Support Support Downloads Knowledge Base Juniper Support Portal Community

Knowledge Base

Search our Knowledge Base sites to find answers to your questions.

Ask All Knowledge Base Sites All Knowledge Base Sites JunosE Defect (KA)Knowledge BaseSecurity AdvisoriesTechnical BulletinsTechnotes Sign in to display secure content and recently viewed articles

Routing Engine operation and troubleshooting



Article ID: KB11615 KB Last Updated: 22 May 2020Version: 22.0

This article provides an overview of the best practices and tips for operating, monitoring, and troubleshooting Routing Engines.



Click a topic link to view configuration or troubleshooting information related to the RE (Routing Engine):

Administration - Operations / Maintenance / Monitoring

General Supported Routing Engines by Chassis

Note: See right column of the link above for the following:

  • Routing Engine Specifications

  • Understanding Internal Ethernet Interfaces

  • Understanding Management Ethernet Interfaces

Routing Engine Network Operation Guide (NOG)

Command 'show chassis routing-engine' example output:

show chassis routing-engine (View)

KB9475 - Mapping between FRU part numbers and model numbers

KB1529 - What Routing Engine models have shipped with M, MX, and T-series routers?

Storage Media

Different Types of Storage Media in Routing-Engine:

Storage Media and Routing Engines

KB11224 - What do the different Junos file system device (Storage Media) names mean?

Software Maintenance

KB10911 - Understanding Junos software components and installation package names

KB11409 - Upgrading/Downgrading/Reinstalling Junos

KB8911 - Procedure to Upgrade JUNOS on a Dual Routing Engine System

Hard Disk Operations

KB9280   - Perform SMART tests from the CLI

KB13103 - Perform SMART tests from the shell

KB11136 - [M/MX/T-series] How to use the 'iostat' shell command to monitor hard disk activity on a Routing Engine

KB12728 - How to locate files on the hard disk drive that have recently been modified

Compact Flash Operations

KB8201 - How to partition newly installed CF on an RE?

KB11413 - How to upgrade a Routing Engine Compact Flash without losing the configuration?

KB11046 - How to check the CompactFlash for errors?


Recovering Root Password:

Recovering Root Password

KB1971 - Routing Engine temperature thresholds

KB7968 - [Junos] How to copy files from one location to another in a Routing Engine

KB12729 - How to synchronize configuration and settings on a newly installed backup Routing Engine

KB11408 - How to simulate an RE failure in order to test GRES



Hard drive

KB11606 - What happens when the Routing Engine's hard drive fails?

KB10751 - Data to collect when in db> prompt to troubleshoot the Cause

KB19024 - Syslog message: Reboot reason(s): 0x2: watchdog

KB8236 - Syslog Message: smartd[2660]: Device /dev/ad1a, STANDBY source "disk-timer", in STANDBY

KB35685 - [SRX] Troubleshooting major RAID failure alarm in Standalone and Cluster Chassis environment

Compact Flash Issues

KB11324 - ad0: Device does not support APM

Memory Issues

KB1796 - How is memory utilization in the 'show chassis routing-engine' command output calculated?

KB20942 - Things which could increase RE Memory Utilization, except routes



Minimizing Failure Impact

Configuring Routing Engine Redundancy and on-disk failure actions:

Configuring Routing Engine Redundancy

NSR ( Non-Stop Active Routing) 

Nonstop Active Routing Concepts

Note: See right column of above link for Configuring Nonstop Active Routing.

GRES (Graceful Routing-Engine Switchover)

Understanding Graceful Routing Engine Switchover

Note: See right column for of above link for Configuring Graceful Routing Engine Switchover.

High Availability Configuration Guide:

Junos®OS : High Availability Feature Guide

Preventing Failures

KB11607 - Periodic Adaptive Standby for RE hard drive

KB11614 - General guidelines for a good logging and tracing policy


Modification History:

2020-05-21: Article checked for accuracy and validity; links updated; no other changes made


Comment on this article > Affected Products Browse the Knowledge Base for more articles related to these product categories. Select a category to begin.

Getting Up and Running with Junos

Getting Up and Running with Junos Security Alerts and Vulnerabilities Product Alerts and Software Release Notices Problem Report (PR) Search Tool EOL Notices and Bulletins JTAC User Guide Customer Care User Guide Pathfinder SRX High Availability Configurator SRX VPN Configurator Training Courses and Videos End User Licence Agreement Global Search