White Papers

retransmissions. Lowering the Last Listener Query Interval reduces the time to detect that there are no remaining receivers for
a group, and so can reduce the amount of unnecessarily forwarded traffic.
To adjust the last-member query interval, use the following command:
INTERFACE Mode
ipv6 mld last-member-query-interval
Displaying MLD groups table
Display MLD groups. Group information can be filtered.
To display MLD groups, use the following command:
EXEC Privilege
show ipv6 mld groups
Dell#show ipv6 mld groups
Total Number of Groups: 1
MLD Connected Group Membership
Group Address Interface Mode Uptime Expires Last Reporter
Ff08::12 Vlan 10 MLDv2 00:00:12 00:02:05 1::2
Displaying MLD Interfaces
Display MLD interfaces.
To display MLD interfaces, use the following command:
INTERFACE
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.
Multicast Listener Discovery Protocol 557