Multimedia Traffic Control with IP Multicast (IGMP)

More on IGMP Operation

Forced Fast-Leave IGMP

Forced Fast-Leave IGMP Features

Feature

Default

Menu

CLI

Web

view the Forced Fast-Leave configuration

 

 

 

 

view the switch’s Forced Fast-Leave state

n/a

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configure Forced Fast-Leave

 

 

 

 

configure Forced Fast-Leave for an individual port

2 (disabled)

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Forced Fast-Leave IGMP speeds up the process of blocking unnecessary IGMP traffic to a switch port that is connected to multiple end nodes. (This feature does not activate on ports where the switch detects only one end node.

Instead, the regular Fast Leave described in the preceding section activates.) For example, in figure 12-6,even if you configured Forced Fast-Leave on all ports in the switch, the feature would activate only on port 7 (which has multiple end nodes) when a Leave Group request arrived on that port.

When a port having multiple end nodes receives a Leave Group request from one end node for a given multicast group “X”, Forced Fast-Leave activates and waits a small amount of time to receive a join request from any other group “X” member on that port. If the port does not receive a join request for that group within the forced-leave interval, the switch then blocks any further group “X” traffic to the port.

Configuration Options for Forced Fast-Leave

Feature

Default

Settings

Function

Forced Fast-

2 (disabled)

1

(enabled)

Uses the setmib command to enable or disable Forced Fast-Leave on

Leave state

 

2

(disabled)

individual ports. When enabled on a port, Forced Fast-Leave operates only if

 

 

 

 

the switch detects multiple end nodes (and at least one IGMP client) on that

port.

Listing the Forced Fast-Leave Configuration. The Forced Fast-Leave configuration includes the state (enabled or disabled) for each port and the Forced-Leave Interval for all ports on the switch.

To list the Forced Fast-Leave state for all ports in the switch:

Syntax: HPswitch# walkmib hpSwitchIgmpPortForcedLeaveState.1

or

HPswitch# walkmib 1.3.6.1.4.1.11.2.14.11.5.1.7.1.15.3.1.5.1

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