In a Catalyst Express 500 switch, the Device Manager does not show utilization on the ports; it shows 0% port utilization. This is because on the Catalyst Express 500 monitoring tools, any traffic loads under 10% do not register in the Device Manager monitoring tools.
If you need to monitor traffic levels under 10%, use the mechanisms provided in the Cisco Network Assistant (CNA) software.
CNA is a free software program that can be downloaded from Cisco.com and run on the PC. CNA offers advanced options to configure and monitor multiple devices. In order to download the CNA application, refer to Cisco Network Assistant.