H3C Technologies H3C S7500E Series Switches - Manual (Page 177)

6-40
To do... Use the command... Remarks
Configure the interface to reject
hello messages without a
generation ID
pim require-genid
Required
By default, hello messages
without Generation_ID are
accepted
Configuring the Prune Delay
If a downstream router does not support the prune override interval field, you can configure a
prune delay interval on the upstream router so that it will not perform the prune action
immediately after receiving the prune message; instead, it maintains the current forwarding
state for the prune delay interval. In this period, if the upstream router receives a join message
from the downstream router, it cancels the prune action.
Follow these steps to configure the prune delay time
To do... Use the command... Remarks
Enter system view system-view —
Enter public instance PIM view
or VPN instance PIM view
pim [ vpn-instance
vpn-instance-name ]
—
Configure the prune delay
interval
prune delay interval
Optional
3 seconds by default
Configuring PIM Common Timers
PIM routers discover PIM neighbors and maintain PIM neighboring relationships with other
routers by periodically sending out hello messages.
Upon receiving a hello message, a PIM router waits a random period, which is smaller than the
maximum delay between hello messages, before sending out a hello message. This avoids
collisions that occur when multiple PIM routers send hello messages simultaneously.
A PIM router periodically sends join/prune messages to its upstream for state update. A
join/prune message contains the join/prune timeout time. The upstream router sets a join/prune
timeout timer for each pruned downstream interface.
Any router that has lost assert election will prune its downstream interface and maintain the
assert state for a period of time. When the assert state times out, the assert losers will resume
multicast forwarding.
When a router fails to receive subsequent multicast data from multicast source S, the router
does not immediately delete the corresponding (S, G) entry; instead, it maintains the (S, G)
entry for a period of time, namely the multicast source lifetime, before deleting the (S, G) entry.
Configuring PIM common timers globally
Follow these steps to configure PIM common timers globally: