I/F CPU WAN WAN2(LAN1) LAN2 LAN3 LAN4
eth0.1 tagged untag off off off off (ID=1, VLAN=1)
eth0.2 tagged off untag off off off (ID=2, VLAN=2)
eth1 untag off off untag untag untag (ID=3, VLAN実質無し)

こんな感じ?