What this means
The IEEE assigned the MA-L block 90B4DD to ZPT R&D. 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 90:B4:DD, it is ZPT R&D hardware.
Frequently Asked Questions
Who owns MAC prefix 90B4DD?
90B4DD is registered to ZPT R&D 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. ZPT R&D's block covers 16,777,216 addresses.
What devices use 90B4DD?
Any network device with a MAC address starting 90:B4:DD was manufactured by or for ZPT R&D.