Network Router User Manual

C-3
Cisco 2600 Series Routers Hardware Installation Guide
OL-2171-06
Appendix C Configuration Register
Configuring the Boot Field
Router> enable
Password:
password
Step 6 At the privileged EXEC prompt (Router#), enter the configure terminal command:
Router# configure terminal
Enter configuration commands, one per line.
Edit with DELETE, CTRL/W, and CTRL/U; end with CTRL/Z
Step 7 Enter the config-register value command, where value is a hexadecimal number preceded by 0x (see
Table C-2), to set the contents of the configuration register:
Router# config-register 0x value
Note Cisco IOS software does not allow you to change the console speed bits directly with the
config-register command. To change the console speed, complete this sequence:
Router# configure terminal
Router(config)# line console 0
Router(config-line)# speed 9600
Step 8 Press Ctrl-z to exit configuration mode.
Step 9 Copy the new console speed to NVRAM:
Router> copy run start
The new settings are saved to NVRAM, but they are not effective until the router restarts; for example,
when you switch the power off and on or when you enter a reload command from the console.
Step 10 Enter the show version command to display the configuration register value currently in effect and the
value that will be used at the next reload. The value is shown on the last line of the display:
Configuration register is 0x142 (will be 0x142 at next reload)
Step 11 Reboot the router. The new value is effective after the router reboots.
Configuring the Boot Field
The lowest four bits of the configuration register (bits 3, 2, 1, and 0) form the boot field. (See Table C-2.)
Table C-2 Explanation of Boot Field Configuration Register Bits (00-03)
Boot Field Meaning
00 Stays at the ROM monitor on a reload or power cycle
01 Boots the first image in flash memory as a system image
02-F Enables default booting from flash memory
Enables boot system commands that override default booting from flash memory