Allied Telesis AT-S63 - Manual (Page 355)

AT-S63 Management Software Menus Interface User’s Guide
Section II: Advanced Operations 355
3. Adjust the following parameters as necessary:
1 - IGMP Snooping Status
Enables or disables IGMP snooping on the switch. After you choose
this selection, type E to enable to D to disable this feature.
2 - Multicast Host Topology
Defines whether there is only one host node per switch port or multiple
host nodes per port. The possible settings are:
Single-Host/Port (Edge)
The Single-Host/Port setting is appropriate when there is only one host
node connected to each port on the switch. This setting causes the
switch to immediately stop sending multicast packets out a switch port
when a host node signals its desire to leave a multicast group by
sending a leave request or when the host node stops sending reports.
The switch responds by immediately ceasing the transmission of
additional multicast packets out the port where the host node is
connected.
Multiple Host/Ports (Intermediate)
The 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 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 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 has become 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 specifies 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, it assumes that the router is no longer active on
the port.
When you select a value for this parameter, it is important to note that
the value you enter actually defines the approximate mid-point of a