R3303-HP HSR6800 Routers IP Multicast Configuration Guide

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Figure 109 Sub-VLAN-based multicast VLAN
After the configuration, IGMP snooping manages router ports in the multicast VLAN and member ports
in each sub-VLAN. When Switch A forwards the multicast data to Switch B, it sends only one copy of the
multicast data to Switch B. Switch B distributes the data to the multicast VLAN's sub-VLANs that contain
receivers.
Port-based multicast VLAN
As shown in Figure 110, Host A, Host B, and Host C are in VLAN 2 through VLAN 4, respectively. All the
user ports (ports with attached hosts) on Switch B are hybrid ports. On Switch B, VLAN 10 is configured
as a multicast VLAN, all the user ports are assigned to VLAN 10, and IGMP snooping is enabled for the
multicast VLAN and VLAN 2 through VLAN 4.
Figure 110 Port-based multicast VLAN
After the configuration, if Switch B receives an IGMP message on a user port, it tags the message with the
multicast VLAN ID and relays it to the IGMP querier. This allows IGMP snooping to uniformly manage the
router ports and member ports in the multicast VLAN. When Switch A forwards multicast data to Switch
B, it sends only one copy of the multicast data to Switch B. Switch B distributes the data to all member
ports in the multicast VLAN.
Source
VLAN 2
VLAN 3
VLAN 4
Eth1/1
Eth1/2
Eth1/3
Eth1/4
Switch B
Multicast packets
Receiver
Host A
Receiver
Host B
Receiver
Host C
Switch A
IGMP querier
VLAN 10 (Multicast VLAN)