In preparation of your CCNA exam, we want to make sure we cover the various concepts that we could see on your Cisco CCNA exam. So to assist you, below we will discuss one of the more difficult CCNA concepts; how to recover from a deleted IOS on a Cisco 2900 or 3550 Switch. As you progress through your CCNA exam studies, I am sure with repetition you will find this topic becomes easier. So even though it may be a difficult concept and confusing at first, keep at it as no one said getting your Cisco certification would be easy!

During our Cisco CCNA certification studies, there will be many times we will make a mistake that we wish we did not. One of them will surely be deleting the IOS on a Cisco router or Cisco switch by mistake. Some times you do this during your Cisco CCNA studies when you are trying to do an IOS upgrade and it goes awry or sometimes just the slip of a keyboard click. In either situation, below we will cover the process for you to reload the Cisco IOS on a Cisco 2900 or 3550 switch using hyperterminal. We will assume you have read our document on how to connect to your switch via hyperteminal already and know how to do that.

So let’s also take this time to review a few commands for your Cisco CCNA studies. Connect via hyperterminal and boot the Cisco 3550 switch(this is also the same process for the Cisco 2900 series, so if you have a 2900 switch, just change the file name).

After you boot the switch, if your IOS is deleted you will end up at the following prompt:

So now time to review CCNA commands. Let’s verify that we actually deleted our IOS on the switch. Issue the following command which will display the contents of your switch’s flash:
switch: dir flash:
2 −rwx 556 Mar 01 1993 00:00:35 vlan.dat
4 −rwx 1595 Mar 01 1993 19:52:41 config.text

Ok, so we verified with our first new CCNA command that there is actually no IOS file in there. IOS files just in case you did not know usually have a .bin extension. We do se a config file and a vlan.dat file. But neither of them are IOS files. So time to practice our Cisco CCNA skills by reloading our Cisco IOS. Now I warn you, this will take a while.

Read this next part a couple of times to make sure you really understand what you are about to do. As you have to do this quite quickly or it will timeout. But being sure you are starting to master your Cisco CCNA concepts, you will pick it up with no problem at all. Worst case, if it times out, you can start over again as it is more practice preparing your for your Cisco CCNA exam!

On your Cisco 2900 or 3550 switch you will be at the following prompt: switch:
type in the following command(assuming this is the name of the Cisco IOS you have loaded on your computer that you are using hyperterminal from)
switch: copy xmodem: flash:c3550-ipservicesk9-mz.122-25.see.bin

In hyperterminal, it will start to say…..
Begin the Xmodem or Xmodem-1K transfer now…

As soon as you see that(quickly) go in the hyperterminal menu to:
Send File
(browse to the IOS filename)
(You should see the file c3550-ipservicesk9-mz.122-25.see.bin)
Double click the c3550-ipservicesk9-mz.122-25.see.bin file.
Click Send

You should see the file start to upload and transfer. Once it is complete, you should see a message similar to this:
File “xmodem:” successfully copied to “flash: c3550-ipservicesk9-mz.122-25.see.bin “

At that point, shut the switch off and turn it back on and see if it boots properly. Hopefully it did and then you have one more Cisco CCNA concept conquered on your way to achieving your Cisco CCNA certification!

I hope you found this article to be of use and it helps you prepare for your Cisco CCNA certification. I am sure you will quickly find out that hands-on real world experience is the best way to cement the CCNA concepts in your head to help you pass your CCNA exam!