>> i think that by default the switch sends multicast traffic to all ports
Actually ig IGMP snooping is enabled and no multicast router is connected to the vlan the switch may block this multicast traffic in an attempt to optimize traffic forwarding.
If a multicast capable router is connected to the vlan and regularly sends out IGMP queries you are fine IGMP snooping will work well moving this multicast traffic only between really interested receivers (your servers).
if no multicast router is connected to the vlan/subnet you should verify if your switch supports a feature called IGMP snooping querier that will send out the regular IGMP queries in order to make IGMP snooping to work correctly.
Otherwise you will need to disable IGMP snooping on that specific vlan (if no multicast router is connected and no switch in use can act as IGMP snooping querier) this will cause multicast traffic to be flooded on the vlan like broadcast.
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...