Administrator Guide

show ipv6 mld interface vlan 20
Dell#show ipv6 mld interface vlan 20
Vlan 20 is up, line protocol is up
Inbound MLD access group is not set
Internet address is fe80::92b1:1cff:fef4:9b63/64
MLD is enabled on interface
MLD query interval is 60 seconds
MLD querier timeout is 125 seconds
MLD max query response time is 10 seconds
MLD last member query response interval is 1000 ms
MLD immediate-leave is enabled for all groups
MLD activity: 0 joins
MLD querying router is 35::1 (this system)
MLD version is 2
MLD Snooping
Multicast packets are addressed with multicast MAC addresses, which represent a group of devices, rather than one unique device.
Switches forward multicast frames out of all ports in a VLAN by default, even though there may be only some interested hosts, which is a
waste of bandwidth. MLD Snooping enables switches to use information in MLD packets to generate a forwarding table that associates
ports with multicast groups so that when they receive multicast frames, they can forward them only to interested receivers.
NOTE: If PIM and MLD snooping is enabled in FHR, then either enable mrouter towards LHR or disable snooping towards
LHR.
Enable MLD Snooping
MLD is automatically enabled when you enable IPv6 PIM, but MLD snooping must be explicitly enabled.
To enable MLD snooping, use the following command:
CONFIGURATION Mode
ipv6 mld snooping enable
Disable MLD Snooping
When MLD is enabled globally, it is by default enabled on all the VLANs.
To disable MLD snooping on a VLAN, use the following command:
INTERFACE VLAN Mode
no ipv6 mld snooping
NOTE: Under the default configuration, there is no need to configure ipv6 mld snooping for any VLAN.
Configure the switch as a querier
Hosts that do not support unsolicited reporting wait for a general query before sending a membership report. When the multicast source
and receivers are in the same VLAN, multicast traffic is not routed, and so there is no querier. You must configure the switch to be the
querier for a VLAN so that hosts send membership reports, and the switch can generate a forwarding table by snooping.
To configure the switch as a querier for a layer 2 VLAN, use the following command:
INTERFACE VLAN Mode
ipv6 mld snooping querier
NOTE:
You must configure an IP address for the VLAN.
The source address of the queries is 0 to distinguish these queries from the router queries. If the system receives a query with a non-zero
address any VLAN interface, it stops sending queries. When a VLAN configured with snooping querier comes up, the VLAN interface waits
for the querier timeout to expire before becoming a querier.
Multicast Listener Discovery Protocol
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