Allied Telesis AT-S63 - Manual (Page 221)

AT-S63 Management Software Web Browser Interface User’s Guide
Section II: Advanced Operations 221
reports and times out. The switch forwards the leave request to the
router and simultaneously ceases transmission of any further multicast
packets out the port where the host node is connected.
The Intermediate (Multi-Host) setting is appropriate if there is more
than one host node connected to a switch port, such as when a port is
connected to an Ethernet hub to which multiple host nodes are
connected. With this setting selected the switch continues sending
multicast packets out a port even after it receives a leave request from
a host node on the port. This ensures that the remaining active host
nodes on the port continue to receive the multicast packets. Only after
all of the host nodes connected to a switch port have transmitted leave
requests (or have timed out) does the switch stop sending multicast
packets out the port.
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 Intermediate Multi-Host Port selection.
Multicast Router Ports Mode
Specifies whether the router ports are determined automatically or if
you enter them manually. If you want the switch to determine the ports
automatically, select Auto-Detect, which is the default. To enter them
yourself, click Manual Select and enter the ports in the field.
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specified time interval, the router is assumed to be no longer active on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 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.
Maximum Multicast Groups
Specifies the maximum number of multicast groups the switch learns.
The range is 1 to 255 groups. The default is 64 multicast groups.
This setting is useful with networks that contain a large number of
multicast groups. You can use the parameter to prevent the switch’s