The router at my salon suite location crashed approximately once a week. Each time, the Wi-Fi died, and each downstream device became unreliable. A person had to drive over and pull the plug. The integrator who installed the network no longer answered. So the repair became a standing appointment: drive over, unplug, count to ten, drive home.
The smoke detector with no battery
So I took over the network myself. On the first visit, I found a WattBox in the rack. A WattBox is a smart power strip. It detects a dead internet connection and power-cycles the router automatically. The device was already installed. It was never turned on. A person bought the smoke detector and never installed the battery. I enabled it. The weekly outage decreased from hours-or-days to approximately six minutes. That is faster than a text message to me.
But that was a repair of the symptom. The router still crashed. I wanted the cause.
Four wrong theories
Here I embarrass myself. I tested five theories. Four were wrong. The lead suspect for two full weeks was old VPN tunnels from the previous setup. That guess came fully from the previous integrator’s reputation. I wrote the guess down with confidence. Later, I treated my own hunch as an established fact. When I finally checked, the VPN page was empty. Zero tunnels. There were never any tunnels. A guess written down with confidence becomes a fact in approximately two weeks.
Negative 106 million seconds
The true answer sat in the router’s system log. The log holds fifty lines. It erases itself on each reboot. One of those fifty lines said this: the router got its internet lease with a renewal scheduled in negative 106,633,522 seconds.
That is negative 3.4 years. That is not a typo. That is a time traveler.
The router had no clock battery. On each cold boot, its clock fell back to approximately the year 1980. Engineers chose 1980 as the start of time. They wanted a clean break from the seventies. Then it fetched an internet lease before it synchronized the true time. Do the lease calculation from 1980, and you get a negative renewal. The negative renewal sent the router into a confused loop. The loop restarted each internal service in a cascade, until the admin interface stopped completely. Each power cycle rolled the same dice. By the night I understood this, the crash interval was one hour, not one week. I watched it occur live, twice, like a nature documentary.
The impossible $2 repair
The repair was a $2 coin battery. I drove over with one and opened the case. There was no battery in the router. There was also no battery holder. The board had a labeled spot for a battery and no place to put one. The $2 repair was physically impossible.
Fortunately, I ordered a $199 UniFi gateway the night before. My theory: hardware plans deserve a plan B. I swapped it in, with approximately fifteen minutes of downtime. In the first hour, the new box flagged a bonus problem. The old router was too sick to see it. Two digital signage players had the same IP address. They fought over it in silence. Nobody knows for how many years.
The salon network is boring since then. Boring is the full goal. The short version of this story lives on the work page. This is the long version. I wrote it for one reason: to never again trust a diagnosis whose only source is me, two weeks ago, with a guess.