Using ipfw in current branch

Hi All,

Here is what I get when I attempt to use any ipfilter type operations:

jason_at_ahab:/home/jason# ipfw flush
Are you sure? [yn] y

ipfw: setsockopt(IP_FW_FLUSH): Protocol not available
jason_at_ahab:/home/jason#

Has the kernel configuration paramaters changed since the official cut of 5.1? 
Before the upgrade i could use ipfw.

Here is a link to my kernconf file:
http://www.dictos.com/JASONKERN

Thanks,
-Jason