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370
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Accidently deleted OS image in 2900 series router

Jochy070661
Level 1
Level 1

I deleted my OS image. The router is an old 2911. It does not boot (not a big surprise). I get stuck in ROMMAN mode. I would like to download a new OS image, but I have not been able to do. There are no more OS images on this box.

There are 2 USB ports. Can I put a USB stick there with an image? Or is there a way to tftp this image, download vis RS232? I didn't find a support document. Most links lead to a 404 page.

Thanks

Jochy

PS: I do know, this is an outdated model. But we can't afford a new one.

1 Accepted Solution

Accepted Solutions

Jochy070661
Level 1
Level 1

In the end, I followed https://icttowers.com/routing-switching/upload-ios-via-tftp-in-rommon/
The only thing I had to do: skipp the -r option in tftpdnld. It did download the file and wanted to boot it, but didn't write it down. Probably, I did something wrong.

Obstacles I had to overcome: You have to specify a DEFAULT_GATEWAY, even if you use a cross-over cable. The gateway must not be the TFTP_SERVER. So I used an IP that didn't exist.

rommon 1> IP_ADDRESS=10.0.0.1
rommon 2> IP_SUBNET_MASK=255.255.255.0
rommon 3> DEFAULT_GATEWAY=10.0.0.10
rommon 4> TFTP_SERVER=10.0.0.2
rommon 5> TFTP_FILE=c2900-universalk9-mz.SPA.157-3.M.bin
rommon 6> tftpdnld 



I thank all of you. You had been very helpful!

Attention: It will delete all files on the disk if you use no option (skip -r)

View solution in original post

9 Replies 9

Joseph W. Doherty
Hall of Fame
Hall of Fame

RS232 download?  That should be possible, although very, very slow, especially if running at default 9600.

tftp (on LAN)?  Might be possible too.

USB? Might be possible to copy .bin from it or possibly even boot from it.  However, Cisco can have issues with non-Cisco USB sticks.

All of the above depends on support of ROMMON.  (For example, prior 2811s required ROMMON update to support USB booting.)

If you cannot find documentation specific to your router, try later ISR router documentation as how earlier gen platform ROMMON features are done seldom changes.

Jochy070661
Level 1
Level 1

Thank you. I don't care how long it takes to download. How do I initiate an RS232 download? I'm kind of stupid, so I need more information to be successful.

Hopefully @balaji.bandi reference should explain how on the router.  It's usually left to you how to do it on the PC.  (Look for file transfer options.)

If you do go the RS232 method, often the router and PC will support a connection faster than 9600, but it will still be very slow.  Also, the router and terminal emulator may support a protocol faster than original xmodem (e.g. xmodem-1k, ymodem).  Using such may also dramatically increase transfer rate, again though, even the very best will still be quite slow.

tftp will require a tftp server, which often can be hosted on your PC.  Again, how that's done on the PC is left to you.  (There are a couple of freebies you might use.)

Like @balaji.bandi and @Richard Burts , I too would suggest tftp as 1st choice unless you have a USB stick that will work on the router.  Balaji's reference also shows directly booting from the USB.  (I sort of expected it might as the 2800s could too [with their later ROMMONs], but again, Cisco platforms often, back then, wouldn't work with most non-Cisco USB sticks.)

balaji.bandi
Hall of Fame
Hall of Fame

yes you can use TFTP  or XMODEM (this take ages to copy)

use below guide to TFTP :

https://www.cisco.com/c/en/us/td/docs/routers/access/1900/software/configuration/guide/Software_Configuration/appendixCrommon.html

BB

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Jochy070661
Level 1
Level 1

nks, great. I'll drop a comemnt if successful.

I agree that tftp is the better option for copying an image to the router. xmodem is a slower option but should be feasible. I believe that the real question is whether the OP has an image file for the old router?

HTH

Rick

Jochy070661
Level 1
Level 1

In the end, I followed https://icttowers.com/routing-switching/upload-ios-via-tftp-in-rommon/
The only thing I had to do: skipp the -r option in tftpdnld. It did download the file and wanted to boot it, but didn't write it down. Probably, I did something wrong.

Obstacles I had to overcome: You have to specify a DEFAULT_GATEWAY, even if you use a cross-over cable. The gateway must not be the TFTP_SERVER. So I used an IP that didn't exist.

rommon 1> IP_ADDRESS=10.0.0.1
rommon 2> IP_SUBNET_MASK=255.255.255.0
rommon 3> DEFAULT_GATEWAY=10.0.0.10
rommon 4> TFTP_SERVER=10.0.0.2
rommon 5> TFTP_FILE=c2900-universalk9-mz.SPA.157-3.M.bin
rommon 6> tftpdnld 



I thank all of you. You had been very helpful!

Attention: It will delete all files on the disk if you use no option (skip -r)

Thanks for the update. Glad that you got it worked out.

It is very interesting (and a bit surprising) that you need to specify a default gateway even when both devices are in the same subnet.

HTH

Rick


@Richard Burts wrote:

It is very interesting (and a bit surprising) that you need to specify a default gateway even when both devices are in the same subnet.


Ditto.

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