“My first instinct was to search for asd (which was difficult with a non-working internet connection) but I found that it’s an ASUS security daemon.”
Doug Brown’s ASUS router lost its connection at 3:24 AM with automatic firmware updates switched off and nothing changed on his network. The culprit was asd, ASUS’s own security daemon, pinned at 50% CPU and flooding its log with errors. Countless other owners hit the same thing the same morning. Turning off updates did not keep ASUS out of the router, it only kept the fix out.