Description

This document explains the meaning of the alarm '​ Mixed Master and Backup RE types ' and provides steps to resolve it.

Symptoms

Active Alarm:

root@host> show chassis alarms no-forwarding
 
1 alarms currently active
Alarm time               Class  Description
2019-07-04 16:08:16 PHT  Minor  Mixed Master and Backup RE types

Error Logs:

Jul 04 16:08:16.476 2019  alarmd[97899]: %DAEMON-4: Alarm set: RE color=YELLOW, class=CHASSIS, reason=Mixed Master and Backup RE types
Jul 04 16:08:16.476 2019  craftd[12011]: %DAEMON-4: Minor alarm set, Mixed Master and Backup RE types

Solution

  1. Primary RE unable to recognize the correct type of Backup RE
  2. Mismatch in hardware types
  3. Mismatch in frequencies of both REs

Verify the RE type by running the commands below:

user@host> show chassis hardware
<snip>
Routing Engine 0          BUILTIN      BUILTIN           RE-MX2008-X8-128G
Routing Engine 1          BUILTIN      BUILTIN           RE-MX2008-X8-128G
<snip>
 
user@host> show chassis routing-engine
Routing Engine status:
  Slot 0:
    Current state                  Master
    Election priority              Master (default)
    Model                          RE-MX2008-X8-128G
    Serial ID                      BUILTIN
  
Routing Engine status:
  Slot 1:
    Current state                  Backup
    Election priority              Backup (default)
    Model                          RE-MX2008-X8-64G   <-- Primary unable to detect correct type of backup RE
    Serial ID                      BUILTIN

Verify Inventory Logs:

Routing Engine 0 REV 11   740-014082   9009003830        RE-A-2000
Routing Engine 1 REV 11   740-026941   P737F-006668      RE-DUO-1800   <-- RE type mismatch

In case the REs are of the same type in inventory logs and the primary RE is unable to detect backup RE, restart the backup RE to check if the alarm clears. This could be due to a transient problem raised during backup RE installation where the primary has not been able to read the correct details of backup RE.

If Primary RE and backup RE are of different types, make sure that both REs are of the same type to avoid this error.

If the RE combination on primary and backup slot is the same, verify the frequencies of both REs.

Verify frequency and CPUs on both REs:

user@host> start shell  <-- On Primary RE
Jun 05 10:40:45
% sysctl kern.smp.cpus
kern.smp.cpus: 4
% sysctl machdep.tsc_freq
machdep.tsc_freq: 2000049172
user@host> request routing-engine login other-routing-engine
Jun 05 10:42:32
Last login: Thu Jun  4 17:18:20 from re0
--- JUNOS 18.1R1.9 Kernel 64-bit  JNPR-11.0-20180308.0604c57_buil
{BACKUP }
user@host> start shell
% sysctl machdep.tsc_freq
machdep.tsc_freq: 2000055948
% sysctl kern.smp.cpus
kern.smp.cpus: 4

As you can see, the above frequencies do not match. This could be a reason for the alarm. In this case, consider upgrading the REs to the latest recommended release. Contact Support to confirm if the release you are trying to upgrade to is suitable for your device.

If the above logs do not help resolve the alarm, please contact Support for assistance.

Modification History

2021-03-25: Updated the article terminology to align with Juniper's Inclusion & Diversity initiatives
2022-09-01: Article reviewed for accuracy; no changes required; article valid and relevant.