I notice on one Windows 2008 R2 DHCP server the device with the first IP in the range has a strange looking Unique ID of the format
636333652e356639322e326262332d445c458e41258s23148914e1554654566661636531
And the DNS name HP.domain.local
See screenshot. Does anyone know what this is and why it doesn't show a standard MAC for the unique ID?
Split the string in pairs and convert hex to ascii, you will get
cc3e.5f92.2bb3-Vlan-interface1
, it is most probably one of your HP switches registering.