Files
hq/03-DESIGN
jschoubben e88a6df924 Public networks are unrelated, and routed rather than bridged
Caught in review: every public address sat in one /24, which made the
three of them look like one network. They are not. The internet is a very
large number of unrelated networks routing to each other, and a machine in
one is many hops from a machine in another with no shared broadcast domain
between them.

Putting them in one prefix would have quietly made four false things true
in the lab: machines resolving each other by ARP and talking directly, TTL
never decrementing, broadcast and multicast crossing between them, and any
two being adjacent.

The third is not hypothetical. The as-is layer records that mesh names are
deliberately not multicast names, after a delay and a one-node-only failure
mode. A lab where the internet is one broadcast domain would let a node
discover a peer by multicast that it could never discover in production,
and report success — the exact false green this effort exists to prevent.

So a scenario has one public segment per public NETWORK, each with its own
unrelated prefix, wired together through a router and never onto a shared
bridge. That is a property of how the lab wires them rather than a field
anyone sets, because no correct scenario has two public networks adjacent.

Addresses now spread across all three RFC 5737 ranges plus RFC 3849 /48s,
chosen to look nothing like each other, and a foreign private network uses
someone else's RFC 1918 range rather than a documentation one.

All three examples in the document rewritten, since two of them still
showed a single flat internet segment and contradicted the new rule.
2026-08-23 23:49:38 +02:00
..

03-DESIGN

The authoritative specification. Implementation is built against what is written here.

Two layers

Folder What it is
00-as-is/ The mesh that exists today. Shipped behaviour, described as it is — including behaviour nobody would choose again.
01-to-be/ The mesh being built toward. Every statement traceable to a record in 02-DECISIONS/.

They are never mixed. A statement about the future does not belong in an as-is document, and an as-is document is never edited to describe an intention.

When a to-be design ships, it does not move. Its as-is counterpart is written or updated, the to-be document's status becomes implemented, and both stand — one describing what runs, the other recording what was intended. Deleting the intention loses the reasoning, which is the expensive half.

Frontmatter

Every design document (not the READMEs) carries:

---
layer: as-is | to-be
status: designed | in-progress | implemented | abandoned
code: []                 # owning code repo(s), from 00-META/repos.md
updated: YYYY-MM-DD      # date of the last status change, not of text edits
decisions: []            # 02-DECISIONS/ records this document rests on
---

For an as-is document, status: implemented is the normal state — it describes something that runs — and code: names where that implementation lives.

Status changes when implementation state changes, never because design text was edited. An implemented claim must be defensible from the owning repository's main branch, not from intent. If it cannot be checked, it is in-progress.

Cross-cutting views are generated from this frontmatter by the hq-status skill and never written to disk.

What belongs here

Functional analysis, architectural description, and specification — prose and diagrams only, no code. A manifest field may be named; a manifest may not be pasted. A document enters the to-be layer only after the decision behind it is recorded in 02-DECISIONS/ and the research that produced it is closed.

Subfolders are encouraged where a layer grows enough to need them.