4.5. Boot Process

4.5. Boot Process
	Chapter 4. System Administration

The FB2900 contains internal Flash memory storage that holds two types of software :-

main application software (generally referred to as the app)
a bootloader - runs immediately on power-up, initialises system, and then loads the app

It is possible for only one of these types of software, or neither of them, to be present in the Flash, but when shipped from the factory the unit will contain a bootloader and the latest factory-release application software. The FB2900 can store multiple app software images in the Flash, and this is used with an automatic fall-back mechanism - if a new software image proves unreliable, it is 'demoted', and the unit falls back to running older software. The show flash contents CLI command can be used to see what is stored in the Flash - see Appendix J.

4.5.1. LED indications

4.5.1.1. Status LED indications

The status LED has three defined states, as shown in Table 4.6 below :-

Table 4.6. Status LED indications

Indication	Status
Off	No power applied to unit (or possibly hardware fault)
Flashing with approximately 1 second period	Bootloader running / waiting for network connection
On	Main application software running

After power-up, the normal LED indication sequence is therefore to go through the ~1 second period flashing phase, and then - if at least one Ethernet port is connected to an active device, or after a few seconds waiting for a factory reset cable - change to solid once the app is running.

Note

The status LED can be configured to be a different colour when the main application software is running, including black (i.e. off). The LED can also be set to different colours and cycle through colours based on active profiles (see Chapter 9).

From power-up, a FB2900 will normally boot and be operational in under five seconds.

4.5.1.2. Port LEDs

Whilst the bootloader is waiting for an active Ethernet connection, the green and yellow LEDs built into the physical port connectors flash in a continual left-to-right then right-to-left sequence. The port LEDs on the panel on the opposite side to the physical ports also flash, in a clockwise sequence.

Note

The same port LED flashing sequences are observed if the app is running and none of the Ethernet ports are connected to an active link-partner. Note that the app continues to run, and the power/status LED will still be on solid.

When connected to an active link-partner, these flashing sequences will stop and the port LEDs will start indicating physical port status, with various status indications possible, controllable via the configuration (see Section 6.4).

Note

The SFP port has no LEDs indicating status.


4.4. Global LED control		Chapter 5. Event Logging