nixos/docs/ip-addressing.md

# IP Addressing Scheme

## Subnets

| Subnet | CIDR | Purpose | Routed? |
|---|---|---|---|
| LAN | `192.168.2.0/24` | General LAN — clients and infrastructure | Yes (gateway .254) |
| Storage | `192.168.4.0/29` | HA file server DRBD replication | No — internal `vmbr1` only, no uplink |

The storage subnet never leaves pve1. `vmbr1` is a Proxmox Linux bridge with no physical port
attached; traffic between the two HA file server VMs stays in-kernel.

The host octet is consistent across subnets for any host that has multiple interfaces — e.g.
ha-node1 is always `.228` (LAN: `192.168.2.228`, storage: `192.168.4.228`).

---

## LAN — 192.168.2.0/24

### Address map

| Range | Purpose |
|---|---|
| .1–.9 | Reserved, never assign |
| .10–.59 | Client DHCP pool (router-assigned) |
| .60–.219 | Unallocated buffer |
| .220–.229 | Virtual nodes (VMs / LXC containers) |
| .230–.239 | Expansion buffer (reserved, unallocated) |
| .240–.249 | Physical nodes (bare-metal hosts) |
| .250–.253 | Network services |
| .254 | Router / gateway |

### Network services (.250–.253)

| IP | Hostname | Role |
|---|---|---|
| `192.168.2.254` | router | Gateway (TP-Link) |
| `192.168.2.253` | domain-controller | FreeIPA — authoritative DNS for `sweet.home`, Kerberos, LDAP |
| `192.168.2.250`–`.252` | — | Reserved for future network services |

### Physical nodes (.240–.249)

| IP | Hostname | Role |
|---|---|---|
| `192.168.2.245` | pve1 | Proxmox VE hypervisor |
| `192.168.2.244` | pbs | Proxmox Backup Server |
| `192.168.2.243` | nixos | Bare-metal workstation (`baremetal-gui`) |
| `192.168.2.246`–`.249` | — | Reserved — second Proxmox node and associated services |
| `192.168.2.240`–`.242` | — | Reserved |

pve1 sits mid-range deliberately so a second Proxmox node can slot in on either side.

### Virtual nodes (.220–.229)

All VMs and LXC containers run on pve1.

| IP | Hostname | Role | Status |
|---|---|---|---|
| `192.168.2.229` | ha-vip | HA file server iSCSI floating VIP (Pacemaker) | Future |
| `192.168.2.228` | ha-node1 | HA file server node 1 (DRBD + XFS + iSCSI) | Future |
| `192.168.2.227` | ha-node2 | HA file server node 2 (DRBD + XFS + iSCSI) | Future |
| `192.168.2.226` | server | Current NFS/ZFS file server — retires when HA is live | Retiring |
| `192.168.2.225` | docker | Docker / Traefik stack | Active |
| `192.168.2.224` | nix-cache | Nix binary cache + remote builder | Active |
| `192.168.2.223` | pxe-boot | PXE / TFTP / HTTP netboot server | Active |
| `192.168.2.222` | tailscale-router | Tailscale exit node / router | Active |
| `192.168.2.221` | tor-relay | Tor relay | Active |
| `192.168.2.220` | pdm | Proxmox Deploy Manager | Active |

### Client DHCP pool (.10–.59)

Assigned by the router. DNS option points to `192.168.2.253` (domain-controller).

Devices in this range: phones, laptops, IoT, Canon printer, any non-infrastructure host.
No static reservations for infrastructure hosts — all infra uses static IP configuration
on the guest itself (not DHCP reservations), so IPs survive VM recreation regardless of
MAC address churn.

---

## Storage network — 192.168.4.0/29

Internal to pve1 only. Proxmox bridge `vmbr1`, no physical NIC attached.

| IP | Hostname | Interface role |
|---|---|---|
| `192.168.4.228` | ha-node1 | DRBD replication NIC |
| `192.168.4.227` | ha-node2 | DRBD replication NIC |
| — | no gateway | Isolated — not routed to LAN or internet |

---

## Migration reference

Current → target IP for every host being renumbered.

| Host | Current IP | New IP | Config location |
|---|---|---|---|
| router | `192.168.2.254` | `192.168.2.254` | unchanged |
| domain-controller | `192.168.2.138` | `192.168.2.253` | `/etc/sysconfig/network-scripts/ifcfg-eth0` on guest |
| pve1 | `192.168.2.250` | `192.168.2.245` | `/etc/network/interfaces` on Proxmox host |
| pbs | `192.168.2.108` | `192.168.2.244` | static config on PBS host |
| nixos workstation | `192.168.2.119` | `192.168.2.243` | `networking.interfaces` / NetworkManager on guest |
| ha-node1 | — | `192.168.2.228` | future |
| ha-node2 | — | `192.168.2.227` | future |
| ha-vip | — | `192.168.2.229` | future (Pacemaker resource) |
| server | `192.168.2.252` | `192.168.2.226` | static config on guest |
| docker | `192.168.2.249` | `192.168.2.225` | static config on guest |
| nix-cache | `192.168.2.120` | `192.168.2.224` | static config on guest |
| pxe-boot | `192.168.2.247` | `192.168.2.223` | static config on guest; update `vars.pxeServerIp` in `variables.nix` ✓ |
| tailscale-router | `192.168.2.121` | `192.168.2.222` | static config on guest |
| tor-relay | `192.168.2.107` | `192.168.2.221` | static config on guest |
| pdm | `192.168.2.248` | `192.168.2.220` | static config on guest |

### Cutover notes

- **Do domain-controller first** — it becomes the DNS server; everything else depends on it
  having its new IP and FreeIPA DNS configured before Pi-hole is retired.
- **pve1 last among physical hosts** — changing the Proxmox management IP drops the web UI
  briefly; all guests keep running.
- **Update Pi-hole custom.list / FreeIPA DNS A records** to new IPs before flipping any host,
  so name resolution stays valid throughout the migration.
- **variables.nix already updated** for `pxeServerIp` (.247→.223), `pbsIp` (.108→.244), and
  new `domainControllerIp` (.253). Rebuild affected hosts after renumbering.
- **Router DHCP**: once domain-controller is at .253 and FreeIPA DNS is serving `sweet.home`,
  switch router DHCP on with pool .10–.59 and DNS option pointing to .253; retire Pi-hole CT.
- **Pi-hole's iPXE dnsmasq config** (`99-ipxe-chainload.conf`) moves to the pxe-boot CT as a
  dnsmasq proxy-mode config before Pi-hole is decommissioned.