A3, the one probe the whole audit exists for, has never fired in six
runs. It was never the network: the profile names the DEVICE eth0, but
inside a VM guest predictable naming renames it enp5s0, so every address
lookup — first the '(eth0)' CSV match, then 'ip addr show dev eth0' —
was hunting an interface that does not exist. I fixed that symptom twice
without ever questioning the assumption underneath it.
Read the address from inside the box and select by SUBNET (10.87.x, what
claudenet hands out) rather than by interface name. docker0's 172.17.x
is the decoy; the NIC's name is the guest's business, not ours.
A3 also gains a guard it should have had from the start: if the peer and
the source hold the SAME address, refuse to probe. That is not
hypothetical — clones were inheriting their source's machine-id, hence
its DHCP lease, hence its address, so 'archive → peer' was archive
probing itself and would have reported a cheerful 'reachable' as an
isolation failure.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>