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Catalyst 2960 Switch SoftwareConfiguration Guide
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Chapter20 Configuring IGMP Snooping and MVR
Configuring IGMP Snooping
If you disable IGMP report suppression, all IGMP reports are forwarded to the multicast routers. For
configuration steps, see the “Disabling IGMP Report Suppression” section on page 20-14.
Configuring IGMP Snooping
IGMP snooping allows switches to examine IGMP packets and make forwarding decisions based on their
content. These sections contain this configuration information:
Default IGMP Snooping Configuration, page 20-6
Enabling or Disabling IGMP Snooping, page 20-6
Setting the Snooping Method, page 20-7
Configuring a Multicast Router Port, page 20-8
Configuring a Host Statically to Join a Group, page 20-9
Enabling IGMP Immediate Leave, page 20-9
Configuring the IGMP Leave Timer, page 20-10
Configuring TCN-Related Commands, page 20-11
Configuring the IGMP Snooping Querier, page 20-13
Disabling IGMP Report Suppression, page 20-14

Default IGMP Snooping Configuration

Table20-3 shows the de fault 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.
Table20-3 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