Our internet went out.
I did the routine: check the gateway, restart it, etc.1
The power’s fine, the wifi works, but my “broadband” lights are flashing red. Something must be wrong with the line—but where? Is it me or my internet service provider? There could be a break anywhere between my gateway and AT&T’s nearest point of presence.
Maybe it’s a neighborhood outage? (The power went out earlier this week, and there was a storm last night…) I pull up the app on my phone and check.
Nope, no outage. Looks like it’s just me.
But it was working an hour ago. Why randomly fail now?
It’s not my gateway and it’s not AT&T, so it’s got to be something in between.
Maybe something happened to the cable outside?
I follow the wires from the back of my gateway, to the backyard, and around to the garage. No broken strands.
Now I’m stumped. What’s left to check?
Shooting in the Dark
Maybe I missed something with the gateway. Maybe I did something stupid and forgot about it—who knows? So I reset everything: reset the gateway to its factory settings, restart my devices, wait annnnnd—nope, still dead.
Earlier when I was checking for outages I did schedule a tech appointment just in case, but I can’t wait three days for an answer. Maybe there’s something obvious, some magic they can do over the phone instead?
So I call tech support. We talk, and… nothing.
I start replaying everything in my head. What did I miss? At this point, it’s either blatantly obvious or out of my hands.
Time to Walk Away
I check on the contractors remodeling our bathroom, then go and play Legos with the kids.
It’s always after you walk away, isn’t it?
I remembered the technician who installed it last year: “If those lights ever turn red, it’s probably something with this box.”
The box in the garage!
It didn’t click the first time I looked, but now I saw the fiber box in our garage—it was unplugged.
Up until that point, I’d assumed there were only two points between me and the Internet: my gateway (the modem/router device in my house) and the cable box outside (technically an NID, a Network Interface Device).2
But there was a third box (the ONT, Optical Network Terminal) and that was the missing link.3
Our contractors had unplugged the ONT to use its power outlet earlier that day when they were working on the house. That’s when our Internet went out.
All I needed to fix the problem was a clear understanding of what broke:
My Computer → Gateway → ❌ ONT → NID → AT&T → Internet4
Once I plugged it in, everything went back to normal.
If you want to solve a problem, try to understand it first.
You’ll be surprised how much further you can go (and how quickly you can make progress) with a little extra digging.
Wired people should know something about wires.5
“Gateway” = modem & router combined in a single device. ↩
Network interface device on Wikipedia. ↩
Passive optical network on Wikipedia. ↩
Fiber to the premises on Wikipedia. ↩
Discover the physical side of the internet on TED, by Andrew Blum. ↩