PfSense is an open$-$source router$/$firewall that protects you virtual machines from outside

attacks. It also provides networking service $($routing traffic$)$ for networks. As you already have

the pfSense as $$Open Virtualization Format Archive $(.$ova$),$ you need to import it only as an

appliance from the VirtualBox Manager window.

$1.$ Select File, Import Appliance from the VirtualBox Manager window.

$2.$ From the file dialog, go to the file with pfsense.ova file extension.

$3.$ Click Import to open the Appliance Settings screen.

$4.$ Keep the default settings and click on Next, then Finish.

You can think of the pfSense firewall as a gatekeeper that stands between the internet and your

internal network. It will inspect traffic entering and leaving your network to ensure that your

internal network is secure from outside attackers. This creates a safe place for you to add

vulnerable machines that only you can attack. The firewall$/$router needs two interfaces to

connect the VMs$.$

$5.$ Right$-$click pfSense in your list of virtual machines and then click Settings.

$6.$ Click the Network tab and make sure that the network adapter in the Adapter $1$ tab is

enabled and attached to a NAT Adapter. NAT mode will mask all network activity as if

it came from your Host OS and the VM will be able to access external resources $($such

as Internet$).$ Next, click the Adapter $2$ tab and make sure Enable Network Adapter is

enabled and that it is attached to an Internal Network that we will name $$intnet$.$ This

internal network will connect pfSense to our other virtual machines. Once you click

OK$,$ the internal network should be available to other virtual machines.