TWO GA-R5 rulings, taken in SEPARATE exchanges, recorded separately.

A -- family matrix. Operator: "IPv6 on all planes except for metal-admin and
provider-public which will remain dual stack". metal-internal, data-tenant,
storage, replication and lb-mgmt become IPv6-ONLY. Amends D-101's matrix twice:
metal-internal's "datastore east-west stays v4-bound" is superseded, and lb-mgmt
(ruled v6-only by D-101 but NEVER carved anywhere) becomes a first-class plane.

B -- addressing model. Operator: "Full GUA on every plane (Recommended)". Every
plane carves from its DC's GUA /48 on the :10/:11/:20/:21/:30/:40/:50/:80 octet
map VR0 DC0 and the Willamette site ALREADY use -- conforming to an existing org
standard, not inventing one. The ULA /48 fd50:840e:74e2::/48 is RETIRED for VR1.
Amends D-101 and D-111. Deciding reason is measurable: RFC 6724 ranks IPv4-mapped
at precedence 35 and ULA at 3 while GUA falls under ::/0 at 40, so on a dual-stack
plane a ULA leg LOSES address selection to IPv4 and is decorative. SEC-010, D-052,
D-125 and D-107 unchanged -- containment lives at the forwarding layer.

THE RECORDED ROOT CAUSE OF THE v4-ONLY CONTAINERS WAS WRONG AND THIS REPO CARRIED
IT (GA-R1 C2 -- measurement corrects the document). CURRENT-STATE said MAAS "has
nothing to give for v6". Measured, and re-verified independently: subnet
statistics on fd50:840e:74e2:220::/64 returns available_string "100%",
num_available 18446744069414584320. Zero ipranges rows means zero RESTRICTIONS,
not zero availability. dc-plane-ipam.sh:368-372 has carried the correct behaviour
since 2026-07-27, in the tree, contradicting the authoritative doc the whole time.

The real mechanism is juju-side and there is NO knob: EthernetDeviceForBridge
(tag v3.6.27) takes addrs[0] from an UNSORTED query and derives one CIDR -> one
LinkSubnetArgs. gomaasapi documents "Any number of STATIC links can exist on an
interface", so MAAS would accept both families; the limit is juju's. LP #1723240
is this exact symptom, Triaged/Low since 2017, and the theory this repo recorded
is the one its reporter rebutted in-thread. Consequence: on a container plane
DUAL-STACK IS NOT EXPRESSIBLE while v6-only IS -- ruling A is the achievable
configuration, not merely the desired one.

SNAP PROXY: dc0 INSTALLED, RUNNING, check dc0 PASS exit 0 (16 assertions,
re-verified independently). A REAL SNAP PAYLOAD WAS FETCHED THROUGH IT -- HTTP 206,
first bytes hsqs. No longer fixture-green. BUG-3 confirmed by measurement, no
assertion changed. BUG-4 fixed at BOTH sites (the review named one); T20b/T41b NEW.

OWNED: my BUG-1 fix was WRONG. ip route get 10.12.8.4 -> src 10.12.8.2; .4 is a
SECONDARY and Linux never auto-selects a secondary as a source, so the rule is
still dead. Not fixed now -- editing the generator turns the LIVE gate red until
install re-runs. T23b annotated so nobody "fixes" the test to a wrong value.
Generalisable: any ACL keyed to a service ALIAS (the whole D-134 utility .4 band)
misses that host's own traffic -- same exposure in dc-mirror.sh, dc-cache-proxy.sh.

OWED, unverified: the deployed jammy /etc/gai.conf, which can override the RFC 6724
default table that ruling B rests on. Nothing of D-139 is executed.

repo-lint 0 fail; tests/dc-snap-proxy 55/55; 4 mutations killed.

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