What this means
The IEEE assigned the MA-L block D040EF to Murata Manufacturing Co., Ltd.. Every network interface they manufacture under this block has a MAC address beginning with these digits, followed by a unique per-device identifier. If a device on your network shows a MAC starting D0:40:EF, it is Murata Manufacturing Co., Ltd. hardware.
Frequently Asked Questions
Who owns MAC prefix D040EF?
D040EF is registered to Murata Manufacturing Co., Ltd. in the IEEE MA-L registry.
What does the MA-L registry type mean?
An MA-L assignment, the IEEE's original OUI format, gives the vendor the first three octets and 16,777,216 device addresses under them. Murata Manufacturing Co., Ltd.'s block covers 16,777,216 addresses.
What devices use D040EF?
Any network device with a MAC address starting D0:40:EF was manufactured by or for Murata Manufacturing Co., Ltd..