Cisco subinterface 802.1Q
!!switch interface FastEthernet0/1 switchport access vlan 10 switchport mode access ! interface FastEthernet0/2 switchport access vlan 20 switchport mode access ! interface GigabitEthernet0/1 switchport mode trunk !! router int g0/0 no sh ! int g0/0.1 encapsulation dot1Q 10 ip add 192.168.10.1 255.255.255.0 ! int g0/0.2 encapsulation dot1Q 20 ip add 192.168.11.1 255.255.255.0