FRITZ!Box 7581 Service - Knowledge Base
Accessing multiple IP networks behind a FRITZ!Box over VPN connection between two FRITZ!Boxes
Through VPN (Virtual Private Network), you can establish securely encrypted connections over the internet between two FRITZ!Box networks at different locations. A computer in the IP network of one of the FRITZ!Boxes can access all of the network devices in the IP network of the other FRITZ!Box over this VPN connection.
If another network router in one of the two FRITZ!Box networks connects the IP network of this FRITZ!Box with a second IP network, you must configure additional settings to be able to access network devices in the second IP network over the VPN connection.
Example values used in this guide
In this guide we show you how to configure access from FRITZ!Box A's network to another IP network behind FRITZ!Box B. When adjusting the connection settings, replace the values used in this example with actual values.
- IP network of FRITZ!Box A:
192.168.10.0 (subnet mask: 24 - 255.255.255.0)
- IP network of FRITZ!Box B:
192.168.20.0 (subnet mask: 24 - 255.255.255.0)
- IP network of the network router connected to FRITZ!Box B:
192.168.21.0 (subnet mask: 24 - 255.255.255.0)
- IP addresses of the network router in FRITZ!Box B's network:
192.168.20.2 and 192.168.21.1
Requirements / Restrictions
- The Configure FRITZ!Box VPN Connection software was used to configure the VPN connection.
Note:The Configure FRITZ!Box VPN Connection software is available for Windows 10 / 8 / 7 (64-bit and 32-bit) on our VPN service page.
Note:The configuration procedure and notes on functions given in this guide refer to the latest FRITZ!OS for your FRITZ!Box.
1 Adjusting FRITZ!Box A's VPN settings
- Start the Configure FRITZ!Box VPN Connection software.
- In the "Existing Configurations" window, select the MyFRITZ! domain name of FRITZ!Box A (pi80ewgfi72d2os42.myfritz.net) and click on "Explorer".
- Open the file named "fritzbox_[...].cfg" with a text editor, for example WordPad.
- Look for the entry "accesslist" and add the IP network of the network router connected to FRITZ!Box B to this entry:
- acesslist =
- "permit ip any 192.168.20.0 255.255.255.0",
- "permit ip any 192.168.21.0 255.255.255.0";
Important:Entries for the IP networks must be separated by commas and the value for "accesslist" must close with a semicolon.
- Save the changes and import the adjusted file "fritzbox_[...].cfg" to FRITZ!Box A.
2 Configuring a static IP route in FRITZ!Box B
You must configure a static IP route in FRITZ!Box B to allow network devices to access the network router's IP network (192.168.21.0/24) over FRITZ!Box B:
- Click "Home Network" in the user interface of FRITZ!Box B.
- Click "Network" or "Home Network Overview" in the "Home Network" menu.
- Click on the "Network Settings" tab.
- Click "IPv4 Routes". If the button is not displayed, enable the Advanced View first.
- Click the "New IPv4 Route" button.
- Enter the IP network of the network router connected to FRITZ!Box B (192.168.21.0) as the "IPv4 network".
- Enter the subnet mask of the other IP network (255.255.255.0) in the "Subnet mask" field.
- For "Gateway", enter the IP address of the network router in FRITZ!Box B's network (192.168.20.2) that connects the two IP networks.
- Enable the option "IPv4 route active".
- Click "OK" to save the settings.
3 Adjusting additional IP settings for the VPN connection
Configuring the IP route in the network router
- Configure the network router according to the manufacturer's instructions so that it routes between FRITZ!Box B's IP network (192.168.20.0) and its own IP network (192.168.21.0).
Note:If you are using a Windows computer with several network adapters as the network router, you must enable "IP routing" in Windows. Refer to Microsoft for information on configuring IP routing.
Configuring network devices in the network router's IP network
- Either: On the network devices, configure the IP address of the network router from its own IP network (192.168.21.1) as the default gateway.
- Or: On the network devices, configure a static IP route to the IP network of FRITZ!Box B (192.168.20.0) that uses the network router as the gateway (192.168.21.1).