What this means
The IEEE assigned the MA-L block 00400C to GENERAL MICRO SYSTEMS, INC.. 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 00:40:0C, it is GENERAL MICRO SYSTEMS, INC. hardware.
Frequently Asked Questions
Who owns MAC prefix 00400C?
00400C is registered to GENERAL MICRO SYSTEMS, INC. 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. GENERAL MICRO SYSTEMS, INC.'s block covers 16,777,216 addresses.
What devices use 00400C?
Any network device with a MAC address starting 00:40:0C was manufactured by or for GENERAL MICRO SYSTEMS, INC..