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Wireless device cannot connect to the FRITZ!Box

Your smartphone or another wireless device can't connect to the FRITZ!Box via Wi-Fi? ✔ Here's what to do.

A wireless device cannot connect to the FRITZ!Box. One of the following error messages may be displayed by the wireless device:

  • "Error during authentication"
  • "Unable to connect to this network"
  • "Connection failed"

If the wireless device does not display the name of the FRITZ!Box's Wi-Fi network (SSID) when it searches for Wi-Fi networks, proceed as described in the guide FRITZ!Box's Wi-Fi network cannot be found.

Simply proceed as described below. After each measure, check whether the problem is solved.

Note:All instructions on configuration and settings given in this guide refer to the latest FRITZ!OS for the FRITZ!Box.

1 Checking Wi-Fi access information

  1. Make sure that the correct Wi-Fi access information was used to configure the Wi-Fi connection to the FRITZ!Box.

2 Optimizing the FRITZ!Box's Wi-Fi settings

Perform the following steps on a different device connected to the FRITZ!Box:

Important:If you cannot access the FRITZ!Box with any device, proceed as described in the guide FRITZ!Box user interface cannot be opened.

Disabling the MAC address filter

  1. Click "Wi-Fi" ("Wireless") in the FRITZ!Box user interface.
  2. Click "Security" in the "Wi-Fi" ("Wireless") menu.
  3. Click "Restrict Access to Wi-Fi".
  4. Enable the option "Allow all new wireless devices".
  5. Click "Apply" to save the settings.

Enabling the WPS function

  1. Click "Wi-Fi" ("Wireless") in the FRITZ!Box user interface.
  2. Click "Security" in the "Wi-Fi" ("Wireless") menu.
  3. Click on the "WPS Quick Connection" tab.
  4. Enable the option "Push-button method enabled".
  5. Click "Apply" to save the settings.

Unlocking the buttons

  1. Click "System" in the FRITZ!Box user interface.
  2. Click "Buttons and LEDs" in the "System" menu.
  3. Click on the "Keylock" tab.
  4. Disable the "Buttons locked" checkbox.
  5. Click "Apply" to save the settings.

Adjusting the name of the Wi-Fi network (SSID)

  1. Click "Wi-Fi" ("Wireless") in the FRITZ!Box user interface.
  2. Click "Wi-Fi Network" ("Radio Network") in the "Wi-Fi" ("Wireless") menu.
  3. Click "Additional Settings for the Wi-Fi Network" and disable the option "Different names for the Wi-Fi networks on 2.4 and 5 GHz" to use the same name (SSID) for both Wi-Fi networks. Only then can the FRITZ!Box automatically steer your wireless devices to the ideal frequency band ("band steering").
  4. Click "More Information on the Wi-Fi Network" and disable the option "Hide name of the Wi-Fi network". This way, all wireless devices can connect to the FRITZ!Box and the FRITZ!Box can optimally control your wireless devices in the Mesh ("Mesh Wi-Fi Steering").
  5. If you changed the name of the FRITZ!Box's Wi-Fi network (SSID), remove all special characters from the Wi-Fi network name. Since some wireless devices do not support all of the special characters allowed by the FRITZ!Box, only use letters (but not special characters such as ä, ë, ö, ü, á, é, í), numbers, and spaces.
  6. Click "Apply" to save the settings. If the wireless devices were only connected to the 5 GHz Wi-Fi network with a different name, you must then reconfigure the Wi-Fi connection on those devices.

3 Updating FRITZ!OS and Wi-Fi software

Updates contain improvements, bug fixes, and new functions. Therefore, install the latest FRITZ!OS and software versions on all FRITZ! products and wireless devices:

Installing the latest FRITZ!OS for the FRITZ!Box

  1. Install the latest FRITZ!OS on the FRITZ!Box.

Installing the latest software for the wireless device

  1. Install the latest software version for the wireless device (for example Android, iOS) or the latest driver for the computer's wireless network adapter (for example from the Intel Download Center).

    Note:Refer to the device's manufacturer for information on how to update, for example consult the manual.

4 Connecting a wireless device to the 2.4 GHz Wi-Fi network

Some wireless plugs, robotic vacuum cleaners, and other wireless devices that are connected via app only support the 2.4 GHz frequency band. To set up the Wi-Fi connection, the mobile device with the app must be connected to the 2.4 GHz Wi-Fi network of the FRITZ!Box. Therefore, deactivate the FRITZ!Box's 5 GHz Wi-Fi network before setting it up. This way you ensure that the app transmits the correct frequency band to the device:

Disabling the 5 GHz Wi-Fi network

  1. Click "Wi-Fi" ("Wireless") in the FRITZ!Box user interface.
  2. Click "Wi-Fi Channel" ("Radio Channel") in the "Wi-Fi" ("Wireless") menu.
  3. Enable the option "Adjust Wi-Fi channel settings".
  4. Disable the Wi-Fi network for the 5 GHz frequency band.
  5. Click "Apply" to save the settings.

