L2 Functions > Multicast > Mld Snooping - D-Link DGS-1210-10 Manual

4 Web-based Switch Configuration
D-Link Smart Managed Switch User Manual
L2 Functions > Multicast > MLD Snooping
Multicast Listener Discovery (MLD) Snooping is an IPv6 function used similarly to IGMP snooping in IPv4. It
is used to discover ports on a VLAN that are requesting multicast data. Instead of flooding all ports on a
selected VLAN with multicast traffic, MLD snooping will only forward multicast data to ports that wish to
receive this data through the use of queries and reports produced by the requesting ports and the source of
the multicast traffic.
MLD snooping is accomplished through the examination of the layer 3 part of an MLD control packet
transferred between end nodes and a MLD router. When the Switch discovers that this route is requesting
multicast traffic, it adds the port directly attached to it into the correct IPv6 multicast table, and begins the
process of forwarding multicast traffic to that port. This entry in the multicast routing table records the port,
the VLAN ID, and the associated multicast IPv6 multicast group address, and then considers this port to be
an active listening port. The active listening ports are the only ones to receive multicast group data.
Figure 4.66 – L2 Functions > Multicast > MLD Snooping
MLD Global Settings:
MLD Snooping: Enable or disable the MLD Snooping.
Host Timeout (130-153025 sec): Specifies the time interval in seconds after which a port is removed from a
Multicast Group. Ports are removed if a Multicast group MLD report was not received from a Multicast port
within the defined Host Timeout period. The possible field range is 130 - 153025 seconds. The default
timeout is 260 seconds.
Router Timeout (60-600): Specifies the time interval in seconds the Multicast router waits to receive a
message before it times out. The possible field range is 60 - 600 seconds. The default timeout is 125
seconds.
Robustness Variable (2-255): The Robustness Variable allows adjustment for the expected packet loss
on a subnet. If a subnet is expected to be lossy, the Robustness Variable may be increased. The
Robustness Variable cannot be set to zero, and SHOULD NOT be one. Default is 2 seconds. Last Member
Query Interval (1-25 sec): The Last Member Query Interval is the Max Response Time inserted into Group-
Specific Queries sent in response to Leave Group messages, and is also the amount of time between
Group-Specific Query messages. This value may be adjusted to modify the "leave latency" of network. A
60