IPF+IPNAT and port redirection

[Odhiambo Washington]

I have a FreeBSD router box running IPF/IPNAT.
With the advent of Viruses that have their own SMTP engines,
I would like to capture any traffic going out from internal LAN
to port 25 and redirect those to port 25 of my router.
I believe this is the equivalent of "reverse port mapping", if
I can call it that. 
How do I redirect this using ipnat?
Right now I have the following in my /etc/ipnat.rules:

map rl0 10.0.0.0/24 -> 0.0.0.0/32 portmap tcp/udp auto
map rl0 10.0.0.0/24 -> 0.0.0.0/32

.... rl0 being my oif, and xl0 being iif.

Given that my iip is 10.0.0.2, I would like to do this:

rdr xl0 0.0.0.0/24 port 25 -> 10.0.0.2 port 25

The problem is 10.0.0.2 is a subset of 0.0.0.0/24. Shall I redirect then
to the external IP instead?

I am damn confused with these IPNAT stuff ;)



-Wash

http://www.netmeister.org/news/learn2quote.html

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