Using a 9300 cisco switch? keep track of them using the built-in RFID tag.
from 9300 manual
The chassis has a built-in,passive RFID tag that uses UHF RFID technology and requires an RFID reader with compatible software. It provides auto-identification capabilities for asset management and tracking. The RFID tags are compatible with the Generation 2 GS1 EPC Global Standard and are ISO 18000-6C compliant. They operate in the 860- to 960-MHz UHF band. For more information, see Radio Frequency Identification (RFID) on Cisco Catalyst 9000 Family
Switches White Paper.
Looked like TSL.com has pretty good software and readers you could use. Unfortunate that most modern phones don’t have reader capability, even though they have 800 mhz software defined radios. I like this bluetooth reader with optical scanner.