CLI Reference Guide-R04

Chapter 25 | Multicast Filtering Commands
IGMP Snooping
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When an upstream multicast router receives this solicitation, it will also
immediately issues an IGMP general query.
◆ The ip igmp snooping tcn query-solicit command can be used to send a
query solicitation whenever it notices a topology change, even if the switch is
not the root bridge in the spanning tree.
Example
The following example instructs the switch to issue an IGMP general query
whenever it receives a spanning tree topology change notification.
Console(config)#ip igmp snooping tcn-query-solicit
Console(config)#
ip igmp snooping
unregistered-data-
flood
This command floods unregistered multicast traffic into the attached VLAN. Use the
no form to drop unregistered multicast traffic.
Syntax
[no] ip igmp snooping unregistered-data-flood
Default Setting
Disabled
Command Mode
Global Configuration
Command Usage
Once the table used to store multicast entries for IGMP snooping and multicast
routing is filled, no new entries are learned. If no router port is configured in the
attached VLAN, and unregistered-flooding is disabled, any subsequent multicast
traffic not found in the table is dropped, otherwise it is flooded throughout the
VLAN.
Example
Console(config)#ip igmp snooping unregistered-data-flood
Console(config)#