On Mon, 4 Oct 1999 10:46:53 Ingolf Koch <ingolf@djo-jena.de> writes:

>is it possible to use ipnat for forwarding e.g. port 21
>on the firewall to port 21 on a certain machine on my
>LAN? (I'd like to make the ftp server on one of my machines
>accessible to the outside, but do not want to run the
>server on the firewall.) If this is possible, which rule
>do I have to add to ipnat.conf?
>
>If not, are there any other tools to do this (besides
>writing a program myself)?

I think you are looking for "rdr".  I think the following will work.

 rdr <external interface> <external addr>/<netmask> port 21 -> <internal addr> port 21 tcp

tcp can be tcp/udp ... I think.

Hope that helps.

Paul