The Digest That Mailed Itself Nothing
Building a daily DNS digest surfaced an n8n footgun that had been mailing three other production alerts with empty bodies for who knows how long.
Controld
The Cache That Lied to One in Five Queries
A DNS cache had been quietly discarding one in five queries across the house for weeks. Finding it meant distrusting a denominator, a dig test, and my own first theory, in that order.
The Health Check That Slept Through the Outage
The DNS probe I built last week was healthy the entire time phones were dropping off the internet. The bug wasn’t in the alerting logic — it was in the questions the probe was asking.
Three of Eleven
I added two unrelated VLANs in UniFi and quietly broke IPv6 DNS routing for almost every other one — including a guest-filter bypass nobody asked for. The IPv4 rules never moved. Only the v6 half of the map silently rotted.
The Canary Has to Block First
Building a DNS drift monitor for the UDM Pro required a canary domain, a four-state decision matrix, a dedup state machine, and a two-layer architecture to work around n8n’s Code-node sandbox. The evaluation order of the matrix is the whole trick.
DNS Archaeology: Cleaning Up the Strata
The Netbird migration was ‘done’ — but the config still had a layer from three architectures ago. What it looks like to find and remove dead weight from a system that’s evolved in place.