---
title: WireGuard VPN — Eagle to Kraken
created: '2026-05-23'
updated: '2026-05-23'
type: tech
namespace: personal
tags: [infra, kraken]
sources: [family/how-to/wireguard-vpn.md]
confidence: high
---

# WireGuard VPN — Eagle to Kraken

Split-tunnel VPN connecting Eagle (Mac M4, home) to Kraken (RPi5, home) via
a VPS relay. Enables SSH to Kraken from anywhere and routes Time Machine
backups over the tunnel. Two VPS interfaces avoid hairpin forwarding.

## Topology

```
Eagle (10.99.0.2) ←→ wg0 VPS (10.99.0.1) ←→ wg1 VPS (10.99.1.1) ←→ Kraken (10.99.1.2)
                         :51820                    :51821
```

SNAT rewrites source address: Eagle packets arrive at Kraken with src
`10.99.1.1` (VPS wg1), not Eagle's `10.99.0.2`. FORWARD runs wg0→wg1
on the VPS with nftables.

## VPN Addresses

| Node | VPN IP |
|------|--------|
| VPS wg0 | 10.99.0.1 |
| VPS wg1 | 10.99.1.1 |
| Eagle | 10.99.0.2 |
| Kraken | 10.99.1.2 |

`kraken` hostname resolves via dnsmasq on VPS (`DNS = 10.99.0.1` in Eagle's
wg0.conf). DNS is scoped to the `kraken` domain only (see DNS section).

## Persistence

| Component | Node | How it survives reboot |
|-----------|------|------------------------|
| wg-quick@wg0 + wg-quick@wg1 | VPS | systemd enabled |
| PostUp FORWARD + SNAT rules | VPS | embedded in `/etc/wireguard/wg0.conf` |
| nftables (10.99.0.0/16 forward) | VPS | `/etc/nftables.conf`, systemd enabled |
| dnsmasq (`kraken` → 10.99.1.2) | VPS | `/etc/dnsmasq.d/vpn-hosts.conf`, systemd enabled |
| wg-quick@wg0 | Kraken | systemd enabled |
| wg-auto LaunchDaemon | Eagle | `/Library/LaunchDaemons/top.eagle.wg-auto.plist` |

## Auto-Connect on Eagle

`/usr/local/bin/wg-auto.sh` polls every 30 seconds via launchd
(`StartInterval`, **not** WatchPaths):

- At home (router MAC `f0:79:59:77:9b:70` visible on ARP) → `wg-quick down`
- Off home network → `wg-quick up`

**Why StartInterval and not WatchPaths:** WatchPaths triggered a race —
`wg-quick down` changes DNS via `networksetup`, which writes to
`/Library/Preferences/SystemConfiguration/`, which re-fires launchd,
tearing the tunnel down immediately after connecting.

## DNS (Scoped Resolver)

wg0.conf uses **no global `DNS =`**. PostUp/PostDown manage a
macOS scoped resolver for the `kraken` domain only:

```
PostUp   = mkdir -p /etc/resolver && \
           echo "nameserver 10.99.0.1" > /etc/resolver/kraken && \
           killall -HUP mDNSResponder
PostDown = rm -f /etc/resolver/kraken && killall -HUP mDNSResponder
```

Result: only `kraken` resolves via VPS dnsmasq. Global DNS and Wi-Fi IP
are untouched — prevents address-bar breakage during tunnel transitions.

## Time Machine

| Setting | Value |
|---------|-------|
| Old destination (broken) | `smb://timemachine@kraken._smb._tcp.local./TimeMachine` |
| New destination (working) | `smb://timemachine@kraken/TimeMachine` |

mDNS (`_smb._tcp.local`) doesn't work off the local LAN. VPN DNS (`kraken`
→ 10.99.1.2 via dnsmasq) works from anywhere. Container on Kraken:
`mbentley/timemachine:smb`, `restart: unless-stopped`.

## Public Keys

| Node | Public Key |
|------|------------|
| VPS wg0 | `6W6hSw0JFLm0BbyeNp1g7wF7dKKTZmGvPRdir68mz0w=` |
| VPS wg1 | `ssRV2497NQ3Lfzvx/FLO0jDlcCXdK/RReJQ36i0yuR8=` |
| Eagle | `dDgIjBUNguodOHWoz7iFsImvKhteodHcFWM8mMe4UiE=` |
| Kraken | `8kIdCKMIoMsW09/aQX6+pU0SS/rN4PysJL59w17eGRg=` |

## Diagnostics

```bash
# Eagle — check tunnel state
sudo wg show
ping kraken

# VPS
ssh root@91.207.28.205 "wg show all"

# Kraken
ssh kraken "sudo wg show"

# Eagle auto-connect log
cat /var/log/wg-auto.log
```

## Related

- [[tech/kraken-network]] — Kraken SSH access, media volume paths
- [[personal-os-architecture]] — Eagle hardware, home infra overview