HP 3500YL - Manual (Page 136)

PIM-SM (Sparse Mode)
Configuring PIM-SM on the Router
Enabling or Disabling LAN Prune Delay
Syntax: [no] ip pim-sparse lan-prune-delay
[no] vlan < vid > ip pim-sparse lan-prune-delay
Enables the LAN Prune Delay option on the current VLAN.
With
lan-prune-delay enabled, the router informs
downstream neighbors how long it will wait before pruning
a flow after receiving a prune request. Other, downstream
routers on the same VLAN must send a Join to override the
prune before the
lan-prune-delay time if they want the flow to
continue. This prompts any downstream neighbors with
multicast receivers continuing to belong to the flow to reply
with a Join. If no Joins are received after the
lan-prune-delay
period, the router prunes the flow. The propagation-delay and
override-interval settings (below) determine the lan-prune­
delay setting.
Uses the
no form of the command to disable the LAN Prune
Delay option.
(Default: Enabled.)
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