Upgrading IOS Version

You will need a tftp server on which to put the latest IOS version and to which to can backup the old one. A Windows based one is easy [1]. This assumes that the switch already has an IP set, otherwise follow this link [2]. Below works for Catalyst 29XX and 37XX models. For Catalyst 49XX models, change flash to bootflash.

1. Determine the boot image on the switch:

  switch# show flash

2. Backup the flash image to the tftp server

  switch# copy flash:flashimagename tftp://192.168.X.X/flashimagename

where 192.168.X.X is the IP address of the TFTP server.

3. If there is room, leave the old image in place. Otherwise do OPTIONAL and DANGEROUS:

  switch# delete flash:imagename

If the flash image is in a directory:

  switch# delete /force /recursive flash:flashdirectory

4. Upload the new flashimage

  switch# copy tftp://192.168.X.X/newflashimage flash:newflashimage

5. Make the new image the boot image and reboot

  switch# config t
  switch(config)# no boot system flash:oldflashimage
  switch(config)# boot system flash:newflashimage
  switch(config)# exit
  switch# wr mem

6. Reboot the switch

  switch# reload