(Optional) Modifying State-Refresh control parameters

This section describes how to modify State-Refresh control parameters. You can configure the interval at which State-Refresh messages are sent, the timeout period for receiving the next State-Refresh message, and the TTL of State-Refresh messages.

Context

On a PIM-DM network, the periodic flooding-pruning wastes lots of network resources. To avoid that the pruned interface is restored to forward packets because the Prune timer expires, you can enable the NetEngine 8000 F to send State-Refresh messages periodically, refresh the Prune state of the interfaces, and maintain the SPT. The NetEngine 8000 F allows you to modify the State-Refresh parameters according to the network environment. If there is no special requirement, the default value is recommended.

Procedure

Run system-view
The system view is displayed.
Run pim
The PIM view is displayed.
Run state-refresh-interval interval
The interval at which the router sends State-Refresh messages is configured.
- This command applies to the first hop router closest to the multicast source.
- The interval at which Status-Refresh messages are sent must be shorter than the expiration time of the Prune state. You can run the holdtime join-prune command to configure the expiration time of the Prune state.
Run state-refresh-rate-limit interval
The timeout period for receiving the next State-Refresh message is configured.
On a PIM-DM network, it is possible for a router to receive State-Refresh messages from more than one router. Some of these messages are duplicate. When a router with the state-refresh-rate-limit command configuration receives the first State-Refresh message, it immediately resets the Prune timer and starts the State-Refresh timer. The lifetime of the State-Refresh timer is equal to the timeout period for receiving the next State-Refresh message.
- Before the timer expires, the router discards the repeated State-Refresh messages it receives.
- After the State-Refresh timer times out, the router is allowed to receive the next State-Refresh message.
Run state-refresh-ttl ttl-value
The TTL of State-Refresh messages to be sent is configured.

On a PIM-DM network, the router deducts 1 from the TTL of a received State-Refresh message, and then sends the message to the downstream device. When the TTL is decreased to 0, the message is not forwarded. On a small-scale network, State-Refresh messages are transmitted circularly on the network. You can modify the TTL according to the network scale by running the state-refresh-ttl command.

This command takes effect only on the router directly connected to the multicast source.
Run commit
The configuration is committed.