Having windows use one connection for all internet destined traffic

Question

Searched for this answer on the site, but it looked to be only applicable for mac OSX. If there is one that I missed, please link, and I'll vote to close.

In a nutshell I have a laptop running windows vista, which is currently connected to the internet via the wireless network that exists in the house, using the wireless adapter that came preinstalled. However when I plug in the network cable to connect to the local switch that allows me to connect to my local file server, the laptop doesn't seem to know which way to go to get to the internet. How can I tell it to always take a particular adapter to get to the internet?

EDIT: If instructions aren't the same, knowing how to do this via windows 7 will be handy since I'll be upgrading to it in a few weeks.

Answer 1

Make sure your wired LAN connection doesn't have a default gateway on its IP settings. If your local file server is doing DHCP resolution, then you need to edit the options to not include a gateway.

You can tell by going to the command prompt and typing ipconfig /all. Or look under the Network Adapter connections, then clicking Properties then Details.

If there is no default gateway then it won't use it to send out internet packets.

Next, go into the Network Sharing Center and clikc the Change adapter settings.

Go to the Menu bar and click Advanced and Advanced settings. Make sure your wireless connection i at the top of the list of Adapters and Bindings.

Lastly, look at your routing table. You can do that by opening a command prompt and typing netstat -r.

On the output, you should see an IP4 routing table. Look at the network destination 0.0.0.0 and mask 0.0.0.0. The IP address under interface should match the IP address of your wireless connection. If it isn't then double check the wired lan connection doesn't have a gateway attached to it.

If it does and you are sure your file server isn't handing out a gateway through DHCP, then type ipconfig /release then ipconfig /renew at the command prompt. This will force your computer to retrieve new settings from the DHCP.

Answer 2

Change Interface Metric

Here is how to use the command line to change the metric of the interface. The lower the metric the more precedence is given for packets to be destined via that hardware (I believe for packets beyond the local network)

NOTE: Must be run from an elevated shell.

netsh interface ipv4 set interface "<<INTERFACE NAME>>" metric=value

Example:

Using the wireless network for all packets beyond local network:

netsh interface ipv4 set interface  "Wireless Network Connection" metric=10

See An explanation of the Automatic Metric feature for Internet Protocol routes for understanding how the metric flag works.

You can also right click the adapter, go properties, select IPV4, click Properties button, click Advanced button, untick Automatic metric, and enter your number.

Answer 3

Manually Set the Routing Table - (Source)

1. Open a Command Prompt
2. Type: route print
3. Under IPv4 Route Table: Network destination of 0.0.0.0 means anything that's not on the LAN (e.g. Internet traffic) will be sent to this network card's default gateway. Because you have 2 LAN cards active, you'll have two routes listed for 0.0.0.0.
4. Type: route delete 0.0.0.0
   • You need to remove both routes (because you can't remove them one at a time).
   • This command will knock both of the top entries out of your list.
   • After deleting the route, you can't access the internet at all.
5. Now you need to add back only the network path you want to use. Pick the card you want to use. You should be able to ID it by IP address.
6. Type: route add 0.0.0.0 MASK 0.0.0.0 200.200.200.251
   • Replace 200.200.200.251 with the IP of the network connection of your choice.
7. This will direct all internet traffic though the connection you choose.
8. To confirm: Do another route print and you should now just see the one entry for 0.0.0.0.