Who owns MAC prefix 5821E9?

5821E9 is registered to TWPI in the IEEE MA-L registry.

What devices use 5821E9?

Any network device with a MAC address starting 58:21:E9 was manufactured by or for TWPI.

MA-L · OUI prefix

TWPI

Any MAC address starting 58:21:E9 is registered to TWPI in US.

OUI prefix	5821E9
Vendor	TWPI
Registry	MA-L (24-bit, large block)
Country	US
Example MAC	58:21:E9:00:00:00

What this means

The IEEE assigned the MA-L block 5821E9 to TWPI. 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 58:21:E9, it is TWPI hardware.

Look up another MAC