Changelog 2026-07-10 -- Proposed netem parameters + ULA/GUA generation guidance (DOCFIX-168)

No live infrastructure touched -- documentation only, no repo mutation beyond a new doc and gap-register/ledger pointers. Addresses tooling gap register items #4(d) and #11.

Item

1. DOCFIX-168 -- docs/dc-dc-netem-and-ula-gua-proposal.md

FILES: docs/dc-dc-netem-and-ula-gua-proposal.md (new), docs/dc-dc- deployment-workflow.md (gap items #4(d) and #11 updated to reference it).

WHAT: two independent parts, neither of which invents or decides a value the operator/NetBox must own -- both make the NEXT step fast once the operator is ready, per this repo's discipline of presenting options rather than silently deciding anything not yet ADOPTED.

Part 1 -- proposed tc netem parameters (D-100 gap #4(d)): a concrete recommendation (1ms delay, 0.2ms jitter, 0.01% loss, uncapped rate), each with reasoning grounded directly in the buildout design's own stated "same-metro dark fiber, low single-digit ms" lean (not invented from nothing) -- presented as a table for explicit operator ratification, with instructions to record the ruling as a D-100 sub-item amendment in docs/design-decisions.md (mirroring how every other Stage-0 redline item was recorded) once accepted or adjusted.

**Part 2 -- ULA/GUA/DC2-supernet generation guidance (D-101 gap #11 + gap

#3's data half):** explicitly does NOT generate the org ULA /48, obtain the real per-DC GUA carve, or assign DC2's supernet -- gives the operator the exact, safe command to generate a real RFC 4193-compliant ULA /48 themselves (openssl rand -hex 5, confirmed via research this evening that a cryptographically random 40 bits satisfies RFC 4193's statistical- uniqueness requirement, matching what every independent ULA-generator tool checked tonight actually does), and explains precisely why the GUA carve and DC2 supernet are NOT generation tasks at all but real IPAM/ARIN coordination requiring visibility and authority this session does not have.

VERIFIED: bash scripts/repo-lint.sh 0 fail, 1 documented legacy warn.

REVERT: rm docs/dc-dc-netem-and-ula-gua-proposal.md && git checkout HEAD~ -- docs/dc-dc-deployment-workflow.md (safe -- no infrastructure touched, no value generated or applied).

Next actionable step

Both parts wait on the operator: Part 1 needs an explicit accept/adjust ruling (recordable as a D-100 amendment in one sitting); Part 2's ULA command takes two minutes to run once the operator is ready, after which netbox/dc-dc-prefixes-import.py --dc dc1 becomes runnable for real (only ORG_ULA_48/DC_GUA_PREFIX are needed for dc1; DC2_V4_SUPERNET additionally for dc2).