Edge-Core ES3510MA-DC, Management Manual, Page: 902 / 1098

C
HAPTER
38
| Multicast Filtering Commands
IGMP Snooping
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ip igmp snooping
tcn-query-solicit
This command instructs the switch to send out an IGMP general query
solicitation when a spanning tree topology change notification (TCN)
occurs. Use the no form to disable this feature.
S
YNTAX
[ no ] ip igmp snooping tcn-query-solicit
D
EFAULT
S
ETTING
Disabled
C
OMMAND
M
ODE
Global Configuration
C
OMMAND
U
SAGE
◆
When the root bridge in a spanning tree receives a topology change
notification for a VLAN where IGMP snooping is enabled, it issues a
global IGMP leave message (query solicitation). When a switch receives
this solicitation, it floods it to all ports in the VLAN where the spanning
tree change occurred. 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.
E
XAMPLE
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.
S
YNTAX
[ no ] ip igmp snooping unregistered-data-flood
D
EFAULT
S
ETTING
Disabled
C
OMMAND
M
ODE
Global Configuration
C
OMMAND
U
SAGE
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,