Concept Guide
waste of bandwidth. MLD Snooping enables switches to use information in MLD packets to generate a forwarding table that associates
ports with multicast groups so that when they receive multicast frames, they can forward them only to interested receivers.
Enable MLD Snooping
MLD is automatically enabled when you enable IPv6 PIM, but MLD snooping must be explicitly enabled.
To enable MLD snooping, use the following command:
CONFIGURATION Mode
ipv6 mld snooping enable
Disable MLD Snooping
When MLD is enabled globally, it is by default enabled on all the VLANs.
To disable MLD snooping on a VLAN, use the following command:
INTERFACE VLAN Mode
no ipv6 mld snooping
NOTE: Under the default conguration, there is no need to congure ipv6 mld snooping for any
VLAN.
Congure the switch as a querier
Hosts that do not support unsolicited reporting wait for a general query before sending a membership report. When the multicast source
and receivers are in the same VLAN, multicast trac is not routed, and so there is no querier. You must congure the switch to be the
querier for a VLAN so that hosts send membership reports, and the switch can generate a forwarding table by snooping.
To congure the switch as a querier for a layer 2 VLAN, use the following command:
INTERFACE VLAN Mode
ipv6 mld snooping querier
NOTE
: You must congure an IP address for the
VLAN.
The source address of the queries is 0 to distinguish these queries from the router queries. If the system receives a query with a non-
zero address any VLAN interface, it stops sending queries. When a VLAN congured with snooping querier comes up, the VLAN
interface waits for the querier timeout to expire before becoming a querier.
Specify port as connected to multicast router
To statically specify or view a port in a VLAN, use the following commands:
1 Statically specify a port in a VLAN as connected to a multicast router.
INTERFACE VLAN mode
ipv6 mld snooping mrouter
2 View the ports that are connected to multicast routers.
532
Multicast Listener Discovery Protocol