Allied Telesis AT-S62 - Manual (Page 325)

AT-S62 Management Software Menus Interface User’s Guide
Section II: Advanced Operations 325
security by restricting the flow of multicast packets only to those switch
ports connected to host nodes.
Without IGMP snooping a switch would have to flood multicast packets out
all of its ports, except the port on which it received the packet. Such
flooding of packets can negatively impact switch and network
performance.
The AT-8500 Series switch maintains its list of multicast groups through an
adjustable timeout value, which controls how frequently it expects to see
reports from end nodes that want to remain members of multicast groups,
and by processing leave requests.
Note
The default setting for IGMP snooping on the switch is disabled.