The spt-switch-threshold command sets the rate threshold of the multicast packets when the DR at the member side joins the SPT.
The undo spt-switch-threshold command restores the default value.
By default, the system performs SPT switchover on receiving the first multicast data packet through the RPT.
spt-switch-threshold { traffic-rate | infinity } [ group-policy { basic-acl6-number } [ order order-value ] ]
undo spt-switch-threshold [ traffic-rate | infinity ] [ group-policy { basic-acl6-number } ]
| Parameter | Description | Value |
|---|---|---|
| traffic-rate | Specifies the threshold rate for the switchover from the RPT to the SPT. NOTE:
Setting this parameter may affect operation of multicast services. You are advised to use the default triggering condition. That is, an SPT switchover is triggered immediately after the first multicast data packet is received from the RPT. The default triggering condition can reduce the number of multicast packets forwarded on the RPT. |
The value is an integer that ranges from 1 to 4194304, in kbit/s. |
| infinity | Indicates that the SPT switchover is never enabled. | - |
| basic-acl6-number | Specifies an entry of the group-policy list. It works with the multicast group that matches basic-acl6-number to enable the threshold. basic-acl6-number specifies the number of the basic ACL that defines the range of multicast groups. | If the parameter is not set, the threshold is applied to all multicast groups. The value ranges from 2000 to 2999. |
| order order-value | Adjusts the order of the ACLs in the group-policy list. If a group matches multiple ACLs, the threshold is selected in the order specified by order-value. order-value specifies the updated number. | The value is an integer. The value is any value other than original one in the current group-policy list. If the parameter is not set, the order of the ACLs in the group-policy list does not change. |
Usage Scenario
The source's DR encapsulates multicast packets in a Register message, and then transmits the unicast Register message to the RP. Then, the RP decapsulates the Register message and forwards the multicast packets to the receivers along the RPT. By default, when the RP or receiver's DR receives the first multicast packet, it initiates an SPT switchover to the source.
After the spt-switch-threshold command is executed on the receiver's DR, the receiver's DR periodically checks the forwarding rate of multicast packets. When the forwarding rate exceeds the threshold, the receiver's DR sends a Join messages to the source, triggering the SPT switchover.
Prerequisites
IPv6 multicast routing has been enabled globally using the multicast ipv6 routing-enable command in the system view.
Configuration Impact
If this command is used several times for the same group, the first matched command takes effect.
This command is valid to all devices that may function as the DR at the member side, but is invalid to RPs.
Precautions
This command is valid for only PIM-SM (IPv6).
# Set the threshold to 4 kbit/s. If the transmission rate of packets from the source to the multicast group is higher than the threshold, the switch switches packets to the SPT towards the source.
<HUAWEI> system-view [HUAWEI] multicast ipv6 routing-enable [HUAWEI] pim-ipv6 [HUAWEI-pim6] spt-switch-threshold 4
# Add a group-policy: the ACL number, rate threshold, and order of the group-policy are 2010, 100 kbit/s, and 1 respectively.
<HUAWEI> system-view [HUAWEI] acl ipv6 2010 [HUAWEI-acl6-basic-2010] rule permit source ff02:: 96 [HUAWEI-acl6-basic-2010] quit [HUAWEI] multicast ipv6 routing-enable [HUAWEI] pim-ipv6 [HUAWEI-pim6] spt-switch-threshold 100 group-policy 2010 order 1