Should work for Vagrant managed VirtualBox virtual machines hosted on OS X (up to OS X Maverics which has ipfw
-based firewall. OS X Yosemite has another pf
-based firewall so not sure about that...)
Run with sudo and pass in your VirtualBox managed VM's vboxnet
IP address or address range:
sudo ruby add_ipfw_exception.rb 172.16.0.0/12