NAT with forwarding to multiple destinations
I appoligize that this reply will probably not thread correctly, I just joined this list because I'm also looking for something like this. So I'm just pasting this from the web archive...
Quoted 12 lines · Jan Engelhardt
Quoted 10 lines · Alberto Quattrini Li
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The multiplexing you want is probably best done with a program that does just that - think of sprucing up rinetd.
As far as I know, all of the programs like that are programs that run as a process in the middle, so it introduces an overhead (because they are in userspace and have to receive the packet and then process it and finally forward it), whereas if it was processed by netfilter it would be quicker and more efficient (actually some testing and comparisons should be done, but in principle it ought to be so).
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However it seems that there doesn't exist any solution in netfilter. Can you give me a reference (e.g. documentation and guides) to patch netfilter with such functionality?
I'm looking for something like this as well. Specifically I need to be able to create a rule that will take packets sent to a given specified address & port and forward them to either an ip range or and ipset. An ipset is preferred because that way the destinations can be dynamically changed. I've tried several reflectors/forwarders and they generally suck. Futhermore none of them are dynamic (that I have found at least) And of course this limiting something like this to datagram packets would probably be a smart precaution.
Has anybody come up with something for this? I'm nowhere near competent enough to tackle something like this on my own. I'm a lousy hack. Basically my need for this is to be able to send a live rtp video stream to a dynamically changing group of unicast destinations. But changing destinations means stopping and restarting the stream. Doing this outside the streaming app gets around this. Multicasting is of course a great solution, but I have to hook into other peoples networks where I have no control over rules and layout, and there is rarely multicast support. And even where there is multicast support, I sometimes have to send through VPNs or subnet gateways where the multicast wouldn't reach anyway.
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You could write your own extension, based upon
xt_TEE.