181Configuring PIM common timersPIM routers discover PIM neighbors and maintain PIM neighboring relationships with other routers byperiodically sending out hello messages.After receiving a hello message, a PIM router waits a random period, which is smaller than the maximumdelay between hello messages, before sending a hello message. This delay avoids collisions that occurwhen multiple PIM routers send hello messages simultaneously.A PIM router periodically sends join/prune messages to its upstream for state update. A join/prunemessage contains the join/prune timeout time. The upstream router sets a join/prune timeout timer foreach pruned downstream interface.Any router that has lost assert election will prune its downstream interface and maintain the assert statefor 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 notimmediately delete the corresponding (S, G) entry. Instead, it maintains the (S, G) entry for a period oftime (namely, the multicast source lifetime) before deleting the (S, G) entry.NOTE:If no special networking requirements are raised, use the default settings.Configuring PIM common timers globallyStep Command Remarks1. Enter system view. system-view N/A2. Enter public network PIM viewor VPN instance PIM view.pim [ vpn-instancevpn-instance-name ] N/A3. Configure the hello interval. timer hello interval Optional.30 seconds by default.4. Configure the join/pruneinterval. timer join-prune interval Optional.60 seconds by default.5. Configure the join/prunetimeout time. holdtime join-prune interval Optional.210 seconds by default.6. Configure assert timeout time. holdtime assert interval Optional.180 seconds by default.7. Configure the multicast sourcelifetime. source-lifetime interval Optional.210 seconds by default.Configuring PIM common timers on an interfaceStep Command Remarks1. Enter system view. system-view N/A
