67Switch A, it sends only one copy of multicast data to Switch A in the multicast VLAN, and Switch Adistributes the data to all the member ports in the multicast VLAN.For more information about IGMP snooping, router ports, and member ports, see "Configuring IGMPsnooping."For more information about VLAN tags, see Layer 2—LAN Switching Configuration Guide.Multicast VLAN configuration task listTask RemarksConfiguring a sub-VLAN-based multicast VLANRequiredUse either approach.Configuring a port-basedmulticast VLANConfiguring user port attributesConfiguring multicast VLAN portsNOTE:If you have configured both sub-VLAN-based multicast VLAN and port-based multicast VLAN on adevice, the port-based multicast VLAN configuration is given preference.Configuring a sub-VLAN-based multicast VLANBefore you configure sub-VLAN-based multicast VLAN, complete the following tasks:• Create VLANs as required.• Enable IGMP snooping in the VLAN to be configured as a multicast VLAN.Configuration guidelines• For the S5500-EI switches, you cannot configure multicast VLAN on a device with IP multicastrouting enabled.• The VLAN to be configured as a multicast VLAN must exist.• The VLANs to be configured as sub-VLANs of the multicast VLAN must exist and must not bemulticast VLANs or sub-VLANs of any other multicast VLAN.• The total number of sub-VLANs of a multicast VLAN must not exceed the maximum number thesystem can support.Configuration procedureIn this approach, you configure a VLAN as a multicast VLAN and configure user VLANs as sub-VLANsof the multicast VLAN.To configure a sub-VLAN-based multicast VLAN:
