3Com S7906E - Switch, Configuration Manual

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After the configuration, upon receiving an IGMP message on a user port, Switch A tags the message
with the multicast VLAN ID and relays it to the IGMP querier, so that IGMP Snooping can uniformly
manage the router ports and member ports in the multicast VLAN. When forwarding multicast data to
Switch A, Router A needs to send only one copy of multicast traffic to Switch A in the multicast VLAN,
and Switch A distributes the traffic to all the member ports in the multicast VLAN.
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For information about IGMP Snooping, router ports, and member ports, refer to IGMP Snooping
Configuration in the IP Multicast Volume .
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For information about VLAN tags, refer to VLAN Configuration in the Access Volume .
Multicast VLAN Configuration Task List
Complete the following tasks to configure multicast VLAN:
Task Remarks
Configuring Sub-VLAN-Based Multicast VLAN
Configuring User Port Attributes
Configuring Port-Based
Multicast VLAN
Configuring Multicast VLAN Ports
Required
Use either approach.
Configuring the Maximum Number of Forwarding Entries in a Multicast
VLAN
Optional
If you have configured both sub-VLAN-based multicast VLAN and port-based multicast VLAN on a
device, the port-based multicast VLAN configuration is given preference.
Configuring Sub-VLAN-Based Multicast VLAN
Configuration Prerequisites
Before configuring sub-VLAN-based multicast VLAN, complete the following tasks:
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Create VLANs as required
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Enable IGMP Snooping in the VLAN to be configured as a multicast VLAN