UPLOAD OR UPGARDE IOS ON ROMMON MODE

How to upgrade from Rommon using the boot image? Or How can I upgrade 

IOS or upload IOS switch  3750 on Rommon mode?

What Is the Boot Image? (Rx-boot)

The boot image is a subset of the Cisco IOS® software that is used to 

download main Cisco IOS software images to the router using TFTP in recovery 

situations. The user can interact with this image through a command line 

interface signified by the prompt Router(boot)#. Some platforms 

(Cisco 1600, 2500) have it in ROM; others (high-end routers) have it in 

bootflash. This image can be called xboot image, rxboot image, bootstrap 

image, or boot loader or helper image, which 

depends on your platform.

rommon 1 > confreg 0x2101

or

> o/r 0x2101

You must reset or power cycle for the new configuration to take effect.

The configuration register has now been changed to boot the boot 
image.

boot the boot image by resetting the router:

rommon 2 > reset

or

> i

The System Bootstrap message appears and the router boots its 

boot image. On the screen, you should see something like this:

System Bootstrap, Version 11.1(10)AA, EARLY DEPLOYMENT RELEASE SOFTWARE (fc1)

……..

program load complete, entry point: 0x4018060, size: 0x1e1568

Restricted Rights Legend 

Router(boot)>

You should now have a prompt similar to Router(boot)>.

If you are still in ROMmon, that means your boot image is either missing 

or corrupted. If your router has no valid image in Flash or Bootflash,

Connect the Ethernet interface 0 of your router to the network, through 

which you can reach the TFTP server. Configure the IP address on the 

Ethernet interface of the router.

Router(boot)>enable

Router(boot)#configure terminal 

Router(boot)(config)#interface ethernet 0 

Router(boot)(config-if)#ip address 10.77.241.160 255.255.255.0    

Router(boot)(config-if)#no shutdown

Routers that run boot images do not have routing capabilities. 

Therefore, a default gateway for this router must be configured. Issue 

the ip default-gateway global configuration command to set the 

appropriate default gateway for this router. This should point to the IP 

address of the router attached to the same subnet as your Ethernet 0 

interface.

Router(boot)(config)#ip default-gateway 10.77.241.129

Before you copy the Cisco IOS image from the TFTP server, make sure 

that the router has connectivity to the TFTP server.

Router(boot)#ping 10.77.233.94

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echoes to 10.77.233.94, timeout is 2 seconds:

.!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 4/4/4 ms

Router(boot)#

Copy the Cisco IOS image from the TFTP server to the Flash memory on 

the router.

Router(boot)#copy tftp flash

Address or name of remote host [255.255.255.255]? 10.77.233.94 

!--- Enter the IP address of the TFTP Server.

Source file name? c1600-y-l.122-10d.bin

!--- This is the filename of the Cisco IOS image that you want to copy from

!--- the TFTP server.

Destination file name [c1600-y-l.122-10d.bin]?

!--- Press 'Enter'.

 

Accessing file 'c1600-y-l.122-10d.bin' on 10.77.233.94...

Loading c1600-y-l.122-10d.bin from 10.77.233.94 (via Ethernet0):

 [OK]  Device needs erasure before copying new file

Erase flash device before writing? [confirm]y

!--- Press 'y' or 'Enter'.

!--- On Class B Flash file systems, the router gives you the option of erasing

!--- the existing contents of Flash memory before writing to it. If no free Flash

!--- memory is available, or if no files have ever been written to Flash memory,

!--- the erase routine is required before new files can be copied. If there is

!--- enough free Flash memory, the router gives you the option of erasing the

!--- existing Flash memory before writing to it. The system will inform you

!--- of these conditions and prompt you for a response.

!--- If you enter 'n' after the "Erase flash before writing?" prompt, the copy

!--- process continues.  If you enter 'y' and confirm the erasure, the erase

!--- routine begins.  Make sure to have ample Flash memory space before entering "n"

!--- at the erasure prompt.

Copy 'c1600-y-l.122-10d.bin' from server as 'c1600-y-l.122-10d.bin' 

into Flash WITH erase? [yes/no]yes  

!--- Entering 'yes' erases all the files in Flash.

Erasing device... eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee

eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee  ...erased

Loading c1600-y-l.122-10d.bin from 10.77.233.94 (via Ethernet0): !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

!!!!!!!!!!!!!!!!!!

[OK - 7220632/16777216 bytes]Verifying checksum...  OK (0x6526)

Flash device copy took 00:05:57 [hh:mm:ss]

Router(boot)#

Change the configuration register value back to 2102 for the router to 

boot with the newly downloaded Cisco IOS image during the next reload.

Router(boot)#configure terminal

Router(boot)(config)#config-register 0x2102

Router(boot)(config)#exit

Router(boot)#

         
        Reload the router by issuing the reload command.

Router(boot)#reload

System configuration has been modified. Save? [yes/no]: no

  Building configuration...

  [OK]

  Proceed with reload? [confirm]

!--- Press 'Enter'.

     

  %SYS-5-RELOAD: Reload requested

  System Bootstrap, Version 11.1(10)AA, EARLY DEPLOYMENT 

RELEASESOFTWARE (fc1)

  Copyright (c) 1997 by cisco Systems, Inc.

  C1600 processor with 18432 Kbytes of main memory

  program load complete, entry point: 0x4018060, size: 0x1e1568

  .

!--- Output omitted.

  Router>

To verify if the correct image has been loaded into the router, check the 

Cisco IOS image version in the router by issuing the show version 

command.

Router>show version

Cisco Internetwork Operating System Software

IOS (tm) 1600 Software (C1600-Y-L), Version 12.2(10d), 

RELEASESOFTWARE (fc1

System image file is "flash:c1600-y-l.122-10d.bin"

System running from FLASH

7K bytes of non-volatile configuration memory.

16384K bytes of processor board PCMCIA flash (Read ONLY)

Configuration register is 0x2102

Router>

You are now running the new Cisco IOS image that has been loaded from a 

TFTP server.