What this means
The IEEE assigned the MA-L block 002157 to National Datacast, Inc.. 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 00:21:57, it is National Datacast, Inc. hardware.
Frequently Asked Questions
Who owns MAC prefix 002157?
002157 is registered to National Datacast, Inc. 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. National Datacast, Inc.'s block covers 16,777,216 addresses.
What devices use 002157?
Any network device with a MAC address starting 00:21:57 was manufactured by or for National Datacast, Inc..