FRITZ!Box 4020 Service - Knowledge Base
Can VPN connections be established to a FRITZ!Box being used on a DS-Lite Internet connection?
With the DS-Lite ("Dual Stack Lite") procedure you can continue to use IPv4 applications, such as the FRITZ!Box's VPN solution, even with new IPv6 Internet connections.
If the remote site also has a public IPv4 address, then you can also use the FRITZ!Box on an Internet connection with the DS-Lite procedure to establish a VPN connection between two FRITZ!Box networks (LAN-LAN linkup) or a connection from the FRITZ!Box to a company VPN.
FRITZ!VPN and other VPN software can also be used on DS-Lite Internet connections to connect to VPN servers that are accessible at public IPv4 addresses.
It is only not possible for a FRITZ!Box being used on a DS-Lite Internet connection to accept incoming VPN connections, for example with FRITZ!VPN or a smartphone.
However, the FRITZ!Box supports the new Port Control Protocol (PCP), which will make VPN connections to the FRITZ!Box and other incoming IPv4 connections over DS-Lite possible. To use it, the Internet service provider must also support PCP. The first providers offering DS-Lite Internet connections may start to support PCP in the course of 2017.
Note:The FRITZ!Box does not support IPv6 VPN connections since they cannot transmit IPv4 data. Furthermore, this type of IPv6 connection can only be established if both parties have an IPv6 Internet connection, which is not the case in most mobile communication networks and wireless hotspots, for example.