如下图所示,3com和Cisco公司的交换机相互连接,在两台交换机之间需传输VLANID为1、10、20和30的5个VLAN信息,Catalyst3548交换机VLANTrunk的正确配置是()
A.Switch-3548(config-if)#switchport trunk encapsulation dotlq
Switch-3548(config-if)#switchport trunk allowed vlan 1,10,20,30
B.Switch-3548(config-if)#switchport mode trunk
Switch-3548(config-if)#switchport trunk encapsulation is1
Switch-3548(config-if)#switchport tnmk allowed vlan 1-30
C.Switch-3548(config-if)#switchport mode trunk
Switch-3548(config-if)#switchport trunk encapsulation negotiate
Switch-3548(config-if)#switchport trunk allowed vlan 1-30
D.Switch-3548(config-if)#switchport mode trunk
Switch-3548(config-if)#switchport trunk encapsulation dotlq
Switch-3548(config-if)#switchport trunk allowed vlan 1,10,20,30