Jan 252008

Any software is pron to have software upgrades either to fix a bug or a Security vulnerability or even for the fact the software has reached its end of life.

While Network devices and appliances are no exception, the upgrade process requires a lot of precautions and measures are taken to ensure that the upgrade process doesn't fail or cause problems post installation. Upgrading Cisco IOS is no exception. Care has to be taken to ensure that the newer version is tested on a test bed before deploying in the production network especially if we are talking core network switches and routers.

The following procedure takes you through the steps to successfully upgrade Cisco IOS in a Cisco Router or a Switch. The latest version of the Cisco IOS can be downloaded from the Cisco Software Downloade center. You need to be a registered user to be able to download the software.


Write Unsaved configurations

ciscorouter# write memory
Building configuration…

Check space on Flash Memory

ciscorouter# show flash

Backup Startup Configuration

Setup a TFTP server in the same IP range as the Cisco device to backup the configs, IOS image and also for later to upload the new IOS image.

ciscorouter# copy startup-config tftp
Address or name of remote host []?
Destination filename [startup-config]?
1278 bytes c opied in 0.100 secs

Click the links for Backups using FTP & Hyperterminal

Backup Current IOS Image

ciscorouter# copy flash: tftp:
Source filename []? xxxxx-xx-xx.121-x.XB
Address or name of remote host []?
Destination filename [xxxxx-xx-xx.121-x.XB]?

Now, we are all set. Load the new IOS image from the TFTP onto the flash

ciscorouter# copy tftp: flash:
Address or name of remote host []?
Source filename []? xxxxx-xx-xx.121-x.XB
Destination filename [xxxxx-xx-xx.121-x.XB]?
%Warning:There is a file already existing with this name
Do you want to over write? [confirm]
Accessing tftp://…
Erase flash: before copying? [confirm]
Erasing the flash filesystem will remove all files! Continue? [confirm]
Erasing device… eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
ee …erased
Erase of flash: complete
Loading xxxxx-xx-xx.121-x.XB from (via Ethernet0): !!!!!!!!!!!!!!!!!!!!

[OK – 3802992/7605248 bytes]

Verifying checksum…  OK (0x1ABC)
3802992 bytes copied in 68.236 secs (65568 bytes/sec)

 This may error if there isn't enough memory in which case, you need to delete the existing image and copy the newer image onto the router  or switch.

On a Cisco Catalyst 3560

ciscorouter# delete /force /recurssive flash:/c3560-ipbase-mz.122-35.SE5 

ciscorouter#sh flash:
Directory of flash:/

   3  -rwx        1216   Mar 1 1993 00:10:27 +00:00  config.text
   4  -rwx           5   Mar 1 1993 00:10:27 +00:00  private-config.text

15998976 bytes total (15995904 bytes free)

That deletes the existing image and the show command just show that.

Now copy the newer image onto the flash

ciscorouter#copy tftp: flash:
Address or name of remote host []?
Source filename []? c3560-ipbasek9-mz.122-40.SE.bin
Destination filename [c3560-ipbasek9-mz.122-40.SE.bin]?
Accessing tftp://…
Loading c3560-ipbasek9-mz.122-40.SE.bin from (via Vlan1): !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[OK – 8295106 bytes]

8295106 bytes copied in 124.571 secs (66589 bytes/sec)

Check if the version is upgraded

ciscorouter# sh flash

Update the system config to boot with new image.

ciscorouter(config)#boot system flash:/c3560-ipbasek9-mz.122-40.SE.bin 

If it looks ok. Reload the Cisco Router

ciscorouter# reload

When is back online check if the cisco device has booted with the new Cisco IOS image.

ciscorouter# sh ver

Thats it. We are rocking!!!!

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  19 Responses to “How to Upgrade Cisco IOS in a Cisco Router or a Switch”

  1. Hi I am Bippin srivathsa, I am interested in formattin the flash, plz let me know if it is possible

  2. format flash:

    should do….but this completely removes everything from the flash

  3. hello

    Please send me How Download New Flash file and how to upgrade
    flash file

    plase send ..

    in which side free download .bin flle of flash memory


  4. Hi I am Bippin srivathsa, I am interested in formattin the flash, plz let me know if it is possible

  5. it still post error message

  6. Thanks for this info, I was stuck just at the last hurdle of setting the new IOS to start after the reload. Wasnlt putting :/ beforee the .bin filename



  7. Hi,

    I tried as shows this output but if you can see at the end you’ll see where I’m blocked

    BC-KIN-HQ-SW_LOG#sh flash

    Directory of flash:/

    2 -rwx 1304 Mar 12 1993 00:37:15 +01:00 vlan.dat
    4 -rwx 7216 Mar 24 1993 07:43:19 +01:00 config.text
    5 drwx 192 Mar 1 1993 01:06:46 +01:00 c3560-ipbase-mz.122-35.SE5
    463 -rwx 5 Mar 24 1993 07:43:19 +01:00 private-config.text

