The spt-switch-threshold infinity command configures a DR on the group member side never to trigger an SPT switchover.
The undo spt-switch-threshold infinity command restores the default configuration.
By default, a receiver's DR performs a switchover from the RPT to the SPT immediately after receiving the first multicast data packet.
Usage Scenario
In PIM-SM, a source's DR encapsulates multicast data packets in a Register message and sends the Register message to the rendezvous point (RP). The RP then transmits the multicast data packets along the RPT. The RP and the receiver's DR are responsible for checking the rate of multicast data packets.
If a rate threshold is configured on the receiver's DR, the receiver's DR sends a Join message to the source only it finds that the rate of multicast data packets exceeds the threshold and then triggers the switchover from the RPT to the SPT. To set such a rate threshold, run the spt-switch-threshold command. This command takes effect on the Router that functions as the receiver's DR, but does not take effect on the RP.Prerequisites
The multicast routing function has been enabled using the multicast ipv6 routing-enable command in the public network instance view.
Precautions
If the spt-switch-threshold command is run more than once for one multicast group, the first command that the multicast group matches takes effect.