How to let all multicast traffic through all ports with the GS110TP

Hi Martmel

Disabling IGMP Snooping globally is the right way: by doing that we ensure any kind of Multicast traffic is flooded to all ports.

Unfortunately your screenshot is lowres and I can't really figure if this is done correctly on your switch. Do you have VLANs? 

At this point I think we need to check if you disable all together:

Switching-->Multicast-->IGMP Snooping-->IGMP Snooping Configuration

• Auto-Video Configuration
• IGMP Snooping Status
• Validate IGMP IP Header
• Block Unknown Multicast Addresses

Switching-->Multicast-->IGMP Snooping-->IGMP Snooping Interface Configuration

• Click All for all ports and all LAGs
• Ensure Admin Mode is disabled for all ports

For all that please refer to the GS110TP Software Administration Manual page 41, then page 43, and then page 44-45.

Once checked please save the configuration and reboot the switch. Now we made sure there is no more Multicast filtering at Layer 2 in the switch. Your KNX routers should be able to send and receive Multicast traffic without being IGMP compliant. Please note this is very unsual use case though. At Layer 2 Multicast devices are expected to send and receive IGMP messages. If it still doesn't work, we will need to learn more about your KNX devices, and check if they are really sending Multicast traffic - and if they are succesfully working with other type of Ethernet switch - Unmanaged for instance. 

It makes me realize it might be broadcast traffic instead? Sanity check: please go to Security-->Traffic Control, and then click the Storm Control link on the left menu and verify Storm Control is disabled all the way (no filtering at all - please see page 174 in the manual).