Restoring a flash image

The switch can lose its operating system if either the primary or secondary flash image location is empty or contains a corrupted OS file and an operator uses the erase flash command to erase a good OS image file from the opposite flash location.

Recovering from an empty or corrupted flash state

Use the switch's console serial port to connect to a workstation or laptop computer that has the follo wing:

A terminal emulator program with Xmodem capability, such as the HyperTerminal program included in Windows PC software.
A copy of a good OS image file for the switch.

NOTE: The following procedure requires the use of Xmodem and copies an OS image into primary flash only.

This procedure assumes you are using HyperTerminal as your terminal emulator. If you use a different terminal emulator, you may need to adapt this procedure to the operation of your particular emulator.

Start the terminal emulator program.

Ensure that the terminal program is configured as follows:
- Baud rate: 9600
- No parity
- 8 Bits
- 1 stop bit
- No flow control
Use the Reset button to reset the switch.

The following prompt should then appear in the terminal emulator:
```
Enter h or ? for help.

=>
```
Because the OS file is large, you can increase the speed of the download by changing the switch console and terminal emulator baud rates to a high speed. For Example:
1. Change the switch baud rate to 115,200 Bps.
  => sp 115200
2. Change the terminal emulator baud rate to match the switch speed:
  1. In HyperTerminal, select Call|Disconnect.
  2. Select File|Properties.
  3. Click on Configure.
  4. Change the baud rate to 115200.
  5. Click on [OK], then in the next window, click on [OK] again.
  6. Select Call|Connect.
  7. Press [Enter] one or more times to display the => prompt.
Start the Console Download utility by entering do at the =prompt and pressing [Enter]:
```
 => do
```

You then see this prompt:

You have invoked the console download utility. 
Do you wish to continue? (Y/N)>_

At the above prompt:
1. Enter y (for Yes)
2. Select Transfer|File in HyperTerminal.
3. Enter the appropriate filename and path for the OS image.
4. Select the Xmodem protocol (and not the 1k Xmodem protocol).
5. Click on [Send].
If you are using HyperTerminal, you will see a screen similar to the following to indicate that the download is in progress:

Example: of Xmodem download in progress

When the download completes, the switch reboots from primary flash using the OS image you downloaded in the preceding steps, plus the most recent startup-config file.

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