ADR 0032: a scenario is a closed address space. Every segment materialises
as its own isolated link belonging to one instance, so two scenarios raised
from the same declaration hold the same addresses and never meet. The
declaration keeps its literal addresses and they mean what they say —
allocating from a pool would have made them a fiction, so a scenario
reproducing a specific topology would stop reproducing it.
The constraint that follows shapes everything: the lab never reaches into a
scenario over IP. It talks to machines through the virtualisation layer's
own channel. If it reached them by address, the workstation would need a
route into each scenario, and two carrying the same prefix would give it
two routes to one destination — failing not with an error but by one
scenario's traffic arriving in another.
That also makes reachability an honest question. Can this machine reach
that one is asked from INSIDE, by executing on the first, rather than
probed from a workstation that is not on the network and whose opinion
would be a different question with a misleadingly similar answer.
The lifecycle itself: six verbs, of which raise and destroy are enough to
be useful and the rest are what make repetition cheap. Raising is
convergent rather than incremental, because a lab behaving differently
from the thing it tests teaches the wrong habit.
A failed raise leaves the wreckage standing. Tearing down on failure
destroys the only evidence, which is backwards — a scenario that failed to
raise is more interesting than one that succeeded.
Snapshots are whole-scenario. Per-machine would be cheaper and wrong: the
mesh keeps state spanning nodes, so restoring one machine while its peers
move on produces a mesh that has never existed, and faults found there
would be artefacts of the lab.
Closes the declaration's open question about running several scenarios at
once.
The lab provides the underlay; the mesh builds the overlay. This is the
boundary that decides whether the lab is worth having: a scenario that
assigns overlay addresses, elects the hub and writes peer configuration
certifies its own work — if the mesh's peering is broken, that scenario
still comes up green. The most valuable thing the lab can test is exactly
the part pre-building would replace.
So a scenario declares what a hosting provider and a home router would
provide: segments, which machine sits where at which address, what NAT is
between them, which ports are forwarded, which machines are detached. It
declares nothing about overlay addresses, hubs, peering, names or
certificates, all of which become outcomes to observe.
The declaration has four parts — segments, machines, place, snapshot — and
the two scenario classes differ only in place. That is what makes one a
strict subset of the other rather than a fork.
Research 004's most important finding becomes a format constraint rather
than a footnote: the routable segment must use RFC 5737 documentation
space, because the mesh decides public versus private by matching the
address, and a private range there makes the hub test as unreachable while
the mesh silently never forms. A segment without behind: is routable, and a
non-documentation address in it should be refused before anything is
raised — ADR 0008 applied to a configuration file, since the failure it
prevents has no error at all.
Four things left open, including the one that matters most: a lab machine
is always privileged, so the user and edge profiles have no scenario that
exercises them.
papa-hq reads 01 research -> 03 decision -> 02 design. The order is a
scar, not a choice: 02-DESIGN existed from its initial commit, and when
adr/ was finally promoted on 2026-07-13 it took the next free number
rather than its place in the sequence. By then design was too settled to
renumber.
hal-hq was three commits old, so it is not. adr/ becomes 02-DECISIONS and
02-DESIGN becomes 03-DESIGN, and following the folder numbers now walks
the process in the order it happens: research produces a decision, the
decision authorises a design.
00-GENESIS becomes 00-META, matching papa's rename from the same
restructure.
Every path reference rewritten across documents, frontmatter, playbooks
and skills. All links resolve; all 58 frontmatter blocks parse and their
path fields still point at files that exist.
jschoubben