3Com WX3000 operation manual Igmp Snooping Configuration Task List

immediately delete the forwarding entry corresponding to that port from the forwarding table; instead, it resets the aging timer of the member port.

Upon receiving the IGMP leave message from a host, the IGMP querier resolves from the message the address of the multicast group that the host just left and sends an IGMP group-specific query to that multicast group through the port that received the leave message. Upon receiving the IGMP group-specific query, a device forwards it through all the router ports in the VLAN and all member ports of that multicast group, and performs the following to the receiving port:

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If any IGMP report in response to the group-specific query arrives to the member port before its aging timer expires, this means that some other members of that multicast group still exist under that port: the device resets the aging timer of the member port.

If no IGMP report in response to the group-specific query arrives to the member port before its aging timer expires as a response to the IGMP group-specific query, this means that no members of that multicast group still exist under the port: the device deletes the forwarding entry corresponding to the port from the forwarding table when the aging timer expires.

After a device enables IGMP Snooping, when it receives the IGMP leave message sent by a host in a multicast group, it judges whether the multicast group exists automatically. If the multicast group does not exist, the device drops this IGMP leave message.

IGMP Snooping Configuration

IGMP Snooping Configuration Task List

Complete the following tasks to configure IGMP Snooping:

Operation	Remarks
Enabling IGMP Snooping	Required
Configuring the Version of IGMP Snooping	Optional
Configuring Timers	Optional
Configuring Fast Leave Processing	Optional
Configuring a Multicast Group Filter	Optional
Configuring the Maximum Number of Multicast Groups on a Port	Optional
Configuring IGMP Querier	Optional
Suppressing Flooding of Unknown Multicast Traffic in a VLAN	Optional
Configuring Static Member Port for a Multicast Group	Optional
Configuring a Static Router Port	Optional
Configuring a Port as a Simulated Group Member	Optional

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