H3C S9500 Series Operation Manual page 371

Operation Manual – Multicast Protocol
H3C S9500 Series Routing Switches
If the corresponding MAC multicast group exists but does not contains the port received
the report message, the switch adds the port into the multicast group and starts the port
aging timer. And then the switch checks if the corresponding IP multicast group exists.
If it does not exist, the switch creates a new IP multicast group and adds the port
received the report message to it. If it exists, the switch adds the port to it.
If the MAC multicast group corresponding to the message exists and contains the port
received the message, the switch will only reset the aging timer of the port.
IGMP leave message: Transmitted from the multicast group member to the
multicast router to notify that a host left the multicast group. When received a leave
message of an IP multicast group, the Ethernet switch transmits the specific query
message concerning that group to the port received the message, in order to
check if the host still has some other member of this group and meanwhile starts a
maximum response timer. If the switch has not receive any report message from
the multicast group after the timer expires, the port will be removed from the
corresponding MAC multicast group. If the MAC multicast group does not have
any member, the switch will notify the multicast router to remove the branch from
the multicast tree.
2.2 IGMP Snooping Configuration
The main IGMP Snooping configuration includes:
Enabling/Disabling IGMP Snooping
Configuring Router Port Aging Time
Configuring Maximum Response Time
Configuring Aging Time of Multicast Group Member Ports
Configuring Unknown Multicast Packets not Broadcasted within a VLAN
Configuring the Filtering Rule of Multicast Groups
Enabling/Disabling IGMP Snooping Fast Leave
Among the above configuration tasks, enabling IGMP Snooping is required, while
others are optional for your requirements.
2.2.1 Enabling/Disabling IGMP Snooping
You can use the following commands to enable/disable IGMP Snooping to control
whether MAC multicast forwarding table is created and maintained on Layer 2.
Perform the following configuration in system view and VLAN view.
Table 2-1 Enabling/Disabling IGMP Snooping
Enable/disable IGMP Snooping
Operation
Chapter 2 IGMP Snooping Configuration
Command
igmp-snooping { enable | disable }
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