Replaces it with why the remaining segments have no eligible hosts:
two are appliance-only and three have no IPv6 enabled yet, pending the
firewall-policy pass that SLAAC on a client segment would require.
esh-pve-nas and esh-vm-db join esh-docker-vm on 4411:b105, at
:50:55 and :50:60 respectively, each applied by the same prefix-deriving
if-up.d hook so the last two groups read straight off the IPv4 address.
Two obstacles are recorded because both will recur. The Proxmox node had
link-local only despite every relevant sysctl appearing correct, because
its bridge carries per-interface forwarding and the kernel ignores router
advertisements on a forwarding interface unless accept_ra is explicitly
two rather than one. The fix takes the advertised prefix while declining
the default route, so the hypervisor gains an address without any change
to how it routes; this was verified after applying, with the v6 default
route count still at zero.
The database VM refuses key authentication for the privileged accounts
and its unprivileged login cannot escalate without a password, so the
hook went in through the QEMU guest agent from the hypervisor, which
executes as root inside the guest. The document notes the base64
indirection needed to get a multi-line script through intact.
The scheme has existed since August as a single line of persistent
memory, which a snapshot then deleted. It is a naming convention
rather than temporal state, so it now lives in docs/pfi as a proper
document, and the memory entry is reduced to a pointer at it. The
document carries the full table, the address structure, the reasoning
about which slots can and cannot hold a name, and the recipe for
applying one to a host.
It also corrects the conclusion the original note ended on. That note
held that these names could never appear on the wire, which is true
of everything UniFi is able to assign but not of what a host can
assign to itself, and the distinction is the whole difference between
a joke and an address.
AdGuard on esh-docker-vm now holds the esh-server name, at
2607:73c0:402:1d02:4411:b105:50:45, where the segment identity and the
IPv4 address are both legible. It is applied by an if-up.d hook that
derives the prefix at runtime rather than hardcoding it, backgrounds
itself with a retry so it cannot stall interface bring-up, and adds
nothing to the existing interface configuration.
This is load-bearing rather than decorative. The gateway advertises an
IPv6 resolver to clients, macOS prefers it over the IPv4 one, and it
previously pointed at an address derived from that host's MAC.
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