Users Guide

Example of Configuration Output After Removing a Group-Port Association
Dell(conf-if-vl-100)#show config
!
interface Vlan 100
no ip address
ip igmp snooping fast-leave
shutdown
Dell(conf-if-vl-100)#
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 interface interface
– For a 10-Gigabit Ethernet interface, enter the keyword TenGigabitEthernet then the slot/port information.
– For a 40-Gigabit Ethernet interface, enter the keyword fortyGigE then the slot/port information.
– For a Port Channel interface, enter the keywords portchannel then a number.
• 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 so there is no querier. Configure the
switch to be the querier for a VLAN so that hosts send membership reports and the switch can generate a forwarding table by
snooping.
• Configure the switch to be the querier for a VLAN by first assigning an IP address to the VLAN interface.
INTERFACE VLAN mode
ip igmp snooping querier
IGMP snooping querier does not start if there is a statically configured multicast router interface in the VLAN.
Internet Group Management Protocol (IGMP) 407