Correct AP-isolation guess: confirmed as a 4addr forwarding gap instead

Tested live: AP isolation was already off on the TP-Link BE9300, and a
second wireless device (phone) failed identically to the laptop - rules
out isolation entirely. Real cause is the router's 4addr/WDS handling
not forwarding wireless-client broadcast/ARP traffic to pve-test's WDS
association, even though wired forwarding to it works fine. Since ARP
never resolves for wireless peers, this affects every protocol (web UI
included), not just ICMP - corrects an earlier draft of this doc that
speculated TCP might still work.

CLAUDE.md

@@ -0,0 +1,84 @@
+# CLAUDE.md
+
+Guidance for Claude Code working in this repo. IMPORTANT: these
+instructions OVERRIDE any default behavior and must be followed exactly
+as written.
+
+## Repo purpose
+
+Base configuration/hardening toolset and planning docs for Proxmox VE
+hosts (`scripts/`, `config/`, `docs/`) — see `README.md` and
+`docs/00-overview.md`. Scripts in this repo are meant to be run **on**
+the target Proxmox host itself (as root), not orchestrated remotely.
+
+## Two Proxmox nodes: `pve1` (production) and `pve-test` (sandbox)
+
+Two SSH-reachable Proxmox nodes exist on the LAN. They are **not
+interchangeable** — see `docs/05-node-roles.md` for full background on
+what each one is and why.
+
+### `pve1` (production — off-limits to Claude by default)
+
+A real, live Proxmox node hosting production VMs/containers (see
+`docs/05-node-roles.md` for the current guest list) — not a sandbox, and
+not Claude's to touch by default.
+
+- **Off-limits at all times unless the operator has given explicit,
+  same-session instructions to act on this specific host.** That
+  authorization is scoped to the task it was given for — don't carry it
+  forward to unrelated later work in the same conversation, and never
+  assume it from a previous session.
+- **Read-only for existing state is always fine, authorization or not.**
+  SSH in (or use `pvesm`, `qm list`, `pct list`, `qm config`, `pct
+  config`, the Proxmox API, etc.) to inspect config, storage, and any
+  existing VM/container freely.
+- **Never** modify, stop, restart, delete, reconfigure, or create
+  anything on this node (`qm set`, `pct set`, `qm destroy`, `pct
+  destroy`, `qm stop`, `pct stop`, `qm create`, `pct create`, snapshot
+  operations, storage changes, running any script in this repo against
+  it, etc.) without that explicit go-ahead. Use `pve-test` for anything
+  exploratory instead.
+- If a guest on `pve1` is HA-managed, be aware of the self-fence hazard
+  described in `docs/05-node-roles.md`'s cluster-teardown section before
+  doing anything that could cost the node quorum.
+
+### `pve-test` (sandbox — Claude's default target)
+
+A separate node set aside for testing — safe to create, interrogate, and
+destroy scratch VMs/containers on without asking first.
+
+- **Test VMs/containers are allowed, but must be torn down.** Anything
+  created this way must be destroyed again in the same session, before
+  ending the task. Use an obviously-scratch VMID/name.
+- **Node-level config is still not yours to change by default.**
+  Creating/destroying your own scratch guests is fine; Proxmox host
+  config, storage pools, and networking on `pve-test` itself need the
+  operator's explicit go-ahead too, same as on `pve1` — the "sandbox"
+  status covers guest-level experimentation, not the host's own
+  identity. (`pve-test`'s current network config, `docs/06-pve-test-wifi-network.md`,
+  was applied under exactly that kind of explicit, same-session
+  authorization — it's not a standing invitation to keep changing it
+  further without asking again.)
+- **Never re-cluster `pve-test` with `pve1`** without the operator
+  explicitly asking for it and being aware of the wifi/corosync
+  incompatibility in `docs/06-pve-test-wifi-network.md` — the two were
+  deliberately de-clustered for this reason once already.
+
+## Safety rules
+
+- Any script in `scripts/` that isn't `audit.sh` (read-only) makes real
+  changes when run for real. Don't run one against `pve1`, or against
+  `pve-test`'s node-level config, without the same-session go-ahead
+  described above. Running a script *against pve-test's own guests* — a
+  scratch VM/CT you created for this task — doesn't need separate
+  permission.
+- Do not commit secrets: SSH private keys, wifi passphrases, sops/age
+  keys, or PVE credentials. `scripts/setup-wifi-bond-network.sh` takes
+  the SSID/passphrase via environment variables for exactly this reason
+  — never hardcode them into the script or a committed config file.
+- Live changes to a node's own management network (the interface/bridge
+  carrying the SSH session you're using) can strand the box — see the
+  "what went wrong once" section in `docs/06-pve-test-wifi-network.md`
+  before touching `pve-test`'s networking again. Prefer applying via
+  `ifreload -a` over raw `ip link` surgery, and arm an auto-revert
+  watchdog first when acting without someone physically at the console.

