Specifications

Hardware Reference 23
C613-03086-00 REV A
Router Start-Up
At start-up, the manager can choose to run either the software release stored in
the flash boot block, or the software release specified by the INSTALL
parameters previously set using the SET INSTALL command.
All code is executed out of system RAM. At power-up the boot code is loaded
from the flash boot block to RAM. The boot code checks the INSTALL
information then reloads RAM with the selected temporary, preferred, or default
install release (stored in flash) and runs this code.
The release is uncompressed as it loads to RAM. This may take 10–30 seconds.
At this point, any required patches are loaded from the flash file system. Any
patch is also uncompressed as it loads to RAM. This procedure ensures that the
code runs at maximum speed, and allows updates to be made to the code.
Updates can be downloaded over the network from a TFTP server and stored
in the flash file system until required at power-up.
To download software onto the router, see the Operation chapter in the
Software Reference.
All router software, patches, and configuration settings are stored as files in
flash memory. Typically, the following files will be present in flash:
■ The current installed software release. Additional software releases may
also be present.
■ The current installed patch, if any. Additional patches may also be present.
■ The online help file. All online help is stored in a separate text file designed
to be language independent. The online help file is loaded with a software
release.
■ The boot script boot.cfg. The boot script contains standard router
commands (executed on start-up to configure the router).
■ Additional user-defined configuration scripts containing commands to
configure the router for different functions. These scripts are created using
the built-in editor, the add script command (in the Scripting chapter,
Software Reference), or the create config command (in the Operation
chapter, Software Reference).
Configuration information is stored in flash memory as configuration scripts.
These scripts contain standard router commands. When a configuration
command is entered at the command prompt from a terminal, terminal
emulation program, or Telnet session, the command alters the dynamic
configuration only; this is not saved over a power cycle. To ensure that
configuration changes resulting from such commands are retained across a
power cycle, the dynamic configuration must be saved as a configuration
script, using the create config command.
When the router starts up following either a power cycle or an operator-
initiated reboot (using the restart reboot command in the Operation chapter,
Software Reference), the following sequence of operations is performed:
1. Perform start-up self tests.
2. Load the flash boot block release as the INSTALL boot into the router’s
RAM.
3. Prompt the manager for changes to the default start-up procedure:
Force EPROM download (Y)?
The manager may press one of the keys listed in Table 1-5 on page 24 to
override the default installation procedure.