How do I properly support two network cards in one Windows 7 PC?

Question

I've upgraded from Vista to Windows 7. On Vista I used to run one network card (Intel 82566DC -2 Gigabit) for my internet which was connected to a Dovado USB mobile broadband router connected to a 3G modem. The IP setup on the card is set on DHCP. The second card (3com Ethernet link) was used to connect to our town's local WUG (wireless user group) and all worked fine.

Now the problem I have with Windows 7 is that when I connect to the internet with the (Intel) first card, the internet work fine but as soon as I connect the second card to the wug my internet drops. If I then disconnect the first card (internet one) and try to connect to the wug it works.

It seems that the two cards are fighting each other. Is there maybe something I can do to fix the problem? As you probably can gather from this post is that I am not an expert on PC's so please if you do answer do I in simple terms. :)

Answer 1

Remove the gateway for the private network on the second interface. I had this same problem for a while, so I have my wireless network interface with internet on 192.168.1.0/24 with a the gateway as 192.168.1.1 and my private on 10.0.0.0/8 with no gateway.

If you set up 2 gateways on different networks & NIC's windows will send all outbound traffic though the NIC with the highest bandwidth regardless of metric (in my case at least)

Since the wireless was only type G (54Mpbs) versus the wired GigE (1000Mbps) it sent any and all traffic though the wired connection.

Once I took the private networks gateway out (with only a static ip & subnet left on) I could still browse the internet and access my private fileserver.

If you are running the private networks NIC into a router however, the any devices plugged into the router will not have internet access.

The way I have my network set up is I have my first wired NIC plugged into the WAN port on my router, and within windows I have that NIC and the Wirless NIC bridged. I then run the second wired NIC into a port on the router with only IP & subnet configured.

This allowed my fileserver to still have internet access, and let me access it while still keeping the entire wired network private and giving only myself access to it, and preventing others on my shared wifi connection from being able to access my fileserver.