port-sparc64: redirect tcp/udp

Subject: redirect tcp/udp
To: None <port-sparc64@netbsd.org>
From: gaspo <gaspolo@gmail.com>
List: port-sparc64
Date: 02/20/2005 16:00:34

i wanna know how in netbsd i can rediretc tcp /udp connection to other
internal LAn client..
like external ip: 23.252.146.82 internal client "A" 192.168.0.4
i wanna redirect tcp 412 from 23.252.146.82 to A
and Udp 413  from 23.252.146.82 to A

in other *bsd sistem i have used portFwD...
but i cannot find that packages  binary on netbsd...
and the source give a lot of error when compiling..
some idea?