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Dokument informacyjny #339

IP communication over a VPN connection (client-LAN) is not possible

Although the device (for example a computer with WireGuard or FRITZ!VPN) establishes a VPN connection to the remote FRITZ!Box, the device cannot access devices, shared files, and printers or other services in the remote network. Devices in the remote network do not respond to pings.

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

1 Adjusting the network settings

VPN communication is not reliable if an IP address from the remote FRITZ!Box's IP network is assigned to the computer's LAN or wireless network adapter. VPN communication may even be disrupted if the network adapter is not used at all.

Example:
If the remote FRITZ!Box uses the IP address 192.168.178.1 (subnet mask 255.255.255.0), no network adapters may be assigned an address from the 192.168.178.xxx range.

On the computer, disable all network adapters that have an IP address from the remote FRITZ!Box's IP network:

Windows 11

  1. Click (Start) and then (Settings) in the Windows task bar.
  2. Click "Network & Internet" in the "Settings" menu.
  3. Click "Advanced network settings".
  4. Click "Change adapter options" in the section "Change your networking settings".
  5. Click "Disable" by the respective network connection.

Windows 10

  1. Click (Start) and then (Settings) in the Windows task bar.
  2. Click "Network & Internet" in the "Settings" menu.
  3. Click "Change adapter options" in the section "Change your networking settings".
  4. Right-click the respective network connection and select "Disable" from the context menu.

macOS

  1. Open the Finder and click "Applications".
  2. Click "System Preferences" and "Network".
  3. On the left side, select the respective network adapter.
  4. Click the gear symbol next to the plus and minus (+/-) symbols and select "Make Service Inactive".
  5. Click "Apply" to save the settings.

2 Restarting the FRITZ!Box

You may be temporarily unable to correctly establish the VPN connection due to an error in the FRITZ!Box or its internet connection. Therefore, restart the FRITZ!Box so that it reinitializes the firewall and re-establishes the internet connection:

  1. Click "System" in the FRITZ!Box user interface.
  2. Click "Backup" in the "System" menu.
  3. Click on the "Restart" tab.
  4. Click the "Restart" button.

3 Deleting a VPN connection and reconfiguring it

If IP communication is still not possible over the VPN connection, the VPN connection is configured incorrectly, for example because the FRITZ!Box uses the IP network 192.168.100.0 which is reserved for the cable provider, due to other incorrect or unsuitable IP settings, or errors when editing the settings file. Therefore, reconfigure the VPN connection:

  1. Delete the VPN connection on the device and in the FRITZ!Box user interface.
  2. Reconfigure the VPN connection in the FRITZ!Box. Proceed as described in the corresponding guide:
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