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This document describes the procedure for performing password recovery on Cisco 750/760 series routers using the NVRAM erase code (750erase.hex or 760erase.hex). Choose the appropriate Terminal Emulation Package (Windows95 and Windows3.1x instruction are included).
Power cycle the router. While it is booting up, press the ESC key a couple of times. This will put the unit into a software load mode. The unit will respond with the following prompts:
Ready to upload new firmware into flash. Baud (1=19.2K, 2=2400, 3=38.4K, 9=9600)?
Select the baud rate for the transfer (in this example 9600 is chosen). The unit will respond with the following prompt.
Begin ascii upload at 8n1/9600 baud.
Start the ascii file transfer of the image, 750erase.hex for the 750 series or 760erase.hex for the 760 series. These files are not interchangeable. This file must be treated as a text file for loading into the unit via the console port. At 9600, the transfer takes approximately 12 minutes. While the transfer is occuring, the LINE LED will be flashing rapidly. When the transfer is complete the unit will respond with the following prompts and then reboot itself:
Firmware transfer successful.
Now writing firmware into FLASH, standby ...
Firmware upload complete.
Erase Version of 750/760 firmware This will erase all configured parameters
ERASING NVRAM...
(reboots itself)
Ready to upload new firmware into flash.
Baud (1=19.2K, 2=2400, 3=38.4K, 9=9600)?
At this point, reload the original software repeating step 2.
Procedure for performing a text/ascii transfer using Windows95 Hyperterminal
Choose Properties from the File Menu
Choose Settings Tab
Choose ASCII Setup Button
Make sure that both "Line Delay" and "Character Delay" are set to zero.
Make sure that "Send line ends with line feeds is check marked".
Click the OK Button on both screens.
Close Hyperterminal and then restart it.
Choose Send Text File... from the Transfer menu.
Locate file (may have to change Files of Type to All Files) and highlight it.
Click the OK Button.
The file is now being transferred to the unit...there may not be any indication that the file is transferring except for the LINE LED on the front of the unit. While the transfer is occuring, the LINE LED will be flashing rapidly on the front of the unit.
Procedure for performing a text/ascii transfer using Windows Terminal
Choose Text Transfers... from the Settings Menu.
Make sure that "Standard Flow Control" is chosen.
Click the OK Button.
Choose Send Text File... from the Transfer Menu.
Locate file (may have to change List Files of Type to All Files) and highlight it.
Make sure that neither Append LF nor Strip LF are check marked.
Click the OK Button.
The file is now being transferred to the unit...there may not be any indication that the file is transferring except for the LINE LED on the front of the unit. While the transfer is occuring, the LINE LED will be flashing rapidly on the front of the unit. |
