How To Recover Cisco Router From Rommon Mode
I'm new to IT. Just bought a cisco lab and working towards my CCNA. I'm working on getting into Rommon mode as one of the lessons in the curric. I go into Tera Term to do the Send BREAK (alt-B) to prevent a normal reboot. I also tried sending a break from PuTTY but I'm not seeing the Router respond w a Rommon1 prompt. Press break on the terminal keyboard within 1 minute of power up in order to the router into ROMmon. Enter in confreg 0x2142 at the rommon 1 prompot in order to boot the from Flash. Type reset at the rommon 2 prompt. Type no after each setup question or press Ctrl+C to bypass all questions. Type enable at the Router prompt.
Contents
Introduction
This document explains how to recover Cisco 2500, 3000, AS5100, and uBR900 Series Routers stuck in ROMmon (rommon#> or > prompt).
Prerequisites
Requirements
To recover a router from ROMmon mode, the router should be physically accessible and should have a terminal connected to the console port. Recovering a router from ROMmon is not possible by telneting to any of the interfaces. You must know how to copy the Cisco IOS® software image from a TFTP server to the router.
Components Used
The information in this document is based on the:
Cisco 2500 Series Router
Cisco 3000 Series Router
Cisco AS5100 Series Universal Access Server
Cisco uBR900 Series Router
The information presented in this document was created from devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If you are working in a live network, ensure that you understand the potential impact of any command before using it.
Conventions
For more information on document conventions, see the Cisco Technical Tips Conventions. Windows 10 photos app crashes.
Verify the Configuration Register Value
The first thing that needs to be investigated is why the router is booting up in ROMmon mode (indicated by the 'rommon # >' or '>' prompt). Determine whether the cause is due to the change of the configuration register value, or a corrupted Cisco IOS software image.
If the router has a valid Cisco IOS software image, then simply changing the configuration value register to 0x2102 will recover the router. The procedure for this is explained below.
If the ROMmon prompt is '>', type the following at the ROMmon prompt:
If the ROMmon prompt is 'rommon #>', type the following at the prompt:
You must reset or power cycle the router for the new configuration to take effect:
If the router boots up successfully, then the cause was a configuration register value issue.
If the router boots up in ROMmon again, proceed to Download Cisco IOS Image Using the Boot Image from a Trivial File Transfer Protocol (TFTP) Server.
Download Cisco IOS Image Using the Boot Image from a Trivial File Transfer Protocol (TFTP) Server
There is only one way to install an image on the 2500, 3000, AS5100, or uBR900 Series Routers if the main Cisco IOS software has been deleted or corrupted. You must use its boot image.
Since you have already determined that the cause of the router booting up in ROMmon is not due to the configuration register value, the only option available for recovery is to re-install or upgrade the Cisco IOS software from a TFTP server using the built-in boot image (Rx-boot) in ROM.
To get into the Rx-boot mode or boot image, do the following:
If the rommon prompt is 'rommon # >', type:
You must reset or power cycle the router for the new configuration to take effect:
If the rommon prompt is '>', type:
Notice that the prompt is now 'router (boot)>', confirming that the router has booted up using the boot image.
Note: If the router boots up in ROMmon again, most likely the boot image is corrupt or missing and the only way to recover is by replacing the processor board System Flash or hardware.
The next step is to upgrade the Cisco IOS software as follows:
Use the show flash command to verify the newly-loaded Cisco IOS image version.
After successfully copying the Cisco IOS image to the router, make sure that you change the configuration register back to 0x2102 and reload the router to boot from the Cisco IOS image.
Use the show version command to verify the configuration register value and the newly-loaded Cisco IOS image version.
The show version command output above shows that the router has loaded the new Cisco IOS image and the configuration register value is 0x2102.
See Software Installation and Upgrade Procedure for the 1600, 2000, 2500, 3000, AS5100, and AS5200 for more information.
Related Information
If the IOS image of your Router is corrupted for some reason, or if you want to install a newer version, you can do so easily with Rommon Mode. This mode can be expressed as a disaster recovery area.
How to Recover Cisco IOS with Rommon Mode from TFTP Server
You can also use different methods to back up or restore an iOS image. However, if the IOS software is corrupted or missing, you can turn on your device in Rommon monitor and recover the IOS software after setting up the TFTP server information.
