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Catalyst 3560 Switch Software Configuration Guide
OL-8553-06
Chapter 23 Configuring IGMP Snooping and MVR
Configuring IGMP Snooping
Configuring the IGMP Leave Timer, page 23-11
Configuring TCN-Related Commands, page 23-12
Configuring the IGMP Snooping Querier, page 23-14
Disabling IGMP Report Suppression, page 23-15
Default IGMP Snooping Configuration
Tabl e 23-3 shows the default IGMP snooping configuration.
Enabling or Disabling IGMP Snooping
By default, IGMP snooping is globally enabled on the switch. When globally enabled or disabled, it is
also enabled or disabled in all existing VLAN interfaces. IGMP snooping is by default enabled on all
VLANs, but can be enabled and disabled on a per-VLAN basis.
Global IGMP snooping overrides the 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.
Beginning in privileged EXEC mode, follow these steps to globally enable IGMP snooping on the
switch:
To globally disable IGMP snooping on all VLAN interfaces, use the no ip igmp snooping global
configuration command.
Tab l e 23-3 Default IGMP Snooping Configuration
Feature Default Setting
IGMP snooping Enabled globally and per VLAN
Multicast routers None configured
Multicast router learning (snooping) method PIM-DVMRP
IGMP snooping Immediate Leave Disabled
Static groups None configured
TCN1 flood query count
1. TCN = Topology Change Notification
2
TCN query solicitation Disabled
IGMP snooping querier Disabled
IGMP report suppression Enabled
Command Purpose
Step 1 configure terminal Enter global configuration mode.
Step 2 ip igmp snooping Globally enable IGMP snooping in all existing VLAN interfaces.
Step 3 end Return to privileged EXEC mode.
Step 4 copy running-config startup-config (Optional) Save your entries in the configuration file.