Igmp-Snooping Fast-Leave - 3Com Switch 4500 Family Manual

Although both Layer 2 and Layer 3 multicast protocols can run on the same switch simultaneously,
they cannot run simultaneously in the same VLAN and on the corresponding VLAN interface.
Before enabling IGMP Snooping in a VLAN, be sure to enable IGMP Snooping globally in system
view; otherwise the IGMP Snooping setting will not take effect.
If IGMP Snooping and VLAN VPN are enabled on a VLAN at the same time, IGMP queries are
likely to fail to pass the VLAN. You can solve this problem by configuring VLAN tags for the IGMP
queries. For details, see
Examples
# Enable the IGMP Snooping feature on the switch.
<Sysname>system-view
System View: return to User View with Ctrl+Z.
[Sysname] igmp-snooping enable
Enable IGMP-Snooping ok.

igmp-snooping fast-leave

Syntax
igmp-snooping fast-leave [ vlan vlan-list ]
undo igmp-snooping fast-leave [ vlan vlan-list ]
View
System view, Ethernet port view
Parameters
vlan vlan-list: Specifies a VLAN list. With the vlan-list argument, you can provide one or more individual
VLAN IDs (in the form of vlan-id) and/or one or more VLAN ID ranges (in the form of vlan-id1 to vlan-id2,
where vlan-id2 must be greater than vlan-id1). The effective range for a VLAN ID is 1 to 4094 and the
total number of individual VLANs plus VLAN ranges cannot exceed 10.
Description
Use the igmp-snooping fast-leave command to enable fast leave processing.
With this function enabled, when the switch receives an IGMP leave message on a port, it directly
removes that port from the forwarding table entry for the specific group.
Use the undo igmp-snooping fast-leave command to disable fast leave processing.
By default, fast leave processing is disabled.
igmp-snooping vlan-mapping.
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