CHAPTER
29-1
Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS 15.2(5)Ex
 
29
Configuring IPv6 Multicast Listener Discovery 
Snooping
Use Multicast Listener Discovery (MLD) snooping to enable efficient distribution of IP version 6 (IPv6) 
multicast data to clients and routers in a switched network on the Catalyst 4500 series switch.
This chapter includes these sections: 
• About MLD Snooping, page 29-1
• Configuring IPv6 MLD Snooping, page 29-5
• Displaying MLD Snooping Information, page 29-10
Note For complete syntax and usage information for the switch commands used in this chapter, see the
Cisco IOS Command Reference Guides for the Catalyst 4500 Series Switch.
If a command is not in the Cisco Catalyst 4500 Series Switch Command Reference , you can locate it in 
the Cisco IOS Master Command List, All Releases.
About MLD Snooping
In IP version 4 (IPv4), Layer 2 switches can use Internet Group Management Protocol (IGMP) snooping 
to limit the flooding of multicast traffic by dynamically configuring Layer 2 interfaces so that multicast 
traffic is forwarded to only those interfaces associated with IP multicast devices. In IPv6, MLD snooping 
performs a similar function. With MLD snooping, IPv6 multicast data is selectively forwarded to a list 
of ports that want to receive the data, instead of being flooded to all ports in a VLAN. This list is 
constructed by snooping IPv6 multicast control packets.