- A. The POST was successful.
- B. The switch has a problem with the internal power supply and needs an external power supply to be attached.
- C. POST failed and there is a problem that prevents the operating system from being loaded.
- D. The switch has experienced an internal problem but data can still be forwarded at a slower rate.
- E. The switch passed POST, but all the switch ports are busy.
Each time you power up the switch, eight Power-On Self Tests (POSTs) run automatically. POSTs check the most important system components before the switch begins to forward packets. When the switch begins the POST, the port status LEDs display amber for two seconds, and then display green. As each test runs, the port status LEDs go out. 1x is the first to go out. The port status LEDs for ports 2x through 8x go out sequentially as the system completes a test. When the POST completes successfully, the port status LEDs go out. This indicates that the switch is operational. If a test fails, the port status LED associated with the test displays amber.
The system LED also displays amber.
Not E. From Cisco IOS Software Release 11.2(8.5) SA6 onwards, the port and system LEDs both remain amber after a POST failure. In the earlier Cisco IOS
Software Releases, only the LEDs of failed linked ports remained amber.