IGMP/Multicast over GRE tunnel
We're running pfSense 2.2.5, and are trying to receive multicast data over the internet via a GRE tunnel from a Cisco device from a 3rd party.
The GRE tunnel comes up nice and easy, and we can see the receipt of multicast data on the relevant port if they force it to send.
However - pfSense doesn't seem to see the LAN side of things, and so the JOINs don't get through properly.
IGMPproxy doesn't seem to be helping (with either the GRE tunnel, or the WAN interface it's a child of as upstream, and the relevant LAN as downstream).
Firewall rules are open for that sort of traffic (allowing IGMP, w/ IP options enabled, the relevant UDP port, etc) - unless I've missed something.
The 3rd party source would prefer PIM-DM, but seems like the documentation for that in pfSense is pretty minimal…short of allowing it as a firewall rule.
Any other suggestions from anybody?