Files
lab/migration/CUTOVER.md
Michal f81c94af43 feat(migration): dual WAN, cloned MAC, and the new 10.8.0.0/23 Private VLAN
Two corrections from reading the live USG instead of trusting UniFi's fields,
which report wan_type=dhcp for both WANs and are simply wrong:

  - There are TWO WANs, not one. WAN2 is the 10 gig ISP on VLAN 53, plain DHCP
    with a PUBLIC address (87.192.101.48/21, gw 87.192.96.1) on the USG's eth2 --
    and it is what actually carries traffic. WAN1 is Vodafone PPPoE on VLAN 51,
    the failover. The delta had PPPoE as the only WAN, which would have left the
    primary line unconfigured.
  - The DHCP lease is bound to MAC, so bond0.53 now clones the USG's WAN2 MAC
    (f0:9f:c2:12:9b:4f). That is how VyOS keeps the existing public lease rather
    than negotiating a new one -- or getting none, if the ISP allows one per
    line. Distances: 10 gig at 1, Vodafone at 10.

Only ONE box may hold the cloned MAC, so --with-wan gates the entire WAN, NAT
and firewall section. vyos001 gets it (320 set lines); vyos002 gets none (234,
zero WAN/NAT/firewall) and routes the LAN only. Pretending both could hold it
would have meant a duplicate MAC on VLAN 53 and a flapping switch table.

Private was rebuilt at 10.8.0.0/23 (VLAN 9) after the old 10.0.8.0/23 was
deleted. bond0.9 and the VRRP group were moved to 10.8.0.252/.253 with VIP
10.8.0.254 on both boxes, and the delta now targets 10.8.0.1.

Creating that network first required breaking a deadlock in UniFi: every LAN
write was rejected with api.err.WanIpOverlapped / 0.0.0.0/0, because WAN1 was
set to DHCP on a line that only speaks PPPoE, so it sat at 0.0.0.0 forever and
the validator treated that as a subnet overlapping everything. Verified
server-side, not a UI bug -- the API rejected it identically. Setting
wan_type=pppoe let it dial (90.241.226.213, MTU 1492), which cleared the phantom
overlap and incidentally PROVED the Vodafone credentials and line work, which
had been listed as untestable before cutover.

dhcp-options no-default-route-dns does not exist; the valid set is client-id,
default-route-distance, host-name, mtu, no-default-route, reject, user-class,
vendor-class-id. Caught by validating the delta against vyos001's real config on
the labsim router before installing.

After adding the network, the gateway's dhcpd.conf was checked with
`dhcpd3 -t -cf` (valid) and confirmed to contain the new subnet only after a
force-provision -- controller state is not device state.

Both boxes: mode unifi, VRRP unchanged, unifi.boot re-captured (232 lines,
carrying the new VLAN 9), no config drift.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DMVzWZgiKW2wquf5z8S1yH
2026-08-16 18:16:25 +01:00

