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Catalyst 3550 Multilayer Switch Software Configuration Guide
78-11194-03
Chapter4 Assigning the Switch IP Address and Default Gateway
Modifying the Startup Configuration
Table 4 -5 describes the function of the most common environment variables.
Table4-5 Environment Variables
Variable Boot Loader Command IOS Global Configuration Command
MANUAL_BOOT set MANUAL_BOOT yes
Determines whether the switch
automatically or manually boots.
Valid values are 1, yes, 0, and no. If it is set
to no or 0, the boot loader attempts to
automatically boot the system. If it is set to
anything else, you must manually boot the
switch from the boot loader mode.
boot manual
Enables manually booting the switch during
the next boot cycle and changes the setting of
the MANUAL_BOOT environment variable.
The next time you reboot the system, the
switch is in boot loader mode. To boot the
system, use the boot loader boot
flash:filesystem:/file-url command, and
specify the name of the bootable image.
BOOT set BOOT filesystem:/file-url ...
A semicolon-separated list of executable
files to try to load and execute when
automatically booting. If the BOOT
environment variable is not set, the system
attempts to load and execute the first
executable image it can find by using a
recursive, depth-first search through the
Flash file system. If the BOOT variable is set
but the specified images cannot be loaded,
the system attempts to boot the first bootable
file that it can find in the Flash file system.
boot system filesystem:/file-url
Specifies the IOS image to load during the
next boot cycle. This command changes the
setting of the BOOT environment variable.
CONFIG_FILE set CONFIG_FILE flash:/file-url
Changes the filename that IOS uses to read
and write a nonvolatile copy of the system
configuration.
boot config-file flash:/file-url
Specifies the filename that IOS uses to read
and write a nonvolatile copy of the system
configuration. This command changes the
CONFIG_FILE environment variable.
CONFIG_BUFSIZE set CONFIG_BUFSIZE size
Changes the buffer size that IOS uses to hold
a copy of the configuration file in memory.
The configuration file cannot be larger than
the buffer size allocation. The range is from
4096 to 524288 bytes.
boot buffersize size
Specifies the size of the file system-simulated
NVRAM in Flash memory. The buffer holds a
copy of the configuration file in memory. This
command changes the setting of the
CONFIG_BUFSIZE environment variable.
You must reload the switch by using the
reload privileged EXEC command for this
command to take effect.