IEEE Registration Authority - MAC Prefix 1C21D1 (MA-L)

What this means

The IEEE assigned the MA-L block 1C21D1 to IEEE Registration Authority. 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 1C:21:D1, it is IEEE Registration Authority hardware.

Frequently Asked Questions

Who owns MAC prefix 1C21D1?

1C21D1 is registered to IEEE Registration Authority 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. IEEE Registration Authority's block covers 16,777,216 addresses.

What devices use 1C21D1?

Any network device with a MAC address starting 1C:21:D1 was manufactured by or for IEEE Registration Authority.

Other IEEE Registration Authority prefixes

IEEE Registration Authority holds 439 registered blocks in total.

OUI prefix	1C21D1
Vendor	IEEE Registration Authority
Registry	MA-L (24-bit, large block)
Block size	16,777,216 addresses
Country	US
Other blocks by this vendor	439 total
Example MAC	1C:21:D1:00:00:00