Cisco Catalyst 4500 Series - About MLD Snooping

CHAPTER
26-1
Software Configuration Guide—Release IOS XE 3.3.0SG and IOS 15.1(1)SG
OL-25340-01
26
Configuring IPv6 MLD 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 26-1
• Configuring IPv6 MLD Snooping, page 26-5
• Displaying MLD Snooping Information, page 26-10
Note For complete syntax and usage information for the switch commands used in this chapter, first 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 Series Switch Command Reference, it will be found 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.