Need help to convert rule iptables to ipfw

[budsz]

Dear,

I've some problem with nat and rdr onto the same network like sample:

iptables -t nat -I PREROUTING -i eth1 -p tcp -d 202.xxx.yyy.123 --dport
6112 -j DNAT --to-destination 192.168.0.1:6112

iptables -t nat -I PREROUTING -i eth0 -p tcp -s 192.168.0.0/24 -d
202.xxx.yyy.123 --dport 6112 -j DNAT --to-destination 192.168.0.1:6112

iptables -t nat -I POSTROUTING -o eth0 -s 192.168.0.0/24 -d
192.168.0.0/24 -j SNAT --to-source 202.xxx.yyy.123

That rules using iptables on Linux mechine. Now,  I've already run
ipfw2 with FreeBSD box. My questions is how to implement rule like
that if use ipfw2. Does ipfw support feature PREROUTING/POSTROUTING
like iptables on Linux system?.

Thanks you.


-- 
budsz