README.md

@@ -15,15 +15,22 @@ deferred).
   backed by Ceph. Needs dedicated hardware node 1 (`pve1`, an ASUS PN53 mini
   PC) doesn't have — see `docs/01-hardware-node1.md`.
 
+See `CLAUDE.md` for the guardrails Claude Code follows when working
+against these hosts (`pve1` is production and off-limits by default;
+`pve-test` is the sandbox).
+
 ## Repo layout
 
 - `docs/` — planning docs: hardware layout, storage migration, networking,
-  security hardening. Read `docs/00-overview.md` first.
+  security hardening, node roles. Read `docs/00-overview.md` first, then
+  `docs/05-node-roles.md` for what `pve1`/`pve-test` actually are.
 - `scripts/` — scripts to apply configuration on a node (SSH hardening, repo
-  switch, firewall, updates, etc). Idempotent, safe to re-run.
-  `scripts/bootstrap.sh` runs the full Stage 1 sequence end to end;
-  `scripts/audit.sh` verifies it (read-only). `scripts/lib/` holds shared
-  helpers (`common.sh`) sourced by the other scripts.
+  switch, firewall, updates, wifi/bond networking, etc). Idempotent, safe
+  to re-run. `scripts/bootstrap.sh` runs the full Stage 1 sequence end to
+  end; `scripts/audit.sh` verifies it (read-only).
+  `scripts/setup-wifi-bond-network.sh` reproduces `pve-test`'s wifi
+  network (see `docs/06-pve-test-wifi-network.md`). `scripts/lib/` holds
+  shared helpers (`common.sh`) sourced by the other scripts.
 - `config/` — reference config files/snippets to drop onto a node (firewall
   rules, sshd config, etc.).
 

config/pve-firewall/cluster.fw.example

@@ -26,6 +26,13 @@ policy_out: ACCEPT
 IN ACCEPT -source +mgmt -p tcp -dport 8006 -log nolog
 IN ACCEPT -source +mgmt -p tcp -dport 22 -log nolog
 
+# ICMP echo (ping) from the management network - diagnostic convenience
+# only, nothing else depends on it. Without this, policy_in DROP silently
+# eats ping while SSH/web UI keep working - looks like an outage during
+# troubleshooting when the host is actually fine. See
+# docs/06-pve-test-wifi-network.md for a case this caused real confusion.
+IN ACCEPT -source +mgmt -p icmp -icmp-type echo-request -log nolog
+
 # Stage 2: Corosync (cluster quorum) - uncomment once node 2/3 join and
 # the corosync network/VLAN exists.
 # IN ACCEPT -source <COROSYNC_CIDR> -p udp -dport 5404:5405 -log nolog

docs/00-overview.md

@@ -59,6 +59,16 @@ require or assume the split-disk/multi-NIC layout Stage 2 wants.
 Everything below this point is the target design for when nodes 2 and 3
 are actually being provisioned. Not applicable to `pve1` as it stands.
 
+**`pve-test` existing does not mean node 2 exists.** A second physical
+node (`pve-test`) does run alongside `pve1` — see `05-node-roles.md` —
+but it's a sandbox/test box, not built to this Stage 2 design, and as of
+this writing runs on **wifi** networking
+(`06-pve-test-wifi-network.md`), which is directly incompatible with
+corosync's latency/jitter requirements below. `pve-test` and `pve1` were
+briefly clustered and then deliberately de-clustered for exactly this
+reason. Don't treat `pve-test` as progress toward Stage 2 without a
+deliberate decision to rebuild its networking first.
+
 ### End goal
 
 3-node Proxmox VE cluster with HA-managed VMs backed by **Ceph** — true

docs/03-networking.md

@@ -11,6 +11,17 @@ PVE datacenter firewall (default-deny inbound otherwise). That's
 sufficient until Stage 2 needs actual separate physical/VLAN paths for
 corosync and Ceph traffic — see below.
 
