# Network

Physical and logical network topology for the homelab.

## Why

The homelab runs on a dedicated internal subnet (`192.168.8.0/24`) isolated from the main household LAN (`192.168.178.0/24`). Isolation is enforced at Proxmox: LXC/VM traffic is bridged only on the internal `vmbr0` bridge; Proxmox routes packets out to Fritz!Box via `vmbr1`. The main LAN cannot reach homelab services directly without a Fritz!Box static route (which is configured to allow inbound).

Fritz!OS 8.x does not support second IP networks on LAN ports, so Proxmox (`hubris`) acts as the subnet router rather than the Fritz!Box.

## Hardware

| Device | Role |
|---|---|
| Fritz!Box 7590 | Main router / ISP gateway (`192.168.178.1`) |
| SODOLA 5-Port 2.5Gbit Managed | Homelab switch — flat L2, all ports native |
| hubris (Proxmox) | Subnet router — routes between `192.168.8.0/24` and `192.168.178.0/24` |

## Topology

```
ISP
 └── Fritz!Box 7590 (192.168.178.1)
      │   static route: 192.168.8.0/24 → 192.168.178.10
      │
      └── SODOLA 5-Port 2.5Gbit
           ├── Port 1  uplink → Fritz!Box LAN
           ├── Port 2  hubris eno1 → vmbr1 (192.168.178.10)
           ├── Port 3  [device]
           ├── Port 4  [device]
           └── Port 5  spare

hubris internal bridges:
  vmbr1  192.168.178.10/24  eno1 (uplink, DHCP-reserved)  gateway 192.168.178.1
  vmbr0  192.168.8.77/24    no physical port (internal)
         192.168.8.1/24     alias — LXC default gateway
            ├── all 16 LXCs
            └── HAOS VM
```

## Subnets

| Subnet | Gateway | Purpose |
|---|---|---|
| `192.168.178.0/24` | `192.168.178.1` | Household LAN — laptops, phones, Fritz!Box DHCP |
| `192.168.8.0/24` | `192.168.8.1` (Proxmox `vmbr0` alias) | Homelab — all LXCs and VMs |

## DHCP

- **Household (`192.168.178.x`)**: Fritz!Box built-in DHCP. Proxmox `vmbr1` has a reservation: MAC `84:47:09:6b:e7:58` → `192.168.178.10`.
- **Homelab (`192.168.8.x`)**: Technitium on [CT 107](../containers/107-dns.md) at `192.168.8.2`. Range `192.168.8.100–192.168.8.240`, gateway `192.168.8.1`, DNS `192.168.8.2`.

Most homelab LXCs use static IPs below `.100`. DHCP only covers new/transient containers.

## DNS

Split-horizon DNS for `*.hubris.network` served by Technitium on [CT 107](../containers/107-dns.md) at `192.168.8.2:53`. See [dns.md](dns.md) for full detail.

## Routing

Proxmox has `net.ipv4.ip_forward=1` (already enabled by PVE). Packets from LXCs on `vmbr0` destined for the internet exit via `vmbr1` → Fritz!Box. Fritz!Box masquerades all outbound WAN traffic. Fritz!Box has a static route (`192.168.8.0/24 → 192.168.178.10`) so return traffic reaches the LXCs.

No NAT on Proxmox — traffic flows without double-NAT.

## Remote access

- **NetBird mesh** — primary path for remote administration. Authenticated via [Authentik on the VPS](../vps/).
- **Tailscale** — legacy, being phased out. See [mesh.md](mesh.md).

## Related

- [DNS](dns.md) — split-horizon config and entry list
- [Ingress](ingress.md) — public entry points via VPS traefik
- [Mesh](mesh.md) — NetBird / Tailscale VPN overlay
- [hosts/hubris.md](../hosts/hubris.md) — Proxmox host (vmbr0/vmbr1 config)
- [CT 107 — dns](../containers/107-dns.md) — Technitium DNS + DHCP server

## Changelog

### 2026-06-02 — Executed migration; Proxmox as subnet router
Fritz!OS 8.x does not support second IP networks on LAN ports, so the final design uses Proxmox as the router: `vmbr1` (eno1 → SODOLA → Fritz!Box) is the uplink at `192.168.178.10`; `vmbr0` is a portless internal bridge with `192.168.8.1` alias as the LXC gateway. Technitium DHCP enabled for `192.168.8.100–240`. Caddy service unit was missing and recreated. See [migration plan](../plans/2026-06-01-slate-ax-to-sodola-migration.md).

### 2026-06-01 — Initial network doc; Slate AX retired; SODOLA switch added
Replaced the GL.iNet Slate AX sub-router with the SODOLA 5-Port 2.5Gbit managed switch. Eliminated double-NAT. See [migration plan](../plans/2026-06-01-slate-ax-to-sodola-migration.md).