Enhancements

With the CLI, you can configure these additional options:
Auto/blocked/forward
You can use the console to configure individual ports to any of the following states:
Auto

(Default) Causes the switch to interpret IGMP packets and to filter IP multicast traffic based on the IGMP packet information for ports belonging to a multicast group. This means that IGMP traffic will be forwarded on a specific port only if an IGMP host or multicast router is connected to the port.

Blocked

Causes the switch to drop all IGMP transmissions received from a specific port, and also blocks all outgoing IP Multicast packets for that port, thus preventing IGMP traffic from moving through specific ports.

Forward

Causes the switch to forward all IGMP and multicast transmissions through the port.

Operation with or without IP addressing

This feature helps to conserve IP addresses by enabling IGMP to run on VLANs that do not have an IP address. See Operation with or without IP addressing. This is also referred as IGMP Snooping.

Querier capability

The switch performs querier function for IGMP on VLANs having an IP address when there is no other device in the VLAN acting as querier. See Using the switch as querier.

To configure high priority settings for traffic, see “Quality of Service: managing bandwidth more effectively” in the Advanced Traffic Management Guide.

NOTE:

Whenever IGMP is enabled, the switch generates an Event Log message only after the querier election.

IP multicast traffic groups are identified by IP addresses in the range of 224.0.0.0 to 239.255.255.255. Also, incoming IGMP packets intended for reserved, or "well-known" multicast addresses, automatically flood through all ports (except the port on which the packets entered the switch). For more on this topic, see Well-known or reserved multicast addresses excluded from IP multicast filtering

For more information about IGMP, see How IGMP operates.