@John1234 Right.... I'm a bit confused now, why would switch pass unknown multicast traffic? This will flood the network... What is the point of the IGMP snooping if network is floded with multicast...

@John1234 We found one older TP-Link device and manage to make it running - TL-SG2008 (FW 1.0.0). For this device we had to to set "Unknown Multicast" option to Discard. Regarding the test...

I have two TL-SG108E v6 manageable switches which we bought because of IGMP snooping. We have local IPTV setup multicasting ~100Mbit/s so IGMP snooping is crucial. Unfortunately none of them behaves...