68Step Command Remarks1. Enter system view. system-view N/A2. Configure the specified VLANas a multicast VLAN and entermulticast VLAN view.multicast-vlan vlan-id By default, a VLAN is not amulticast VLAN.3. Configure the specifiedVLANs as sub-VLANs of themulticast VLAN.subvlan vlan-list By default, a multicast VLAN hasno sub-VLANs.Configuring a port-based multicast VLANWhen you configure a port-based multicast VLAN, you must configure the attributes of each user portand then assign the ports to the multicast VLAN.A user port can be configured as a multicast VLAN port only if it is an Ethernet port, or Layer 2 aggregateinterface.In Ethernet interface view or Layer 2 aggregate interface view, configurations that you make are effectiveon only the current port. In port group view, configurations that you make are effective on all ports in thecurrent port group.Configuration prerequisitesBefore you configure a port-based multicast VLAN, complete the following tasks:• Create VLANs as required.• Enable IGMP snooping in the VLAN to be configured as a multicast VLAN.• Enable IGMP snooping in all the user VLANs.Configuring user port attributesFirst, configure the user ports as hybrid ports that permit packets of the specified user VLAN to pass, andconfigure the user VLAN to which the user ports belong as the default VLAN.Then, configure the user ports to permit packets of the multicast VLAN to pass and untag the packets.Thus, after receiving multicast packets tagged with the multicast VLAN ID from the upstream device, theLayer 2 device untags the multicast packets and forwards them to its downstream device.To configure user port attributes:Step Command Remarks1. Enter system view. system-view N/A
