What this means
The IEEE assigned the MA-L block 4857DD to Facebook 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 48:57:DD, it is Facebook Inc hardware.
Frequently Asked Questions
Who owns MAC prefix 4857DD?
4857DD is registered to Facebook 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. Facebook Inc's block covers 16,777,216 addresses.
What devices use 4857DD?
Any network device with a MAC address starting 48:57:DD was manufactured by or for Facebook Inc.