Operator: "The dual stack configuration was supposed to have included charms. We
have had conversations and decisions were made to approval the dual stack
configuration all the way down." CHECKED AGAINST THE RECORD, not accepted: the
operator is CORRECT. D-101's 2026-07-25 note carries "Dual stack deployment for
DC0 and DC1" verbatim and R2 re-confirmed it. A grep for any decision text
covering the LXD CONTAINER layer returns NOTHING.

MEASURED MECHANISM: the host is fully dual-stacked -- juju built a bridge per
plane on machine 0, every one with a global v6. What is missing is anything to
ALLOCATE: 10.12.8.0/22 has a dynamic range .201-.254 plus the D-134 reserved
bands; fd50:840e:74e2:220::/64 has NO IP RANGES AT ALL. juju asks MAAS for a
container address on the bound space, gets v4, and there is nothing for v6 -- so
every container is v4-only on a dual-stacked host.

THIS INVERTS THE FIX DIRECTION AND MY EARLIER FRAMING WAS WRONG. Dropping
prefer-ipv6 from the seven would make the deploy green by ABANDONING a ruled
posture at the charm layer, and would leave the dual-family v6 VIPs on
containers with no v6 leg.

STATED AND UNVERIFIED: whether juju REQUESTS a v6 address for a container when
an allocatable v6 range exists. Adding a range is necessary; it is NOT proven
sufficient, and that must be measured before any range is created.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HvCyrwvYTTcDYnRErfMsNf