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Router not booting

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  • Router not booting

    I had a interview question, If the IOS is corrupted and Hardware is fine, How to boot the router or switch?????????
    My answer was a layman's answer---restart the router/switch and check whether its working fine or not. Else we have bad Hardware. Now do we have situation, where the Hardware is fine and still we would be able to recover the IOS!!!!!!!!!!!!!!!!

  • #2
    Re: Router not booting

    You may have to reinstall the IOS image via tftp server, hope you have the configs dumped to file somewhere...


    • #3
      Re: Router not booting

      You can boot into rommom and upload a new image using tftp
      Technical Consultant

      MCITP(EA, SA), MCSA/E 2003:Security, CCNA, SNAF, DCUCI, CCSA/E/E+ (R60), VCP4/5, NCDA, NCIE - SAN, NCIE - BR, EMCPE
      "No matter how secure, there is always the human factor."

      "Enjoy life today, tomorrow may never come."
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      • #4
        Re: Router not booting

        Be aware some devices, mainly some cisco switches dont have a tftp option in ROMMON so the only other alternative is using xmodem which takes forever.
        CCNA, CCNA-Security, CCNP
        CCIE Security (In Progress)


        • #5
          Re: Router not booting

          most cisco routers have a flash card
          just copy an IOS on the flash card using a reader with your PC after you remove the old IOS from it (be sure to copy the old IOS to your PC just incase)
          and then insert the card to your router.

          when the router starts booting it'll search for the IOS image that is stated in the configuration, but if it doesn't find it then it'll boot from the image you have on the disk.

          after you boot your router with the new image clean the old configuration and put in the new IOS boot command.


          • #6
            Re: Router not booting

            The correct answer would be to put the router into ronmon mode and use either tftp or Xmodem to put new IOS onto the router.

            Ive had to recover a few of these over the yrs
            Shadow2k - MCP, MCSA, MCSA:Security, MCSE, MCSE:Security, MCTSx8, MCITP:SA, MCITP:EA, MCITP:EDA, MCITP:VA, MCITP:EDST