L2TP Client: pfSense
pfSense is an open source firewall distribution, built on top of the FreeBSD Operating System.
It is possible to create a L2TP client interface and route both IPv4 and IPv6 traffic over it.
The first step is to add a new L2TP Interface to pfSense.
This is done by navigating from Interfaces ⟶ (assign), then clicking on 'PPPs' and then press the '+ Add' button.