+## pve-test as built (sandbox, current)
+
+Different node, different design, not a Stage 1/2 example to generalize
+from: `pve-test` runs `vmbr0` bridged over a wifi NIC in 4addr client mode
+(active-backup bonded with a wired NIC as an automatic fallback). Full
+detail, including why this is normally impossible and how it was
+validated before trusting it with the management IP, in
+`06-pve-test-wifi-network.md`. This is intentionally a one-off for a
+standalone sandbox box — never extend it to a node that's clustered or
+Ceph-connected (see the Stage 2 note in `00-overview.md`).
+
 ## Target design (Stage 2, future cluster)
 
 ## Required separation

docs/04-security-hardening.md

@@ -54,6 +54,23 @@ Default-deny at datacenter/node level, whitelist only what's needed (see
 `config/pve-firewall/cluster.fw.example`, applied by
 `scripts/deploy-firewall.sh`.
 
+**ICMP echo (ping) is explicitly allowed from the management network**,
+alongside SSH/8006 — not required for anything to function, but without
+it `policy_in: DROP` silently eats ping while SSH/web UI keep working.
+That split (ping dead, everything else fine) reads exactly like a real
+outage mid-troubleshooting; see `06-pve-test-wifi-network.md` for a case
+this caused genuine confusion after a network change. If you ever debug
+"can't ping but can SSH", check this firewall before assuming the
+network itself is broken.
+
+**This file is cluster-wide, not per-node**: `cluster.fw` lives in
+`/etc/pve/firewall/` — shared via pmxcfs across every node in a cluster.
+A node that joins a cluster inherits whatever's already there, and (per
+`docs/05-node-roles.md`) keeps its own local copy after leaving. Don't
+assume a node's firewall state matches what `deploy-firewall.sh` was
+last run with directly against it — check `pve-firewall status` /
+`/etc/pve/firewall/cluster.fw` on the actual node.
+
 ## Repos and updates
 
 Fresh installs point at the enterprise repo, which fails on `apt update`

docs/05-node-roles.md

@@ -0,0 +1,83 @@
+# Node Roles: pve1 and pve-test
+
+Two Proxmox VE hosts exist on the LAN. They are **not interchangeable** —
+different purpose, different risk tolerance, different guardrails. See
+`CLAUDE.md` for the actual rules Claude follows; this doc is the
+background/context those rules assume.
+
+## pve1 (production)
+
+ASUS PN53 mini PC (Ryzen 7 7735HS, 32GB RAM) — see `01-hardware-node1.md`
+for the full hardware layout. Stage 1 base hardening applied and verified
+(`04-security-hardening.md`).
+
+Runs real production workloads:
+
+- `server-nixos` (VM) and LXC containers `pihole`, `claude`, `nix-cache`,
+  `docker`, `pdm`, `pxe-boot` — DNS, this Claude Code environment itself,
+  the LAN's Nix binary cache, etc.
+
+Off-limits to Claude by default — see `CLAUDE.md`.
+
+## pve-test (sandbox)
+
+A separate physical node kept for testing. Has a capable GPU (earmarked
+for future GPU workloads — transcoding, local inference, etc. — nothing
+built on it yet as of this writing). No production guests run here.
+
+Safe for Claude to create/destroy scratch VMs and containers on without
+asking — see `CLAUDE.md` for the exact boundary (node-level config is
+still not free-for-all even here).
+
+### History: briefly clustered with pve1, then deliberately separated
+
+On 2026-07-21/22, pve-test was joined to pve1 in a 2-node Proxmox cluster
+(corosync + shared `/etc/pve`) for a period, then the cluster was
+**intentionally destroyed** at the operator's explicit request — not a
+failure or accident. Rationale: the operator wanted pve-test moved onto
+wifi networking (see `06-pve-test-wifi-network.md`), and wifi is
+fundamentally unsuitable for corosync's latency/jitter requirements (token
+timeouts, flapping membership). Rather than fight that, the cluster was
+torn down first, then wifi was configured on the now-standalone node.
+
+Teardown procedure used (safe to repeat if pve-test or pve1 is ever
+reclustered and needs separating again):
+
+1. Un-manage any HA-assigned resources first if HA is in use
+   (`ha-manager remove <sid>` per resource) — **critical**: if a node has
+   HA-managed guests and its watchdog is still armed when it loses
+   quorum, HA's self-fence behavior can force-reboot it. Removing the
+   resource assignments first (not stopping the guests — just
+   un-managing them) prevents this.
+2. Stop `pve-ha-lrm`/`pve-ha-crm` on all nodes once no resources remain
+   assigned, confirm via `ha-manager status` that fencing is no longer
+   armed.
+3. From a node that will remain in the cluster: `pvecm delnode <name>`
+   for the node being removed. In a 2-node cluster with no QDevice, this
+   can itself cause the *remaining* node to transiently lose quorum
+   (killing a node's live corosync membership drops total votes below
+   expected votes before the nodelist file can be rewritten to match) —
+   this is expected, not a failure; proceed to step 4 regardless.
+4. On **each** node being separated (including one you just ran `delnode`
+   from, if it's also being decoupled): `systemctl stop pve-cluster
+   corosync`, `pmxcfs -l` (local mode, bypasses the quorum requirement
+   for local writes), remove `/etc/pve/corosync.conf` and
+   `/etc/corosync/*`, `killall pmxcfs`, `systemctl start pve-cluster`.
+   This is the official "separate a node without reinstalling" procedure
+   and doesn't touch any running VM/CT — they're independent OS
+   processes, unaffected by corosync/pmxcfs state either way.
+5. Optional cosmetic cleanup: the node(s) staying up may retain a stale
+   `/etc/pve/nodes/<removed-node>/` directory (cached VM/CT configs from
+   when they were clustered) — safe to `rm -rf` once separation is
+   confirmed; it's dead data, not a live reference to anything.
+
+Guests were never at risk during this procedure (confirmed: all 7 of
+pve1's guests ran continuously throughout) — the only real hazard is the
+HA/watchdog self-fence path in step 1, and losing corosync-provided quorum
+temporarily blocking `/etc/pve` writes (not guest execution) in step 3.
+
+### Current state: standalone, wifi-primary networking
+
+pve-test now runs entirely independently of pve1, on the network design
+documented in `06-pve-test-wifi-network.md`. **Do not re-cluster
+pve-test while it's on wifi** — see that doc for why.