    15998976 bytes total (6936576 bytes free)

    BC-KIN-HQ-SW_LOG#copy flash tftp
    Source filename []? config.text
    Address or name of remote host []?
    Destination filename [config.text]?
    7216 bytes copied in 0.025 secs (288640 bytes/sec)

    BC-KIN-HQ-SW_LOG#copy flash tftp
    Source filename [config.text]? vlan.dat
    Address or name of remote host []?
    Destination filename [vlan.dat]?
    1304 bytes copied in 0.008 secs (163000 bytes/sec)

    BC-KIN-HQ-SW_LOG#copy flash tftp
    Source filename [c3560-ipbase-mz.122-35.SE5.bin]? c3560-ipbase-mz.122-35.SE5
    Address or name of remote host []?
    Destination filename [c3560-ipbase-mz.122-35.SE5]?
    %Error reading flash:c3560-ipbase-mz.122-35.SE5 (Is a directory)

    My big problem is the last message. I can’t copy the ios from the flash to my computer. it says : %Error reading flash:c3560-ipbase-mz.122-35.SE5 (Is a directory)

    Can U help me soleve this issue please

  8. I erased the flash

    and now I want to restaure the system

    can you help me

  9. flashfs[0]: 0 files, 1 directories
    flashfs[0]: 0 orphaned files, 0 orphaned directories
    flashfs[0]: Total bytes: 32514048
    flashfs[0]: Bytes used: 1024
    flashfs[0]: Bytes available: 32513024
    flashfs[0]: flashfs fsck took 7 seconds.
    …done Initializing Flash.
    Boot Sector Filesystem (bs) installed, fsid: 3
    Loading “flash:c3560-ipbase-mz.122-35.SE5/c3560-ipbase-mz.122-35.SE5.bin”…flas
    h:c3560-ipbase-mz.122-35.SE5/c3560-ipbase-mz.122-35.SE5.bin: no such file or dir

    Error loading “flash:c3560-ipbase-mz.122-35.SE5/c3560-ipbase-mz.122-35.SE5.bin”

    Interrupt within 5 seconds to abort boot process.
    Boot process failed…

    The system is unable to boot automatically. The BOOT
    environment variable needs to be set to a bootable


  10. Thanks …. really help this explanation. I have upgrade IOS without any error.

    Thanks Again.

  11. my i do upgrade the ios remotely after deleting the current image in the router

  12. Thanks for the tip. I treat my Cisco routers like my women. Well, maybe that doesn’t make sense, however, I jotted down your tips.

  13. %Error reading flash:c3560-ipbase-mz.122-35.SE5 (Is a directory)

    Hi u got this error bcos u tried to copy the whole directory so go under the directory c3560-ipbase-mz.122-35.SE5.

    cd flash:c3560-ipbase-mz.122-35.SE5
    Directory of flash:/c3560-ipbase-mz.122-35.SE5/

    8 -rwx 6875865 Mar 1 1993 00:06:58 +00:00 c3560-ipbase-mz.122-35.SE5.bin
    9 drwx 4160 Mar 1 1993 00:07:19 +00:00 html
    464 -rwx 422 Mar 1 1993 00:07:53 +00:00 info


    copy flash:c3560-ipbase-mz.122-35.SE5/c3560-ipbase-mz.122-35.SE5.bin tftp:
    Address or name of remote host []?
    Destination filename [c3560-ipbase-mz.122-35.SE5.bin]?
    6875865 bytes copied in 20.048 secs (342970 bytes/sec)

    that is it.


  14. Hi, Chill

    I got the same error:

    %Error reading flash:c3560-ipbase-mz.122-35.SE5 (Is a directory)

    Following as below it’s working

    Switch#copy flash tftp
    Source filename [c3750-ipbasek9-mz.122-50.SE1.bin]? c3750-ipbasek9-mz.122-50.SE1/c3750-ipbasek9-mz.122-50.SE1.bin
    Address or name of remote host []?
    Destination filename [c3750-ipbasek9-mz.122-50.SE1.bin]?
    10281014 bytes copied in 36.692 secs (280198 bytes/sec)

  15. on deleting current ios recursive is misspelled on how to…very nice instructions though!

  16. hi i have some problem in my IT work plz help me.

  17. hi i am humza I have a problem in my switch catalyst 3500 series so the problem is that they show in the starting this format switch: so please recommend me for the solution.


  18. Thanks alot for your help


  19. could some one help how we delete the image permamenently from flash. becoz i try that but it again see to me with some [] value just like we delete some files and it see in recycle bin so any one who can give me the command in 3560 switch

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