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Example: Controlling OSPF Designated Router Election

This example shows how to control OSPF designated router election.

Requirements

Before you begin:

Overview

This example shows how to control OSPF designated router election. Within the example, you set the OSPF interface to ge-/0/0/1 and the device priority to 200. The higher the priority value, the greater likelihood the routing device will become the designated router.

By default, routing devices have a priority of 128. A priority of 0 marks the routing device as ineligible to become the designated router. A priority of 1 means the routing device has the least chance of becoming a designated router.

Configuration

CLI Quick Configuration

To quickly configure an OSPF designated router election, copy the following command and paste it into the CLI.

[edit] set protocols ospf area 0.0.0.3 interface ge-0/0/1 priority 200

Step-by-Step Procedure

To control OSPF designated router election:

  1. Configure an OSPF interface and specify the device priority.

    Note: To specify an OSPFv3 interface, include the ospf3 statement at the [edit protocols] hierarchy level.

    [edit]user@host# set protocols ospf area 0.0.0.3 interface ge-0/0/1 priority 200
  2. If you are done configuring the device, commit the configuration.
    [edit]user@host# commit

Results

Confirm your configuration by entering the show protocols ospf command. If the output does not display the intended configuration, repeat the instructions in this example to correct the configuration.

user@host# show protocols ospf
area 0.0.0.3 { interface ge-0/0/1.0 {priority 200; }}

To confirm your OSPFv3 configuration, enter the show protocols ospf3 command.

Verification

Confirm that the configuration is working properly.

Verifying the Designated Router Election

Purpose

Based on the priority you configured for a specific OSPF interface, you can confirm the address of the area’s designated router. The DR ID, DR, or DR-ID field displays the address of the area’s designated router. The BDR ID, BDR, or BDR-ID field displays the address of the backup designated router.

Action

From operational mode, enter the show ospf interface and the show ospf neighbor commands for OSPFv2, and enter the show ospf3 interface and the show ospf3 neighbor commands for OSPFv3.

Published: 2014-10-01