Run 10, on a doctor-clean host: 48/49, every #15 probe answered.
A3, the probe the whole exercise existed for and which nine runs failed
to fire, says sibling isolation DOES NOT HOLD. Box A's SYN reaches box
B and B answers with a RST. #12 reasoned from the code that the
10.0.0.0/8 egress drop covered box-to-box traffic "belt and braces";
two boxes on one bridge share an L2 segment, so their traffic is
switched, never routed, and never meets that rule. The tool's contract —
"a box reaches the public internet and nothing else" — is false: it also
reaches every other box on the host.
Also settled: ipv4_filtering breaks the box (measured on a baseline that
had already passed egress, unlike run 7's void verdict); dns.mode=none is
viable after all, retracting a veto I posted on one bad reading;
@internal is unsupported on bridge ACLs.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
