Cisco 300 Series Cli Manual page 525

Virtual Local Area Network (VLAN) Commands
78-21075-01 Command Line Interface Reference Guide
Example
The following example displays the VLANs that are used internally by the switch:
show vlan internal usage
User Reserved VLAN list after reset: 4080-4094
Current User Reserved VLAN list: 4090-4094
VLAN Usage
---- --------
4094 gi12
4093 gi23
4092 tunnel 1
32
525