若port2要下接另外一台網管交換器，
則port2要加vlan tag，則必須設為trunk
設定如下：
先進入交換器的console
Vty-0#configure
Vty-0(config)#interface ethernet 1/2
Vty-0(config-if)#switchport mode trunk
Vty-0(config-if)#switchport allowed vlan add 11,22,33,44,55,66,99,101 tagged
Vty-0(config-if)#exit
Vty-0(config)#exit
儲存設定檔的指令
Vty-0#copy run startup-config
好了按enter
Startup configuration file name [startup1.cfg]:
Write to FLASH Programming.
Write to FLASH finish.
Success.
