(Optional) Configuring the SPT Switchover Condition
Context
A high volume of multicast data traffic increases the load of a rendezvous point (RP) and may result in a fault. The designated router (DR) at the receiver side can trigger an SPT switchover to reduce the burden of the RP.
By default, a receiver DR triggers an SPT switchover immediately after receiving the first multicast data packet from the rendezvous point tree (RPT). You can configure a receiver DR to trigger an SPT switchover when the traffic rate exceeds a threshold or disable it from triggering SPT switchovers.
Setting the traffic rate threshold for triggering an SPT switchover may affect the operation of multicast services. The default triggering condition is recommended because it can reduce the number of multicast packets forwarded on the RPT.
Default Settings
Table 1 lists the default settings of SPT switchover conditions.
| Parameter | Default Setting |
|---|---|
Group policy that specifies the groups to which the SPT switchover conditions apply |
No group policy configured (The SPT switchover conditions apply to all multicast groups.) |
Interval for checking the multicast data forwarding rate |
15s |
Procedure
- Run system-view
The system view is displayed.
- Run pim [ vpn-instance vpn-instance-name | all-instance ]
The PIM view is displayed.
- Run spt-switch-threshold { traffic-rate | infinity } [ group-policy basic-acl-number [ order order-value ] ]
The SPT switchover condition is configured.
traffic-rate specifies the rate threshold that triggers an SPT switchover. infinity indicates that the SPT switchover is never triggered.
- Run timer spt-switch interval
The interval for checking the multicast data forwarding rate is set.