docs(network): establish IP addressing scheme and update infra IPs

Defines the new structured 192.168.2.0/24 layout:
- .10–.59   client DHCP (router-assigned, DNS → .253)
- .220–.229 virtual nodes (VMs / LXC containers)
- .230–.239 expansion buffer
- .240–.249 physical nodes (pve1 at .245, PBS at .244)
- .250–.253 network services (router .254, FreeIPA/DC .253)

Storage network 192.168.4.0/29 defined for HA DRBD replication
(internal vmbr1 bridge, no uplink). Host octet matches LAN throughout.

Updates variables.nix: pxeServerIp .247→.223, pbsIp .108→.244,
adds domainControllerIp .253. Updates pxe-boot.md IP references.
Full migration before/after table in docs/ip-addressing.md.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

docs/ip-addressing.md

@@ -0,0 +1,128 @@
+# 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.

docs/pxe-boot.md

@@ -64,8 +64,8 @@ The HTTP iPXE chain is:
 ```text
 undionly.kpxe or ipxe.efi
   -> autoexec.ipxe from the TFTP root, when iPXE requests it
-  -> http://192.168.2.247/boot.ipxe
+  -> http://192.168.2.223/boot.ipxe
-  -> http://192.168.2.247/menu.ipxe
+  -> http://192.168.2.223/menu.ipxe
 ```
 
 The generated menu currently exposes entries for:
@@ -141,7 +141,7 @@ The `stage-systemrescue.service` oneshot extracts that ISO into:
 /srv/pxe/http/systemrescue
 ```
 
-The rescue menu entry then chains `http://192.168.2.247/systemrescue.ipxe`,
+The rescue menu entry then chains `http://192.168.2.223/systemrescue.ipxe`,
 which loads the SystemRescue kernel and initramfs from the extracted tree and
 uses `archiso_http_srv` to fetch the squashfs payload over HTTP.
 

variables.nix

@@ -4,8 +4,9 @@
   homeDomain = "sweet.home"; # base LAN domain for service subdomains (pve., docker.)
   tailnetDomain = "tail13f623.ts.net"; # Tailscale MagicDNS suffix
   lanCidr = "192.168.2.0/24"; # LAN subnet
-  pxeServerIp = "192.168.2.247"; # pxe-boot host's LAN IP
+  pxeServerIp = "192.168.2.223"; # pxe-boot host's LAN IP
-  pbsIp = "192.168.2.108"; # Proxmox Backup Server LAN IP
+  pbsIp = "192.168.2.244"; # Proxmox Backup Server LAN IP
+  domainControllerIp = "192.168.2.253"; # FreeIPA domain controller / primary DNS
 
   # Cross-host references (LAN hostnames/users other hosts reach over the network)
   nixCacheHost = "nix-cache"; # substituter/remote-builder hostname