Asus GigaX2024B - Manual (Page 40)

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GigaX2024B L2 Managed Switch User Manual
4.5.6 IGMP snooping
IGMP snooping helps reduce the multicast traffics on the network by allowing
the IGMP snooping function to be turned on or off.
The first part provides the following settings,
Enable IGMP Snooping: Globally enable IGMP snooping in all existing
VLAN interfaces. By default, IGMP snooping is globally enabled on the
switch. When globally enabled or disabled, it is also enabled or disabled in
all existing VLAN interfaces.
If global snooping is disabled, you cannot enable VLAN snooping. If global
snooping is enabled, you can enable or disable VLAN snooping.
Last Member Query Interval: Without Immediate Leave, when the switch
receives an IGMP leave message from a subscriber on a receiver port, it
sends out an IGMP query on that port and waits for IGMP group membership
reports. If no reports are received in a configured time period, the receiver
port is removed from multicast group membership.
The second part provides the following settings,
Status: If global snooping is enabled, you can enable or disable VLAN
snooping.
Immediate leave: When you enable IGMP Immediate-Leave processing, the
switch immediately removes a port when it detects an IGMP version 2 leave
message on that port. You should use the Immediate-Leave feature only
when there is a single host present on every port in the VLAN. Immediate
Leave is supported with only IGMP version 2 hosts.
However, if the static entries occupy all 256 spaces, the IGMP snoop does not
work normally. The switch only allows 256-layer 2 multicast groups.
Figure 27. IGMP Snooping