ipfw fwd on FreeBSD 8.1, does it work?

[Unga]

Hi all

Following ipfw rule develop error indicated:
ipfw add 100 fwd 127.0.0.1,1234 tcp from any to any 1234 out via wlan0

Error:
ipfw: getsockopt(IP_FW_ADD): Invalid argument

What I want to do is forward any packet going out of the computer to port 1234 forward back to 127.0.0.1:1234.

There is a test daemon listening to port 1234. The wlan0 exists and used for all Internet traffic.

The objective is to test a daemon. In actual practice the router is expected forward packets passing to port 1234 to this daemon.

I have built the kernel with "options IPFIREWALL_FORWARD".

This is FreeBSD 8.1.

What's the error here? Is the rule incorrect?

Does ipfw fwd work with FreeBSD 8.1?

Can I forward packets generating in the computer back to the same computer with ipfw fwd?

Many thanks in advance.

Unga