• Creator
  • #2209444

    How to restore cisco IOS switch( catalyst 3750 series)


    by tawfikm ·

    By mistake , I remove IOS cisco switch (catalyst 3750 series ) and I don’t have any backup!!!

    What is the best way to restore the switch IOS ? If there is no backup for it .

All Answers

  • Author
    • #2444505


      by tawfikm ·

      In reply to How to restore cisco IOS switch( catalyst 3750 series)


    • #2444472

      Fairly easy to fix

      by robo_dev ·

      In reply to How to restore cisco IOS switch( catalyst 3750 series)

      You can copy the bin file from a PC using hyperterminal (and xmodem) to transfer to the device with the console cable. While the official answer is that you need to get the image from Cisco, with some google searches, you will find a copy somewhere on the Internet. Of course if you have another 3750, you can also copy the bin file to the PC using hyperterminal/xmodem. (of course if this were a router it would have a flash-card slot,which is a lot faster way to do this).

      • #2445371

        Reponse To Answer

        by tawfikm ·

        In reply to Fairly easy to fix

        Copying the IOS from another 3750 it will be better , but how can I do the copying from another 3750 ??

    • #2445334

      Loadup a TFTP server on your PC

      by robo_dev ·

      In reply to How to restore cisco IOS switch( catalyst 3750 series)

      Such as the free Solarwinds TFTP server

      Using Hyperterminal to telnet to switch, at the enable prompt:

      show flash

      copy the file name of the flash by highlighting it with mouse, right click, copy

      copy flash: tftp:

      it will ask source filename (paste what you copied above)
      it will ask address or name of remote host
      it will ask destination filename

      then it will copy the flash to the PC

      (also good time to make copy of your config)

      Now to get the flash back onto the messed up router, you need to connect via serial console cable, connect via Hyperterminal to it, and use Xmodem to transfer it from your PC to the blank device.

      Cisco 3750 software recovery

      Text below copied from link above:

      2. Connect to the switch using Hyperterminal at 9600 baud, 8 N 1.

      3. You should see a prompt that says ???switch:???. This is the bootloader mode. If you don???t see that, either you???re booted up, and you don???t need these instructions, your switch is properly broken, or you???ve got your terminal settings wrong. Try power-cycling the Catalyst while holding the ???Mode??? button on the front in to get the bootloader.

      4. Now downloading the .bin file at 9600 baud is going to take a loooong time (about 2 hours), so we will change the baud rate of the console port temporarily. Enter the command ???set BAUD 115200???. After you enter this command, you will start to get funny characters in Hyperterminal because its baud rate and the Catalyst???s are now mis-matched.

      5. Close Hyperterminal and re-connect using 115200 baud instead. You should get intelligible stuff on the screen once more.

      6. Type ???flash_init??? to initialise the filesystem. (In our case, this wasn???t necessary)

      7. Type ???load_helper??? to load any helper files (in our case there weren???t any since we???d just wiped the flash).

      8. Tell the switch to expect a file by Xmodem, and put it on the flash: ???copy xmodem: flash:??? <<??? and the IOS will load up.

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