Notes from the lab and the job

Writing

Mostly post-mortems. What broke, what the evidence actually said rather than what it looked like it said, and the wrong turns on the way — those are usually the useful part.

2026-09-16

The firewall that ate fragmented UDP

A game server answered every small query and none of the large ones. No counter moved anywhere — not the NIC, not the kernel, not the firewall. Here is why.

9 min