Which Of The Following Configuration Register

Table Of Contents

Configuration Register Information

Configuration Bit Meanings

Bits 0-3

Flake half-dozen

Bit 7

Flake 8

Bit x and Bit 14

Bit xi and Bit 12

Bit 13

Bit 15

Displaying the Configuration Annals While Running Cisco IOS

Displaying the Configuration Annals While Running ROM Monitor

Setting the Configuration Register While Running Cisco IOS

Setting the Configuration Register While Running ROM Monitor

Configuration Register Information

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The following data is found in this appendix:

• Configuration Bit Meanings

• Displaying the Configuration Annals While Running Cisco IOS

• Displaying the Configuration Annals While Running ROM Monitor

• Setting the Configuration Register While Running Cisco IOS

• Setting the Configuration Register While Running ROM Monitor

Configuration Bit Meanings

Use the processor configuration register data independent in this appendix to do the following:

•Ready and display the configuration register value

•Force the system into the bootstrap program

•Select a boot source and default boot filename

•Enable or disable the Intermission function

•Control broadcast addresses

•Set up the console terminal baud charge per unit

•Load operating software from ROM

•Enable booting from a Trivial File Transfer Protocol (TFTP) server

Table A-1 lists the pregnant of each of the configuration retentiveness bits. Post-obit the table is a more than in-depth description of each setting.

Tabular array A-1 Configuration Annals Bit Settings

Chip No.	Hex	Meaning
00-03	0x0000-0x000F	Boot field
06	0x0040	Causes the arrangement software to ignore nonvolatile random-access memory (NVRAM) contents
07	0x0080	OEM (original equipment manufacturer) bit enabled
08	0x0100	Break disabled
ten	0x0400	IP broadcast with all zeros
11-12	0x800-0x1000	Console line speed
13	0x2000	Boots default ROM software if initial boot fails
14	0x4000	IP broadcasts practise not accept network numbers
15	0x8000	Enables diagnostic messages and ignores NVRAM contents

Bits 0-3

The lowest four bits of the processor configuration register (bits 3, ii, one, and 0) form the boot field. Tabular array A-2 provides information nigh the bits settings.

Table A-two Bits 0-3 Settings

Boot Field	Meaning
0	Stays at the organisation bootstrap prompt (ROM monitor) on a reload or power cycle
one	Boots the kick helper image every bit a system image
2	Full boot process, which loads the Cisco IOS image into Flash retention
two-F	Specifies a default filename for booting over the network from a TFTP server

The boot field specifies a number in binary. If you set the kicking field value to 0, you must have a console port access to boot the operating system manually. Boot the operating system by entering the b command at the bootstrap prompt as follows:

> b [tftp] flash filename

Definitions of the diverse control options follow:

b—Boots the default organisation software from ROM

b flash—Boots the offset file in Wink retentiveness

b filename [host]—Boots over the network using TFTP

b flash filename—Boots the file (filename) from Flash memory

If yous set the boot field value to a value of 2 through F, and at that place is a valid system boot control stored in the configuration file, the router boots the arrangement software as directed by that value. (See Table A-iii.) If you set the boot field to whatever other bit blueprint, the router uses the resulting number to grade a default boot filename for netbooting.

If there are no boot commands in the configuration file, the router attempts to boot the first file in system Flash retentivity. If no file is found in system Flash memory, the router attempts to netboot a default file with a name derived from the value of the kick field (for example, cisco2-7500). If the netboot attempt fails, the kick helper prototype in boot flash memory will kicking up.

If boot commands are in the configuration file, the router software processes each boot command in sequence until the process is successful or the end of the list is reached. If the cease of the list is reached without a file existence successfully booted, the router will retry the netboot commands up to six times if bit 13 of the configuration register is ready, otherwise information technology volition load the operating organization software available in ROMmon. If fleck thirteen is not set, the router will go along to netboot images indefinitely. The default setting for bit 13 is 0. If flake 13 is set, the system boots the kick helper image establish in boot flash memory without any retries.

The server creates a default filename as part of the automatic configuration processes. To grade the kicking filename, the server starts with Cisco and links the octal equivalent of the boot field number, a dash, and the image proper name. Table A-3 lists the default kick filenames or deportment.

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Note A kicking organisation configuration command in the router configuration in NVRAM overrides the default netboot filename.

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Table A-3 Default Boot Filenames

Action/File Name	Chip 3	Scrap 2	Fleck i	Flake 0
Bootstrap manner	0	0	0	0
ROM software	0	0	0	1
Wink software	0	0	ane	0
cisco3-< image-name1>	0	0	1	one
cisco4-<image-name2>	0	1	0	0
cisco5-<image-name3>	0	1	0	one
cisco6-<image-name4>	0	1	1	0
cisco7-<image-name5>	0	1	1	1
cisco10-<image-name6>	1	0	0	0
cisco11-<image-name7>	i	0	0	1
cisco12-<image-name8>	one	0	1	0
cisco13-<image-name9>	i	0	ane	ane
cisco14-<paradigm-name10>	1	ane	0	0
cisco15-<image-name11>	1	1	0	1
cisco16-<image-name12>	1	1	one	0
cisco17-<image-name13>	1	1	1	1

Bit 6

Chip six causes the arrangement software to ignore nonvolatile random-access retentiveness (NVRAM) contents.