docs/06-pve-test-wifi-network.md

@@ -0,0 +1,230 @@
+# pve-test's Wifi-Primary Network
+
+Non-standard, deliberately chosen against normal Proxmox guidance (a
+hypervisor's management network is not supposed to be wireless). Applies
+**only** to `pve-test` as a standalone sandbox node — see
+`05-node-roles.md` for why this and cluster membership don't mix, and
+never apply this pattern to a node that's joined (or might join) a
+cluster.
+
+## Why this works at all
+
+Wifi (802.11) normally cannot be bridged the way Ethernet can: an access
+point only accepts frames whose source MAC matches the MAC that
+associated with it. A Linux bridge with a wifi port as a member sends
+frames tagged with whatever MAC actually generated them (the bridge's own
+MAC, a VM's MAC, etc.) — none of which match the wifi card's hardware
+MAC, so the AP silently drops them. This isn't a Linux/Proxmox limitation,
+it's how WiFi association works.
+
+**4addr (WDS) client mode** is the exception: if both the wifi driver and
+the AP support it, the client tags frames with a 4th address field
+carrying the original MAC, and the AP forwards them like a real Ethernet
+segment. Most consumer routers do **not** support this (it's common on
+OpenWrt/DD-WRT/enterprise APs, rare on stock ISP hardware) — it has to be
+confirmed empirically, per-AP, before trusting it with a management IP.
+
+pve-test's card (Intel AX200, `iwlwifi` driver, interface `wlp3s0`)
+supports 4addr client-side generically (this is a `mac80211` core
+feature, not driver-specific). The home AP it associates to
+(`nbn-fttp-net-5G`) was confirmed to honor it — see validation method
+below.
+
+## Validate before ever touching a live management IP
+
+Don't add the wifi NIC straight into your real bridge to "see if it
+works" — if 4addr isn't actually honored, you lose access to the box with
+no diagnostic trail (association succeeds; only the *data plane* silently
+fails). Test in an isolated scratch namespace first:
+
+```bash
+# assumes wlp3s0 already associated with 4addr on (see systemd unit below)
+ip link add testbr0 type bridge && ip link set testbr0 up
+ip link set wlp3s0 master testbr0 && ip link set wlp3s0 up
+
+ip netns add wifitest
+ip link add veth-host type veth peer name veth-ns
+ip link set veth-host master testbr0 && ip link set veth-host up
+ip link set veth-ns netns wifitest
+ip netns exec wifitest ip link set veth-ns address 02:11:22:33:44:55  # deliberately NOT the wifi card's MAC
+ip netns exec wifitest ip link set veth-ns up
+ip netns exec wifitest ip link set lo up
+
+ip netns exec wifitest dhclient -v -1 veth-ns   # real DHCP lease = AP forwards foreign MACs = 4addr genuinely works
+```
+
+If that gets a lease (or at minimum a ping reply from the gateway) from a
+MAC that was never the one that associated, the AP is forwarding
+arbitrary-MAC frames — real bridge mode will work. If not, don't proceed
+to bridge mode; fall back to a routed/NAT design instead (wifi gets its
+own IP via DHCP, VMs NAT out through it — never covered here since it
+wasn't needed, but keep this fallback in mind if reproducing on different
+hardware/AP).
+
+Tear the test namespace/bridge down afterwards (`ip netns del wifitest;
+ip link del veth-host; ip link set wlp3s0 nomaster; ip link del testbr0`)
+— it's scratch, not part of the real config.
+
+## Final architecture
+
+```
+wlp3s0 (wifi, 4addr client mode) ─┐
+                                    ├─ bond0 (active-backup, wlp3s0 primary) ─ vmbr0 (192.168.2.251/24)
+nic0 (wired, LAN backup)          ─┘
+```
+
+- **`wpa-4addr-<iface>.service`** (systemd unit, `Before=network-pre.target`) —
+  sets 4addr mode and starts `wpa_supplicant` *before* ifupdown2 processes
+  `/etc/network/interfaces`. Deliberately not using `wpasupplicant`'s own
+  `wpa-conf` ifupdown2 hook integration — its ordering relative to a
+  custom `pre-up iw ... set 4addr on` line is implementation-specific and
+  not worth gambling on for something this hard to debug if it's wrong.
