I have a UPnP media server on my workstation and I occasionally stream media to my DNLA capable Smart-TV. I used to have a flat network with one subnet and everything worked but as soon as I split the network I can't stream media to my Smart-TV anymore. My workstation is connected to a CRS305-1G-4S+IN which is connected to an ASUS RT-AC68U running DD-WRT. The Smart-TV is connected to the Asus router. I am 99% sure that the problem is that DLNA is multicast over 126.96.36.199 and uses SSDP. I managed to install the RouterOS multicast package and I was hoping to get everything working with IGMP Proxy - but something is still broken. I am not sure if the problem is at CRS side or Asus side.
To make things even more complicated all non-local traffic from the Smart-TV is routed to a OpenVPN tunnel between the Asus router and a VPN provider For that I have a special ip rule and alternative routing table. The br0 device in the Asus router (the physical port to which the Smart-TV connects is add to this bridge) has IGMP snooping on.
I tried playing with the IGMP-Proxy but I have no idea which interface should be marked upstream and even if IGMP proxy could help me in this scenario. Do I have to configure anything on the Asus router also?
I am attaching my home network schematic. The Smart-TV is 10.0.0.10 and my workstation is 10.1.11.10.