Multimedia Traffic Control with IP Multicast (IGMP)
How IGMP Operates
Leave. The Querier will continue to transmit the multicast group during this short time, and because the group is no longer registered the switch will then flood the multicast group to all ports.
On ProCurve switches that do support
Because of the multicast flooding problem mentioned above, the IGMP FastLeave feature is disabled by default on all ProCurve switches that do not support
hpSwitchIgmpPortForceLeaveState.< vid >.< port number>
However, this is not recommended as this will increase the amount of multicast flooding during the period between the client's IGMP Leave and the Querier's processing of that Leave. For more on this topic, refer to “Forced
ProCurve recommends that the following settings be used.
■Use Delayed Group Flush on the Series 2600 switches whenever Fast Leave or Forced Fast Leave are set on a port (see page
■Forced fast leave can be used when there are multiple devices attached to a port.
Automatica.Connected to only one end node
b.The end node currently belongs to a multicast group; i.e. is an IGMP client
c.The end node subsequently leaves the multicast group
Then the switch does not need to wait for the Querier status update interval, but instead immediately removes the IGMP client from its IGMP table and ceases transmitting IGMP traffic to the client. (If the switch detects multiple end nodes on the port, automatic