Or (this is how it is on my 3550) use the 'no switchport' command first. The interfaces default to switchport mode so you can't apply an IP address or other layer 3 commands. Once you take it out ...

How in the blazing f*£& do I change the static IP address of a Cisco SG350-10 without using a console cable? I've updated it to the latest firmware, 2.5.0.92, and reset to factory defaults after ...