Topic
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 behavior | Description |
| Solid Green | Normal Power ON condition |
| Off (none) | Normal Power OFF condition |
| Solid Red | Standby 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 behavior | Description |
| Solid Green | Active |
| Solid Yellow | Standby |
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 behavior | Description |
| Intermittent Yellow | Activity 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 Level | LED behavior |
| 0 – Warning | Solid Yellow |
| 1 – Error | Blink Yellow |
| 2 – Alert | Solid Red |
| 3 – Critical | Solid Red |
| 4 – Emergency | Blink 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:
| Description | Alert Level | LED behavior |
| CPU Temp too high | 3 – Critical | Solid Red |
| CPU fan too slow | 3 – Critical | Solid Red |
| CPU fan bad | 3 – Critical | Solid Red |
| Chassis Temp too high | 3 – Critical | Solid Red |
| Chassis Fan bad | 3 – Critical | Solid Red |
| Power Supply bad | 4 – Emergency | Blink Red |
| Unit going standby | 0 – Warning | Solid Yellow |
| Unit going Active | 0 – Warning | Solid Yellow |
| The license validation failed | 2 – Alert | Solid Red |
| The license has expired | 2 – Alert | Solid Red |
| Blocking DoS attack | 2 – Alert | Solid Red |
| Hard disk is failing | 4 – Emergency | Blink 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.