Managing two NICs and two Internet connections in one computer (Win 7)

Factual Questions
1

TL;DR We have two broadband connections in the house. One is rarely used by humans; I want to know when that one goes down. I have a Win 7 PC with onboard LAN and a USB NIC.

Details:

We have two broadband ISPs. The main (cable) connection is connected to my motherboard’s onboard LAN; the other (DSL) is connected to the USB NIC. I want my computer to use the cable connection and simply monitor the other (i.e. just letting me know if it has gone down).
The cable broadband connection goes: modem > A/B switch 1 > router > motherboard’s onboard LAN.

The DSL broadband connection goes: modem > A/B switch 2 > USB NIC.

Normally, the A/B switches are set so that most of the house is on the cable connection while just our VOIP line is on the DSL connection. When one ISP has an outage, we change the A/B switches to have the entire house on one or the other until both are stable.

Because we don’t use the DSL connection directly, there have been times when it went down for a while before we noticed.

In the Network and Sharing Center, under “view your basic network information,” I see My PC > Multiple networks > Internet.

Under “view your active networks” They both say “home network,” (I selected that when I first connected to the network), both say “access type: Internet,” and both say “HomeGroup: joined.” The “Connections” name is correct for each.

My public IP address is via the cable ISP (this may be because that was connected before I plugged the other Ethernet cable into the USB NIC).

That’s everything I can think of that’s relevant (sorry if it was overkill). Is there a way to keep tabs on that second connection?

2

This A/B switch: It’s not like a network ethernet switch, but something that physically/electrically switches between the two setups?

Does your computer even see the DSL connection when the A/B switch is set to the other one, or is it electrically isolated until it’s switched?

3

Is your PC directly connected to the provider equipment, with no router or anything in between?

If so, you should be able to write a small batch file that will periodically ping the next hop router on the DSL connection and save the results to a file.

4

If your computer can always see the DSL connection, I made a simple scheduled task for you:
https://www.dropbox.com/s/rqfz2wr2wtrg6sp/Alert%20when%20connection%20down.xml?dl=0

Download that, open Task Scheduler (taskschd.msc) and Action -> Import it. A message box will pop up when any connection goes down, as long as the computer is on and you’re logged in.

You can further modify the task if you’d like, such as to make it only monitor the DSL connection, or to run as a service whenever your computer is on, or to make it email/text you when it goes down.

A more reliable solution might be to stick another cheap computer (Raspberry Pi, Beaglebone) on that same line and program it to do something similar. Or just beep when it goes down.

Edit: You can tinker more with the Task Scheduler and Event Viewer to make custom triggers. Windows actually logs a shit ton of hardware and software events behind the scenes, it just doesn’t pop up UI notifications for most of them. It probably knows within a second or two whenever a connection breaks; you just have to tell it to let you know.

5

(On preview: I wrote this to answer the A/B question without seeing the next replies—holy cow thank you for the task; I’ll start looking at it as soon as I can!)
Apologies if this is overdetailed, but I’m not sure what’s relevant or not. Also, the setup is a few years old (doing some searching, I found my old threadfrom 2011! **Palooka **was right—they were much easier to find when I called them RJ45 switches).

It’s also possible that this is overcomplicating things—I’m not a programmer and have trouble thinking through basic logic gates and whatnot, so please forgive me if this is an ungraceful kludge to a simple problem (or if load balancing routers have come down in price to make this setup moot).

My goal was twofold: first, to be able to easily switch the house or phone to one ISP went the other went down (easy to the point where a babysitting mother-in-law can do it when we’re travelling). We run our business from our home in rural New York, so ISP outages are not uncommon, hence the DSL connection is mostly our backup ISP. Second, I wanted to keep the house/office on the faster cable connection and keep the phone on the ‘slower’ DSL connection (among other things, large uploads can kill call quality). So I thought to use a pair of A/B switches.

I made a oversimplified drawing to help Mrs. Devil et al understand the setup, so it might help here too. Imgur link

Switch 1 has the cable connection as its A input and the DSL connection as its B input. The box’s output goes to our router. Most of the house and office is connected to the router.

Switch 2 has that same router connected as its A input and the DSL connection as its B input. Its output goes to a hub, which then connects to our VOIP adapter and my USB NIC.

The ‘normal’ setting (i.e. both ISPs are up), Switch 1=A and Switch 2=B. So the router sees the cable modem and distributes that throughout the house, and my USB NIC and the phone see just the DSL connection.

When cable goes down, we make one change to the switch boxes so it’s Switch 1=B and Switch 2=B. That way, the router sees the DSL connection (with no change to the second box the USB NIC and phone still see the DSL).

When the DSL goes down, we make the opposite change, so it’s Switch 1=A and Switch 2=A. That way, the router sees the cable connection (this is its ‘normal’ state). And, because there is an output from the router to the input of Switch 2, the USB NIC and the phone only see the cable connection. The router treats them just like regular branches.

When making these switches reconnecting is faster to log into the router and release/renew its IP address, but if not it eventually figures things out.

6

Holy crap! It’s like one of those dastardly IQ logic tests. “If the router is 4 years old, blue, and can only take odd numbers, how many Ferraris can cross the river before the tiger reaches the end?” :eek:

I THINK I understood your setup. Is this right?
Rhythmdvl Network

If so, the event viewer/batch file should still work. Basically your PC sees both the cable and DSL so can monitor both connections.

If not, use that link above as a template and correct the network topography if you can, please :slight_smile:

7

Your life might also be greatly simplified by a router with 2 WAN ports, like this one. In theory you can plug both the cable and DSL into it and configure it so that the DSL is a failover for the cable, or just have it load balance the two. You can likely also set it up so that the phone is on its own vlan and always uses the DSL, whereas the computer will be load-balanced or switched between both Cable and DSL.

I don’t have one these so I can’t say for sure, but the reviews suggest it’s pretty nifty. Only $50 too. If ya get it, let us know how well it works…

Also, hmm… if you’re using a hub with the DSL, don’t you only have one IP address to share between the VOIP adapter and the USB NIC? It’s a hub, not a router, right? What happens when the USB NIC and VOIP adapter are both on?