How to skip an unknown multicast so that it is not blocked?

Question

Cisco

There is a task to pass an unknown multicast through 2 switches, according to a certain (but only one) vlan, on other vlans it should be blocked, at the moment, it is either on all vlans, or on none. The multicast vlan function also does not work.

Answer 1

TriRyblia and please write what kind of switches you have - brand, model, software version?

Answer 2

Perhaps the static binding of groups to ports will help, using the same igmp
For ports and vlans on which unknow multicast is needed, we do not bind.
Plus, on L3 interfaces, filtering by ACL - on the interface looking into the vlan for unknow multicast - we do not prohibit, on the rest we allow only known groups.
Also, on other ports, you can block L2 unknow multicast:

(config-if)#switchport block ?
  multicast  Block unknown multicast addresses
  unicast    Block unknown unicast addresses