Mld Snooping Settings - D-Link Xstack DES-3528 Series Reference Manual

xStack® DES-3528/DES-3552 Series Layer 2 Managed Stackable Fast Ethernet Switch Web UI Reference Guide
query, which advertises a specific multicast address that is also ready. These two types of messages are
distinguished by a multicast destination address located in the IPv6 header and a multicast address in the
Multicast Listener Query Message.
2. Multicast Listener Report, Version 1 – Comparable to the Host Membership Report in IGMPv2, and
labeled as 131 in the ICMP packet header, this message is sent by the listening port to the Switch stating
that it is interested in receiving multicast data from a multicast address in response to the Multicast Listener
Query message.
3. Multicast Listener Done – Akin to the Leave Group Message in IGMPv2, and labeled as 132 in the
ICMPv6 packet header, this message is sent by the multicast listening port stating that it is no longer
interested in receiving multicast data from a specific multicast group address, therefore stating that it is
"done" with the multicast data from this address. Once this message is received by the Switch, it will no
longer forward multicast traffic from a specific multicast group address to this listening port.
4. Multicast Listener Report, Version 2 - Comparable to the Host Membership Report in IGMPv3, and
labeled as 143 in the ICMP packet header, this message is sent by the listening port to the Switch stating
that it is interested in receiving multicast data from a multicast address in response to the Multicast Listener
Query message.
Data Driven Learning
The Switch allows you to implement data driven learning for MLD snooping groups. If data-driven learning, also
known as dynamic IP multicast learning, is enabled for a VLAN, when the Switch receives IP multicast traffic on the
VLAN, an MLD snooping group is created. Learning of an entry is not activated by MLD membership registration,
but activated by the traffic. For an ordinary MLD snooping entry, the MLD protocol will take care of the aging out of
the entry. For a data-driven entry, the entry can be specified not to age out or to age out by a timer.
When the data driven learning State is enabled, the multicast filtering mode for all ports is ignored. This means
multicast packets will be forwarded to router ports.
NOTE: If a data-driven group is created and MLD member ports are learned later, the entry will
become an ordinary MLD snooping entry. In other words, the aging out mechanism will follow
the conditions of an ordinary MLD snooping entry.
Data driven learning is useful on a network which has video cameras connected to a Layer 2 switch that is
recording and sending IP multicast data. The Switch needs to forward IP data to a data centre without dropping or
flooding any packets. Since video cameras do not have the capability to run MLD protocols, the IP multicast data
will be dropped with the original MLD snooping function.

MLD Snooping Settings

Users can configure the settings for MLD snooping.
To view the following window, click L2 Features > L2 Multicast Control > MLD Snooping > MLD Snooping
Settings, as shown below:
Figure 4-54 MLD Snooping Settings window
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