Important Points to Remember for IGMPQuerier• The IGMP snooping Querier supports version 2.• You must configure an IP address to the VLAN interface for IGMP snooping Querier to begin. The IGMPsnooping Querier disables itself when a VLAN IP address is cleared, and then it restarts itself when an IPaddress is reassigned to the VLAN interface.• When enabled, IGMP snooping Querier does not start if there is a statically configured multicast routerinterface in the VLAN.• When enabled, IGMP snooping Querier starts after one query interval in case no IGMP general query(with IP SA lower than its VLAN IP address) is received on any of its VLAN members.• When enabled, IGMP snooping Querier periodically sends general queries with an IP source address ofthe VLAN interface. If it receives a general query on any of its VLAN member, it checks the IP sourceaddress of the incoming frame.If the IP SA in the incoming IGMP general query frame is lower than the IP address of the VLAN interface,the switch disables its IGMP snooping Querier functionality.If the IP SA of the incoming IGMP general query is higher than the VLAN IP address, the switch continuesto work as an IGMP snooping Querier.clear ip igmp snooping groupsClear snooping entries from the group cache table.C9000 SeriesSyntax clear ip igmp snooping groups [group-address interface |interface]Parameters group-address (OPTIONAL) Enter the IP multicast group address in dotteddecimal format.interface interface Enter the following keywords and slot/port or numberinformation:• For a 1-Gigabit Ethernet interface, enter the keywordGigabitEthernet then the slot/port information.• For a 10-Gigabit Ethernet interface, enter the keywordTenGigabitEthernet then the slot/port information.• For a 40-Gigabit Ethernet interface, enter the keywordfortyGigE then the slot/port information.• For a port channel interface, enter the keywords port-channel then a number.Command Modes EXECInternet Group Management Protocol (IGMP) 1143
