White Papers

Table Of Contents
Configuring the Switch as Querier
Dell(conf)#ip igmp snooping enable
Dell(conf)#do show running-config igmp
ip igmp snooping enable
Dell(conf)#
Removing a Group-Port Association
To configure or view the remove a group-port association feature, use the following commands.
Configure the switch to remove a group-port association after receiving an IGMP Leave message.
INTERFACE VLAN mode
ip igmp fast-leave
View the configuration.
INTERFACE VLAN mode
show config
DellEMC(conf-if-vl-100)#show config
!
interface Vlan 100
no ip address
ip igmp snooping fast-leave
shutdown
DellEMC(conf-if-vl-100)#
Enabling IGMP Immediate-Leave
If the querier does not receive a response to a group-specific or group-and-source query, it sends another (querier robustness
value). Then, after no response, it removes the group from the outgoing interface for the subnet.
IGMP immediate leave reduces leave latency by enabling a router to immediately delete the group membership on an interface
after receiving a Leave message (it does not send any group-specific or group-and-source queries before deleting the entry).
Configure the system for IGMP immediate leave.
ip igmp immediate-leave
View the enable status of the IGMP immediate leave feature.
EXEC Privilege mode
show ip igmp interface
View the enable status of this feature using the command from EXEC Privilege mode, as shown in the example in Selecting an
IGMP Version.
Disabling Multicast Flooding
If the switch receives a multicast packet that has an IP address of a group it has not learned (unregistered frame), the switch
floods that packet out of all ports on the VLAN.
When you configure the no ip igmp snooping flood command, the system drops the packets immediately. The system
does not forward the frames on mrouter ports, even if they are present. Disable Layer 3 multicast (no ip multicast-
routing) in order to disable multicast flooding.
Configure the switch to only forward unregistered packets to ports on a VLAN that are connected to mrouter ports.
CONFIGURATION mode
no ip igmp snooping flood
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Internet Group Management Protocol (IGMP)