D-Link DGS-3620-28TC-SI Product Manual - Page 123

xStack® DGS-3620 Series Managed Switch Web UI Reference Guide 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. MLD Control Messages Three types of messages are transferred between devices using MLD snooping. These three messages are all defined by four ICMPv6 packet headers, labeled 130, 131, 132, and 143. 1. Multicast Listener Query - Similar to the IGMPv2 Host 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. 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. 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. 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 show below: Figure 4-69 MLD Snooping Settings window The fields that can be configured are described below: Parameter Description MLD Snooping State Click the radio buttons to enable or disable the MLD snooping state. Click the Apply button to accept the changes made for each individual section. Click the Edit button to configure the MLD Snooping Parameters Settings for a specific entry. Click the Modify Router Port link to configure the MLD Snooping Router Port Settings for a specific entry. Enter a page number and click the Go button to navigate to a specific page when multiple pages exist. After clicking the Edit button, the following page will appear: 113