HP procurve 2500 Manuale Utente

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Operation and Enhancements for Multimedia Traffic Control (IGMP)

Forced Fast-Leave IGMP

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 105, 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

CLI: 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:

HP2512# walkmib hpSwitchIgmpPortForcedLeaveState.1
or
HP2512# walkmib 1.3.6.1.4.1.11.2.14.11.5.1.7.1.15.3.1.5.1

   view the switch’s Forced Fast-Leave state

n/a

    —

    —

   configure Forced Fast-Leave for an individual port

2 (disabled)

    —

    —

Forced Fast-
Leave state

2 (disabled) 1 (enabled)

2 (disabled)

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