hello-option override-interval (IPv4)

Function

The hello-option override-interval command sets the interval for overriding the prune action in a Hello message.

The undo hello-option override-interval command restores the default interval.

Format

hello-option override-interval interval

undo hello-option override-interval

Parameters

Parameter	Description	Value
interval	Specifies the interval for overriding the prune action in a Hello message.	The value is an integer that ranges from 1 to 65535, in milliseconds.

Views

PIM view

Default Level

2: Configuration level

Usage Guidelines

By default, the interval for overriding the prune action in a Hello message is 2500 ms.

Usage Scenario

Hello messages sent by FWs carry lan-delay and override-interval. The override-interval parameter refers to the period during which a downstream FW overrides the prune action.

When one FW sends a Prune message to the upstream FW in the same network segment, if other FW still requests the multicast data, it needs to send a Join message to the upstream FW in the override-interval period.

When the values of override-interval on all FWs on the same link are different, the maximum value of these values is used.

The value of PPT is obtained by the value of lan-delay plus the value of override-interval. When receiving a Prune message from a downstream interface, the FW does not perform the prune action until the PPT times out. If the FW receives a Join message from the downstream interface in PPT, the interface cancels the Prune action.

The hello-option override-interval command can be used in the PIM view of a VPN instance to change the interval at which the prune action is overridden on all the interfaces in the VPN instance.

Prerequisites

The multicast routing-enable command has been run.

Configuration Impact

This command is cyclical in nature. That is, the latest command overwrites the previous one, and takes effect.

Precautions

This command is valid for PIM-SM and PIM-DM.

This command functions in the same way as the pim hello-option override-interval command in the interface view, except for the view. By default, if the configuration on the interface is not done, the value configured in the PIM view is used; otherwise, the value configured in the interface view is used.

Example

# Set the interval for denying the prune action in a Hello message to 2000ms.

<sysname> system-view
[sysname] multicast routing-enable
[sysname] pim
[sysname-pim] hello-option override-interval 2000