Monday, 26 March 2012

Break Sequence to access Rommon on a Cisco Router

I was handed a lovely new laptop by work, but it didn't have a pause/break key.  I needed to perform password recovery on a router we'd have for too long and thus I though I was stuck for a minute.

But you can initiate a break sequence by doing the following:
  • Obviously connect to the router via the console port
  • Open a hyperterminal/terminal session (I use Putty.exe) and set the connection to use serial and a speed of 1200.
  • Power off the router and back on again, whilst pressing the keyboard every second, for 10-15 seconds.  You will just see a load of crap on the screen, but thats not a problem.
  • Close the terminal session (do not power cycle the router or anything) and open a new one with the correct baud speed of 9600.  You may have to press enter, but it'll put you at the Rommon prompt.

6 comments:

  1. Thank you this worked for me :)

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  2. Nice tip! Tks

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  3. Great tip! I actually needed to keep pressing keys for over 30 seconds but it worked in the end. Thanks

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  4. This is epic. Thanks

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