The following tip is similar to the one on the Router IOS image transfer. It is highly recommended that you are familiar with Router IOS image transfer procedure (including the troubleshooting) before attempting Switch IOS image transfer, especially when it comes to troubleshooting.
As a warning, you won’t enjoy recovering a switch that has no valid IOS image on its flash memory. The procedure to recover is more complicated and somewhat complex than router IOS image recovery.
1) In order to transfer the tar file you need a TFTP program. One example is located at »Cisco Forum FAQ »How to prepare TFTP server
When you are done downloading the tar file confirm the md5.
2) Issue dir flash: to verify you have enough space.
SW1#dir flash:
Directory of flash:/ Continue reading “How do I upgrade an IOS tar file on a 2950 Catalyst switch?”