sw3设置优先级

Switch>ena
Switch#conf t
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)#span
Switch(config)#spanning-tree vlan 1 pr
Switch(config)#spanning-tree vlan 1 priority ?
<0-61440> bridge priority in increments of 4096
Switch(config)#spanning-tree vlan 1 priority 4096

sw3查看生成树

Switch#show spanning-tree

VLAN0001
Spanning tree enabled protocol ieee
Root ID Priority 1
Address aabb.cc00.1000
Cost 100
Port 1 (Ethernet0/0)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 4097 (priority 4096 sys-id-ext 1)
Address aabb.cc00.3000
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec

Interface Role Sts Cost Prio.Nbr Type

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Et0/0 Root FWD 100 128.1 Shr
Et0/1 Desg FWD 100 128.2 Shr
Et0/2 Desg FWD 100 128.3 Shr
Et0/3 Desg FWD 100 128.4 Shr
Et1/0 Desg FWD 100 128.5 Shr
Et1/1 Desg FWD 100 128.6 Shr
Et1/2 Desg FWD 100 128.7 Shr