Recovering IOS on a Catalyst Switch

Recovery on a Cisco switch Cisco IOS image that is very nice to know, don't need it and need it, do not know one of its tasks. In the field, you may find yourself faced with a Cisco switch doesn't start or crashes, when you start the IOS image due to possible damage.

Lab Prerequisites:

• The lab will require genuine exchanger, because you can't use GNS3 emulation of the lab.
• Cisco IOS on switches must perform this lab is damaged or missing, to simulate this error can erase Flash to practice this lab.
• Equipment the active console session is required.
• You will need to use HyperTerminal/SecureCRT PuTTY does not support xModem.

Lab Objectives:

• Boot the exchanger to exchanger ROM mode.
• Initialize the Flash file system.
• Optional-if you want Flash file system formats. (This will remove your boot configuration)
• Is set to 115,200 baud rate increase the Xmodem transfer speed and reduce the time required to recover the IOS image.
• Via xModem copy the Cisco IOS image to Flash memory:
• To set the new image name located Flash startup parameters:
• Cancel set the baud rate, it will default to 9,600 back.
• Start switch, and verify that the switch boots.

Lab Instruction:

Restore a previous hotfix to configure Cisco Catalyst series switch Cisco IOS image is quite a big difference and a lot of "old school" way IOS image restoration. Unfortunately, fixed-configuration switches need to use xModem restore corrupt or missing IOS images with Cisco and Cisco 4,500 6,500 series supervisor engine, uses Compact Flash cards of different

Step 1. Start your exchanger to exchanger ROM mode. This usually involves holding down a STAT button when you plug in the power supply before the switch. You can click here to check out the program you need!

As soon as you boot your exchanger to exchanger ROM mode you will see the following schedule;

Boot Sector Filesystem (bs) installed, fsid: 2

Base ethernet MAC Address: 00:14:f2:d2:41:80

Xmodem file system is available.

The password-recovery mechanism is enabled.

The system has been interrupted prior to initializing the

flash filesystem.  The following commands will initialize

the flash filesystem, and finish loading the operating 

system software:

    flash_init

    boot

Step 2. Once you have the boot ROM to switch modes, you need to initialize the Flash file system by executing the flash_init command, as shown below;

switch: flash_init

Initializing Flash...

flashfs[0]: 1 files, 1 directories

flashfs[0]: 0 orphaned files, 0 orphaned directories

flashfs[0]: Total bytes: 15998976

flashfs[0]: Bytes used: 12474880

flashfs[0]: Bytes available: 3524096

flashfs[0]: flashfs fsck took 10 seconds.

...done Initializing Flash.

Step 3. optional if your image is damaged you can format your Flash file system by performing a format Flash: command, but this will remove your boot configuration looks like this!!!

Switch: format flash:

Are you sure you want to format "flash:" (all data will be lost) (y/n)?y

flashfs[0]: 0 files, 1 directories

flashfs[0]: 0 orphaned files, 0 orphaned directories

flashfs[0]: Total bytes: 7741440

flashfs[0]: Bytes used: 1024

flashfs[0]: Bytes available: 7740416

flashfs[0]: flashfs fsck took 12 seconds.

Filesystem "flash:" formatted

Step 4. To speed up the xModem file transfer rate you need by doing sets the baud rate of 115,200 console line baud rate is set to 115,200. If you do this you will need to disconnect the console session with the serial line speed from 9,600 to 115,200. But if you do not set the baud rate is 115,200 your file transfer can be up to 3 hours

switch: set BAUD 115200.

Step 5. Once the baud rate setting and reconnect to your Cisco switch console, you are ready to copy the IOS image via xModem to the switch's Flash memory, through the implementation of xModem file transfer that copy the Xmodem:Flash:filename.bin and start from the terminal emulation software to the client looks like this;

switch: copy xmodem: flash:c3560-ipservicesk9-mz.122-53.SE.bin

Begin the Xmodem or Xmodem-1K transfer now...

CCC

Starting xmodem transfer.  Press Ctrl+C to cancel.

Transferring c3560-ipservicesk9-mz.122-53.SE.bin...

  100%   12181 KB    6 KB/s 00:31:56       0 Errors

.................................................................

.................................................................

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File "xmodem:" successfully copied to "flash:c3560-ipservicesk9-mz.122-53.SE.bin"

switch: