A.Switch-3548(config-if)#switchport trunk encapsulation dotl q
	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 isl
	Switch-3548 f config-if)#switchport trunk allowed vlan 1-30
	C.Switch-3548(config-if)#switehport 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)#switehport mode trunk
	Switch-3548(comqg-if)#switchport trunk encapsulation dotl q
	Switch-3548(config-if)#switchport trunk allowed vlan 1,10,20,30