- Preface
- Product Overview
- Command-Line Interfaces
- Configuring the Switch for the First Time
- Administering the Switch
- Configuring Virtual Switching Systems
- Configuring the Cisco IOS In-Service Software Upgrade Process
- Configuring the Cisco IOS XE In Service Software Upgrade Process
- Configuring Interfaces
- Checking Port Status and Connectivity
- Configuring Supervisor Engine Redundancy Using RPR and SSO on Supervisor Engine 6-E and Supervisor Engine 6L-E
- Configuring Supervisor Engine Redundancy Using RPR and SSO on Supervisor Engine 7-E, Supervisor Engine 7L-E, and Supervisor Engine 8-E
- Configuring Cisco NSF with SSO Supervisor Engine Redundancy
- Environmental Monitoring and Power Management
- Configuring Power over Ethernet
- Configuring the Catalyst 4500 Series Switch with Cisco Network Assistant
- Configuring VLANs, VTP, and VMPS
- Configuring IP Unnumbered Interface
- Configuring Layer 2 Ethernet Interfaces
- Configuring EVC-Lite
- Configuring Cisco IOS Auto Smartport Macros
- Configuring SmartPort Macros
- Configuring STP and MST
- Configuring Flex Links and MAC Address-Table Move Update
- Configuring Resilient Ethernet Protocol
- Configuring Optional STP Features
- Configuring EtherChannel and Link State Tracking
- Configuring IGMP Snooping and Filtering, and MVR
- Configuring IPv6 Multicast Listener Discovery Snooping
- Configuring 802.1Q Tunneling, VLAN Mapping, and Layer 2 Protocol Tunneling
- Configuring Cisco Discovery Protocol
- Configuring LLDP, LLDP-MED, and Location Service
- Configuring UDLD
- Configuring Unidirectional Ethernet
- Configuring Layer 3 Interfaces
- Configuring Cisco Express Forwarding
- Configuring Unicast Reverse Path Forwarding
- Configuring IP Multicast
- Configuring ANCP Client
- Configuring Bidirectional Forwarding Detection
- Configuring Policy-Based Routing
- Configuring VRF-lite
- Configuring Quality of Service
- Configuring Voice Interfaces
- Configuring Private VLANs
- Configuring MACsec Encryption
- Configuring 802.1X Port-Based Authentication
- Configuring the PPPoE Intermediate Agent
- Configuring Web-Based Authentication
- Configuring Wired Guest Access
- Configuring Port Security
- Configuring Auto Security
- Configuring Control Plane Policing and Layer 2 Control Packet QoS
- Configuring Dynamic ARP Inspection
- Configuring DHCP Snooping, IP Source Guard, and IPSG for Static Hosts
- Configuring DHCP Snooping, IP Source Guard, and IPSG for Static Hosts
- Configuring Network Security with ACLs
- Support for IPv6
- Port Unicast and Multicast Flood Blocking
- Configuring Storm Control
- Configuring SPAN and RSPAN
- Configuring Wireshark
- Configuring Enhanced Object Tracking
- Configuring System Message Logging
- Onboard Failure Logging (OBFL)
- Configuring SNMP
- Configuring NetFlow-lite
- Configuring Flexible NetFlow
- Configuring Ethernet OAM and CFM
- Configuring Y.1731 (AIS and RDI)
- Configuring Call Home
- Configuring Cisco IOS IP SLA Operations
- Configuring RMON
- Performing Diagnostics
- Configuring WCCP Version 2 Services
- Configuring MIB Support
- ROM Monitor
- Acronyms and Abbreviations
ROM Monitor
This chapter describes the Cisco Catalyst 4500 series switch ROM monitor (also called the bootstrap program). The ROM monitor firmware runs when the router is powered up or reset. The firmware helps to initialize the processor hardware and boot the operating system software. You can use the ROM monitor to perform certain configuration tasks, such as recovering a lost password or downloading software over the console port. If there is no Cisco IOS software image loaded on the router, the ROM monitor runs the router.
