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Configuring IGMP Snooping and MVR
Information About IGMP Snooping and MVR
IGMP Configurable-Leave Timer
You can configure the time that the switch waits after sending a group-specific query to determine if hosts are still
interested in a specific multicast group. The IGMP leave response time can be configured from 100 to 5000 milliseconds.
The default leave time is 1000 milliseconds. The timer can be set either globally or on a per-VLAN basis. The VLAN
configuration of the leave time overrides the global configuration.
The actual leave latency in the network is usually the configured leave time. However, the leave time
might
vary around
the configured time, depending on real-time CPU load conditions, network delays and the amount of traffic sent through
the interface.
Note:
The IGMP configurable leave time is only supported on hosts running IGMP Version 2.
IGMP Report Suppression
Note:
IGMP report suppression is supported only when the multicast query has IGMPv1 and IGMPv2 reports. This feature
is not supported when the query includes IGMPv3 reports.
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
Disabling IGMP Report Suppression, page 438
.
Default IGMP Snooping Configuration
Snooping Methods
Multicast-capable router ports are added to the forwarding table for every Layer 2 multicast entry. The switch learns of
such ports through one of these methods:
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
TCN
1
flood query count
1.
TCN = Topology Change Notification
2
TCN query solicitation
Disabled
IGMP snooping querier
Disabled
IGMP report suppression
Enabled
Summary of Contents for IE 4000
Page 12: ...8 Configuration Overview Default Settings After Initial Switch Configuration ...
Page 52: ...48 Configuring Interfaces Monitoring and Maintaining the Interfaces ...
Page 108: ...104 Configuring Switch Clusters Additional References ...
Page 128: ...124 Performing Switch Administration Additional References ...
Page 130: ...126 Configuring PTP ...
Page 140: ...136 Configuring CIP Additional References ...
Page 146: ...142 Configuring SDM Templates Configuration Examples for Configuring SDM Templates ...
Page 192: ...188 Configuring Switch Based Authentication Additional References ...
Page 244: ...240 Configuring IEEE 802 1x Port Based Authentication Additional References ...
Page 298: ...294 Configuring VLANs Additional References ...
Page 336: ...332 Configuring STP Additional References ...
Page 408: ...404 Configuring DHCP Additional References ...
Page 450: ...446 Configuring IGMP Snooping and MVR Additional References ...
Page 490: ...486 Configuring SPAN and RSPAN Additional References ...
Page 502: ...498 Configuring Layer 2 NAT ...
Page 770: ...766 Configuring IPv6 MLD Snooping Related Documents ...
Page 930: ...926 Configuring IP Unicast Routing Related Documents ...
Page 976: ...972 Configuring Cisco IOS IP SLAs Operations Additional References ...
Page 978: ...974 Dying Gasp ...
Page 990: ...986 Configuring Enhanced Object Tracking Monitoring Enhanced Object Tracking ...
Page 994: ...990 Configuring MODBUS TCP Displaying MODBUS TCP Information ...
Page 996: ...992 Ethernet CFM ...
Page 1066: ...1062 Using an SD Card SD Card Alarms ...