Allied Telesis AT-S63 - Manual (Page 298)

Chapter 18: IGMP Snooping
298 Section III: IGMP Snooping, MLD Snooping, and RRP Snooping
If a switch has a mixture of host nodes, that is, some connected
directly to the switch and others through an Ethernet hub, you should
select the Multi-Host Port (Intermediate) selection.
3 - Host/Router Timeout Interval
Specifies the time period in seconds at which the switch determines
that a host node is inactive. An inactive host node is a node that has
not sent an IGMP report during the specified time interval. The range
is from 0 second to 86,400 seconds (24 hours). The default is 260
seconds. If you set the timeout to zero (0), the timer never times out,
and the timeout interval is essentially disabled.
This parameter also controls the time interval used by the switch in
determining whether a multicast router is still active. The switch makes
the determination by watching for queries from the router. If the switch
does not detect any queries from a multicast router during the
specified time interval, the router is assumed to be no longer active on
the port.
The actual timeout may be ten seconds less that the specified value.
For example, a setting of 25 seconds can result in the switch
classifying a host node or multicast router as being inactive after just
15 seconds. A setting of 10 seconds or less can result in the
immediate timeout of an inactive host node or router.
4 - Maximum IGMP Multicast Groups
This parameter specifies the maximum number of IGMP multicast
groups the switch can learn. This parameter is useful with networks
that contain a large number of multicast groups. The range is 0 to 255
groups. The default is 64 multicast groups.
Note
The combined number of multicast address groups for IGMP and
MLD snooping cannot exceed 255.
5 - Router Port(s)
Specifies the port on the switch where a multicast router is detected.
You can let the switch determine this automatically by selecting Auto
Detect, or you can specify the port yourself by entering a port number.
You can specify more than one port. To specify all ports, enter ALL. To
specify no ports, enter NONE, To select Auto Detect, enter AUTO.
Note
A change to any parameter in this menu is immediately activated on
the switch.