Who owns MAC prefix 0021B3?

0021B3 is registered to Ross Controls in the IEEE MA-L registry.

What devices use 0021B3?

Any network device with a MAC address starting 00:21:B3 was manufactured by or for Ross Controls.

MA-L · OUI prefix

Ross Controls

Any MAC address starting 00:21:B3 is registered to Ross Controls in US.

OUI prefix	0021B3
Vendor	Ross Controls
Registry	MA-L (24-bit, large block)
Country	US
Example MAC	00:21:B3:00:00:00

What this means

The IEEE assigned the MA-L block 0021B3 to Ross Controls. 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 00:21:B3, it is Ross Controls hardware.

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