3Com 4510G - Protocols and Standards; IGMP Snooping Configuration Task List

2-5
Upon receiving the IGMP leave message from a host, the IGMP querier resolves the multicast group
address in the message 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, the switch
forwards it through all its router ports in the VLAN and all member ports for that multicast group, and
performs the following to the port on which it received the IGMP leave message:
z If any IGMP report in response to the group-specific query is received on the port (suppose it is a
dynamic member port) before its aging timer expires, this means that some host attached to the
port is receiving or expecting to receive multicast data for that multicast group. The switch resets
the aging timer of the port.
z If no IGMP report in response to the group-specific query is received on the port before its aging
timer expires, this means that no hosts attached to the port are still listening to that group address:
the switch removes the port from the outgoing port list of the forwarding table entry for that
multicast group when the aging timer expires.
Protocols and Standards
IGMP Snooping is documented in:
z RFC 4541: Considerations for Internet Group Management Protocol (IGMP) and Multicast
Listener Discovery (MLD) Snooping Switches
IGMP Snooping Configuration Task List
Complete these tasks to configure IGMP Snooping:
Task Remarks
Enabling IGMP Snooping Required
Configuring Basic Functions
of IGMP Snooping
Configuring the Version of IGMP Snooping Optional
Configuring Aging Timers for Dynamic Ports Optional
Configuring Static Ports Optional
Configuring Simulated Joining Optional
Configuring IGMP Snooping
Port Functions
Configuring Fast Leave Processing Optional
Enabling IGMP Snooping Querier Optional
Configuring IGMP Queries and Responses Optional
Configuring IGMP Snooping
Querier
Configuring Source IP Address of IGMP Queries Optional
Configuring a Multicast Group Filter Optional
Configuring Multicast Source Port Filtering Optional
Configuring the Function of Dropping Unknown
Multicast Data
Optional
Configuring IGMP Report Suppression Optional
Configuring Maximum Multicast Groups that Can
Be Joined on a Port
Optional
Configuring an IGMP
Snooping Policy
Configuring Multicast Group Replacement Optional