Setting up a Wi-Fi connection to the FRITZ!Box

  1. Set up the Wi-Fi connection from the wireless device to the FRITZ!Box according to the manufacturer's instructions.

Enabling the 5 GHz Wi-Fi network

  1. Click "Wi-Fi" ("Wireless") in the FRITZ!Box user interface.
  2. Click "Wi-Fi Channel" ("Radio Channel") in the "Wi-Fi" ("Wireless") menu.
  3. Enable the option "Adjust Wi-Fi channel settings".
  4. Enable the Wi-Fi network for the 5 GHz frequency band.
  5. Click "Apply" to save the settings.

5 Adjusting FRITZ!Box's Wi-Fi security settings

If the wireless device still does not connect to the FRITZ!Box, it does not support the modern security functions used by the FRITZ!Box. To connect the wireless device anyway, you must adjust the security settings in the FRITZ!Box:

Disabling WPA3 transition mode (WPA2 + WPA3)

WPA transition mode allows simultaneous connections with WPA3 and WPA2 encryption using the same Wi-Fi network name and network key. With connections with WPA2 encryption, however, WPA3 transition mode has higher security requirements than usual for WPA2 (CCMP).

Some wireless devices cannot establish a Wi-Fi connection if WPA3 transition mode is enabled. This is the case with iPhones and iPads with iOS older than 12.1.1, older wireless printers, IP cameras, and wireless plugs, for example:

  1. Click "Wi-Fi" ("Wireless") in the FRITZ!Box user interface.
  2. Click "Security" in the "Wi-Fi" ("Wireless") menu.
  3. If WPA mode "WPA2 + WPA3" is selected in the section "WPA Encryption", select the WPA mode "WPA2 (CCMP)" from the drop-down list.
  4. Click "Apply" to save the settings.

Disabling PMF

PMF (Protected Management Frames) encrypts the control information for establishing and using Wi-Fi connections, thus ensuring greater security. PMF is always enabled for WPA3 encryption and optional for WPA2 encryption.

Some wireless devices, for example older wireless printers, cannot establish a Wi-Fi connection if PMF is enabled:

  1. Click "Wi-Fi" ("Wireless") in the FRITZ!Box user interface.
  2. Click "Security" in the "Wi-Fi" ("Wireless") menu.
  3. Disable the option "Enable support for protected logins by wireless devices (PMF)" in the section "Additional Security Settings".
  4. Click "Apply" to save the settings.

Disabling WPA compatibility mode (WPA + WPA2)

WPA compatibility mode allows simultaneous connections with WPA2 and WPA encryption using the same Wi-Fi network name and network key.

However, some wireless devices, for example IP cameras from D-Link, cannot establish a Wi-Fi connection if WPA compatibility mode is enabled:

  1. Click "Wi-Fi" ("Wireless") in the FRITZ!Box user interface.
  2. Click "Security" in the "Wi-Fi" ("Wireless") menu.
  3. If WPA mode "WPA + WPA2" is selected in the section "WPA Encryption", select the WPA mode "WPA2 (CCMP)".
  4. Click "Apply" to save the settings.

Enabling Wireless 802.11b

The wireless standard 802.11b is disabled in the FRITZ!Box by default because the Wi-Fi speed in the 2.4 GHz Wi-Fi network is reduced when 802.11b is enabled, even if none of the wireless devices are using this standard.

However, some older wireless devices, for example Fitbit Aria scale (Version 1), only support 802.11b with WPA encryption:

ATTENTION!Wireless standard 802.11b can only be enabled on the FRITZ!Box (Mesh Master). The affected wireless devices must therefore be connected directly to the FRITZ!Box.

  1. Click "Wi-Fi" ("Wireless") in the FRITZ!Box user interface.
  2. Click "Wi-Fi Channel" ("Radio Channel") in the "Wi-Fi" ("Wireless") menu.
  3. Enable the option "Adjust Wi-Fi channel settings".
  4. Select the standard "Wi-Fi 4 (802.11b+g+n)" for the 2.4 GHz frequency band from the "Wireless standard" drop-down list.
  5. Click "Apply" to save the settings.
  6. Click "Security" in the "Wi-Fi" ("Wireless") menu.
  7. Select the WPA mode "WPA + WPA2" in the section "WPA Encryption".
  8. Click "Apply" to save the settings.