Who owns MAC prefix 002181?

002181 is registered to Si2 Microsystems Limited in the IEEE MA-L registry.

What devices use 002181?

Any network device with a MAC address starting 00:21:81 was manufactured by or for Si2 Microsystems Limited.

MA-L · OUI prefix

Si2 Microsystems Limited

Any MAC address starting 00:21:81 is registered to Si2 Microsystems Limited in IN.

OUI prefix	002181
Vendor	Si2 Microsystems Limited
Registry	MA-L (24-bit, large block)
Country	IN
Example MAC	00:21:81:00:00:00

What this means

The IEEE assigned the MA-L block 002181 to Si2 Microsystems Limited. 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 00:21:81, it is Si2 Microsystems Limited hardware.

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