+  The systemd unit gives full, deterministic control over sequencing
+  instead.
+- **`bond0`** — active-backup bonding, `wlp3s0` as `bond-primary`,
+  `nic0` as backup, `bond-miimon 100`. Bonding a wifi interface works here
+  because `mac80211`/`iwlwifi` properly reports carrier state
+  (`netif_carrier_on/off`) on association/disassociation, which is what
+  bonding's `miimon` (with the default `use_carrier=1`) actually watches
+  — it doesn't require a "real" MII-capable NIC.
+- **`vmbr0`** — unchanged IP (`192.168.2.251/24`), bridged over `bond0`
+  instead of directly over a physical NIC.
+
+Reproduce with `scripts/setup-wifi-bond-network.sh` — see its header
+comment for usage and required env vars (SSID/passphrase, management
+address/gateway). It stages `/etc/network/interfaces` and the systemd
+unit but does **not** auto-apply (`ifreload -a`) — see the next section
+for why that step needs care, not automation.
+
+## Applying a live bridge-port change: what went wrong once, and what worked
+
+Moving `vmbr0`'s underlying port live — while SSH'd in over the very
+address that lives on that bridge — is inherently risky: if the new port
+doesn't actually pass traffic, you lose the connection you're using to
+fix it.
+
+**What failed**: doing the port swap via raw `ip link set nic0 nomaster`
++ `ip link set nic0 down` (with `wlp3s0` already added as a second bridge
+member) caused an extended outage that needed a physical power-cycle to
+recover — `nic0` never came back up on its own even well past a 60s
+auto-revert watchdog's deadline. Importantly, the *host itself* never
+crashed — `journalctl -b -1` showed completely normal operation (a
+`pvestatd` polling loop, no gaps, no panic/OOM/watchdog trigger) right up
+until a keyboard was plugged in and it was manually reset. So the failure
+was specifically in the live network transition, not the OS — root cause
+unconfirmed, but plausibly bridge FDB/MAC-identity handling when a port
+carrying an already-live IP is swapped out via raw `ip link` rather than
+a coordinated reconfiguration.
+
+**What worked**: writing the final state into `/etc/network/interfaces`
+and applying with `ifreload -a` (Proxmox's own supported hot-reload path)
+instead. Same end state, same risk window, but ifupdown2 evidently
+sequences the transition in a way raw `ip link` surgery didn't. This
+succeeded on the first retry using this method.
+
+**Either way, expect ~30-60 seconds of apparent breakage even on a
+successful change** — the upstream switch/AP needs to relearn which port
+`192.168.2.251`'s MAC now lives behind. Don't judge success/failure
+before that window passes; a `ping`/SSH failure at the 5-10s mark is not
+yet a sign anything is wrong.
+
+**Recommended safety net for any future live change here**: arm a
+backgrounded auto-revert-on-timeout before applying, e.g.:
+
+```bash
+cp /etc/network/interfaces /etc/network/interfaces.bak
+cat > /root/revert.sh <<'EOF'
+#!/bin/bash
+cp /etc/network/interfaces.bak /etc/network/interfaces
+ifreload -a
+EOF
+chmod +x /root/revert.sh
+setsid nohup bash -c "sleep 45 && /root/revert.sh" >/root/revert.log 2>&1 < /dev/null &
+disown
+# now apply the real change, e.g.: ifreload -a
+# once confirmed working: pkill -f "sleep 45 && /root/revert.sh"
+```
+
+This only self-heals if the box stays responsive enough for the
+backgrounded job to run to completion — it is not a substitute for
+physical/console access being available, just a way to avoid needing it
+for the common case.
+
+## Troubleshooting: "can't ping it, web UI won't load" isn't necessarily an outage
+
+Two independent things can make `pve-test` look dead when it isn't:
+
+1. **Stale ARP after any change to `vmbr0`'s active port.** `vmbr0`'s MAC
+   address follows whichever interface is currently active in `bond0`
+   (`wlp3s0`'s MAC while wifi is primary, `nic0`'s if it fails over) — it
+   is *not* fixed. Other devices on the LAN (including your own
+   workstation) that cached the old MAC before a change won't notice
