natd port redirection

[Alfonso Romero]

I typed the following, as instructed in the FreeBSD Handbook:

natd -redirect_port tcp 192.168.0.101:80 80

so I can use my FreeBSD box with IP address 192.168.0.101 as a Web server. I´m running natd on my other FreeBSD box acting as a gateway. I get the following error: 

natd: aliasing address not given

what could be wrong?


Thanks in advance,

Alfonso Romero