A3 has now gone unprobed for three runs, and the cause was in eth0_ip:
'incus list' name filters are not regexes, so the anchored "^peer$" form
matched nothing — while run 3's own DNS note showed peer resolving to
10.87.0.210, proving the address was there all along. Read it from
inside the box with 'ip -4 -o addr show dev eth0' instead: unambiguous,
no CSV quoting, no filter semantics to get wrong.
Runs 2 and 3 also DISAGREED on B3's egress half — broken, then intact.
Setting dns.mode restarts the network's dnsmasq, so a probe fired
immediately can catch it mid-restart. The probe now distinguishes a
transient outage (recovers within 30s) from a real break (does not), so
#16 gets a verdict it can design on rather than a coin flip.
The docker check now probes the daemon with sudo (a fresh exec session
may lack the docker group) and actually pulls and runs a container,
which is the thing ipv4_filtering could plausibly break.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>