Allied Telesis AT-S62 - Manual (Page 207)

AT-S62 User’s Guide
Section II: Advanced Operations 207
The options in the menu are defined below:
1 - IGMP Snooping Status
Enables and disables IGMP snooping on the switch. After selecting
this option, type E to enable or 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. Possible settings are Single-Host/Port
(Edge) and Multiple Host/Ports (Intermediate).
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.
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 will 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 will 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 1 second to 86,400 seconds (24 hours). The default
is 260 seconds.
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the specified time interval, it assumes that the router is no longer
active on the port.