Copying Cisco IOS from One Router to Another

Sometimes, we need to transfer IOS from one router/platform to another. Other times, we can end up in Rommon> prompt because an IOS download failed of similar issue.

Let’s start with a stranded router. It is strongly suggested that you get a PCMCIA memory card, insert it into a good router. From priviledged mode on the good router enter the following:

Cell_Router#dir flash:

This will show you the filename of the .bin file you need. For this example, we will call it: SOURCE-IOS-FILE.bin

Now issue the following command to copy the binary to the PCMCIA card:

Cell_Router#copy flash:SOURCE-IOS-FILE.bin slot0:

You will be prompted to erase the card and then it will copy.

Next, remove the PCMCIA card fromt he good router and insert it into the bad router that is at Rommon prompt.

Enter the following command:

Rommon1>boot slot0:

This will start up the router using the IOS on the PCMCIA card. Once booted and in priviledge mode, you can now copy the binary from the PCMCIA card to flash:

Router#copy slot0:SOURCE-IOS-FILE.bin flash:

This should be quite fast.

Now a little clean up. First, remove the PCMCIA from the bad router. Next, check the flash directory with the following command:

Router#dir flash:

If the copied .bin is there and alone in the directory, you are good to go with a reload. If not, you may want to delete any other binary using the delete command. Now reload.


Another option is this way: on the source router that contains the IOS file that you want to copy, issue the following command:

Router(config)#tftp-server flash:/SOURCE-IOS-FILE.bin

Where SOURCE-IOS-FILE.bin is the name of the IOS file that you want to copy.

Now you can TFTP to the router and copy the file.  This command will make the router act as a TFTP server.

See the How to Upgrade IOS process for further information.

After you complete the copy operation, issue the command:

Router(config)#no tftp-server flash:/SOURCE-IOS-FILE.bin

We hope that helps!

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