Reference Guide

shutdown
Dell(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
Specifying a Port as Connected to a Multicast Router
To statically specify or view a port in a VLAN, use the following commands.
• Statically specify a port in a VLAN as connected to a multicast router.
INTERFACE VLAN mode
ip igmp snooping mrouter
• View the ports that are connected to multicast routers.
EXEC Privilege mode.
show ip igmp snooping mrouter
Configuring the Switch as Querier
To configure the switch as a querier, use the following command.
Hosts that do not support unsolicited reporting wait for a general query before sending a membership
report. When the multicast source and receivers are in the same VLAN, multicast traffic is not routed and
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Internet Group Management Protocol (IGMP)