# WiFi / CAPsMAN Troubleshooting Guide

**Last Updated:** 2026-03-12
**Purpose:** Document known pitfalls, root causes, and diagnostic procedures for WiFi and CAPsMAN issues on the MikroTik HAP ax³ + cAP XL ac setup.

---

## Pitfall 1: Empty Inline Security Overrides = Open Network

**Severity:** CRITICAL

**Problem:** Setting `security.authentication-types=""` on a WiFi interface does NOT mean "inherit from security profile." RouterOS interprets an empty string as **no authentication (open network)**.

**Symptoms:**
- Devices connect but show empty AUTH-TYPE in registration table
- IoT devices that try WPA/WPA2 handshake silently fail — router logs show ZERO connection attempts
- Other devices connect fine (they accept open)

**Root Cause:** Attempting to "clear inline overrides" to inherit from the security profile by setting empty values. RouterOS treats empty string as explicit "no auth."

**Fix:**
```routeros
# Always set explicit values on the interface
/interface wifi set wifi2 \
    security.authentication-types=wpa-psk,wpa2-psk \
    security.encryption=tkip,ccmp
```

**Rule:** NEVER set `security.authentication-types=""` or `security.encryption=""`. Always use explicit values matching the security profile.

---

## Pitfall 2: CAPsMAN Re-Provisioning Wipes Interface Config

**Severity:** HIGH

**Problem:** Running `/interface wifi capsman remote-cap provision` clears all configuration from cap-wifi interfaces — security, channel, datapath, and SSID are all removed. Interfaces show "SSID not set" and remain inactive.

**Fix:** After re-provisioning, manually re-apply full config:
```routeros
# 2.4GHz (cap-wifi1 = MAC :BE = 2.4GHz radio)
/interface wifi set cap-wifi1 \
    configuration=cfg-xtrm2 security=sec-xtrm2 datapath=dp-cap \
    channel.frequency=2472 channel.band=2ghz-g channel.width=20mhz

# 5GHz (cap-wifi2 = MAC :BF = 5GHz radio)
/interface wifi set cap-wifi2 \
    configuration=cfg-xtrm security=sec-xtrm datapath=dp-cap \
    channel.frequency=5180 channel.band=5ghz-ac \
    channel.width=20/40/80mhz channel.skip-dfs-channels=all

# Re-enable both
/interface wifi enable cap-wifi1
/interface wifi enable cap-wifi2
```

---

## Pitfall 3: Interface IDs Change After Re-Provisioning

**Severity:** HIGH

**Problem:** After CAPsMAN re-provisioning, cap-wifi interface internal IDs change (e.g., `*20`/`*21` become `*22`/`*23`). Access-list rules referencing old IDs stop matching.

**Symptom:** `client was disconnected because could not assign vlan` error on CAP interfaces.

**Fix:**
```routeros
# Check current IDs
:foreach i in=[/interface wifi find where name~"cap"] do={
    :put ([/interface wifi get $i name] . " = " . $i)
}

# Update access-list rules
/interface wifi access-list set [find where interface=*OLD] interface=*NEW
```

**Best practice:** Don't use CAP-specific access-list rules. Let all clients (HAP and CAP) use the same MAC-based access list. The HAP handles VLAN assignment uniformly via CAPsMAN.

---

## Pitfall 4: CAP Radio-to-Interface Mapping Swap

**Severity:** MEDIUM

**Problem:** After re-provisioning, `cap-wifi1` and `cap-wifi2` may swap which physical radio they map to. Assigning 5GHz config to the 2.4GHz radio (or vice versa) causes "no available channels" error.

**Identification:** Check MAC addresses:

| MAC suffix | Radio | Must receive |
|------------|-------|--------------|
| :BE | 2.4GHz | 2.4GHz config (XTRM2) |
| :BF | 5GHz | 5GHz config (XTRM) |

**Fix:** Match config to the correct radio MAC, not the interface name.

---

## Pitfall 5: CAP Band Must Be AC, Not AX

**Severity:** MEDIUM

**Problem:** The cAP XL ac only supports 802.11ac. Setting band to `5ghz-ax` results in the radio not starting.

**Fix:** Always use `5ghz-ac` for the CAP 5GHz channel configuration.

---

## Pitfall 6: IoT Devices Need Legacy WiFi Settings

**Severity:** HIGH

**Problem:** Many IoT devices (vacuums, smart gateways, ovens) require legacy WiFi settings to connect. Using 802.11n-only or WPA2-only silently prevents connections — the router sees zero attempts.

