24.7.5 Multicast when different VLANs are used together

When multiple MAC VLANs exist on the same port, or a port VLAN and MAC VLAN are both on the same port, if the terminals belonging to each VLAN also belong to the same multicast group, the terminals will receive the same frames more than once. This is because the same multicast frames are sent for each VLAN.

The following figure shows an example network configuration in which terminals receive multicast data more than once.

Figure 24-10: Multicast when VLAN are mixed