+   until their ARP entry naturally expires or gets flushed
+   (`ip neigh flush <ip>` / `arp -d <ip>`). Symptom: intermittent or
+   totally dead connectivity from one specific device while others (or
+   the host itself) are fine.
+2. **ICMP ping is blocked by the management firewall, unrelated to
+   network health.** See `04-security-hardening.md`'s firewall section —
+   `cluster.fw`'s `policy_in: DROP` only explicitly allows TCP 22/8006
+   (now also ICMP echo-request, after this was hit) from the mgmt
+   network. Before that rule was added, `ping` failed 100% *even with a
+   perfectly correct, fresh ARP entry and full SSH/web UI access* —
+   nothing to do with wifi, bonding, or the network being down. This is
+   exactly what happened once: alarming "can't ping, web UI not loading"
+   turned out to be a stale-ARP moment (which resolved itself) plus a
+   pre-existing firewall policy (ping was never going to work,
+   regardless of wifi).
+
+**When `pve-test` seems unreachable, check in this order before assuming
+a real outage**: SSH (`ssh root@pve-test.sweet.home`) → web UI via `curl
+-sk -o /dev/null -w '%{http_code}' https://pve-test.sweet.home:8006/` →
+only then worry about `ping` specifically, and check
+`/etc/pve/firewall/cluster.fw` before blaming the network.
+
+## Confirmed limitation: no wireless client on the same AP can reach pve-test
+
+**This is not an AP-isolation toggle** — tested and ruled out (router:
+TP-Link BE9300, AP Isolation confirmed unchecked). Two independent
+wireless devices (a laptop and a phone) on the same SSID pve-test uses
+(`nbn-fttp-net-5G`) were both completely unable to reach it — not
+intermittent, not slow, no ARP entry ever resolves (`arp -a` on Windows /
+`ip neigh` on Linux/Mac shows nothing at all, not a stale entry). Every
+wired device tested (this repo's own Claude session, `pve1`) reaches it
+fine, every time.
+
+Root cause: pve-test's wifi connection uses 4-address (WDS) framing to
+make bridging possible at all (see above) — that's what lets the AP
+forward frames from arbitrary MACs (VM traffic, the bridge's own
+identity) instead of only the wifi card's own hardware MAC. This
+router's firmware evidently handles wired↔pve-test forwarding for that
+4addr peer correctly, but doesn't correctly forward *wireless-client*
+broadcast/ARP traffic to it — an asymmetric gap in the AP's own 4addr
+handling, not a policy setting. Likely not fixable short of a firmware
+update from TP-Link (if one ever improves 4addr/WDS handling), possibly
+not fixable on this hardware at all.
+
+**Practical implication**: anything on `vmbr0` — pve-test itself, or any
+VM/CT created on it — is unreachable from a wireless client on this AP,
+full stop, for *any* protocol, not just ICMP. ARP resolution is a
+prerequisite for sending any IP packet at all (TCP included); since ARP
+itself never resolves for a wireless peer here, the web UI (8006) fails
+identically to ping, not just ping — confirmed live, not theoretical.
+This includes VMs on pve-test too, since they ride the same bridge/wifi
+uplink as the host. **Wired access is the only reliable path to
+pve-test and anything running on it** — including reaching a VM's
+console through the Proxmox web UI, which still requires the accessing
+device to reach pve-test's own IP on port 8006 first, so it inherits the
+same requirement.
+
+Don't waste time on ARP flushes, firewall rules, or bonding config for
+this specific symptom (no ARP entry from a wireless peer, wired fine) —
+none of those are the cause.
+
+## Known limitation history
+
+`nic0` (the bond's backup slave) initially had no cable physically
+connected when this was first set up — the bond was correctly configured
+but inert until a cable was plugged in. As of this writing a cable is
+connected and the backup slave is live (confirm with `cat
+/proc/net/bonding/bond0`) — if reproducing this setup, verify the same
+before assuming LAN failover will actually work.