Bit 7

Fleck seven enables the OEM bit. It disables the bootstrap letters at startup.

Fleck 8

Bit 8 controls the console Interruption fundamental. Setting bit 8 (the mill default) causes the processor to ignore the console Interruption primal. Clearing bit 8 causes the processor to translate Break as a command to force the organisation into the bootstrap monitor, halting normal performance. A Break tin be sent in the first threescore seconds while the arrangement reboots, regardless of the configuration settings.

Scrap ten and Scrap 14

Bit x controls the host portion of the Net IP broadcast accost. Setting bit 10 causes the processor to employ all zeros; immigration chip x (the factory default) causes the processor to use all ones. B it 10 interacts with fleck 14, which controls the network and subnet portions of the IP circulate accost. Table A-four shows the combined effect of scrap 10 and bit 14.

Table A-4 Scrap x and Bit 14 Settings

Bit 14	Bit x	IP Address (<net> <host>)
Off	Off	<ones><ones>
Off	On	<zeros><zeros>
On	On	<internet><zeros>
On	Off	<internet><ones>

Chip xi and Bit 12

Bit 11 and Bit 12 in the configuration annals determine the baud charge per unit of the console terminal. Table A-5 shows the bit settings for the iv available baud rates. (The factory set default baud rate is 9600.)

Table A-v Bit 11 and Bit 12 Settings

Baud	Bit 12	Bit 11
9600	0	0
4800	0	ane
2400	1	one
1200	1	0

Bit thirteen

Bit 13 determines the server response to a bootload failure. If kick commands are in the configuration file, the router software processes each kick command in sequence until the process is successful or the terminate of the list is reached. If the stop of the listing is reached without a file existence successfully booted, the router will retry the netboot commands up to six times if fleck 13 of the configuration register is set, otherwise it will load the operating system software bachelor in ROMmon. If bit 13 is not set, the router volition go on to netboot images indefinitely. The default setting for bit 13 is 0. If flake 13 is fix, the system boots the kick helper image found in boot flash retentivity without any retries.

Bit 15

Flake 15 enables diagnostic messages and ignores NVRAM contents.

Displaying the Configuration Register While Running Cisco IOS

The configuration register can be viewed by using the show version or testify hardware control.

The following is sample output of the show version command.

Router# show version

Cisco Internetwork Operating System Software

IOS (tm) RSP Software (RSP-JSV-M), Version 12.0(10r)S1, EARLY DEPLOYMENT

MAINTENANCE Interim SOFTWARE

TAC Support:http://www.cisco.com/cgi-bin/ibld/view.pl?i=support

Copyright (c) 1986-2002 by cisco Systems, Inc.

Compiled Friday 22-Mar-02 sixteen:27 by ninahung

Paradigm text-base of operations:0x60010950, data-base of operations:0x612A2000

ROM:System Bootstrap, Version 12.0(10r)S1, RELEASE SOFTWARE (fc1)

UUT uptime is 2 minutes

Organization returned to ROM past reload at fifteen:33:45 UTC Tue Mar 5 2002

System image file is "disk0:rsp-pv-mz.vip6-iii.022802"

cisco RSP4+ (R5000) processor with 65536K/2072K bytes of retentivity.

R5000 CPU at 200Mhz, Implementation 35, Rev ii.i, 512KB L2 Cache

Terminal reset from power-on

Yard.703/E1 software, Version 1.0.

M.703/JT2 software, Version 1.0.

X.25 software, Version 3.0.0.

1 VIP6 RM7000B controller (ii FastEthernet).

1 GEIP controller (ane GigabitEthernet).

2 FastEthernet/IEEE 802.iii interface(s)

1 Gigabit Ethernet/IEEE 802.3 interface(due south)

123K bytes of non-volatile configuration memory.

47040K bytes of ATA PCMCIA card at slot 0 (Sector size 512 bytes).

16384K bytes of Wink internal SIMM (Sector size 256K).

No slave installed in slot 7.

Configuration annals is 0x0

Displaying the Configuration Register While Running ROM Monitor

If the bootstrap prompt ">", the o command displays the virtual configuration register currently in result. Information technology includes a description of the bits. Come across the following sample output:

>o

Configuration register + 02x100 at last kick

Bit#       Configuration register option settings:

fifteen         Diagnostic mode disabled

xiv         IP broadcasts exercise not have network numbers

13         Boot default ROM software if network boot fails

12-eleven      Panel speed is 9600 baud

10         IP broadcasts with ones

09         Do not use secondary bootstrap

08         Break disabled

07         OEM disabled

06         Ignore configuration disabled

05         Fast boot disabled

04         Fan boot disabled

03-00      Kicking to ROM monitor

If the prompt is "rommon1", the confreg control displays the virtual configuration register currently in effect. It includes a description of the bits. Meet the following sample output:

rommon 1 > confreg

Configuration Summary

enabled are:

load rom after netboot fails

console baud: 9600

boot: the ROM Monitor

Practice you lot wish to change the configuration? y/n  [n]

Setting the Configuration Register While Running Cisco IOS

The configuration annals tin exist gear up in the configuration mode with the config-register 0x<value> command. See the following sample output:

Router# config t

Enter configuration commands, one per line. Finish with CNTRL/Z.

Router(config)#config-annals 0x2142

Router(config)

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