20.
IGMP Snooping
MN700004 Rev 01
245
show ip igmp snooping router-timers
Displays the multicast router timer (RFC 2236) to
synchronize IGMP snooping.
show ip igmp snooping send-query
Displays Query sending parameters.
show mac-address-table multicast
igmp
Displays MAC address table entries for a VLAN.
show ip igmp snooping statistics
Displays Statistics from IGMP snooping.
clear ip igmp snooping
Clears IGMP snooping statistics.
Commands to Configure IGMP Snooping
ip igmp snooping
The
ip igmp snooping
command, in Global Configuration mode, enables IGMP snooping on
all existing VLAN interfaces. The
no
form of this command disables IGMP snooping on all
existing VLAN interfaces.
By default, IGMP snooping is globally disabled on the switch. When enabled or disabled
globally, it is also enabled or disabled in all existing VLAN interfaces. IGMP snooping is by
default enabled on all VLANs, but can be enabled or disabled on a per-VLAN basis. After
you configure a VLAN interface for multicast routing, no configuration is needed for the
switch to access external multicast routers dynamically by using IGMP snooping.
When you enable IGMP snooping, the switch automatically learns the interfaces to which
multicast routers are connected. When you disable IGMP snooping, the entire configuration is
erased.
Global IGMP snooping overrides VLAN IGMP snooping. If global snooping is disabled, you
cannot enable VLAN snooping. If global snooping is enabled, you can enable or disable
VLAN snooping.
Command Syntax
device-name
(config)#
ip igmp snooping
device-name
(config)#
no ip igmp snooping
ip igmp snooping vlan
The
ip igmp snooping vlan
command, in Global Configuration mode, enables IGMP
snooping on the specified VLAN. By default, IGMP snooping is enabled on all the VLANs.
To remove IGMP snooping from a VLAN, use the
no
form of this command.
Command Syntax
device-name
(config)#
ip igmp snooping vlan
<
vlan-id
>
device-name
(config)#
no ip igmp snooping vlan
<
vlan-id>
Argument Description
vlan-id
the VLAN ID in the range <1-4094>