将交换机的端口生成树成本设置为30,使用以下哪个命令()A.ruijie(config)#spanning-t...
A.ruijie(config)#spanning-treecost 30
B.ruijie(config-if-fastethernet0/1)#spanning-tree cost 30
C.ruijie(config)#spanning-tree priority 30
D.ruijie(config-if-fastethernet0/1)#spanning-treepath-cost 30