the switch is more interested in dynamically mapping the receivers of each group.
This subset of ports in a vlan X that are connected to users that have joined for group G can be mantained by using IGMP snooping (that is by analyzing IGMP messages).
This is a forwarding optimization.
The switch builds for each Vlan X and multicast group G a list of ports that need to receive a copy of the frames that are part of the group.
If in a Vlan Y IGMP snooping is disabled the switch can only replicate the frames belonging to multicast stream G2 on all ports of Vlan Y expect the one on which it has been received.
Conversely if for a Vlan Z with IGMP snooping enabled there is no L3 multicast device acting as IGMP querier multicast flows are blocked on the vlan because the switch cannot hear to IGMP reports from hosts.
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...