Configuring Igmp Snooping; Default Igmp Snooping Configuration - Cisco IE 3000 Software Configuration Manual

Configuring IGMP Snooping

The switch uses IGMP report suppression to forward only one IGMP report per multicast router query
to multicast devices. When IGMP router suppression is enabled (the default), the switch sends the first
IGMP report from all hosts for a group to all the multicast routers. The switch does not send the
remaining IGMP reports for the group to the multicast routers. This feature prevents duplicate reports
from being sent to the multicast devices.
If the multicast router query includes requests only for IGMPv1 and IGMPv2 reports, the switch
forwards only the first IGMPv1 or IGMPv2 report from all hosts for a group to all the multicast routers.
If the multicast router query also includes requests for IGMPv3 reports, the switch forwards all IGMPv1,
IGMPv2, and IGMPv3 reports for a group to the multicast devices.
If you disable IGMP report suppression, all IGMP reports are forwarded to the multicast routers. For
configuration steps, see the
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:
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Default IGMP Snooping Configuration

Table 21-3
Table 21-3
Feature
IGMP snooping
Multicast routers
Multicast router learning (snooping) method
IGMP snooping Immediate Leave
Static groups
TCN
TCN query solicitation
Cisco IE 3000 Switch Software Configuration Guide
21-6
"Disabling IGMP Report Suppression" section on page
Default IGMP Snooping Configuration, page 21-6
Enabling or Disabling IGMP Snooping, page 21-7
Setting the Snooping Method, page 21-8
Configuring a Multicast Router Port, page 21-9
Configuring a Host Statically to Join a Group, page 21-9
Enabling IGMP Immediate Leave, page 21-10
Configuring the IGMP Leave Timer, page 21-10
Configuring TCN-Related Commands, page 21-11
Configuring the IGMP Snooping Querier, page 21-13
Disabling IGMP Report Suppression, page 21-14
shows the default IGMP snooping configuration.
Default IGMP Snooping Configuration
1
flood query count
Chapter 21 Configuring IGMP Snooping and MVR
Default Setting
Enabled globally and per VLAN
None configured
PIM-DVMRP
Disabled
None configured
2
Disabled
21-14.
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