So i have ipfire installed in virtualbox, with four adapters:
One for the red network, bridged ( connected to home/institute network).
One for green network, i created a Internal network called empresa in vbox.
Another for orange network, i created another internal network called dmz in vbox.
Another for blue network, i created another internal network called wifi in vbox.
So as ipfire documentation shows:
Green to Red is open. Red to Green is closed.
So i had the problem with Windows7 vm, as client in green network. The problem from the beginning is that i thought that i had to open some ports from red to green ( to get the response from internet). but the problem was the dns. I had to setup that dns server was on ipfire machine 192.168.1.51
So i get back to original problem: what means that green to red is open and red to green is closed. If ipfire policy by default is allow. Why red to green can pass the response if seems closed?