What is Rommon Mode?
Rommon Mode or Rommon monitor is a Bootstrap program. Bootstrap starts the Router hardware and then boots the IOS software. This mode is enabled each time the router is restarted or turned off and on again.
If your router is turned on in Rommon, it means that there is a problem with the IOS software. So we need to restore your robust or new IOS software again using the CLI prompt.
On a router that normally works, users cannot see Rommon monitor. When the IOS image is distorted, the device automatically turns on this mode and can then be manually restarted by the user.
The utility that performs all these operations is called Rommon. It can be compared to the POST system of a computer running at boot.
Rommon is also known as ROM Monitor Mode, Boot Software, Boot Image, and Boot Helper.
How to Use Rommon Mode on Router
In this article, we will restore an deleted iOS software from the TFTP Server using ROM Monitor.
Step 1
After opening your Packet Tracer software, create a simple network topology as follows. And add one TFTP server to the workspace.
Step 2
Configure the TCP/IP settings of the TFTP Server.
Step 3
In the Packet Tracer, click on TFTP Server and from the pop-up window, click on the Services tab and then on TFTP. If there are files in the server, delete them to avoid confusion.
Step 4
Open the Cisco Router CLI tab and configure the GigabitEthernet 0/0 interface as follows.
Step 5
Before uploading the IOS software to the TFTP server, browse to the files on the Router with the show flash: command.
Windows XP Activation Crack Key is one of the most popular products of Microsoft windows. Microsoft developer creates an amazing application on windows XP activation for 32Bit and 64Bit. Basically the purpose of launching to this software is to provide another product key for your windows. It permits to the users to use the new key without any. On SolidWorks 2020 SP5 Crack Incl Serial Number (Latest) SolidWorks 2020 SP5 Crack With Torrent For Mac/Win SolidWorks 2020 Crack Service Pack 5 is the famous software in the field of graphic designing for CAD that is developed for the professional and the beginners. It is one of the best graphic designing software that is used the millions. Windows XP Genuine Crack + Activator Loader With Product Key. The entirety of Windows XP Genuine Product Key utilized on personal computers.It technically released for public use in June 2001. Windows XP has its DAZ and the existing edition of Damaged Windows, which includes all the options that come with a previously released version. Windows xp validation.
Step 6
To upload IOS, follow the instructions below. Be sure to include the full name of the IOS software in the Source Filename section.
Step 7
IOS software successfully backed up to the TFTP server.
Step 8
When you check the TFTP server in the Packet Tracer workspace, you can see the file you copied.
Step 9
After this step, we will explore how to recover IOS through Rommon.
First, to delete the IOS software from the Router, execute the delete flash: command and type in the full name of the file, then press Enter to confirm.
Step 10
After deleting the IOS, use the config-register 0x2100 command to turn on the device in Rommon. Then restart the router with the Reload command.
Step 11
As you can see in the image below, the Router is now in ROM Recovery.
Step 12
You must configure the Rommon mode of the router. Set the TCP/IP information first, and then type the IP address of the TFTP server on your network.
Finally, type the full name of the file you want to copy from the TFTP server.
Step 13
After you set the Rommon settings, use the tftpdnld command to upload the backed up IOS software to the Router.
Step 14
Press Y (Yes) to confirm.
Step 15
After successfully copying the iOS to the device, you must configure the Router to open it from Flash.
Step 16
In rommon mode, execute th confreg-register 0x2102 command and then restart the device with the reset command.
Step 17
Cisco Router restarts …
Step 18
Bootstrap has successfully installed IOS!
Now, you can check the files with the show flash: command on the router.
Video
To restore the IOS software of a Cisco Router on the network from TFTP, you can watch the video below and also subscribe to our YouTube channel to support us!
Final Word
In this article, we have examined how to easily restore the IOS problems that occur in the Routers from Rommon mode. In real scenarios, you may need TFTP software, such as SolarWinds. Thanks for following us!
Related Articles
♦ How to Configure RIP
♦ How to Configure RIPv2
♦ How to Configure EIGRP
♦ How to Configure OSPF
♦ How to Configure Static Routing