Dual Integrated Ethernet?

Qwerty,

You hit it on the head when you said internet connection sharing.

Other uses for dual nics are load balancing for network traffic to your machine. With two nics you can have faster connection times if your network can handle it.

Dual nics can also be used for bridging of networks. I have an old machine acting as my router at home. It actually has four nics in it. One is for my internet in, one for LAN, one for DMZ, and another for wireless access.

Hope that helps

Some people think that dual NICs will give them 2 Gb/s bandwidth for local file transfers if they somehow set it up properly with dual NICs everywhere (and had really fast drive systems). This is a very natural assumption, but sadly, it's wrong.

The catch is that you only get 1 Gb/s per connection. There's a technical reason for this. However, real multi-user servers can take advantage of this for increased bandwidth, because they have multiple concurrent connections from different computers. Each connection can run at up to 1 Gb/s, multiple connections through multiple NICs -> greater than 1 Gb/s in aggregate.

For this, they typically need two or more NICs on the server, software that supports the NICs and provides link aggregation, and a switch that supports link aggregration. The official way to do this is with 802.3ad link aggregation, and that requires a supporting switch. Note especially that you do not use dual NICs on client computers -- this is because every individual connection only runs at 1 Gb/s, even if you have dual NICs available on both ends.

Here's some more on this if you're interested:

http://www.alacritech.com/html/teaming.html

Yes, you can do this. However, many would advise you to get a router for this purpose instead. It would supply you with a hardware firewall, and save you the trouble of configuring and maintaing Windows Internet Connection Sharing.

But if you don't want to buy or set up a router, it'd be an option.

As someone said in another thread here -- people (esp. computer stores) discard 10/100 PCI NICs quite regularly, so the availability of a second NIC in a computer for this purpose, while convenient, is not really a big deal -- you could have achieved that at any time with an add-on PCI NIC, and in your case, perhaps even with an add-on PCIe NIC.