Reference Guide

590 | Multicast Listener Discovery
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Figure 30-3. MLDv2 Multicast Listener Report
Implementation Information
• In FTOS versions prior to 8.3.1.0: when a switch on which MLD snooping is enabled acts as Querier,
queries sent to a specific port (in the event of a port enable, MLD leave, or MLD join), were sent with
an all-zero (::) IPv6 source address. This might unintentionally indicate to another MLD switch that it
is elected the Querier. Beginning with FTOS version 8.3.1.0, all queries are flooded on the VLAN so
that the IPv6 source address is correctly included in all queries.
• MLDv2 Snooping ignores sources specified in exclude reports; all exclude (S,G) reports are treated as
exclude (*,G).
• The following querier commands are available for Layer 3 MLD and MLD Snooping: ipv6 mld
last-member-query-interval, ipv6 mld query-interval, ipv6 mld query-max-resp-time.
Enabling MLD
MLD is enabled automatically when IPv6 PIM is enabled.
Related MLD Configuration Tasks
• Change MLD Timer Values
• Reduce Host Response Burstiness
• Reduce Leave Latency
• Configure a Static Group
• Clear MLD Groups
• Change the MLD Version
• Debug MLD
• MLD Snooping
Version
(6)
Traffic Class
Flow Label
Payload Length
Next Header
(0)
Hop Limit
(1)
ICMPv6 Packet
Preamble
Start Frame
Delimiter
Destination MAC
Source MAC
Ethernet Type
IPv6 Packet
Padding
MLD 0
03
Type
Code
(0)
Multicast Address Record
Checksum
Code: 130: Multicast Listener Query
131: Multicast Listener Report
132: Multicast Listener Done
143: Version 2 Multicast Listener Report
FCS
Next Header
(58)
Header Extension
Length
(0)
Options
(Router Alert)
Reserved
N
Record Type
Aux Data Length
(0)
N
Multicast Address
Source Addresses
Code: 1: MODE_IS_INCLUDE
2: MODE_IS EXCLUDE
3: CHANGE_TO_INCLUDE
4: CHANGE_TO_EXCLUDE
5: ALLOW_NEW_SOURCES
6: BLOCK_OLD_SOURCES