The hello-option lan-delay command sets the delay in transmitting Prune message on the shared network segment.
The undo hello-option lan-delay command restores the default delay.
By default, the delay in transmitting Prune message on the shared network segment is 500 milliseconds.
| Parameter | Description | Value |
|---|---|---|
| interval | Specifies the delay in transmitting Prune message on the shared network segment. | The value is an integer that ranges from 1 to 32767, in milliseconds (ms). |
Usage Scenario
Hello messages sent switches carry lan-delay and override-interval values. The lan-delay parameter indicates the delay in transmitting messages in the LAN. If devices on the same link have different lan-delay values, the maximum value is used.
When a switch sends a Prune message to the upstream device in the same network segment, the other devices that still request multicast data need to send a Join message to the upstream device within the override-interval period.
The value of the Prune-Pending Timer (PPT) is the sum of lan-delay and override-interval values and refer to the delay from the current device receiving a Prune message from the downstream interface to performing the prune action. If the switch receives a Join message from the downstream interface before the PPT timer expires, it cancels the prune action.
Prerequisites
IPv6 multicast routing has been enabled using the multicast ipv6 routing-enable command in the system view.
Precautions
If the delay in transmitting Prune message is too short, the upstream device will stop forwarding multicast packets before the downstream device determines whether to override the Prune action or not. Exercise caution when you run the hello-option lan-delay command.
The hello-option lan-delay command has the same function as the pim ipv6 hello-option lan-delay command in the interface view. By default, if the pim ipv6 hello-option lan-delay command is not used, the value configured in the PIM-IPv6 view is used; otherwise, the value configured in the interface view is used.