What this means
The IEEE assigned the MA-L block 0021D5 to X2E GmbH. 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:D5, it is X2E GmbH hardware.
Frequently Asked Questions
Who owns MAC prefix 0021D5?
0021D5 is registered to X2E GmbH 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. X2E GmbH's block covers 16,777,216 addresses.
What devices use 0021D5?
Any network device with a MAC address starting 00:21:D5 was manufactured by or for X2E GmbH.