Specifications

20 AT-8900, AT-9900, AT-9900s Series Switches
Software Release 3.0.2
C613-03092-00 REV C
AT-9900s Switches
This section explains how AT-9900s switches start initially, including error
messages. The following types of software play key roles during startup.
Process flow When the switch starts, it performs the following operations.
Overrides The AT-9900s switch pauses briefly during startup messages to display the
following prompt:
Boot fallback software (Y)?
If you do nothing, the installed base package loads along with a preconfigured
startup script. For troubleshooting, change the process by using the following
keys.
Software Description
Base Product software that is typically the “preferred” base package installed.
It constitutes a feature set—similar to a "release”—and runs the switch.
A software licence must be enabled for specific base packages.
Fallback A small subset of the base package that runs when the base package is
unavailable. It can download and install a base package, modify
configuration scripts, and monitor the system.
Bootloader Software that runs the switch when it first powers up. It performs basic
initialisation, provides a basic interface for hardware diagnostics, and
executes either the product or fallback software.
Stage This happens... Done by...
1 Self-tests run that check basic operations. Bootloader
2 A prompt is displayed briefly to allow a user-override. Users
can change the startup process by pressing special keys (see
Overrides). If they enter nothing, the process continues.
Bootloader
3 Product software or fallback software is executed, depending
on what the user installed.
Bootloader
4 Hardware boards and software components are initialised. Base or Fallback
5 The startup configuration script that the user specified is
executed.
Base or Fallback
6 Startup is complete and the switch starts switching traffic if
devices connected to it are sending traffic.
Base
Pressing this key... Forces the switch to...
Y Load the fallback software instead of the base package, and skip the
startup configuration script.
S (skip) Load the base package and skip the startup configuration script.
Ctrl+B Display a bootloader prompt. To upgrade a bootloader file, load the
new .bin file into the file system, and enter the command:
copy filename.bin bootloader
For information about the load command, see the Managing
Configuration Files and Software Versions chapter in the Software
Reference.
Ctrl+D Enter diagnostics mode. For more information, see “Diagnostics” on
page 41.