Allied Telesis AT-S60 - Manual (Page 222)

Chapter 14: IGMP Snooping
Section II: Advanced Features 222
Options 1 through 5 are described 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.
The default is disabled.
2 - Multicast Host Topology
Defines whether there is one host node per switch port or
multiple host nodes per port. Possible settings are Single-
Host/Port (Edge) and Multi-Host/Port (Intermediate).
The Single-Host/Port setting is appropriate when there is only one
host node connected to a port on the switch. With this setting, the
switch immediately stops sending multicast packets from a port
when a host node issues a leave request or when a host node
stops sending reports.
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 where multiple host nodes are
connected. With this setting, the switch continues sending
multicast packets out from 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 from the port.
If a switch has a mixture of host nodes, that is, some connected
directly to the switch and others through another switch or hub,
you should select the Multi-Host Port (Intermediate) selection.
3 - Host/Router Timeout Interval
Specifies the time period, in seconds, after 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
watches for queries from the router. If the switch does not detect
any queries from a multicast router during the specified time
interval, it assumes the router is no longer active on the port.
4 - Maximum Multicast Groups
Specifies the maximum number of multicast groups the switch
learns. The range is 1 to 256 groups. The default is 64 multicast
groups.