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