How I Accidentally DDoSed Myself With a Toaster
You know how people say “what’s the worst that could happen?” I’m here to tell you. The worst that could happen is your toaster DDoSing your entire home network on a Tuesday morning while you’re trying to join a Zoom meeting.
I’ve already established that my toaster has a health check endpoint. What I didn’t mention is what happens when the health check fails.
The Incident
It was 8:47 AM. I had a stand-up in 13 minutes. I was feeling good. I’d had my automated coffee. My terminal was clean. My Git repo was in a state I could describe without shame.
Then the internet went down.
Not the ISP. That was fine. My internal network. Everything was unreachable. I couldn’t SSH into anything. I couldn’t ping the router. I couldn’t even load my Home Assistant dashboard to see what was wrong.
I walked to the closet where my rack lives. The switch was blinking like a Christmas tree. All ports were maxed out. Something was flooding the network.
The Investigation
I unplugged devices one by one like a game of network roulette. The NAS? Fine. The server? Fine. The Pi-hole? Fine.
Then I unplugged the toaster.
Silence. The switch stopped screaming. My network took a deep breath.
The toaster’s health check had failed (it was unplugged because I was cleaning the counter). The ESPHome firmware, in its infinite wisdom, decided the best course of action was to send a broadcast storm of MQTT discovery packets in an attempt to “re-establish connectivity.” It sent about 12,000 packets per second for 10 minutes before I mercy-killed it.
The Aftermath
I missed my stand-up. I told my team “I had a network issue.” They didn’t ask for details. They never do.
I updated the firmware to limit retry attempts. I also installed a physical kill switch because I no longer trust my own code. The toaster is currently on a smart plug that is also connected to Home Assistant. The recursion is not lost on me.
My girlfriend asked why there’s a sticky note on the toaster that says “DO NOT UNPLUG WITHOUT CHECKING SLACK FIRST.” I said “it’s complicated.”
Moral of the story: Never give a toaster a network stack. Or if you do, rate-limit it.