This article applies to legacy BIG-IP platforms supported by BIG-IP 9.x through 11.1.0. For information about the LED behavior for current platforms supported by current versions, refer to the platform guide for your specific platform.

Note: For information about how to locate F5 product guides, refer to K12453464: Finding product documentation on AskF5.

Legacy platforms

  • BIG-IP 1500 (C36)
  • BIG-IP 3400 (C62)
  • BIG-IP 4100 (D46)
  • BIG-IP 6400 (D63)
  • BIG-IP 6800 (D68)
  • BIG-IP 8400 (D84)
  • BIG-IP 8800 (D88) – version 9.4 and later only

LED indicators

Legacy platforms use 4 front-panel LEDs to indicate a system’s status:

  • Power
  • Status
  • Activity
  • Alarm

Power LED indicator

The Power LED indicator reports the power status: on (green), off (none), or error (red).

LED behaviorDescription
Solid GreenNormal Power ON condition
Off (none)Normal Power OFF condition
Solid RedStandby Power/Failure

Note: Solid Red Failure indication occurs when there are rapid cycles of power (power-off, power-on, power-off, power-on). This condition can usually be corrected by powering off and waiting 2 minutes before turning the power back on.

Status LED indicator

The Status LED indicator reports the Active or Standby status: Active (green), or Standby (yellow).

LED behaviorDescription
Solid GreenActive
Solid YellowStandby

Activity LED indicator

The purpose of the Activity LED indicator is to indicate traffic going to the CPU for load balancing or other software processing. It is not intended as a substitute for the individual Activity LEDs present on each network interface.

The Activity LED uses hardware inputs as an indication of load balancing activity. On legacy platforms this is driven by a signal from a PHY on an internal Ethernet interface connecting the switch subsystem to the CPU subsystem. It is possible that the Activity LED flickers even when there are no active links on the network interfaces.

LED behaviorDescription
Intermittent YellowActivity on the switch to CPU Ethernet interface

Note: The 8400 platform activity LED illuminates while the system is power cycling, and turns off after the boot process has completed. For more information, refer to: K10161: The Activity LED operation on 8400 platforms.

Alarm LED indicator

A single LED (Alarm) conveys an alert level (warning, error, alert, critical, and emergency). The specific alert condition is communicated by an SNMP trap and a log message. Additionally, the specific alert condition will be indicated on the LCD screen.

Alert level LED behavior

There are 5 alert levels:

Alert LevelLED behavior
0 – WarningSolid Yellow
1 – ErrorBlink Yellow
2 – AlertSolid Red
3 – CriticalSolid Red
4 – EmergencyBlink Red

Alert conditions

Alerts that affect the behavior of the Alarm LED indicator are defined in the /etc/alertd/alert.conf file. The lcdwarn function of an alert definition defines which alerts will modify the Alarm LED indicator.

As an example, the default alertd process conditions in BIG-IP 9.2 are defined in the following table:

DescriptionAlert LevelLED behavior
CPU Temp too high3 – CriticalSolid Red
CPU fan too slow3 – CriticalSolid Red
CPU fan bad3 – CriticalSolid Red
Chassis Temp too high3 – CriticalSolid Red
Chassis Fan bad3 – CriticalSolid Red
Power Supply bad4 – EmergencyBlink Red
Unit going standby0 – WarningSolid Yellow
Unit going Active0 – WarningSolid Yellow
The license validation failed2 – AlertSolid Red
The license has expired2 – AlertSolid Red
Blocking DoS attack2 – AlertSolid Red
Hard disk is failing4 – EmergencyBlink Red

Note: An alert condition is no longer triggered when a node or member has been marked down. For additional information about this functionality, refer to K5486: BIG-IP does not signal an alert condition through the front panel Alarm LED when a node or member is marked down.