Specifications

Chapter 3: Layer 2 Features
Extreme Networks EAS 100-24t Switch Software Manual
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requesting multicast data. There are two types of MLD query messages emitted by the router. The
General Query is used to advertise all multicast addresses that are ready to send multicast data to all
listening ports, and the Multicast Specific 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.
If implementing MLD snooping version 2, two types of messages are transferred between devices.
The two messages are defined by two ICMPv6 packet headers, labeled 130 and 143.
4 Multicast Listener Query, Version 2 – Similar to the IGMPv3 Membership Query for IPv4, and
labeled as 130 in the ICMPv6 packet header, this message is sent by the router to ask if any link is
requesting multicast data. With MLD snooping version 2, there are three types of MLD query
messages emitted by the router, as described below:
a The router sends a General Query message to learn which multicast addresses have listeners on
an attached link. In a General Query, both the Multicast Address field and the Number of Sources
field are set to zero.
b The router sends a Multicast Address Specific Query message to learn if a particular multicast
address has any listeners on an attached link. In a Multicast Address Specific Query, the
Multicast Address field contains the multicast address that the router is interested in, while the
Number of Sources field is set to zero.
c The router sends a Multicast Address and Source Specific Query to learn if any of the sources
from the specified list for the particular multicast address has any listeners on an attached link or
not. In a Multicast Address and Source Specific Query the Multicast Address field contains the
multicast address that the router is interested in, while the Source Address field(s) contain(s) the
source address(es) that the router is interested in.
5 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.
This window is used to enable MLD Snooping on the Switch and to configure the settings for MLD
snooping. To enable the MLD Snooping State, click the Enable radio button under MLD Snooping
Global Settings and click Apply.