I have a cisco 3745 router. Fa0/0 outside interface. Fa0/1 no ip. Fa0/1.1 native vlan ip 192.168.0.1 255.255.255.0. Fa0/1.2 vlan 10 ip 10.0.0.1 255.255.255.0.
I can connect to Internet on either vlan.
I can open ports to specific devices on native vlan. I cannot open ports on vlan 10.