FRITZ!Box 3390 – Service - Knowledge Base

FRITZ!Box 3390 – Service

Setting up the FRITZ!Box as an IP client

When the FRITZ!Box is used as an IP client, it shares the existing Internet connection of your other router. In this case

  • the firewall of the FRITZ!Box is disabled.
  • computers, smartphones, and other devices connected to the FRITZ!Box still obtain their IP settings from the other router.
  • all network devices have unrestricted access to all other devices, regardless of whether they are connected to the FRITZ!Box or the other router.

Requirements / Restrictions

  • You cannot use MyFRITZ!.
  • Parental controls, the online meter, guest access, and all functions that require a public IP address (for example port sharing and incoming VPN connections) are not available in IP client mode.

Note:The configuration procedure and notes on functions given in this guide refer to the latest FRITZ!OS for your FRITZ!Box.

1 Preparations

Determining the throughput of the Internet connection

  • Check which throughput (speed) is available on the router's Internet connection for downstream (receive direction) and upstream (send direction).

    Note:You can find information on the speed of your Internet connection in the router's user interface or contact your Internet service provider.

Determining the router's IP settings

  • If the router is not configured as a DHCP (Dynamic Host Configuration Protocol) server, determine the router's IP address and subnet mask as well as an unused IP address from the router's IP network.

    The router has the IP address (subnet mask This means that it is in the IP network If the IP address is not being used by any other device in the router's IP network, you can use this available IP address.

2 Configuring the FRITZ!Box

  1. Click "Internet" in the FRITZ!Box user interface.
  2. Click "Account Information" in the "Internet" menu.
  3. Select "Other Internet service provider" from the drop-down list "Internet service provider". With some regional settings, this entry will not be displayed until you select "More Internet service providers".
  4. Enable the option "Connection to an external modem or router" in the "Connect via" or "Connection" section.
  5. Enable the option "Share existing Internet connection in the network (IP client mode)" in the "Operating Mode" section.
  6. Enter the speeds of your Internet connection in the "Downstream" and "Upstream" fields.

    Enter 32000 for a downstream of 32 Mbit/s; enter 2000 for an upstream of 2 Mbit/s.

  7. Click on "Change connection settings".
  8. If the router provides a DHCP server, enable the option "Obtain the IP address automatically (DHCP)".
    • If the router does not provide a DHCP server:
      1. Enable the option "Configure the IP address manually".
      2. In the "IP address" field, enter an unused IP address from the router's IP network.
      3. Enter the subnet mask of the router in the "Subnet mask" field.
      4. Enter the IP address of the router in the "Default gateway" and "Primary DNS server" fields.
  9. Click "Apply" to save the settings.

The FRITZ!Box is now configured for operation as an IP client.

Important:In this operating mode, you can no longer open the user interface with Instead, proceed as described in the section "Opening the FRITZ!Box user interface" (see below).

3 Connecting the FRITZ!Box with the network

  • Use a network cable (for example the yellow network cable included with delivery) to connect the "LAN 1" port on the FRITZ!Box either directly to a LAN port on the router, or by means of a hub or switch.

Now the FRITZ!Box uses the Internet connection of the other router.

4 Opening the FRITZ!Box user interface

When used as an IP client, you can no longer open its user interface by entering Instead, you must enter the FRITZ!Box's IP address to open it:

  • If the FRITZ!Box obtains its IP address from the router via DHCP, enter the IP address that the router assigned to the FRITZ!Box, for example, in the web browser.
    • If you entered the IP address in the FRITZ!Box manually, in the web browser, enter the IP address that you entered in the "IP address" field in the user interface, for example
    • Note:: If you cannot determine the FRITZ!Box's IP address or forgot it, you can use the FRITZ!Box's "emergency IP address" to open the user interface.

5 Setting up the FRITZ!Box to conduct calls over another router

The following step is only necessary if you use a smartphone with FRITZ!App Fon or other IP telephones with the FRITZ!Box and would like to use them to conduct calls over the other router's Internet connection:

6 Setting up the FRITZ!Box for wireless roaming

If the other router does not provide a wireless network, you can use the FRITZ!Box as a wireless access point and connect your wireless devices to the FRITZ!Box's wireless network.

If the other router has wireless capabilities, you can use the FRITZ!Box as an additional wireless access point. This way your wireless devices can access the Internet and other devices in the home network over the FRITZ!Box, even if the wireless network of your router is not available.

Configure the following settings in the FRITZ!Box so that your wireless devices can always automatically connect to the wireless network with the strongest signal (wireless roaming):

  1. Click "Wireless" ("WLAN") in the FRITZ!Box user interface.
  2. Click "Radio Network" in the "Wireless" ("WLAN") menu.
  3. For the frequency band being used, enter the name of the router's wireless network as the "Name of the wireless radio network (SSID)".
  4. Click "Apply" to save the settings.
  5. Click "Radio Channel" in the "Wireless" ("WLAN") menu.
  6. Enable the option "Adjust radio channel settings" in the "Radio Channel Settings" section.
  7. From the drop-down list "Radio channel", select the channel used by the wireless router for the wireless frequency band being used.
  8. Click "Apply" to save the settings.
  9. Click "Security" in the "Wireless" ("WLAN") menu.
  10. Enable the wireless encryption used by the wireless router.
  11. Enter the wireless router's network key in the "Network key" field.
  12. Click "Apply" to save the settings.