Description:
When no receivers are present L2 multicast traffic is being flooded in the VLAN.
Multicast traffic is flooded even when "no ip igmp snooping unregistered floodall" command is configured and no receivers are present.
Solution:
The solution to this issue is to use a static mrouter port as a live mrouter port even though nothing is connected. This breaks the loop of sending multicast traffic until a receiver joins. The port used for the mrouter port can be an unused port or a live one, but this port will get flooded with the multicast traffic all the time.
Please configure the following commands to resolve the issue.
Please note that, in the below commands, I have used te1/0/11 as an example, this can be any interface in target VLAN (VLAN 999). The interface can be operationally DOWN or UP. If the interface is UP, then multicast traffic will be flooded on this interface. So it is recommended to use a non-used interface in the below configuration.
config# ip igmp version 2
config# ip igmp snooping vlan 999 mrouter interface te1/0/11
config# ip igmp snooping querier
config# ip igmp snooping querier vlan 999
config# ip igmp snooping querier vlan 999 address 172.20.254.23
config# interface te1/0/11
config#(config-if-te-1/0/11)#switchport access vlan 999
config#(config-if-te-1/0/11)#exit
config# wr mem