2 wan (net balancer) + 2 lan

Hi i’m trying to do this:

– 2 wan from 2 adsl
– 2 lan who can see each other

eth0: wan1
eth1: wan2
eth2: lan1
eth3: lan2

Net Balancer works great, now i’m configuring firewall but i need a help in how. I mean what i want to do is input default drop and open what i need but doing this net balancer goes in fault.

what does net balancer need open in firewall?

thanks