Configuring state refresh parameters

The router directly connected with the multicast source periodically sends state refresh messages. You can configure the interval for sending such messages on that router.

A router might receive duplicate state refresh messages within a short time. To prevent this situation, you can configure the amount of time that the router must wait before it receives next state refresh message. If the router receives a new state refresh message within the specified waiting time, it discards the message. If this timer times out, the router accepts a new state refresh message, refreshes its own PIM-DM state, and resets the waiting timer.

The TTL value of a state refresh message decrements by 1 whenever it passes a router before it is forwarded to the downstream node. The state refresh message stops being forwarded when the TTL value comes down to 0. A state refresh message with a large TTL value might cycle on a small network. To effectively control the propagation scope of state refresh messages, configure an appropriate TTL value based on the network size on the router directly connected with the multicast source.

To configure state refresh parameters:

Step

Command

Remarks

1. Enter system view.

system-view

N/A

2. Enter PIM view.

pim [ vpn-instance vpn-instance-name ]

N/A

3. Configure the interval to send state refresh messages.

state-refresh-interval interval

The default setting is 60 seconds.

4. Configure the time to wait before receiving a new state refresh message.

state-refresh-rate-limit time

The default setting is 30 seconds.

5. Configure the TTL value of state refresh messages.

state-refresh-ttl ttl-value

The default setting 255.