Speeding up your switch XMODEM transfers

I recently put the wrong image onto a 3560. When I rebooted the switch it attempted to load the IOS image, but failed.

The only way to fix this is to load the switch into ROMMON mode and load a new IOS through XMODEM. If you’ve ever done this you know how long this can take with the default settings!

XMODEM uses your baud rate console speed, so if it’s at the default of 9600, that’s a transfer speed of 9.6k per second. i.e. a 12Mb 12.2 (50) ipservices image is going to take over 4 hours to load! And that’s hoping that there is not a single error in the whole process!

How to make this quicker? Once you’re in ROMMON mode, do the following:switch: set BAUD 115200

You’ll now either be disconnected, or see gibberish as your terminal app is still 9600. Close your terminal application and reconfigure it to a baud rate of 115200.

Now start the xmodem transfer:switch: copy xmodem: flash:c3560-ipservices-mz.122-50.SE3.bin

This brough the copy down from 4 hours to 30 minutes.

Once done, set it back:switch: set BAUD 9600

Once again you’ll need to close your app and reconfigure it to connect at 9600 and then reboot:switch: boot flash:c3560-ipservices-mz.122-50.SE3.bin

What you can also do, is try and find the absolute smallest image you can for the xmodem transfer, and then once that image is loaded, use the regular tftp method to install the bigger image.