Troubleshooting the MX104
Troubleshooting Resources for MX104 Routers
Command-Line Interface
The Junos OS command-line interface (CLI) is the primary tool
for controlling and troubleshooting router hardware, the 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.
You enter CLI commands on one or more external management devices connected to ports on the front panel.
For information about using the CLI to troubleshoot the Junos OS, see the appropriate Junos OS configuration guide.
Front Panel LEDs
The front panel on the router contains LEDs that allow you to troubleshoot the router.
LEDs on the front panel include the following:
System LED—One LED labeled SYS OK on the front panel indicates the status of the router.
Alarm LEDs—One yellow and one red LED on the front panel indicate major and minor alarms.
For more information about component and front panel LEDs, see MX104 LEDs Overview.
Alarm Devices and Messages
When a major or minor alarm occurs, it logs the cause of the alarm. If the alarm relay contact is connected to alarm devices, the router also trips the corresponding alarm relay contact.
To view
a detailed description of the alarm cause, issue the show chassis alarms
command:
user@host> show chassis alarms
Understanding Alarm Types and Severity Classes on MX104 Routers
Before monitoring alarms on the router, become familiar with the terms defined in Table 1.
Term |
Definition |
---|---|
alarm |
Signal alerting you to conditions that might prevent normal operation. On a router, the alarm signal is the red system LED lit on the front of the chassis. |
alarm condition |
Failure event that triggers an alarm. |
alarm severity |
Seriousness of the alarm. The level of severity can be either major (steady red) or minor (blinking red). |
chassis alarm |
Predefined alarm triggered by a physical condition on the router or one of the router components. Alarms may be triggered by events such as a power failure, excessive component temperature, or media failure. Chassis alarms are preset and cannot be modified. |
system alarm |
Predefined alarm triggered by a missing rescue configuration or failure to install a license for a licensed software feature. System alarms are preset and cannot be modified, although you can configure them to appear automatically in the J-Web interface display or CLI display. |
interface alarm |
Predefined alarm triggered by a problem with a specific network interface. |
Alarm Severity Classes
Alarms on the MX104 routers have two severity classes:
Major (steady red)—Indicates a critical situation on the router that has resulted from one of the following conditions. A red alarm condition requires immediate action.
One or more hardware components have failed.
One or more hardware components have exceeded temperature thresholds.
An alarm condition configured on an interface has triggered a critical warning.
Minor (steady yellow)—Indicates a noncritical condition on the router that, if left unchecked, might cause an interruption in service or degradation in performance. A minor alarm condition requires monitoring or maintenance.
A missing rescue configuration generates a minor system alarm.
See Also
Verifying Active Alarms on MX104 Routers
Purpose
Use the monitoring functionality to view alarm information for the MX104 routers, including alarm type, alarm severity, and a brief description for each active alarm on the router.
Action
Observe the system LED on the front panel of the router. If the router is functioning normally with no alarms, the system LED lights green steadily.
Issue the CLI
show chassis alarms
command to verify the status of the router. As shown in the sample output, the valueClass
indicates the severity of the alarm.user@host> show chassis alarms 2 alarms currently active Alarm time Class Description 2010-01-01 00:05:24 UTC Minor Loss of communication with Backup RE 2010-01-01 00:05:24 UTC Major Fan Tray Failure
When the router is functioning normally with no active alarms, the CLI displays the output as shown:
user@host> show chassis alarms No alarms currently active
Meaning
Table 2 lists the alarm output fields.
Field |
Values |
---|---|
Alarm time |
Date and time when the failure was detected |
Class |
Alarm severity—either major or minor |
Description |
Brief synopsis of the alarm |
Monitoring System Log Messages on MX104 Routers
Purpose
Use the monitoring functionality to view system log messages for MX Series routers.
Action
To view events in the CLI, enter the show log
command. For more information, see
Displaying a Log
File from a Single-Chassis System.