Hi,
Which switch you have ?
This appendix lists some of the command-line interface (CLI) commands that appear when you enter the question mark (?) at the Catalyst 3750-E or 3560-E switch prompt but are not supported in this release, either because they are not tested or because of Catalyst 3750-E or 3560-E switch hardware limitations. This is not a complete list. The unsupported commands are listed by software feature and command mode
Regards,
Dharmesh Purohit