How to Troubleshoot Error Conditions

You have troubleshooting resources available through Junos OS alarm messages and LED indicators. You can use these links to discover what these alarms and indicators mean when an error occurs.

To troubleshoot a the router, you use the Junos OS CLI, alarms, and LEDs on the network ports, management panel of the Routing Control Board (RCB), and components.

• LEDs—When the Routing Engine detects an alarm condition, it lights the red or yellow alarm LED on the management panel as appropriate. In addition, you can use component LEDs and network port LEDs to troubleshoot the router.

• CLI—The CLI is the primary tool used to flow and troubleshoot hardware, Junos OS, routing protocols, and network connectivity. CLI commands display information from routing tables, information specific to routing protocols, and information about network connectivity derived from the ping and traceroute utilities. For information about using the CLI to troubleshoot Junos OS, see the appropriate Junos OS configuration guide.

• JTAC—If you need assistance during troubleshooting, you can contact the Juniper Networks Technical Assistance Center (JTAC) by using the Web or by telephone. If you encounter software problems, or problems with hardware components not discussed here, contact JTAC.

• Knowledge Base articles—Knowledge Base.

When a Routing Engine detects an alarm condition, it lights the red or yellow alarm LED on the RCB management panel as appropriate. To view a more detailed description of the alarm cause, issue the show system alarms CLI command, which indicates major and minor alarms on the system.

In this example, a fan tray error occurred in slot 4.

user@host> show system alarms
6 alarms currently active
Alarm time               Class  Description
2020-07-21 09:33:09 PDT  Minor  PSM 0 PSM MCU AC minimum supported firmware version mismatch
2020-07-21 09:33:09 PDT  Minor  PSM 1 PSM MCU AC minimum supported firmware version mismatch
2020-07-21 09:33:09 PDT  Minor  PSM 2 PSM MCU AC minimum supported firmware version mismatch
2020-07-21 09:33:08 PDT  Major  PSM 0 Input2 Failed
2020-07-21 09:33:09 PDT  Major  PSM 1 Input2 Failed
2020-07-21 09:33:09 PDT  Major  PSM 2 Input2 Failed

You can also use the variations of the show system errors command to find key information about the error.

• show system errors active—Displays current active errors in the system

• show system errors active fpc—Displays active errors for line cards

• show system errors count—Displays system-wide errors and current count

• show system errors fru detail—Displays detailed FRU-specific error

• show system errors fru detail fpc—Displays information about detected errors based on the FRU

This example shows not only the current errors but also those that are cleared.

user@host> show system errors count
Level   Occurred   Cleared     Action-Taken
-------------------------------------------
Minor         35        32              39
Major          3         0               6
Fatal          0         0               0

Chassis alarms indicate a failure of the device or one of its components. Chassis alarms are preset and cannot be modified.

Chassis alarms on the router have two severity levels:

• Major (red)—Indicates a critical situation on the device that has resulted from one of the conditions described in Table 1. A red alarm condition requires immediate action.

• Minor (yellow or amber)—Indicates a noncritical condition on the device that, if left unchecked, might cause an interruption in service or degradation in performance. A yellow alarm condition requires monitoring or maintenance.

Table 1 describes the chassis alarm messages on the router.