scripts/audit.sh

@@ -58,6 +58,11 @@ if [ -f /etc/pve/firewall/cluster.fw ] && grep -qi '^policy_in:\s*DROP' /etc/pve
 else
     audit_fail "cluster.fw missing or does not default-deny inbound"
 fi
+if [ -f /etc/pve/firewall/cluster.fw ] && grep -qi 'icmp-type echo-request' /etc/pve/firewall/cluster.fw 2>/dev/null; then
+    audit_pass "cluster.fw allows ICMP echo-request from mgmt (ping works)"
+else
+    audit_fail "cluster.fw does not allow ping from mgmt - see docs/04-security-hardening.md firewall section"
+fi
 
 # --- unattended-upgrades ---
 if dpkg -s unattended-upgrades >/dev/null 2>&1 && systemctl is-enabled --quiet unattended-upgrades 2>/dev/null; then

scripts/setup-wifi-bond-network.sh

@@ -0,0 +1,133 @@
+#!/bin/bash
+# Reproduces pve-test's wifi-primary networking: vmbr0 bridged over a wifi
+# NIC in 4addr (WDS) client-bridge mode, active-backup bonded with a wired
+# NIC as an automatic LAN fallback. See docs/06-pve-test-wifi-network.md for
+# why this exists and how it was validated. Idempotent - safe to re-run.
+#
+# Requires: a wifi NIC whose driver/AP both support 4addr mode (verify with
+# docs/06-pve-test-wifi-network.md's isolated-namespace test *before*
+# trusting this against a live management IP - a wifi NIC or AP that
+# doesn't support 4addr will associate fine but silently drop bridged
+# frames from any MAC other than the card's own).
+#
+# Usage (run as root on the target PVE host):
+#   WIFI_SSID="..." WIFI_PASSPHRASE="..." \
+#   MGMT_ADDR=192.168.2.251/24 MGMT_GATEWAY=192.168.2.254 \
+#   ./setup-wifi-bond-network.sh
+#
+# Optional overrides: WIFI_IFACE (default wlp3s0), LAN_IFACE (default nic0)
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+# shellcheck source=lib/common.sh
+source "${SCRIPT_DIR}/lib/common.sh"
+require_root
+
+WIFI_IFACE="${WIFI_IFACE:-wlp3s0}"
+LAN_IFACE="${LAN_IFACE:-nic0}"
+
+for var in WIFI_SSID WIFI_PASSPHRASE MGMT_ADDR MGMT_GATEWAY; do
+    if [ -z "${!var:-}" ]; then
+        echo "$var is not set. See usage in this script's header." >&2
+        exit 1
+    fi
+done
+
+if ! ip link show "$WIFI_IFACE" >/dev/null 2>&1; then
+    echo "No interface named $WIFI_IFACE on this host. Run 'ip -br link' and set WIFI_IFACE=..." >&2
+    exit 1
+fi
+if ! ip link show "$LAN_IFACE" >/dev/null 2>&1; then
+    echo "No interface named $LAN_IFACE on this host. Run 'ip -br link' and set LAN_IFACE=..." >&2
+    exit 1
+fi
+
+echo "=== 1/4: wifi tooling ==="
+apt-get install -y iw wpasupplicant >/dev/null
+echo "installed iw, wpasupplicant"
+
+echo
+echo "=== 2/4: wpa_supplicant config (SSID: $WIFI_SSID, iface: $WIFI_IFACE) ==="
+WPA_CONF="/etc/wpa_supplicant/wpa_supplicant-${WIFI_IFACE}.conf"
