What broke, what I built, and what I’m still learning.
Newest first. The useful failures tend to age well.
My stuff lives in two countries, three time zones, one closet, and a cloud droplet. Tailscale is the reason it behaves like one house — and the one piece of the stack I'd have to replace before anything else could work.
My laptop dropped off the network every five minutes at the lake place. 38 hard disconnects in 5 hours, and the ISP, the router, and the laptop all checked out clean. The culprit was where the desk was.
The new place in cottage country somehow has 2.5-gigabit symmetric fibre — and a Bell router with no bridge mode. That meant double NAT, which meant Tailscale falling back to relay servers. The fix was a fiber modem the size of a stick of gum.
The lake house had a verified 2.3 gigabit fiber line and every WiFi device topped out at 90 megabits. The internet was innocent. It came down to one keystone jack, and the answer to 'why does the internet suck' was a punch-down tool.
The router at my salon suite location crashed weekly, and the fix everyone assumed was wrong. Behind it all: a missing $2 battery that made the router believe it was 1980. Fifteen days, three visits, four bad hypotheses, one $199 box.
I inherited an encrypted backup of a router's config with no password to open it. So I tried to guess. Eleven hundred and fifty-eight guesses later, I did the smarter thing: I stopped.
A dozen self-hosted apps, each remembered as a port number. Three pieces closed it out: a wildcard domain resolving to a private address, genuine wildcard certificates issued to a server no certificate authority can visit, and a deploy that reconciles itself.
The AT&T gateway passed its speed test, but my own router could not get online. The fiber provider had authorized one network-port address while the cable was plugged into another.