This recipe describes how to set up pfSense as a L2TP VPN server.
It’s important to understand that unlike the other VPN implementations, L2TP does not encrypt any data. L2TP is simply a method of encapsulation and should only be used over trusted networks, or in conjunction with IPsec. A major advantage of L2TP, however, is that it can be used with non-IP networks.
Networks connected through VPN must use different subnets. For example, if both networks use the 192.168.1.0/24 subnet, then VPN will not work.