IP Tables Multicast relay/forwarding

Hi all,

I’m working on a little project that uses a Raspberry Pi and Zerotier together. The main uses are for AV remote support (think digital mixing consoles, matrix audio processors, LED Lighting controllers etc).

The issue is that most sites will be using the same IP subnet if deployed in an existing network (out of our control). I am using 1:1 nat on the Pis to map an internal address to a Zerotier address which is working fine but some applications use Multicast to send information such as meter levels (audio/RF etc) which obviously doesn’t work across the two networks.

Does anyone know of a way to bridge or relay multicast data between the zerotier network and the local network of the Pi?

I cannot use layer2 bridging that Zerotier recommends due to many networks being the usual 192.168.1. or 0. range.


Without using the layer 2 support, not sure I know of a way to make that work.


I am actually attempting to do the same thing without the multicast requirement, would you be willing to show me how you setup the 1:1 nat on the pi going back to ZT?