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Cisco 10008 Router PRE4 Installation and Configuration Guide
OL-13840-01
Managing System Boot Parameters
•
The behavior of the Break function
By modifying the boot parameters, you can customize your Cisco 10008 router. For example, a common
configuration register setting in some lab environments is 0x2100. Using this setting, the system boots
to the ROM monitor (ROMmon) prompt, where a technician can load a specific image by entering the
boot
command at the ROMmon prompt.
Changing the Software Configuration Register Settings
The factory default value for the software configuration register is 0x2102. To change the software
configuration register settings while you are running system software, perform the following steps:
Step 1
Enter the
config-register
value
command from the global configuration mode, to set the contents of the
software configuration register;
value
is a hexadecimal number preceded by 0x. For example:
Router(config)#
config-register 0x2100
Consult the hexadecimal column in
for the possible settings to enter as the 4-bit
value
parameter.
Step 2
Exit global configuration mode by pressing
Ctrl-Z
.
Router(config)#
Ctrl-Z
Router#
Step 3
To display the new software configuration register setting, issue the
show version
command.
Router#
show version
.
#Configuration register is 0x141 (will be 0x2100 at next reload)
Step 4
Save the configuration file to preserve the new software configuration register settings.
Router#
copy running-config startup-config
Step 5
Reboot the router.
The router reboots using the new register settings. The software configuration register setting takes
affect only after you reload the system. This happens when you issue the
reload
command from the
console or reboot the router.