Router boots to Romon

Answered Question
Sep 7th, 2009
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Hi,

I recently upgraded the IOS platform of C871 we use in our network. I forgot to issue the router config command "boot system flash: 'name of file' . When i reloaded the router, it keeps booting to romon.

I've tried using "confreg 0x2102" command in the the Romon environment but to no avail. I've done reset and i am even thinking of booting the router from a tftp server but i dont know how and if it will be possible.

Can someone help me with idea on how to solve this?

Thanks.

Tom


Correct Answer by Leo Laohoo about 7 years 8 months ago

Here are some guidelines if you need to boot from USB:


1. Maximum size of USB is 2Gb;

2. Format the USB first (command: format usbflash0:) before copying files into it; and

3. Set boot statement (boot system usbflash0:).


Hope this helps. Please rate when helpful or applicable.

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Mohamed Sobair Mon, 09/07/2009 - 08:47
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Hi TOM,


try on the romon mode the following:


1- confreg 0x2102


2- reset


after you successfuly configure the router , change the config register to 0x2102 and reload , and boot system flash, the next reload for the router should be from the NVRAM.



HTH

Mohamed

tomocisco Mon, 09/07/2009 - 09:44
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Hi Mohammed,

That's the first thing i did, but i didn't work. look at the output i got:


System Bootstrap, Version 12.3(8r)YI4, RELEASE SOFTWARE

Technical Support: http://www.cisco.com/techsupport

Copyright (c) 2006 by cisco Systems, Inc.


C870 series (Board ID: 3-148) platform with 131072 Kbytes of main memory


Booting flash:/c870-advsecurityk9-mz.124-24.T1.bin

ELF Loader: read error

Elf loader error


System Bootstrap, Version 12.3(8r)YI4, RELEASE SOFTWARE

Technical Support: http://www.cisco.com/techsupport

Copyright (c) 2006 by cisco Systems, Inc.


C870 series (Board ID: 3-148) platform with 131072


Booting flash:/c870-advsecurityk9-mz.124-24.T1.bin

ELF Loader: read error

Elf loader error


System Bootstrap, Version 12.3(8r)YI4, RELEASE SOFTWARE

Technical Support: http://www.cisco.com/techsupport

Copyright (c) 2006 by cisco Systems, Inc.


C870 series (Board ID: 3-148) platform with 131072 Kbytes of main memory


rommon 1 > confreg 0x2102



rommon 2 > reset

rommon 3 >

System Bootstrap, Version 12.3(8r)YI4, RELEASE SOFTWARE

Technical Support: http://www.cisco.com/techsupport

Copyright (c) 2006 by cisco Systems, In


C870 series (Board ID: 3-148) platform with 131072 Kbytes of main memory


Booting flash:/c870-advsecurityk9-mz.124-24.T1.bin

ELF Loader: read error

Elf loader error


System Bootstrap, Version 12.3(8r)YI4, RELEASE SOFTWARE

Technical Support: http://www.cisco.com/techsupport

Copyright (c) 2006 by cisco Systems, Inc.


C870 series (Board ID: 3-148) platform with 131072 Kbytes of main memory


Booting flash:/c870-advsecurityk9-mz.124-24.T1.bin

ELF Loader: read error

Elf loader error


System Bootstrap, Version 12.3(8r)YI4, RELEASE SOFTWARE

Technical Support: http://www.cisco.com/techsupport

Copyright (c) 2006 by cisco Systems, Inc.


C870 series (Board ID: 3-148) platform with 131072 Kbytes of main memory


rommon 1 >


what do you think?

Thanks.

Tom


Mohamed Sobair Mon, 09/07/2009 - 10:55
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Hi Tom,


Could you try the command " tftpboot " in the romon.


It should thenshow you what you have to enter.


HTH

Mohamed

Leo Laohoo Mon, 09/07/2009 - 14:30
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Hi Tom,

What's the flash and DRAM of your router?


Try to download (again) the IOS and use TFTPDNLD to copy the IOS to your router. I am suspecting that the IOS got corrupted.


How to Download a Software Image to a Cisco 2600 via TFTP Using the tftpdnld ROMMON Command

http://www.cisco.com/en/US/products/hw/routers/ps259/products_tech_note09186a008015bf9e.shtml


Now, here's the interesting part. You have an c870 router which comes with 2 USB port. If you have any spare USB flash drive with a maximum size of 2Gb, why don't you copy the IOS from the router to the USB? Because you have one of the latest bootstrap, you are able to boot the router FROM the USB flash drive.


If you are interested in this option, make sure you format the USB flash drive first before you copy any IOS into it.


Hope this helps.

tomocisco Mon, 09/07/2009 - 23:38
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Hi,

Thanks so much.

I'll look at the reference above and see how to implement it.

Please how can i boot from the USB flash as you suggested above. I think it may be the easier option because i downloaded the ios to my system and the 871 has 2 USB ports.

Is there any link you can refer me to for more info?


Thanks.

Tom

Correct Answer
Leo Laohoo Tue, 09/08/2009 - 13:43
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Here are some guidelines if you need to boot from USB:


1. Maximum size of USB is 2Gb;

2. Format the USB first (command: format usbflash0:) before copying files into it; and

3. Set boot statement (boot system usbflash0:).


Hope this helps. Please rate when helpful or applicable.

Leo Laohoo Wed, 09/09/2009 - 14:30
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Thanks for the rating Tom.

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