Cisco 2610 Hardware Installation Guide - Page 94

Changing Configuration Register Settings

Page 94 highlights

Changing Configuration Register Settings Appendix C Configuration Register Table C-1 Configuration Bit Meanings (continued) Bit Number Hexadecimal Meaning 10 0x0400 IP broadcast with all zeros. 5, 11, 12 0x0020, Console line speed. 0x0800, 0x1000 13 0x2000 Boots default ROM software if the network boot fails. 14 0x4000 IP broadcasts do not have net numbers. 15 0x8000 Enables diagnostic messages and ignores the contents of NVRAM. Changing Configuration Register Settings You might want to modify the value in the configuration register to perform the following tasks: • Recover a lost password • Change the console data rate • Enable or disable the Break function • Manually boot the operating system using the b command at the ROM monitor prompt • Force the router to automatically boot its system image in flash memory, or boot in accordance with any boot system commands stored in the router's configuration file in NVRAM You can change the configuration register from either the ROM monitor or the operating system software. To change the configuration register from the ROM monitor, see the "Configuration Register Commands" section on page B-7. To change the configuration register from the system software, do the following: Step 1 Connect a console terminal to the console port of the router as described in the "Connecting to the Console Port" section on page 3-20, using the blue RJ-45 to DB-9 console adapter cable. Note If you have a terminal with a DB-25 port, use an RJ-45 rollover cable and DB-25 adapter. The RJ-45-to-DB-25 adapter (Cisco part number 29-0810-01) can be purchased from Cisco. Step 2 Step 3 Step 4 Step 5 For information about cable pinouts, refer to the online document Cisco Modular Access Router Cable Specifications. This document is available online and on the Cisco Documentation CD-ROM. Configure your terminal or terminal emulation software for 9600 baud (default), 8 data bits, no parity, and 1 stop bit. Power on the router. When asked if you would like to enter the initial dialog, answer no: Would you like to enter the initial dialog? [yes]: no Your router is now in the normal operating mode. After a few seconds, you see the user EXEC prompt (Router>). Enter the enable command and your password to enter privileged EXEC mode: Cisco 2600 Series Routers Hardware Installation Guide C-2 OL-2171-06

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
  • 94
  • 95
  • 96
  • 97
  • 98
  • 99
  • 100
  • 101
  • 102
  • 103
  • 104

C-2
Cisco 2600 Series Routers Hardware Installation Guide
OL-2171-06
Appendix C
Configuration Register
Changing Configuration Register Settings
Changing Configuration Register Settings
You might want to modify the value in the configuration register to perform the following tasks:
Recover a lost password
Change the console data rate
Enable or disable the Break function
Manually boot the operating system using the
b
command at the ROM monitor prompt
Force the router to automatically boot its system image in flash memory, or boot in accordance with
any
boot system
commands stored in the router’s configuration file in NVRAM
You can change the configuration register from either the ROM monitor or the operating system
software. To change the configuration register from the ROM monitor, see the
“Configuration Register
Commands” section on page B-7
. To change the configuration register from the system software, do the
following:
Step 1
Connect a console terminal to the console port of the router as described in the
“Connecting to the
Console Port” section on page 3-20
, using the blue RJ-45 to DB-9 console adapter cable.
Note
If you have a terminal with a DB-25 port, use an RJ-45 rollover cable and DB-25 adapter. The
RJ-45-to-DB-25 adapter (Cisco part number 29-0810-01) can be purchased from Cisco.
For information about cable pinouts, refer to the online document
Cisco Modular Access Router Cable
Specifications
. This document is available online and on the Cisco Documentation CD-ROM.
Step 2
Configure your terminal or terminal emulation software for 9600 baud (default), 8 data bits, no parity,
and 1 stop bit.
Step 3
Power on the router.
Step 4
When asked if you would like to enter the initial dialog, answer
no
:
Would you like to enter the initial dialog? [yes]:
no
Your router is now in the normal operating mode.
Step 5
After a few seconds, you see the user EXEC prompt (
Router>
). Enter the
enable
command and your
password to enter privileged EXEC mode:
10
0x0400
IP broadcast with all zeros.
5, 11, 12
0x0020,
0x0800, 0x1000
Console line speed.
13
0x2000
Boots default ROM software if the network boot fails.
14
0x4000
IP broadcasts do not have net numbers.
15
0x8000
Enables diagnostic messages and ignores the contents
of NVRAM.
Table C-1
Configuration Bit Meanings (continued)
Bit
Number
Hexadecimal
Meaning