FRITZ!Box 6850 LTE Service - Knowledge Base

FRITZ!Box 6850 LTE Service

Wireless device cannot establish a connection 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.

Although the name of the FRITZ!Box's Wi-Fi network (SSID) is found when you manually search for Wi-Fi networks or the LEDs on the FRITZ!Box flash during automatic configuration at the touch of a button, a wireless device does not establish a connection to the FRITZ!Box. After entering the Wi-Fi access information or pushing a button, no Wi-Fi connection is established. 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), 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 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" in the FRITZ!Box user interface.
  2. Click "Security" in the "Wi-Fi" menu.
  3. Enable the option "Allow all new wireless devices".
  4. Click "Apply" to save the settings.

Enabling the WPS function

  1. Click "Wi-Fi" in the FRITZ!Box user interface.
  2. Click "Security" in the "Wi-Fi" menu.
  3. Click on the "WPS Quick Connection" tab.
  4. Enable WPS.
  5. Click "Start WPS" to save the settings.

Disabling the keylock

  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" in the FRITZ!Box user interface.
  2. Click "Wi-Fi Network" ("Radio Network") in the "Wi-Fi" ("Wireless") menu.
  3. Disable the option "Different names for the Wi-Fi networks on 2.4 and 5 GHz". This way, the FRITZ!Box uses the same name for the 2.4 GHz and 5 GHz frequency bands and can steer wireless devices into the frequency band that is ideal in the given situation ("band steering").
  4. Enable the option "Name of the Wi-Fi network visible". This way, all wireless devices can establish a connection to the FRITZ!Box and the FRITZ!Box can optimally control wireless devices in the Mesh ("Mesh Wi-Fi Steering").
  5. Click "Apply" to save the settings. If the wireless devices were only connected to the 5 GHz frequency band with a different name, you must then reconfigure the Wi-Fi connection on those devices.

2 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 of the 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 using Windows Update).

    Note:Information on the update can be obtained from the device's manufacturer, for example refer to the manual. You can find the latest drivers for the FRITZ!WLAN Sticks in our download area.

3 Reconfiguring the Wi-Fi connection

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

If the wireless device still does not establish a connection 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" in the FRITZ!Box user interface.
  2. Click "Security" in the "Wi-Fi" 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" in the FRITZ!Box user interface.
  2. Click "Security" in the "Wi-Fi" 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.

Enabling Wireless 802.11b

The wireless standard Wi-Fi 2 is disabled in the FRITZ!Box by default because the Wi-Fi speed in the 2.4 GHz frequency band 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:

  1. Click "Wi-Fi" 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. Click "Additional Settings".
  5. Select the standard "802.11b+g+n (Wi-Fi 4)" from the "2.4-GHz wireless standard" drop-down list.
  6. Click "Apply" to save the settings.
  7. Click "Security" in the "Wi-Fi" menu.
  8. Select the WPA mode "WPA + WPA2" in the section "WPA Encryption".
  9. Click "Apply" to save the settings.