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How to boot with no IOS in flash

dbuckley77
Level 1
Level 1

I have a 2950 that is at the switch: prompt with no IOS in flash.  When I try to copy an IOS image via tftp I get "tftp: access denied."

 

Is there another way that I can copy the image to the flash?

1 Accepted Solution

Accepted Solutions

Peter Paluch
Cisco Employee
Cisco Employee

Hi,

2950 switches in bootloader mode do not support networking. Your only option is downloading the IOS back using console and either HyperTerminal or TeraTerm - you need the Xmodem or Xmodem-1k support.

Proceed as follows:

  1. In the bootloader prompt on the switch, enter set BAUD 115200 and hit Enter. Be sure not to make any typo here. As soon as you enter this command, your console will appear to freeze - at this point, reconfigure your terminal software to use the 115,200 bps and hit Enter a few times - the switch should start responding again.
  2. Have the replacement IOS file prepared on the PC, however, rename it to a simple filename, say, c2950.bin.
  3. Enter the following command on the switch: copy xmodem:c2950.bin flash:c2950.bin and hit Enter. As soon as you do this, a series of 'C' characters will start appearing on the screen.
  4. Using the Send File or Transfer File function in your terminal software, select the Xmodem-1k (preferred) or Xmodem protocol, then locate the c2950.bin file and let the terminal send it to the switch.
  5. Have a coffee - the download can last 15-30 minutes.
  6. After the download is finished, enter the unset BAUD command in the switch and reconfigure your terminal back to 9,600 bps. The console will be unresponsive in the meantime.
  7. Now enter the boot command on the switch and it should boot up fine. After it boots up into IOS, you may want to rename the IOS file in the FLASH back to the original name using the rename privileged EXEC command.

Best regards,
Peter

View solution in original post

5 Replies 5

  • You can try ftp.
  • Also via console you can copy through xmodem (in hyperterminal)

Peter Paluch
Cisco Employee
Cisco Employee

Hi,

2950 switches in bootloader mode do not support networking. Your only option is downloading the IOS back using console and either HyperTerminal or TeraTerm - you need the Xmodem or Xmodem-1k support.

Proceed as follows:

  1. In the bootloader prompt on the switch, enter set BAUD 115200 and hit Enter. Be sure not to make any typo here. As soon as you enter this command, your console will appear to freeze - at this point, reconfigure your terminal software to use the 115,200 bps and hit Enter a few times - the switch should start responding again.
  2. Have the replacement IOS file prepared on the PC, however, rename it to a simple filename, say, c2950.bin.
  3. Enter the following command on the switch: copy xmodem:c2950.bin flash:c2950.bin and hit Enter. As soon as you do this, a series of 'C' characters will start appearing on the screen.
  4. Using the Send File or Transfer File function in your terminal software, select the Xmodem-1k (preferred) or Xmodem protocol, then locate the c2950.bin file and let the terminal send it to the switch.
  5. Have a coffee - the download can last 15-30 minutes.
  6. After the download is finished, enter the unset BAUD command in the switch and reconfigure your terminal back to 9,600 bps. The console will be unresponsive in the meantime.
  7. Now enter the boot command on the switch and it should boot up fine. After it boots up into IOS, you may want to rename the IOS file in the FLASH back to the original name using the rename privileged EXEC command.

Best regards,
Peter

I was able to change the Baud on the switch to 115200 successfully but when I changed the session options in SecureCRt to anything but 9600 baud I could not see the text on the switch.  Anyway I ran it at 9600 Baud.  Took awhile but it's done now.  Thanks

So just so others might not get as confused as I did, the putty referenced is not the very basic putty.  I had one and there was no xmodem transfer part, or at least that I was able to work.  I had to download Extraputty program which has the xmodem transfer capability as part of it. 

 

I hope this helps.

Do not change the filename...it will alter the checksum value of the original file and the switch will fail to load the IOS

 

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