FRITZ!Box 4020 Service - Knowledge Base
Cannot access the internet via a modem (for example a cable modem)
Computers, smartphones, and other devices connected to the FRITZ!Box cannot access the internet when the FRITZ!Box establishes the internet connection through a DSL, fiber optic, or cable modem.
One of the following messages may be displayed in the "Network and Sharing Center" of the respective Windows computer:
- "Unidentified Network"
- "Access: Local only"
- "Access type: No internet access"
Note:All instructions on configuration and settings given in this guide refer to the latest FRITZ!OS for the FRITZ!Box.
Simply proceed as described below. After each measure, check whether the problem persists.
1 Checking the cabling
- Make sure that the modem is connected to your internet connection according to the instructions provided by your internet service provider.
- Use a network cable, for example the network cable included with delivery, to connect the "WAN" port on the FRITZ!Box to a LAN port on the modem. The FRITZ!Box may not be connected to the WAN port on the modem.
2 Restarting the modem
- Restart the modem by unplugging it briefly.
Note:It may take several minutes for the modem to restart. You cannot access the internet while it is restarting.
3 Restarting the FRITZ!Box
- Unplug the FRITZ!Box for 5 seconds.
Note:The FRITZ!Box settings remain intact. The restart will take about 2 minutes. During this time, you cannot access the FRITZ!Box.
4 Checking the event log of the FRITZ!Box
- Click "System" in the FRITZ!Box user interface.
- Click "Event Log" in the "System" menu.
- Select "Internet connection" from the drop-down list.
- Check whether error messages are displayed.
- If the message "PPPoE error: Timeout [...]" is displayed, follow the instructions in our guide FRITZ!Box reports "PPPoE error".
- If you are using the FRITZ!Box on a cable connection and the message "Internet connection failed: Reason for error: 2 (DHCPv4 no answer on DISCOVER)" is displayed, contact your cable provider.
5 Enabling the FRITZ!Box's DHCP server
In the factory settings, the FRITZ!Box automatically assigns the correct IP settings to all devices via DHCP. If you disabled the FRITZ!Box's DHCP server, reenable it:
Important:If the FRITZ!Box uses the internet connection of another router, then the FRITZ!Box's DHCP server is disabled. In this case, the upstream router must assign the IP settings to the devices.
- Click "Home Network" in the FRITZ!Box user interface.
- Click "Network" in the "Home Network" menu.
- Click on the "Network Settings" tab.
- Click the "IPv4 Addresses" button.
- Enable the DHCP server and define the range from which the FRITZ!Box assigns IP addresses.
Note:The FRITZ!Box has the IP address 192.168.178.1 (subnet mask 255.255.255.0) and assigns IP addresses from xxx.20 to xxx.200 in the factory settings.
- Click "OK" to save the settings.
6 Configuring the device to automatically obtain IP settings
To ensure that the device always uses the correct IP settings, make sure that it automatically obtains its IP settings from the FRITZ!Box (this is the standard setting for most devices):
- Configure the device to automatically obtain IP settings via DHCP.
7 Configuring a DNS server in the FRITZ!Box
In the factory settings, the FRITZ!Box uses the internet service provider's DNS server for the name resolution of web addresses. If you set up other DNS servers in the FRITZ!Box, reenable the internet service provider's DNS server:
- Click "Internet" in the FRITZ!Box user interface.
- Click "Account Information" in the "Internet" menu.
- Click on the "DNS Server" tab.
- Enable the option "Use DNSv4 servers assigned by the internet service provider (recommended)".
- If the section "DNSv6 Servers" is displayed, enable the option "Use DNSv6 servers assigned by the internet service provider (recommended)".
- Click "Apply" to save the settings.
8 Configuring the Internet Explorer
Perform the following step only if you are using Microsoft Internet Explorer and it displays the message "Web page unavailable while offline":
- Start the Internet Explorer.
- Open the "Tools" menu.
- If the menu "Work Offline" entry is displayed and there is a checkmark in front of it, click this entry to remove the checkmark.
- Click the "Internet Options" menu entry and then "Connections".
- Enable the option "Never dial a connection".
- Click "OK" to save the settings.
9 Configuring the computer's firewall
A firewall can interfere with the communication between the computer and the FRITZ!Box:
- Configure the firewall on the computer so that it allows connections from the computer to the FRITZ!Box. Refer to the manufacturer of the firewall for information on how to set it up, for example consult the manual.
10 Checking the modem
The modem may be defective or malfunctioning. Therefore, check whether you can establish an internet connection if you connect the modem directly to a computer:
- Use a network cable to connect the modem to a computer.
- On the computer, configure an internet connection that uses the modem. Refer to the manufacturer of the operating system for information on the procedure.
- Check whether the computer can connect to the internet.
- If you were able to successfully connect the internet, proceed with the following section.
- If you were not able to connect to the internet, contact the modem's manufacturer or the retailer or internet service provider you bought your modem from.
11 Reconfiguring the internet connection in the FRITZ!Box
- Reconfigure internet access to rule out incorrect configuration of the FRITZ!Box: