My computer (Windows 7) has two Ethernet ports (ASUS Maximus IV Extreme MOBO), both are Gigabit, and I have one port connected to the Ethernet port in the wall that leads to the central router/modem/switch and the other port on the motherboard connected to the WiFi router in my room (this router is only for WiFi and Ethernet switch purposes only so DHCP is turned off on this router).
Since I've got the whole house including all routers under one DNS/network, both connections from my motherboard are connected to the same network (lets just call this network "Home" for my example). Under "Network Connections", both connections have internet access. In my house on my Home network, I have several other computers and NAS (Network Storage) devices and media players and I was wondering if I could assign one of my motherboard's Ethernet ports to handle all internet-only traffic and the other one to handle only LAN traffic, so that I can download or skype using one Ethernet port on my motherboard while at the same time transferring data between devices on my LAN using only the other Ethernet port on my motherboard. Both Ethernet ports are controlled by an Intel controller.
Keep in mind that when I say "ports" here I'm talking about physical Ethernet ports and that we want both to stay on the same network or DNS or whatever they call it, I just want to allocate one for internet traffic and the other for LAN traffic.
Is this possible? And if so, how do I do it?