I would have thought the rdr in your ip filter rules would have worked.
In /usr/share/examples/ipf/mediaone there is the following example:

#   ep0 is the external interface (to the MediaOne cable modem).
# Redirect incoming RealMedia traffic to a specific machine.
rdr ep0 0/0 port 7070 -> 10.1.0.2 port 7070 udp
rdr ep0 0/0 port 7070 -> 10.1.0.2 port 7070 tcp


I'd keep pushing on this approach, although I haven't done it myself.

-Dan



On Mon, 12 Jul 1999, Matthew Jiggins wrote:

> 
> A question to ponder:
> 
> 	I'm running NetBSD on a  Quadra 700 and using it as a gateway
> machine. It's running IPNAT and IPFilter - most services seem to work ok
> (i was able to figure out the FTP Proxy thing) However I'm having troubles
> with a few Real Video sites... upon further research I found out that this
> was a common problem, made more immenant with Apple's Introduciton of
> QuickTime streaming.
> 
> 	Similar to FTP there are a number of Quicktime/real video sites
> that use different ports other than the ones that the original request was
> sent out on. (ie the request goes out on port 7070tcp but the stream will
> come back on 6980udp) IPNAT has no idea what to do when the data starts
> on port 6980.
> 
> 	I've tried a number of different things, like using rdr on the
> range of ports suggested by Real.com I've also recently tried installing a
> proxy server - seeing as this problem is the same as FTP where there are
> two ports one for authentication/commands and one for data. Surprisingly I
> was able to get the Real Proxy server compiled and running - it accepts
> the outgoing requests from the clients but that's it. The server does not
> pass those requests out AND "ipnat -l" shows no active sessions.
> 
> 	I've tried to compile Apple's rtsp proxy to no luck. (Although
> NetBSD mac68k is not on their list of systems it's supposed to compile on)
> 
> 	I was wondering if anyone had personal experiences to add to this?
> 
> 	OR has anyone successfully compiled or gotten streaming to work???
> 
> Thanks for ANY info
> 
> -matt
> 
> ________________
> matt@barclay.net
> Matthew  Jiggins
> 
>