612 | Multicast Listener Discoveryw w w . d e l l . c o m | s u p p o r t . d e l l . c o m Enable MLD SnoopingMLD is automatically enabled when you enable IPv6 PIM, but MLD Snooping must be explicitly enabled.Disable MLD Snooping on a VLANWhen MLD is enabled globally, it is by default enabled on all VLANs. Disable snooping on a VLAN,using the command no ipv6 mld snooping from INTERFACE VLAN mode. Note that under the defaultconfiguration there is no need to configure ipv6 mld snooping for any VLAN.Configure the Switch as a QuerierHosts that do not support unsolicited reporting wait for a general query before sending a membershipreport. When the multicast source and receivers are in the same VLAN, multicast traffic is not routed, andso there is no querier. You must configure the switch to be the querier for a VLAN so that hosts sendmembership reports, and the switch can generate a forwarding table by snooping.Configure the switch to be the querier for a Layer 2 VLAN using the command ipv6 mld snooping querierfrom INTERFACE VLAN mode. You must configure an IP address for the VLAN.The source address of the queries is 0 to distinguish these queries from router queries. If the systemreceives a query with a non-zero address any VLAN interface, it stops sending queries. When a VLANconfigured with snooping querier comes up, the VLAN interface waits for querier timeout to expire beforebecoming querier.Disable Multicast FloodingIf the switch receives a multicast packet that has an IP address of a group it has not learned (unregisteredframe), the switch floods that packet out of all ports on the VLAN.You can configure the switch to only forward unregistered packets to ports on a VLAN that are connectedto a multicast routers using the command no ipv6 mld snooping flood from CONFIGURATION mode.When flooding is disabled, if there are no such ports in the VLAN connected to a multicast router, theswitch drops the packets.Specify a Port as Connected to a Multicast RouterAll MLD control packets and IP multicast data traffic originating from hosts are forwarded out allinterfaces connected to multicast routers. These interfaces are called multicast router interfaces, or mrouterinterfaces. You can statically specify a port in a VLAN as connected to a multicast router using thecommand ipv6 mld snooping mrouter interface from INTERFACE VLAN mode.Task Command Syntax Command ModeEnable MLD Snooping ipv6 mld snooping enable CONFIGURATION
