Cisco Systems OL-6426-02 Change the Configuration Register

BETA DRAFT - CISCO CONFIDENTIAL

14-10

Cisco1800 Series Integrated Services Routers (Fixed) Software Configuration Guide

OL-6426-02

Chapter14 Troubleshooting

Recovering a Lost Password

Change the Configuration Register

To change a configuration register, follow these steps:

Step1 Connect an ASCII terminal or a PC running a terminal emulation program to the CONSOLE port on the

rear panel of the router.

Step2 Configure the terminal to operate at 9600 baud, 8 data bits, no parity, and 1stop bit.

Step3 At the privileged EXEC prompt (router_name#), enter the show version command to display the

existing configuration register value (shown in bold at the bottom of this output example):

Router# show version

Cisco IOS Software, C180X Software (C180X-ADVENTERPRISEK9-M), Version 12.4(1.8)PI2c

ENGINEERING WEEKLY BUILD, synced to haw_t BASE_LABEL_OF_V124_2_T_THROTTLE

Compiled Fri 27-May-05 16:14 by ccai

ROM: System Bootstrap, Version 12.3(8r)YH4, RELEASE SOFTWARE (fc1)

ng-esw1-uut1 uptime is 1 hour, 21 minutes

System returned to ROM by power-on

System image file is "flash:bootimage.ng-esw1-uut1"

This product contains cryptographic features and is subject to United

States and local country laws governing import, export, transfer and

use. Delivery of Cisco cryptographic products does not imply

third-party authority to import, export, distribute or use encryption.

Importers, exporters, distributors and users are responsible for

compliance with U.S. and local country laws. By using this product you

agree to comply with applicable laws and regulations. If you are unable

to comply with U.S. and local laws, return this product immediately.

A summary of U.S. laws governing Cisco cryptographic products may be found at:

http://www.cisco.com/wwl/export/crypto/tool/stqrg.html

If you require further assistance please contact us by sending email to

export@cisco.com.

Cisco 1801 (MPC8500) processor (revision 0x200) with 118784K/12288K bytes of memory.

Processor board ID FHK091412QA, with hardware revision 0000

9 FastEthernet interfaces

1 ISDN Basic Rate interface

1 ATM interface

31360K bytes of ATA CompactFlash (Read/Write)

Configuration register is 0x2102

Step4 Record the setting of the configuration register.

Step5 Enter the config-register value command to set the new configuration register value. For example, to

enable the break setting (indicated by the value of bit 8 in the configuration register), enter the

config-register 0x01 command from privileged EXEC mode.

•Break enabled—Bit 8 is set to 0.

•Break disabled (default setting)—Bit 8 is set to 1.