You’ll ned to pfSense boxes.

On our example we have both connected to INTERNET each one with one public access on the WAN interface.

For the LAN we’ve set up 2 class C networks. Let’s call pfSenseA the one using 10.110.8.1 (as LAN), and pfSenseB the one using 10.110.9.1.

First, Go to System -> Advance Options and Enable Secure Shell. We’ll connect to one of the boxes in order to create CA certificates.

We’ll start working on pfSeseB which is going to be our SERVER.

Enable Secure Shell

 And then SSH to the box.

> ssh admin@10.110.9.1

You’ll be presented with the Console options:

*** Welcome to pfSense 1.2-RELEASE-embedded on fwofficebackup ***

  OPT1(DMZ)                ->   rl0     ->      NONE

  LAN*                     ->   rl1     ->      10.110.9.1

  WAN*                     ->   rl2     ->      67.63.42.4

 pfSense console setup 

***********************

 0)  Logout (SSH only)

 1)  Assign Interfaces

 2)  Set LAN IP address

 3)  Reset webConfigurator password

 4)  Reset to factory defaults

 5)  Reboot system

 6)  Halt system

 7)  Ping host

 8)  Shell

 9)  PFtop

10)  Filter Logs

11)  Restart webConfigurator

12)  pfSense PHP shell

13)  Upgrade from console

Enter an option: 

Client

 

Make sure that you allow incoming TCP to the OpenVPN port on both ipSense comming from each other.

Now ping from one network to the other, and DONE.