**Required XTRM2 (2.4GHz) settings:**

| Setting | Value | Reason |
|---------|-------|--------|
| Band | `2ghz-g` | NOT `2ghz-n` — IoT devices may only support 802.11g |
| Auth | `wpa-psk,wpa2-psk` | Some devices need WPA1 available |
| Encryption | `tkip,ccmp` | Some devices need TKIP |
| Channel width | `20mhz` | Maximum compatibility |
| FT (802.11r) | Disabled | Causes issues with IoT |

**Known devices requiring legacy support:**
- Roborock S7 Vacuum (B0:4A:39:3F:9A:14)
- Tuya Smart Gateway JMWZG1 (38:1F:8D:04:6F:E4)
- Bosch Oven (94:27:70:1E:0C:EE)
- Various other IoT appliances

---

## 5GHz Channel Separation

HAP and CAP must use different 5GHz channels to avoid co-channel interference:

| Device | Channel | Frequency | Band |
|--------|---------|-----------|------|
| HAP wifi1 | 149 | 5745 MHz | 5ghz-ax |
| CAP cap-wifi2 | 36 | 5180 MHz | 5ghz-ac |

Both use `skip-dfs-channels=all` to avoid radar detection disconnects.

---

## Diagnostic Checklist

When devices can't connect to WiFi, check in this order:

### Step 1: Check Security (Most Common Issue)
```routeros
# Check if AUTH-TYPE is empty in registration table (= open network!)
/interface wifi registration-table print

# Check inline security overrides
:put [/interface wifi get wifi2 security.authentication-types]
:put [/interface wifi get wifi2 security.encryption]
# If empty → security is broken, set explicit values
```

### Step 2: Check Band Compatibility
```routeros
/interface wifi monitor wifi2 once
# If channel shows /n → change to /g for IoT compatibility
```

### Step 3: Enable Debug Logging
```routeros
/system logging add topics=wireless,debug action=memory
# Then check: /log print where topics~"wireless"
```

### Step 4: Check CAP Interface IDs
```routeros
# Verify access-list rules reference current IDs
:foreach i in=[/interface wifi find where name~"cap"] do={
    :put ([/interface wifi get $i name] . " = " . $i)
}
/interface wifi access-list print where interface~"\\*"
```

### Step 5: Check Radio-MAC Mapping
```routeros
# Verify cap interfaces are assigned to correct radios
/interface wifi print where name~"cap" proplist=name,mac-address,channel.band
```

### Step 6: If Router Sees ZERO Attempts
This means:
- **Security mismatch** — device won't even try (most likely empty auth = open)
- **Band incompatibility** — 802.11n-only blocks 802.11g devices
- **Device-side issue** — power cycle device, re-do WiFi setup from scratch

---

## Quick Recovery Commands

### Restore XTRM2 (2.4GHz) to known working state
```routeros
/interface wifi security set sec-xtrm2 \
    authentication-types=wpa-psk,wpa2-psk encryption=tkip,ccmp

/interface wifi set wifi2 \
    security.authentication-types=wpa-psk,wpa2-psk \
    security.encryption=tkip,ccmp \
    security.ft=no security.ft-over-ds=no

/interface wifi channel set ch-2g-hap \
    frequency=2412 band=2ghz-g width=20mhz
```

### Restore XTRM (5GHz) to known working state
```routeros
/interface wifi security set sec-xtrm \
    authentication-types=wpa2-psk,wpa3-psk encryption=ccmp

/interface wifi set wifi1 \
    security.authentication-types=wpa2-psk,wpa3-psk \
    security.encryption=ccmp \
    security.ft=no security.ft-over-ds=no

/interface wifi channel set ch-5g-hap \
    frequency=5745 band=5ghz-ax width=20/40/80mhz skip-dfs-channels=all
```

### Restore CAP interfaces after re-provisioning
```routeros
/interface wifi set cap-wifi1 \
    configuration=cfg-xtrm2 security=sec-xtrm2 datapath=dp-cap \
    channel.frequency=2472 channel.band=2ghz-g channel.width=20mhz
/interface wifi set cap-wifi2 \
    configuration=cfg-xtrm security=sec-xtrm datapath=dp-cap \
    channel.frequency=5180 channel.band=5ghz-ac \
    channel.width=20/40/80mhz channel.skip-dfs-channels=all
/interface wifi enable cap-wifi1
/interface wifi enable cap-wifi2
```