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Catalyst 3560 Switch Software Configuration Guide
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Chapter 3 Assigning the Switch IP Address and Default Gateway
Modifying the Startup Configuration
Modifying the Startup Configuration
These sections describe how to modify the switch startup configuration:
Default Boot Configuration, page 3-16
Automatically Downloading a Configuration File, page 3-16
Booting Manually, page 3-17
Booting a Specific Software Image, page 3-18
Controlling Environment Variables, page 3-18
See also Appendix B, “Working with the Cisco IOS File System, Configuration Files, and Software
Images,” for information about switch configuration files.

Default Boot Configuration

Tabl e 3-3 shows the default boot-up configuration.

Automatically Downloading a Configuration File

You can automatically download a configuration file to your switch by using the DHCP-based
autoconfiguration feature. For more information, see the “Understanding DHCP-Based
Autoconfiguration” section on page 3-3.

Specifying the Filename to Read and Write the System Configuration

By default, the Cisco IOS software uses the file config.text to read and write a nonvolatile copy of the
system configuration. However, you can specify a different filename, which will be loaded during the
next boot-up cycle.
Tab l e 3-3 Default Boot Configuration
Feature Default Setting
Operating system software image The switch attempts to automatically boot up the system using information in the
BOOT environment variable. If the variable is not set, the switch attempts to load and
execute the first executable image it can by performing a recursive, depth-first search
throughout the flash file system.
The Cisco IOS image is stored in a directory that has the same name as the image file
(excluding the .bin extension).
In a depth-first search of a directory, each encountered subdirectory is completely
searched before continuing the search in the original directory.
Configuration file Configured switches use the config.text file stored on the system board in flash
memory.
A new switch has no configuration file.