Description

A yellow alarm LED remains after an FPC in the Backup or Linecard role joins the virtual chassis (VC), but no reason for the alarm is given.

This article illustrates the issue and gives solutions for each scenario.

 

Symptoms

On EX/QFX virtual chassis, LED alarm remains yellow when an FPC in Backup or Linecard role joins the VC, but there is no alarm shown in output of show system alarms or show chassis alarms commands.

 

Solution

Linecard joins the VC

In this example, FPC0 is working as the Primary and FPC1 joins the VC as Linecard.

  1. Before FPC1 joins the VC, yellow alarm LED is on due to missing Rescue config.

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  1. FPC1 joins the VC as Linecard, but yellow alarm LED remains on. No alarm is shown in output of CLI command show system alarms . 
root@QFX5100-2> show system alarms
No alarms currently active

root@QFX5100-2> show chassis led
                LED status for: FPC 0
                -----------------------------------
LEDs status:
    Alarm LED : Off
    System LED: Green Blinking
    Master LED: Green
    Beacon LED: Off

                LED status for: FPC 1
                -----------------------------------
LEDs status:
    Alarm LED : Yellow
    System LED: Green Blinking
    Master LED: Green Blinking
    Beacon LED: Off

When that chassis joins the VC and assumes the Linecard role, alarmd on Linecard will be exited, but yellow LED remains on. However, the primary chassis does not know why the yellow LED is on. That is why there are no alarms shown in output. ​

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  1. When rebooting FPC1, alarmd will not run, as it is in the Linecard role.

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  1. No yellow alarm shows on FPC1 after it joins the VC again.

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Backup joins the VC

In this example, FPC0 is working as the Primary and FPC1 joins the VC as Backup.​

  1. Before FPC1 joins the VC, a yellow LED alarm is on due to a missing Rescue configuration.

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  1. FPC1 joins the VC as Backup but the yellow LED alarm remains on. No alarm is shown in the output of the CLI command  show system alarms .​ 

root@QFX5100-2> show system alarms
No alarms currently active

root@QFX5100-2> show chassis led
                LED status for: FPC 0
                -----------------------------------
LEDs status:
    Alarm LED : Off
    System LED: Green Blinking
    Master LED: Green
    Beacon LED: Off

                LED status for: FPC 1
                -----------------------------------
LEDs status:
    Alarm LED : Yellow
    System LED: Green Blinking
    Master LED: Green Blinking
    Beacon LED: Off

When that chassis joins the VC and assumes the Backup role, alarmd on Backup will not be exited. However, EX/QFX  does not support an  alarmd sync function between Primary and Backup. Therefore, the Primary chassis does not know why the yellow LED is on, and that is why there are no alarms showing in the CLI command output. 

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  1. When rebooting FPC1, alarmd will not run while it is in the Linecard role, but it will be running once it assumes the Backup role. At that time, it will detect the missing rescue configuration.

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  1. The yellow alarm on FPC1 will remain on though it joins the VC again.

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FPC in Linecard role

  • Reboot the linecard to remove alarm LED.

FPC in Backup role

  • Use command request system configuration rescue save on the Primary FPC to save a rescue configuration on Backup as well. 

  • Yellow alarm LED on Backup FPC will be removed. 

 

Modification History

2021-04-07: Updated the article terminology to align with Juniper's Inclusion & Diversity initiatives
2020-03-19: Article reviewed for accuracy; no changes required