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Software Configuration Guide—Release 15.0(2)SG
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Configuring IPv6 MLD Snooping
Note IPv6 MLD Snooping is only supported on Catalyst 4900M, Catalyst 4948E, Supervisor Engine 6-E, and
Supervisor Engine 6L-E.
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 24-1
Configuring IPv6 MLD Snooping, page 24-5
Displaying MLD Snooping Information, page 24-11
Note For complete syntax and usage information for the switch commands used in this chapter, look at the
Cisco Catalyst 4500 Series Switch Command Reference and related publications at this location:
http://www.cisco.com/en/US/products/hw/switches/ps4324/index.html
If the command is not found in the Catalyst 4500 Command Reference, it is located in the larger Cisco
IOS library. Refer to the Cisco IOS Command Reference and related publications at this location:
http://www.cisco.com/en/US/products/ps6350/index.html

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.