Understanding Status LEDs to Troubleshoot

Module LEDs can show you the current status of a module and alert you to a problem with the module or one of its ports. We recommend you familiarize yourself with LED activity so that you can easily detect and correct a module-related problem with minimal or no system downtime.

LED Identification

The system's modules have two sets of status LEDs. The top set indicates overall router and module status. The bottom set indicates module-specific status, such as port status (line modules) or fan status (SRP module).

The number next to the port status LED on a line module corresponds to the number of the port on the I/O module. Some line modules have more port status LEDs than the number of ports on the I/O module. In these cases, only the LEDs for the corresponding ports on the I/O modules are active.

For example, an OCx/STMx line module can pair with either an OC3-4 or an OC12/STM4 I/O module. Consequently, the line module has four port status LEDs for OC3/STM1 operation. However, only the top set of port status LEDs is active during OC12/STM4 operation.

Table 10 presents the functions of the module LEDs and port status LEDs.

Table 10: LED Identification and Activity Descriptions

LED Location

LED Label

LED Indicator

LED Color

OFF to ON

ON to OFF

All modules

OK

Module status

Green

Self-test passed

Failure detected

FAIL

Module status

Red

Failure detected

Diagnostic test running

ONLINE

Module status

Green

Module online

Module offline

All modules

REDUNDANT

Redundancy

Green

See Redundancy Status.

  

NOTE: The REDUNDANT LED on the cOCx/STMx, FE-8, GE/FE, HSSI, OCx/STMx, and X.21/V.35 line modules is nonfunctional.

SRP module

POWER A OK

Power

Green

Power online on source A

Power off

 

POWER B OK

Power

Green

Power online on source B

Power off

 

FAN OK

Fan

Green

Fan online

Critical fan failure

 

FAN FAIL

Fan

Red

Critical fan failure

Fan online

  

NOTE: When the LED alternates between OK and FAIL at 10-second intervals, a noncritical fan failure exists.

 

LINK

Ethernet

Green

Ethernet link up

Ethernet link down

 

ACTIVITY

Ethernet

Green

Blinks when Ethernet traffic on link

No Ethernet traffic on link

Ethernet line modules

LINK

Ethernet

Green

Ethernet link up

Ethernet link down

ACTIVITY

Ethernet

Green

Blinks when Ethernet traffic on link

No Ethernet traffic on link

HSSI line module

SYNC

Port status

Green

If the port is configured as DTE, the LED lights when both the DCE and the clock source are available.

If the port is configured as DCE, the LED lights when the DTE is available.

If the port is configured as DTE, the LED goes out when either the DCE or the clock source becomes unavailable.

If the port is configured as DCE, the LED goes out when the DTE becomes unavailable.

YEL ALM

NOTE: This LED is not functional on the HSSI line module.

RED ALM

Port status

Red

If the port is configured as DTE, the LED lights when either the DCE or the clock source becomes unavailable.

If the port is configured as DCE, the LED lights when the DTE becomes unavailable.

If the port is configured as DTE, the LED goes out when both the DCE and the clock source are available.

If the port is configured as DCE, the LED goes out when the DTE is available.

X.21/V.35 line module

ACTIVE

Port status

Green

Port configured

Port not configured

LOOPBK

Port status

Yellow

Port in local loopback or remote loopback, depending on the type of connection.

Port not in loopback

ERROR

Port status

Red

Port is enabled or comes online

Port is disabled or goes offline

V.35

Port status

Green

V.35 cable connected

V.35 cable disconnected

X.21

Port status

Green

X.21 cable connected

X.21 cable disconnected

DCE

Port status

Green

DCE cable connected

DCE cable disconnected

DTE

Port status

Green

DTE cable connected

DTE cable disconnected

Other line modules

SYNC

Port status

Green

In frame

Not in frame

YEL ALM

Port status

Yellow

Far-end receive failure (FERF) exists

No FERF present

RED ALM

Port status

Red

Loss of sync/frame

In frame

The following figures show a representative module for each of the three variations:

Figure 50: FE2 Module LEDs

FE2 Module LEDs

Figure 51: E3 and T3 Module LEDs

E3 and T3 Module LEDs

LED Activity

When the system boots, it runs a series of tests for each module installed in the system, and the LEDs display various configurations. See Table 11 and Table 12 to understand normal and abnormal LED activity.

