What this means
The IEEE assigned the MA-L block 509F3B to OI ELECTRIC 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 50:9F:3B, it is OI ELECTRIC CO.,LTD hardware.
Frequently Asked Questions
Who owns MAC prefix 509F3B?
509F3B is registered to OI ELECTRIC 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. OI ELECTRIC CO.,LTD's block covers 16,777,216 addresses.
What devices use 509F3B?
Any network device with a MAC address starting 50:9F:3B was manufactured by or for OI ELECTRIC CO.,LTD.