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Catalyst 3750 SwitchSoftware Configuration Guide
OL-8550-09
Chapter3 Assigning the Switch IP Address and Default Gateway
Understanding the Boot Process
Understanding the Boot Process
To start your switch, you need to follow the procedures in the Getting Started Guide or the hardware
installation guide for installing and powering on the switch and for setting up the initial switch
configuration (IP address, subnet mask, default gateway, secret and Telnet passwords, and so forth).
The normal boot process involves the operation of the boot loader software, which performs these
activities:
•Performs low-level CPU initialization. It initializes the CPU registers, which control where physical
memory is mapped, its quantity, its speed, and so forth.
•Performs power-on self-test (POST) for the CPU subsystem. It tests the CPU DRAM and the portion
of the flash device that makes up the flash file system.
•Loads a default operating system software image into memory and boots up the switch.
The boot loader provides access to the flash file system before the operating system is loaded. Normally,
the boot loader is used only to load, uncompress, and launch the operating system. After the boot loader
gives the operating system control of the CPU, the boot loader is not active until the next system reset
or power-on.
The boot loader also provides trap-door access into the system if the operating system has problems
serious enough that it cannot be used. The trap-door mechanism provides enough access to the system
so that if it is necessary, you can format the flash file system, reinstall the operating system software
image by using the Xmodem Protocol, recover from a lost or forgotten password, and finally restart the
operating system. For more information, see the “Recovering from a Software Failure” section on
page 49-2 and the “Recovering from a Lost or Forgotten Password” section on page49-3.
Note You can disable password recovery. For more information, see the “Disabling Password Recovery”
section on page 9-5.
Before you can assign switch information, make sure you have connected a PC or terminal to the console
port, and configured the PC or terminal-emulation software baud rate and character format to match
these of the switch console port:
•Baud rate default is 9600.
•Data bits default is 8.
Note If the data bits option is set to 8, set the parity option to none.
•Stop bits default is 1.
•Parity settings default is none.