Configuring the Boot Field, Boot Field Meaning | Cisco Systems 2600

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-registervalue 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-registercommand. 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-zto 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

Cisco 2600 Series Routers Hardware Installation Guide

	OL-2171-06	C-3

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Cisco Systems 2600 manual Configuring the Boot Field, Boot Field Meaning

Contents

Corporate Headquarters Cisco 2600 Series Routers Hardware Installation Guide Cisco 2600 Series Routers Hardware Installation Guide Iii N T E N T S Serial DTE or DCE Devices Initial Configuration Using the Setup Command Facility Procedure for the tftpdnld Command Configuration Register Vii Objectives Chapter Title Description AudienceOrganization Conventions Bewaar Deze Instructies Safety Warnings Avvertenza Importanti Istruzioni Sulla Sicurezza Warnung Wichtige Sicherheitshinweise Guarde Estas Instruções Aviso Instruções Importantes DE Segurança Xii GEM Disse Anvisninger Xiii Xiv Related Documentation Cisco Product Document Title Xvi Cisco 90-Day Limited Hardware Warranty TermsDuration of Hardware Warranty Replacement, Repair, or Refund Policy for Hardware Ordering Documentation Obtaining DocumentationDocumentation Feedback Cisco.com Xviii Submitting a Service RequestObtaining Technical Assistance Cisco Technical Support Website Xix Definitions of Service Request SeverityObtaining Additional Publications and Information Preface Obtaining Additional Publications and Information Overview of Cisco 2600 Series Routers Hardware Features Cisco Advanced Reading the Front-Panel LEDs Power SYS/RPS RPSActivity PWR ACT Reading the Rear-Panel LEDs Cisco 2613-Rear-Panel LEDs FDX LinkACT CF1 Modules, Interface Cards, and Memory WAN and LAN Interface Numbering Interface Numbering 11 Interface Numbering in Chassis with 1-RU Height Voice Interface Numbering System SpecificationsDescription Specification Regulatory Compliance Safety with Electricity Safety Recommendations Preventing Electrostatic Discharge Damage Site Environment Power Supply ConsiderationsPower Source Input Power Tolerance Limits General Site Requirements Equipment Racks Installation ChecklistSite Configuration Task Verified by Date Creating a Site Log Inspecting the Router Tools and Equipment for Installation and Maintenance Console Port Connections Console and Auxiliary Port Considerations Auxiliary Port Connections Preparing to Connect to a Network Token Ring Connections Ethernet Connections Serial DTE or DCE Devices Configuring Serial ConnectionsSerial Connections Device Type Gender Typical Devices Signaling Standards SupportedDistance Limitations Distance EIA-530 Distance Rate bps Feet Meters Isdn BRI ConnectionsAsynchronous/Synchronous Serial Module Baud Rates EIA/TIA-232 Low-Capacitance Cable 56-K/Switched-56-kbps DSU/CSU Connections OL-2171-06 Installing the Router For AIMs Installing Modules, Interface Cards, and Power SuppliesFor network modules For WICs and VICs For external power supplies Setting Up the ChassisSetting the Chassis on a Desktop For internal power supplies Mounting the Chassis in a Rack Right To the other side of the chassis. Brackets for 19-inch rack Brackets for 19-inch rack To the other side of the chassis Use two screws on each side For 19-inch rack Right bracket Attaching the Brackets to a Router of 2-RU Height V0 EN Installing the Router in a Rack Attaching Wall-Mount Brackets to the Router Mounting the Chassis on the WallAttaching Rubber Feet to the Router 16 Attaching the Wall-Mount Brackets Mounting the Router on the Wall 17 Mounting the Chassis on the Wall Installing the Chassis Ground Connection Ring terminal Connecting Routers to AC Power Power Connections 15A, 120VAC 10A, 240VAC. Statement Connecting Routers to a DC-Input Power SupplyDC Wiring Requirements Router DC Input DC Input Wire Size1 Wiring Procedure for DC Input Port or Connection Port Type, Color Connected To Cable Connecting WAN, LAN, and Voice CablesConnecting Routers to the Cisco Redundant Power System Ports and Cabling LAN, WAN, and Voice Connection Procedures Connecting to the Console Port Connecting to a Console Terminal or Modem 23 Connecting to a Console Terminal Connecting to the Auxiliary Port Identifying a Rollover Cable 24 Connecting a Modem to the Auxiliary Port Routers with 1-RU Chassis Height Powering Up the RouterChecklist for Power Up Front Panel Indicators Routers with 2-RU Chassis Height Power-Up Procedure Configuring the Router Initial Configuration Using the Setup Command Facility Initial Configuration Using SDM Enter a hostname for the router this example uses Configuration is displayed Initial Configuration Using the CLI Manual Configuration To proceed with manual configuration using the CLI, enter no OL-2171-06 Isolating Problems Troubleshooting Environmental Reporting Features Troubleshooting the Power and Cooling Systems Troubleshooting Modules, Cables, and Connections Cisco Technical Assistance Center Recovering a Lost PasswordSystem Messages Entering ROM Monitor Mode Using the ROM Monitor Enter ROM Monitor Mode by Using the reload Command ROM Monitor Commands Command abc ROM Monitor Command Syntax Conventions Boot Commands in the ROM Monitor ROM Monitor Command DescriptionsRouter Management Commands Informational Commands in the ROM Monitor Other Useful ROM Monitor Commands Debugging Commands Modifying the Configuration Register in Menu Mode Configuration Register Commands Modifying the Configuration Register by Hexidecimal Entry Recovering Cisco IOS Software Images Console Requirements Copying an Image from the Console Using the xmodem CommandDescription and Options of the xmodem Command Procedure for the xmodem Command Restrictions on the tftpdnld Command Specify the required variables, for example Procedure for the tftpdnld Command DEFAULTGATEWAY=172.16.19.1 Nvram Configuration Register SettingsBit Number Hexadecimal Meaning Changing Configuration Register Settings Boot Field Meaning Configuring the Boot Field Bit Address net host Baud Bit Enabling Booting from Flash Memory OL-2171-06 IN-1 Numerics IN-2 Dram IN-3 Isdn BRILAN Link LED IN-4 Sdram IN-5 IN-6