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Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
OL-8978-04
Chapter 51 Configuring Multicast Services
Configuring IGMP Snooping on the Switch
Total Valid pkts: 63552
Total Invalid pkts: 0
Other pkts: 2115
MAC-Based General Queries: 0
Failures to add GDA to EARL: 0
Topology Notifications: 0
IGMP packets dropped: 0
IGMP Leave msgs in the list: 0
IGMP V3 IS_IN messages: 13
IGMP V3 IS_EX messages: 5
IGMP V3 TO_IN messages: 0
IGMP V3 TO_EX messages: 1
IGMP V3 ALLOW messages: 0
IGMP V3 BLOCK messages: 1
Console> (enable)
Enabling IGMP Flooding
When you disable IGMP flooding, the source traffic is never flooded in the VLAN and is sent only to
the router ports. IGMP flooding is enabled by default.
To enable or disable IGMP flooding, perform this task in privileged mode:
These examples show how to enable and disable IGMP flooding:
Console> (enable)
set igmp flooding enable
IGMP Flooding enabled (default)
Console> (enable)
set igmp flooding disable
IGMP Flooding disabled
Console> (enable)
Console> (enable)
show igmp flooding
Mcast flooding disabled
Console> (enable)
Specifying the IGMP Snooping Mode
IGMP snooping runs in either IGMP-only mode or IGMP-CGMP mode. The switch dynamically
chooses either IGMP-only or IGMP-CGMP mode, depending on the traffic that is present on the
network. IGMP-only mode is used in the networks with no CGMP devices. IGMP-CGMP mode is used
in the networks with both IGMP and CGMP devices. Auto mode overrides the dynamic switching of the
modes.
To specify the IGMP snooping mode, perform this task in privileged mode:
Task
Command
Step 1
Enable or disable IGMP flooding.
set igmp flooding
{
enable
|
disable
}
Step 2
Display the IGMP flooding state.
show igmp flooding
Task
Command
Step 1
Specify the IGMP snooping mode.
set igmp mode
{
igmp-only | igmp-cgmp | auto
}
Step 2
Display the IGMP snooping mode.
show igmp mode