I've got a commercial internet account at home with Charter Business because I host teamsybase.net out of my home (not much to look at, but it hosts a number of important utilities that TeamSybase members use).
Started having problems with connectivity one Friday night in early November. Saturday morning it's still not working, so I call service and tell them I'll be there until 5PM. The repair guy shows up right at 5, which means I have to leave, but one of my adult kids will stay with him until he's done.
Turns out the guy didn't realize that I'm a commercial account in a residence, so he replaces my defective commercial cable modem with a working residential one. The only problem is that a residential modem won't work on a commercial line, and he didn't bother to check to see if the internet was really working before leaving. When I get home Saturday night I call service again, they send somebody else out, who also doesn't realize until he gets there that I've got a commercial line, so he doesn't have a commercial modem with him either. But at least he realizes what the problem is, and schedules somebody to come out Monday.
Fortunately, the guy who comes out Monday not only realizes I'm a commercial account, but also knows that the commercial modem they originally provided me with has some firmware issues, and so when he comes out he brings me a better modem as well.
That's all well and good, but I was down for a bit over 3 days. I do contracting work remotely, and in just 1 day of downtime I would lose enough to pay for a year of high speed internet service. I decide that I need a backup provider. First thing I do is order a Duolinks SW24 dual WAN input load balancing/ failover router. When I get that in, I realize that it and my existing Dlink DIR-655 won't co-exist with it. Too bad, because it's a great router. All I need instead is an access point, so I pick up a NetGear WN802T. While I'm at it, I add a Dlink DGS-2208 1G switch, because I'm realizing that my wireless devices are operating at a higher throughput (140+ MB/s) than the wired devices (100 MB/s), and I could use the extra ports.
Back in the day when I was using a Linksys WRT54GL router, the only options for IP configuration the device appeared to support was either full DHCP or static IP. Since I needed NAT incoming HTTP requests from the router to the server hosting the website, I had to use static IP. However, both the Dlink DIR-655 and the Duolinks SW24 support DHCP reservation, I switched over to DHCP with a reservation for the server and a few other devices.
Once I had that working, I gave the Verizon folks a call to have FIOS installed as the second provider. The guy who came out really didn't understand (although I must have told him a half a dozen times) that I wasn't replacing the cable with FIOS, I was just adding FIOS. He kept disconnecting the cable. He finally got it, but told me he didn't think it would work. Once I verified that the FIOS was working up to their router, I told the guy I would handle it from there.
I found some instructions on the internet for converting the Verizon router into a bridge and tried that, but I couldn't get my router to pick up the IP address from Verizon. So I gave Verizon service a call, and asked that they either walk me through the bridge configuration or just wire CAT-5 rather than coax from the ONT to my router. They said they didn't support the bridge configuration and would send somebody out the next morning (Thanksgiving) to do the re-wiring.
The first thing the guy that arrives to the wiring asks when he sees what I'm trying to do is "Why don't you just configure the router as a bridge?" Great idea, why didn't I think of that?!?! That's what we end up doing. I did have to change the internal IP address that the DuoLinks was using away from 192.168.1.1 (when I tried the configuration I did it by changing the internal IP address of the Verizon router instead). That also meant I had to re-configure the DHCP reservations. About the only thing other than that which we did different than when I tried it myself is that the service guy rebooted the ONT after the reconfiguration.
In any event, I'm up now with two broadband internet providers load-balanced and fail-overed. Incoming connections (e.g., HTTP, RDP) only go through the commercial cable line, because that's the one I have a fixed external IP address for. But the outgoing traffic gets a choice of whichever provider is up and has more available bandwidth.
So, aside from the fact I'm not living in my mother's basement, I'm well on my way to becoming Warlock from Live Free or Die Hard.