runbooks/dns-change-sheet.md

# DNS change sheet — Cloudron migration (Hostinger → Infomaniak)

Prepared 2026-10-30 from a live zone inventory (`zone_inventory.json`, 41 records).
Registrar: **yoursrs.com** (NS for domains.coop). Cloudron cannot manage these records;
every change below is manual. **Nothing here is time-sensitive except the TTL lowering.**

## Counts, so the switch is not underestimated

- **19 A records** → `179.199.135.72`
- **18 AAAA records** → `2a02:4780:6e:83fd::1` (Hostinger's range)
- 1 MX, 1 SPF TXT, 1 DKIM TXT, 1 DMARC TXT
- **No CAA records**, so no certificate-authority restriction to update.
- **Configured TTL is 3600 s on every record.** (Lower these a day early; the 1090–1204 s
  seen on some answers are cache countdowns, not zone values.)

## Records to change at cutover

| Name | Type | Current | Set to |
|---|---|---|---|
| `chat-legacy.inference.coop` | A | `179.199.135.72` | `179.237.86.116` |
| `chat.inference.coop` | A | `179.199.135.72` | `179.237.86.116` |
| `cloud.inference.coop` | A | `179.199.135.72` | `179.237.86.116` |
| `dashboard.inference.coop` | A | `179.199.135.72` | `179.237.86.116` |
| `docs.inference.coop` | A | `179.199.135.72` | `179.237.86.116` |
| `email.inference.coop` | A | `179.199.135.72` | `179.237.86.116` |
| `forum.inference.coop` | A | `179.199.135.72` | `179.237.86.116` |
| `gateway.inference.coop` | A | `179.199.135.72` | `179.237.86.116` |
| `git.inference.coop` | A | `179.199.135.72` | `179.237.86.116` |
| `inference.coop` | A | `179.199.135.72` | `179.237.86.116` |
| `matrix.inference.coop` | A | `179.199.135.72` | `179.237.86.116` |
| `my.inference.coop` | A | `179.199.135.72` | `179.237.86.116` |
| `newsletter.inference.coop` | A | `179.199.135.72` | `179.237.86.116` |
| `panel.inference.coop` | A | `179.199.135.72` | `179.237.86.116` |
| `portal.inference.coop` | A | `179.199.135.72` | `179.237.86.116` |
| `search.inference.coop` | A | `179.199.135.72` | `179.237.86.116` |
| `status.inference.coop` | A | `179.199.135.72` | `179.237.86.116` |
| `vault.inference.coop` | A | `179.199.135.72` | `179.237.86.116` |
| `www.inference.coop` | A | `179.199.135.72` | `179.237.86.116` |
| `chat-legacy.inference.coop` | AAAA | `2a02:4780:6e:83fd::1` | `2001:1600:18:206::89` |
| `chat.inference.coop` | AAAA | `2a02:4780:6e:83fd::1` | `2001:1600:18:206::89` |
| `cloud.inference.coop` | AAAA | `2a02:4780:6e:83fd::1` | `2001:1600:18:206::89` |
| `dashboard.inference.coop` | AAAA | `2a02:4780:6e:83fd::1` | `2001:1600:18:206::89` |
| `docs.inference.coop` | AAAA | `2a02:4780:6e:83fd::1` | `2001:1600:18:206::89` |
| `email.inference.coop` | AAAA | `2a02:4780:6e:83fd::1` | `2001:1600:18:206::89` |
| `forum.inference.coop` | AAAA | `2a02:4780:6e:83fd::1` | `2001:1600:18:206::89` |
| `gateway.inference.coop` | AAAA | `2a02:4780:6e:83fd::1` | `2001:1600:18:206::89` |
| `git.inference.coop` | AAAA | `2a02:4780:6e:83fd::1` | `2001:1600:18:206::89` |
| `inference.coop` | AAAA | `2a02:4780:6e:83fd::1` | `2001:1600:18:206::89` |
| `matrix.inference.coop` | AAAA | `2a02:4780:6e:83fd::1` | `2001:1600:18:206::89` |
| `my.inference.coop` | AAAA | `2a02:4780:6e:83fd::1` | `2001:1600:18:206::89` |
| `newsletter.inference.coop` | AAAA | `2a02:4780:6e:83fd::1` | `2001:1600:18:206::89` |
| `panel.inference.coop` | AAAA | `2a02:4780:6e:83fd::1` | `2001:1600:18:206::89` |
| `portal.inference.coop` | AAAA | `2a02:4780:6e:83fd::1` | `2001:1600:18:206::89` |
| `search.inference.coop` | AAAA | `2a02:4780:6e:83fd::1` | `2001:1600:18:206::89` |
| `status.inference.coop` | AAAA | `2a02:4780:6e:83fd::1` | `2001:1600:18:206::89` |
| `vault.inference.coop` | AAAA | `2a02:4780:6e:83fd::1` | `2001:1600:18:206::89` |

`www` has no app behind it in the Cloudron inventory — confirm whether it is an alias,
a redirect, or stale before touching it.

## Records that must NOT change, but must be re-verified after the restore

| Name | Type | Value | Why |
|---|---|---|---|
| `inference.coop` | MX | `10 my.inference.coop.` | Follows the A record; no MX edit needed. |
| `inference.coop` | TXT (SPF) | `v=spf1 a:my.inference.coop ~all` | Hostname-based — survives the IP change. |
| `cloudron._domainkey` | TXT (DKIM) | `v=DKIM1; t=s; p=MIGfMA0…` | **Must match the key inside the restored mail app's data.** Mismatch + DMARC below = silently discarded mail. |
| `_dmarc` | TXT | `v=DMARC1; p=reject; pct=100` | Reject policy: misaligned mail is DISCARDED, not junked. |

## Sequence (see the main runbook §4)

1. A day early: set every A and AAAA TTL to 300 s.
2. At cutover: point A records at **`179.237.86.116`**; repoint every AAAA record to **`2001:1600:18:206::89`**
   (the new box has IPv6, so this is a repoint, not a delete — but it must happen in
   the same pass: an IPv6-capable client or homeserver left on Hostinger's address
   reaches the old box even after the A switch).
3. Verify with the resolver set below, not one resolver.

```
for h in inference.coop my.inference.coop matrix.inference.coop gateway.inference.coop; do
  dig +short A $h @1.1.1.1; dig +short A $h @8.8.8.8; dig +short AAAA $h @1.1.1.1
done
```

## The new box (given 2026-10-30)

- **IPv4** `179.237.86.116`  ·  **IPv6** `2001:1600:18:206::89`
- 4 CPU · 12 GB RAM · **250 GB disk** · unlimited traffic
- **1 snapshot slot free** — take a snapshot *after* a clean restore and *before* the DNS
  switch, so a bad restore is a revert rather than a rebuild.
- Location Plan-les-Ouates, Switzerland (same provider as the backup target, so the
  restore reads from inside Infomaniak's network).
- Ubuntu **26.04 LTS** — confirm Cloudron 9.x supports it before installing.
- **Reverse DNS is listed as "configure" for BOTH addresses.** Set PTR → `my.inference.coop`
  on the IPv4 *and* the IPv6. A sending IP without matching PTR is the classic cause of
  fresh-IP mail landing in spam, and DMARC here is `p=reject` on our own domain.