Recovering Cisco IOS Software Images | Cisco Systems 2600 specs

Appendix B Using the ROM Monitor

Recovering Cisco IOS Software Images

enter			to	boot:
0	=		ROM	Monitor
1	=		the	boot helper image
2-15			= boot system
		[0]:		0

Configuration Summary enabled are: diagnostic mode break/abort has effect console baud: 9600 boot: the ROM Monitor

do you wish to change the configuration? y/n [n]:

You must reset or power cycle for new config to take effect

Modifying the Configuration Register by Hexidecimal Entry

Entering the confreg command plus a hexidecimal value changes the contents of the configuration register. The syntax is confreg [hexnum]; values entered are always interpreted as hexadecimal. The following example changes the value of the configuration register to the factory default:

rommon 7> confreg 0x2102

You must reset or power cycle the router for new configuration to take effect.

Recovering Cisco IOS Software Images

If your Cisco router experiences difficulties and no longer contains a valid Cisco IOS software image in flash memory, you can download a new Cisco IOS image using one of the following ROM monitor commands:

•xmodem—(All Cisco 2600 series routers) Use this command to copy a Cisco IOS image from the console, if the computer attached to your console has a terminal emulator with Xmodem capability. See the “Copying an Image from the Console Using the xmodem Command” procedure on

page B-9.

Note Downloading a Cisco IOS image from a console is very slow. This procedure should be used only in an emergency and is not recommended for normal Cisco IOS image upgrades.

For the fastest possible download from a console, set the console speed to 115200 bps by using the confreg ROM monitor command. See the “Configuration Register Commands” procedure on page B-7.

•tftpdnld—(Except Cisco 2691) Use this command to copy a Cisco IOS image from a TFTP server that is accessible through the FastEthernet 0/0, Ethernet 0/0, or Token Ring 0/0 port. See the “Copying an Image from a TFTP Server Using the tftpdnld Command” procedure on page B-10.

Cisco 2600 Series Routers Hardware Installation Guide

	B-8	OL-2171-06

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Cisco Systems 2600 manual Recovering Cisco IOS Software Images, Modifying the Configuration Register by Hexidecimal Entry

Contents

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