hello-option dr-priority (IPv4)

Function

The hello-option dr-priority command configures the priority of the FW that candidates for the Designated Router (DR).

The undo hello-option dr-priority command restores the default priority.

Format

hello-option dr-priority priority

undo hello-option dr-priority

Parameters

Parameter	Description	Value
priority	Specifies the priority of the FW that candidates for the DR. The greater the value, the higher the priority.	The value is an integer ranges from 0 to 4294967295.

Views

PIM view

Default Level

2: Configuration level

Usage Guidelines

By default, the priority of the FW that candidates for the DR is 1.

Usage Scenario

In PIM, FWs on the shared network segment candidates for the DR. The DR is responsible for the registering of the local multicast source and the joining of the receivers.

The DR election is based on the priority and the IP address. To elect the DR, the FWs send the Hello message that contains the priority to each other. The FW with the highest priority functions as the DR. If the FWs have the same priority, the FW with the largest IP address functions as the DR.

If there is at least one FW that does not support Hello packets that contain the priority in the network, the DR election is based on the IP address of each FW. The FW with the largest IP address function as the DR.

The hello-option dr-priority command can be used in the PIM view of a VPN instance to change the priority used by all interfaces in the VPN instance for the DR election.

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 functions in the same way as the pim hello-option dr-priority 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

# In the public network instance, configure the DR priority of a FW to 3.

<sysname> system-view
[sysname] multicast routing-enable
[sysname] pim
[sysname-pim] hello-option dr-priority 3