Allied Telesis AT-S39 - Manual (Page 320)

Section III: Web Browser Management
320
This parameter is useful with networks that contain a large
number of multicast groups. You can use the parameter to
prevent the switch’s MAC address table from filling up with
multicast addresses, leaving no room for dynamic or static MAC
addresses. The range is 1 address to 2048 addresses. The default is
256 multicast addresses.
Multicast Router Port(s)
Specifies the port on the switch to which the multicast router is
detected. You can let the switch determine this automatically by
selecting Auto Detect, or you can specify the port yourself by
clicking on the ports in the graphical image. A white port indicates
a multicast router port.
By default, the switch automatically detects the presence of
multicast routers by watching for queries on its ports. Once it has
received a query, it notes the port on which the query was
received and identifies the port as a multicast port.
If desired, you can deactivate the auto-detection of multicast
routers and indicate the multicast router ports yourself. To
deactivate the auto-detection, click on the Auto Detect check
box. If the check box is empty, auto-detect is deactivated.
To indicate the multicast router ports manually, use the graphical
image of the switch. Clicking a port toggles it to white, indicating
that the port is connected to a multicast router.
5. After setting the IGMP parameters, click Apply.