This appendix contains the following sections:
- Entering the ROM Monitor
- ROM Monitor Commands
- ROM Monitor Command Descriptions
- Configuration Register
- Console Download
- Debug Commands
- Exiting the ROM Monitor
Note
For complete syntax and usage information for the switch commands used in this chapter, see the Cisco Catalyst 4500 Series Switch Command Reference and related publications at this location:
http://www.cisco.com/en/US/products/hw/switches/ps4324/index.html
If a command is not in the Catalyst 4500 Series Switch Command Reference, you can locate it in the Cisco IOS library. See related publications at this location:
http://www.cisco.com/en/US/products/ps6350/index.html
Entering the ROM Monitor
To use the ROM monitor, you must be using a terminal or PC that is connected to the router over the console port. Refer to the installation chapter in the Cisco 806 Router Hardware Installation Guide that came with the router to connect the router to a PC or terminal.
To configure the router to boot up in ROM monitor mode the next time it is rebooted, perform this task:
|
|
|
|
|---|---|---|
|
|
||
|
|
||
|
|
||
|
|
Reboots the router with the new configuration register value. The router remains in ROM monitor and does not boot the Cisco IOS software. As long as the configuration value is 0x0, you must manually boot the operating system from the console. See the boot command in the “ROM Monitor Command Descriptions” section in this appendix. After the router reboots, it is in ROM monitor mode. The number in the prompt increments with each new line. |
ROM Monitor Commands
Enter ? or help at the ROM monitor prompt to display a list of available commands and options, as follows:
Commands are case sensitive. You can halt any command by pressing the Break key on a terminal. If you are using a PC, most terminal emulation programs halt a command when you press the Ctrl and the Break keys at the same time. If you are using another type of terminal emulator or terminal emulation software, refer to the documentation for that product for information on how to send a Break command.
ROM Monitor Command Descriptions
Table 76-1 describes the most commonly used ROM monitor commands.
Configuration Register
The virtual configuration register is in nonvolatile RAM (NVRAM) and has the same functionality as other Cisco routers. You can view or modify the virtual configuration register from either the ROM monitor or the operating system software. Within ROM monitor, you can change the configuration register by entering the register value in hexadecimal format, or by allowing the ROM monitor to prompt you for the setting of each bit.
Changing the Configuration Register Manually
To change the virtual configuration register from the ROM monitor manually, enter the confreg command followed by the new value of the register in hexadecimal, as shown in the following example:
The value is always interpreted as hexadecimal. The new virtual configuration register value is written into NVRAM but does not take effect until you reset or reboot the router.
Changing the Configuration Register Using Prompts
Entering confreg without an argument displays the contents of the virtual configuration register and a prompt to alter the contents by describing the meaning of each bit.
In either case, the new virtual configuration register value is written into NVRAM but does not take effect until you reset or reboot the router.
The following display shows an example of entering the confreg command:
Console Download
You can use console download, a ROM monitor function, to download over the router console port either a software image or a configuration file. After download, the file is either saved to the mini-Flash memory module or to main memory for execution (image files only).
Use console download when you do not have access to a Trivial File Transfer Protocol (TFTP) server.
Note If you want to download a software image or a configuration file to the router over the console port, you must use the ROM monitor command.
Note If you are using a PC to download a Cisco IOS image over the router console port at 115,200 bps, ensure that the PC serial port is using a 16550 universal asynchronous transmitter/receiver (UART). If the PC serial port is not using a 16550 UART, we recommend using a speed of 38,400 or less when downloading a Cisco IOS image over the console port.
Error Reporting
Because the ROM monitor console download uses the console to perform the data transfer, error messages are only displayed on the console when the data transfer is terminated.
If an error does occur during a data transfer, the transfer is terminated, and an error message is displayed. If you have changed the baud rate from the default rate, the error message is followed by a message telling you to restore the terminal to the baud rate specified in the configuration register.
Debug Commands
Most ROM monitor debugging commands are functional only when Cisco IOS software has crashed or is halted.
The following are ROM monitor debugging commands:
- frame —Displays an individual stack frame.
- sysret —Displays return information from the last booted system image.
This information includes the reason for terminating the image, a stack dump of up to eight frames, and, if an exception is involved, the address where the exception occurred.
- meminfo —Displays size in bytes, starting address, available range of main memory, the starting point and size of packet memory, and size of NVRAM.
Exiting the ROM Monitor
You must set the configuration register to a value from 0x2 to 0xF for the router to boot a Cisco IOS image from flash memory upon startup or reloading.
The following example shows how to reset the configuration register and cause the router to boot a Cisco IOS image stored in flash memory:
The router will boot the Cisco IOS image in flash memory. The configuration register will change to 0x2101 the next time the router is reset or power cycled.
Feedback