Port utilization has reached 100% and User Device Tracker is showing fewer ports than are available on the switch.
This is caused by 1 of 2 reasons: not all ports being added to UDT for monitoring during the discovery process or the missing port type is missing from UDT's monitored port listing.
By default, when doing a discovery only "operationally up" ports are selected to UDT for monitring. This is configurable when performing the discovery. If the port type is also not selected as a monitored port type, then it will never show up in the listing of ports as well.
A switch may have 48 ports, if there are 10 ports "operationally up", only these 10 ports will be selected by default.
A switch may have 48 ports, 30 of which are ethernet-csmacd (type 6) ports, 18 are ethernet-3Mbit (type 26) ports
If the port is missing due to discovery:
How to run a port discovery:
If the port is missing due to it being an unmonitored port type: