Breaking / Password Recovery - Cisco C8500-12X

[PatrickAndersen]

Hi,

Our company recently acquired 2 x Cisco C8500-12X. 

One of my colleagues initially setup the first C8500-12X however, forgot to add a local user / enable password, but did setup tacacs authentication. We can no longer access the device, since it asks for credentials. Unfortunately it wasn't fully configured yet, so no IP's has been setup to trick a connection towards our tacacs server.

However, the problem is that we cannot initiate a password recovery process / initate rommon / break the device. I'm 99% sure that my colleague did not disable password recovery, primarily because we've never had the need to do so.

Any creative ideas as to how we may succesfully break the device, in order to initiate the password recovery / factory reset the device?

Best Regards,

Patrick Andersen

[Leo Laohoo]

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@PatrickAndersen wrote:

the problem is that we cannot initiate a password recovery process / initate rommon / break the device

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Why not? 

When the router is rebooting, what happens if someone keeps bashing Ctrl+C?

[PatrickAndersen]

Hi Leo,

I'll post the full output during reboot first thing tomorrow morning, but a quick recap is that it never enters the part where it allows you to break the device into rommon. Despite spamming Ctrl+C or other similar options.

Best Regards,

Patrick Andersen

[PatrickAndersen]

Hi Leo,

I've attached the boot output as a txt file.

It does display some file system not clean errors, but admittedly haven't looked into it, since it boots fine in general (aside from not presenting a break/interrupt option during boot ofc).

Best Regards,

Patrick Andersen

[Leo Laohoo]

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@PatrickAndersen wrote:

no valid BOOT image found

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Well, looks like someone really munted the config really bad. 

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@PatrickAndersen wrote:

System Bootstrap, Version 17.3(2r), RELEASE SOFTWARE
Copyright (c) 1994-2020  by cisco Systems, Inc.

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Get a different machine.  Once you get to this part, start bashing the Ctrl+C like your life depend on it. 

If Ctrl+C does not work, try Ctrl+Break.  

[PatrickAndersen]

Hi Leo,

I'll give it another shot.

Best Regards,

Patrick Andersen

[PatrickAndersen]

Hi Leo,

Unfortunately no luck.

Best Regards,

Patrick Andersen

[Leo Laohoo]

RMA time

[PatrickAndersen]

Hej Leo,

What a shame, but such is life.

Thanks for the assistance

Best Regards,

Patrick Andersen

[brianmeldrum0404]

so just had this problem as well, and i found that i really had to lay into the break command, i ended up hitting it about 15 times just after applying power and it finally took. it seems the window for breaking into these new routers is much tighter then it was before.