spanning-tree vlan 2 打开与关闭树
Spanning-tree vlan 2 root primary 设置主 root根网桥
Spanning-tree vlan 3 root secondary 设置备份 root 备份网桥
Spanning-tree vlan 3 priority 8192 设置优先级(0,4096,8192.。。。 到 61440)
配置可选功能:
Spanning-tree backbonefast (不是连接 本交换机的链路失效时) 30 秒
Spanning-tree uplinkfast (连接本交换机链路失效 1-5 分钟
Spanning-tree uplinkfast max-update-rate (0-32000)
Spanning-tree portfast default
Spanning-tree portfast bpdufilter default