+wpa_passphrase "$WIFI_SSID" "$WIFI_PASSPHRASE" > "$WPA_CONF"
+sed -i '/^\s*#psk=/d' "$WPA_CONF"
+chmod 600 "$WPA_CONF"
+echo "wrote $WPA_CONF (passphrase hashed, not stored in plaintext)"
+
+echo
+echo "=== 3/4: systemd unit to set 4addr mode + start wpa_supplicant ==="
+UNIT="/etc/systemd/system/wpa-4addr-${WIFI_IFACE}.service"
+write_if_changed "$UNIT" "[Unit]
+Description=wpa_supplicant on ${WIFI_IFACE} with 4addr mode enabled
+Before=network-pre.target
+Wants=network-pre.target
+
+[Service]
+Type=simple
+ExecStartPre=/sbin/ip link set ${WIFI_IFACE} down
+ExecStartPre=/sbin/iw dev ${WIFI_IFACE} set 4addr on
+ExecStartPre=/sbin/ip link set ${WIFI_IFACE} up
+ExecStart=/sbin/wpa_supplicant -i ${WIFI_IFACE} -c ${WPA_CONF}
+Restart=on-failure
+RestartSec=3
+
+[Install]
+WantedBy=multi-user.target"
+systemctl daemon-reload
+systemctl enable --now "wpa-4addr-${WIFI_IFACE}.service"
+sleep 5
+if ! iw dev "$WIFI_IFACE" link | grep -q "^Connected"; then
+    echo "WARNING: ${WIFI_IFACE} did not associate to '$WIFI_SSID' within 5s - check:" >&2
+    echo "  systemctl status wpa-4addr-${WIFI_IFACE}.service" >&2
+    echo "  journalctl -u wpa-4addr-${WIFI_IFACE}.service" >&2
+    exit 1
+fi
+echo "associated: $(iw dev "$WIFI_IFACE" link | grep '^Connected')"
+
+echo
+echo "=== 4/4: /etc/network/interfaces (bond0 active-backup: ${WIFI_IFACE} primary, ${LAN_IFACE} backup) ==="
+IFACES_FILE="/etc/network/interfaces"
+backup_file "$IFACES_FILE"
+cat > "$IFACES_FILE" <<EOF
+auto lo
+iface lo inet loopback
+
+iface ${LAN_IFACE} inet manual
+
+iface ${WIFI_IFACE} inet manual
+
+auto bond0
+iface bond0 inet manual
+	bond-slaves ${WIFI_IFACE} ${LAN_IFACE}
+	bond-mode active-backup
+	bond-miimon 100
+	bond-primary ${WIFI_IFACE}
+	bond-updelay 200
+	bond-downdelay 200
+
+auto vmbr0
+iface vmbr0 inet static
+	address ${MGMT_ADDR}
+	gateway ${MGMT_GATEWAY}
+	bridge-ports bond0
+	bridge-stp off
+	bridge-fd 0
+
+source /etc/network/interfaces.d/*
+EOF
+echo "wrote $IFACES_FILE"
+
+echo
+echo "Config staged but NOT applied yet - applying it live can drop your"
+echo "current management connection for ~30-60s while the switch/AP"
+echo "relearns MAC locations (expected, self-resolves; see"
+echo "docs/06-pve-test-wifi-network.md). Recommended: run this from the"
+echo "physical console, or arm a revert-on-timeout watchdog first, e.g.:"
+echo
+echo "  cp ${IFACES_FILE}.bak.* /tmp/interfaces.orig  # pick the backup just made"
+echo "  (sleep 45 && cp /tmp/interfaces.orig ${IFACES_FILE} && ifreload -a) &"
+echo "  ifreload -a"
+echo "  # then kill the backgrounded revert job once you confirm connectivity"
+echo
+echo "Apply now with: ifreload -a"
+echo "Verify after with: cat /proc/net/bonding/bond0 ; ip -4 -br addr show vmbr0"