608 | Multicast Listener Discovery
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Figure 27-3.  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 on page 609
• Reduce Host Response Burstiness on page 609
• Reduce Leave Latency on page 609
• Configure a Static Group on page 610 
• Clear MLD Groups on page 611
• Change the MLD Version on page 611
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
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