H3C Technologies H3C WX3000 Series Unified Switches - Manual (Page 443)

44-13
To do… Use the command… Remarks
Configure a VLAN tag for
query messages igmp-snooping
vlan-mapping vlan vlan-id
Required
By default, no VLAN tag is configured for general
and group-specific query messages sent or
forwarded by IGMP Snooping.
Configuring Multicast VLAN
In traditional multicast implementations, when users in different VLANs listen to the same multicast
group, the multicast data is copied on the multicast router for each VLAN that contains receivers. This is
a big waste of network bandwidth.
In an IGMP Snooping environment, by configuring a multicast VLAN and adding ports to the multicast
VLAN, you can allow users in different VLANs to share the same multicast VLAN. This saves bandwidth
because multicast streams are transmitted only within the multicast VLAN. In addition, because the
multicast VLAN is isolated from user VLANs, this method also enhances the information security.
Multicast VLAN is mainly used in Layer 2 switching, but you must make the corresponding
configurations on the Layer 3 device.
Follow these steps to configure multicast VLAN on the Layer 3 device:
To do… Use the command… Remarks
Enter system view system-view —
Create a multicast VLAN and enter
VLAN view
vlan vlan-id —
Return to system view quit —
Enter VLAN interface view interface Vlan-interface vlan-id —
Enable IGMP igmp enable
Required
By default, the IGMP feature is
disabled.
Return to system view quit —
Enter Ethernet port view for the
Layer 2 device to be configured interface interface-type
interface-number
—
Define the port as a trunk or hybrid
port
port link-type { trunk | hybrid } Required
port hybrid vlan vlan-id-list
{ tagged | untagged }
Specify the VLANs to be allowed to
pass the Ethernet port
port trunk permit vlan vlan-list
Required
The multicast VLAN defined on the
Layer 2 device must be included,
and the port must be configured to
forward tagged packets for the
multicast VLAN if the port type is
hybrid.
Follow these steps to configure multicast VLAN on the Layer 2 device: