HP LaserJet M9040M9050 Multifunction Printer series - Manual (Page 249)

its physical address to the hardware address that is listed on the HP Jetdirect configuration page
in the section called HP Jetdirect Configuration. If the addresses match, all network
communications are valid.
4. If you cannot verify that the MFP is communicating over the network, contact the network
administrator.
ENWW Solve network connectivity problems 235