197 lines
8.2 KiB
Markdown

# Cutover runbook — USG to VyOS
**Print this.** During the cutover there is no internet, so there is no
assistant and no web search. Everything you need is on this page and on the
boxes themselves.
## Use these addresses. Not the other ones.
| | use this | do NOT use |
|---|---|---|
| vyos001 (MASTER) | **`10.0.1.252`** | ~~192.168.8.143~~ |
| vyos002 (BACKUP) | **`10.0.1.253`** | ~~192.168.8.144~~ |
`ssh vyos@10.0.1.252` — by IP, not by name.
**The `192.168.8.x` addresses stop working the instant the USG is unplugged.**
That is not a maybe. Your workstation is on LoT (`10.0.0.210/23`) and reaching
`192.168.8.x` requires routing *through the USG*:
```
ip route get 192.168.8.143 -> via 10.0.0.1 <- the USG. Gone.
ip route get 10.0.1.252 -> dev lanbr0 <- same L2. Survives.
```
`10.0.1.252` and `.253` are on the LoT VLAN, the same broadcast domain as your
workstation, so they need no gateway at all. They are the only remote path that
survives the cutover.
**Between unplugging the USG and finishing the switch there is no inter-VLAN
routing.** In that window:
- the **JetKVMs are unreachable** from your workstation (they are on Management
and kvm) — they are *not* a fallback during the gap
- **Tailscale is down** with the internet
- your workstation keeps `10.0.0.210` (86400s lease) and can still resolve via
`10.0.0.194`, which is also link-scope
If LoT SSH fails, the next step is physical console, not the network.
| | |
|---|---|
| JetKVMs (after routing is restored) | `192.168.1.28`, `192.168.1.29`, `192.168.3.6` |
| Switch script | `/config/vyos-unifi-switch` on each box |
| Login | user `vyos` |
---
## If something is wrong, do this
```
sudo /config/vyos-unifi-switch unifi
```
Then reconnect the USG. That command runs no health checks, asks nothing and
cannot refuse. It restores a byte-exact copy of the configuration the box had
before the cutover — verified by diff, not by assumption.
**You do not have to be quick.** If you do nothing at all after
`vyos-unifi-switch vyos`, the box reverts by itself within 10 minutes. Verified:
config returns to the previous state and the box does **not** reboot
(`uptime` and boot-id unchanged across an auto-revert).
---
## What has actually been tested
Proven on the labsim router (same VyOS version, isolated OVS bridge with no
physical NIC), by loading **vyos001's real running config** and applying the
**real production delta**:
- All 317 commands accepted, and the whole delta **commits** (`COMMIT OK`).
- `unifi` mode restores the previous config **byte-exact** (diff clean).
- Auto-revert fires when the commit is not confirmed: config returns to the
saved state and the box does **not** reboot — `uptime` and boot-id unchanged
across the revert.
- Failed health checks trigger an immediate revert rather than waiting out the
timer.
Two bugs were found this way and would each have failed the entire switch,
since the delta commits as one unit: `bond0.51` did not exist for PPPoE to
reference, and `translation port` rejects a port list.
**Not tested, and untestable in advance:**
- **PPPoE.** The line permits one session and the USG holds it. The first real
attempt is during the cutover.
- **The commit on the real boxes.** The rehearsal ran with vyos001's `eth2` and
`eth3` stanzas stripped, because the sim VM has only two NICs. Those are
plain interface configs that already work on the real hardware, but they were
not part of what committed.
## Before you unplug anything
1. Tether your workstation to your phone if you want the assistant available.
Cutting the USG cuts your internet, not your LAN.
2. On **both** boxes, confirm the machinery is present:
```
sudo /config/vyos-unifi-switch status
ls -la /config/modes/ # unifi.boot + to-vyos.commands
ls -la /config/wan-secrets # must be 0600
```
`status` must report `mode: unifi`. If `unifi.boot` is missing, **stop** —
there is no way back without it.
3. Confirm the revert action is `reload`, not `reboot`:
```
show configuration commands | match commit-confirm
```
Must show `action 'reload'`. Without it a failed switch **reboots** the
firewall instead of reverting it. The switch script refuses to run if this
is missing, but check anyway.
## The cutover
0. **Open both SSH sessions BEFORE you unplug anything**, and leave them open:
```
ssh vyos@10.0.1.253 # vyos002, BACKUP
ssh vyos@10.0.1.252 # vyos001, MASTER
```
If either will not connect, stop. Do not unplug the USG.
1. **Physically disconnect the USG.** Not just powered off — disconnected. The
switch script refuses to run while anything still answers on a gateway
address, because two devices on `.1` is the worst available outcome.
You cannot switch first and unplug after, for exactly that reason.
2. In the **vyos002 (BACKUP)** session, first:
```
sudo /config/vyos-unifi-switch vyos
```
3. Watch the health checks. They cover PPPoE, the default route, kea, the DNS
forwarder and reachability. On failure the script reverts immediately and
tells you so.
4. If vyos002 came up clean, repeat on **vyos001 (MASTER)**.
5. Check a real client: does it get an address, and is it the *same* address as
before? Every active client has a reservation, so it should be.
## What will probably go wrong first
**The WAN.** There are two, and they behave differently:
| | line | VLAN | transport | notes |
|---|---|---|---|---|
| WAN2 | 10 gig ISP | **53** | DHCP, public `87.192.101.48/21` | primary, distance 1 |
| WAN1 | Vodafone | **51** | PPPoE, ~900/700 Mbit | failover, distance 10 |
VyOS clones the USG's WAN2 MAC (`f0:9f:c2:12:9b:4f`) on `bond0.53`, which is how
it keeps the existing public lease rather than asking for a new one. **Only
vyos001 carries the WAN** — the MAC must be unique, so vyos002 routes the LAN
and holds the VIPs but has no internet path until the WAN is moved deliberately.
PPPoE is no longer an unknown: it was proven on the USG before cutover
(`pppoe0` came up with `90.241.226.213`, MTU 1492). What remains untested is
VyOS dialling it, and whether the ISP hands the same lease to the cloned MAC.
If the WAN check fails:
```
show interfaces pppoe pppoe0
sudo journalctl -u ppp@pppoe0 -n 50 --no-pager
```
Check the credential in `/config/wan-secrets` and that VLAN 51 actually reaches
the box. If it will not come up, run `vyos-unifi-switch unifi`, reconnect the
USG, and debug with the internet back on.
## Things that are true and easy to forget
- **WiFi keeps working, but through VyOS.** The SSIDs stay in UniFi and the APs
are untouched, but 37 of 83 active clients are wireless and every one is on
LoT — they get their addresses from VyOS now.
- **DHCP leases last 24h (86400s).** A device that does not renew promptly keeps
its old address for a while. That is fine, not a symptom.
- **The firewalls resolve via `8.8.8.8` / `8.8.4.4`** — matching the DNS the USG
used on its WAN. This means their own name resolution now depends on the
*internet* being up, so between unplugging the USG and PPPoE establishing,
the boxes have no DNS at all. That is expected and harmless: they only need
DNS for NTP hostnames, and the switch's own health checks use it precisely to
prove the WAN came up. Nothing in the switch itself resolves a name.
- Internal `ad.itaz.eu` names still resolve through Google, because that zone is
published publicly with private addresses in it (`nas001` → `10.0.0.194`,
`kvm-macstudio1` → `192.168.3.8`). Convenient here; worth knowing it is public.
- **The USG was a DNS resolver** for every VLAN except LoT. VyOS now runs
`dns forwarding` in its place. If names stop resolving but IPs still work,
that is where to look.
- **`eth2` and `bond0.2` are both in `192.168.8.0/23`.** It works, but if you
see odd source-address behaviour on the management NIC, that is why.
## Afterwards
Once it has been stable for a day:
- Re-run `migration/unifi-export.py` — the UniFi controller is no longer the
source of truth for DHCP, and the export will drift.
- The VPN rules (ESP, UDP 500/4500) are carried over but the VPN itself still
terminated on the USG. Decide whether it moves.
- `labsim` still holds a deliberate `kvm→k8s` drop rule from earlier testing.