349
Configuring IPv6 multicast VLANs
This section describes IPv6 multicast VLAN, how to configure IPv6 multicast VLANs, and
configuration examples.
Overview
As shown in
, Host A, Host B, and Host C reside in different VLANs and require the same
IPv6 multicast programs-on-demand service. Router A (Layer 3 device) must forward a separate
copy of the IPv6 multicast data for each user VLAN to Switch A (Layer 2 device). This occupies large
bandwidth and increases the burden on the Layer 3 device.
Figure 99 Multicast transmission without the IPv6 multicast VLAN feature
The IPv6 multicast VLAN feature on the Layer 2 device is the solution to this issue. With the IPv6
multicast VLAN feature, Router A sends the IPv6 multicast data to the IPv6 multicast VLAN on
Switch A. Switch A sends a separate copy of the data to each user VLAN. This saves the network
bandwidth and lessens the burden on the Layer 3 device.
The IPv6 multicast VLAN feature can be implemented in a sub-VLAN-based IPv6 multicast VLAN
and a port-based IPv6 multicast VLAN.
Sub-VLAN-based IPv6 multicast VLAN
As shown in
•
Host A, Host B, and Host C are in different user VLANs.
•
On Switch A, VLAN 10 is configured as an IPv6 multicast VLAN.
All user VLANs are configured as sub-VLANs of VLAN 10.
MLD snooping is enabled for the IPv6 multicast VLAN.
Source
Receiver
Host A
IPv6 Multicast packets
VLAN 2
VLAN 3
VLAN 4
VLAN 2
VLAN 3
VLAN 4
Switch A
Receiver
Host B
Receiver
Host C
Router A
MLD querier