What this means
The IEEE assigned the MA-M block 78392D5 to IO Master Technology. 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 78:39:2D:5, it is IO Master Technology hardware.
Frequently Asked Questions
Who owns MAC prefix 78392D5?
78392D5 is registered to IO Master Technology in the IEEE MA-M registry.
What does the MA-M registry type mean?
An MA-M assignment covers 28 bits of the address, giving the vendor 1,048,576 device addresses, a quarter of a full MA-L block. IO Master Technology's block covers 1,048,576 addresses.
What devices use 78392D5?
Any network device with a MAC address starting 78:39:2D:5 was manufactured by or for IO Master Technology.