Connecting two FRITZ!Box networks (LAN-LAN linkup)
AVM Content
Identifying the address range of the IPv4 address for the internet connection
In order for computers, smartphones, and other network devices to communicate with each other, each device must be addressable via a unique IP address. For communication on the internet, the FRITZ!Box obtains an IP address from the internet service provider when it connects to the internet.
If Internet Protocol version 4 (IPv4) is used, each IP address can be associated with one of the following address ranges:
- Private address ranges:
- IP addresses from private address ranges are intended exclusively for communication in private networks (for example the FRITZ!Box home network) and can therefore be used in an unlimited number of networks at the same time. Since they are never forwarded (routed) over the internet, devices with IP addresses from private IP address ranges cannot be accessed from the internet.
Note:For more information on "private addresses", see Wikipedia.
- IP addresses from private address ranges are intended exclusively for communication in private networks (for example the FRITZ!Box home network) and can therefore be used in an unlimited number of networks at the same time. Since they are never forwarded (routed) over the internet, devices with IP addresses from private IP address ranges cannot be accessed from the internet.
- Public address ranges:
- IP addresses from public address ranges are only used by a single device at a time worldwide. Since they make it possible to unequivocally identify network devices, they are forwarded on the internet (routed) and therefore allow the network devices to be accessed from the internet.
Note:This guide is valid for FRITZ!OS 8 or later. If you are using an older FRITZ!OS version, the configuration may differ or functions may not be available. You can find the FRITZ!OS version on the "Overview" page of the user interface.
Identifying the address range of an IP address
- Click "Internet" in the FRITZ!Box user interface.
- Click "Online Monitor" in the "Internet" menu.
- Click on the "Connection Details" tab.
- Check which IP address is displayed in the line "Internet, IPv4".
- If an IP address from one of the following ranges is displayed, the FRITZ!Box has an IP address from the private address range and cannot be reached via IPv4 in the internet.
- 10.0.0.0 - 10.255.255.255
- 100.64.0.0 - 100.127.255.255 (carrier-grade NAT)
- 172.16.0.0 - 172.31.255.255
- 192.0.0.0 - 192.0.0.7 (DS-Lite tunnel, Dual-Stack Lite)
- 192.168.0.0 - 192.168.255.255
- If an IP address from a different range is displayed, the FRITZ!Box has an IP address from the public address range and can be reached via IPv4 in the internet.
- If no IP address is displayed, the FRITZ!Box cannot be reached in the internet via IPv4.