A、 SW1(config-if)# switchport trunk encapsulation dot1q SW1(config-if)# switchport mode trunk SW1(config-if)# switchport trunk native DATA SW1(config-if)# switchport trunk allowed vlan 1,10,20 B、 SW1(config-if)# switchport trunk encapsulation dot1q SW1(config-if)# switchport mode dynamic auto SW1(config-if)# switchport trunk native DATA SW1(config-if)# witchport trunk allowed vlan add 1,10,20 C、 SW1(config-if)# switchport trunk encapsulation dot1q SW1(config-if)# switchport mode dynamic desirable SW1(config-if)# switchport trunk native vlan DATA SW1(config-if)# switchport trunk allowed vlan 1,10,20 D、 SW1(config-if)# switchport trunk encapsulation dot1q SW1(config-if)# switchport mode dynamic desirable SW1(config-if)# switchport trunk native vlan 10 SW1(config-if)# switchport trunk allowed vlan 1,10,20 E、 SW1(config-if)# switchport trunk encapsulation dot1q SW1(config-if)# switchport mode dynamic Desirable SW1(config-if)# switchport trunk native vlan 10