e.g.: If the host has an IP of 192.168.20.22, the VM will be something like 192.168.20.23 and be accessible by all of the elements in that network.

Bridge: the VM will be on the same network as the host.

NAT: the virtual machine is assigned to a different subnet and can access the network outside the host, but access from the host to the VM is not allowed unless ports are forwarded.

It is usually used to create a network between the host and several VMs.

Host-Only: the virtual machine is assigned an IP, but it is only reachable by the host.

There are several kinds of networking modes that we can choose for our virtual network adapters, each one of them with a certain set of characteristics and properties (very well described in VirtualBox documentation) that we need to take into consideration for our setup to work as expected. VirtualBox Networking Modes – Choosing the Right Adapter

TL DR: we will need to set up the WAN interface as NAT, and the LAN as Host-Only (as can be seen in the image above), but if you want to know why, keep reading. Let’s start by analyzing our target design: Logic Diagram – pfSenseĪs we can see in the diagram, the router is going to need 2 interfaces: one external to access the internet (WAN), and one internal for all our virtual machines to connect to (LAN), and here is where we have the first challenge: which network adapter should we choose in VirtualBox for each one of them? In particular, why and how to choose the correct adaptor for our virtual network to operate properly.

In this post, I will cover how to install a virtual instance of pfSense in VirtualBox but before we start, there are several key concepts that are needed in order to follow the explanation and understand why things are set up in a certain way.

Pfsense vbox