Who owns MAC prefix 40040C?

40040C is registered to A&T in the IEEE MA-L registry.

What devices use 40040C?

Any network device with a MAC address starting 40:04:0C was manufactured by or for A&T.

MA-L · OUI prefix

A&T

Any MAC address starting 40:04:0C is registered to A&T in KR.

OUI prefix	40040C
Vendor	A&T
Registry	MA-L (24-bit, large block)
Country	KR
Example MAC	40:04:0C:00:00:00

What this means

The IEEE assigned the MA-L block 40040C to A&T. 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 40:04:0C, it is A&T hardware.

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