Note: When you reboot the system after installing a new version of the software, the line modules appear to boot twice.

Table 11: Normal Activity of Functional Status LEDS During Booting

OK

FAIL

ONLINE

Status Process

off

on

(off for GE-2 LM and GE-HDE LM)

off

1. Module is in the power-up restart state; the FAIL LED stays on briefly.

off

on

off

2. Module is initializing, and diagnostic tests are running; the FAIL LED stays on briefly.

on

off

off

3. Module passed the diagnostics; the system boots.

on

off

on

4. Module is now up and running.

If the system detects an error during booting, the FAIL LED lights. Some failure conditions can cause the module not to boot. In this case, the LEDs might all be off. The system then resets the module.

If the operational software detects an error, the FAIL LED lights. Some errors can cause a module reset. Crash information is displayed at the console at the next reboot.

Table 12: Troubleshooting Abnormal LED Activity on Modules

Diagnostic Signs

Possible Problems

Actions

  • POWER A OK LED is not lit
  • POWER B OK LED is not lit
  • System is not receiving power from Power A.
  • System is not receiving power from Power B.
  1. Make sure Power A and Power B terminal connections are securely attached.
  2. Verify that power switches are on.
  3. Make sure connections to power sources are securely attached.
  4. If system still does not operate, contact Juniper Networks Customer Service.

FAIL LED lights

  • The line module and I/O module are incompatible.
  • A hardware failure, such as a failed module.
  1. Make sure that the line modules and I/O modules are compatible; replace if necessary.
  2. If you replaced the I/O module only, issue the reload slot slot_number command.
  3. If you replaced the line module or if there was a hardware failure, the system is supposed to automatically reset the module.
  4. If the condition persists, contact Juniper Networks Customer Service.
  • FAN OK LED does not light
  • FAN FAIL LED lights
  • Fan is not working properly or has slowed down.
  • Fan needs replacement.

Contact Juniper Networks Customer Service; the system must be serviced.

LINK LED is not lit

  • Ethernet connection is down.
  1. Make sure that Ethernet cables are properly connected to both the Ethernet port and the appropriate network device.
  2. Contact Juniper Networks Customer Service.

RED ALM is lit

  • System does not recognize a port connection.
  • Cabling is not connected properly.
  • Cable is faulty.
  • Clocking problem exists.
  1. Make sure that all cables are firmly plugged into the ports and the attached network device.
  2. Verify that cables are clean.
  3. Test for faulty cables.
  4. Verify clock source and configuration.
  5. Reset system.

    NOTE: Problem is corrected when normal LED activity occurs.

YEL ALM is lit

NOTE: This LED is not functional on the HSSI line module.

  • Far end receive failure (FERF) exists.
  1. Correct FERF problem.
  2. Reset system.

    NOTE: Problem is corrected when normal LED activity occurs.

  • System does not boot.
  • Modules held offline.
  • FAIL LED lights.
  • A slot group is overloaded.
  1. Issue the show version command to display module status.
  2. Review section on proper slot group configuration in Installing Modules.
  3. Reconfigure system with correct slot group configuration.
  4. Reset system.

No LED indications or obvious signs.

  • System temperature is too high.
  • Vents are blocked.
  • Fans are not operating.
  1. Look at your console for a message indicating the problem. If you have the system log set to a severity of WARNING or higher, a Warning message indicates the failure.
  2. Issue the show environment command to display the temperatures. If the temperature is too high, power down the system.
  3. Regulate temperature.
  4. Reset system.

Redundancy Status

You can determine the redundancy state of line modules by examining the ONLINE and REDUNDANT status LEDs (ERX7xx and ERX14xx models only). See Table 13.

Note: The REDUNDANT LED on the cOCx/STMx, FE-8, GE/FE, HSSI, and OCx/STMx modules is nonfunctional.

Table 13: Redundancy Status of a Line Module

ONLINE LED

REDUNDANT LED

State of the Line Module

Off

Off

Module is booting or is an inactive primary line module.

On

Off

Module is active, but no standby module is available.

Off

On

Module is in standby state.

On

On

Module is active, and a standby module is available.