I thought it was net.link.ether.bridge_ipfw=1 to enable IPFW at the
data link layer. That and running it both on the data link layer and
network layer just seems like a bad idea, I usually disable IPFW at
the network layer when I do bridging (DUMMYNET). Though I probably
misunderstood you completely and there's nothing but decaf in the
house right now T_T.