What this means
The IEEE assigned the MA-L block 205F3D to Adtran 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 20:5F:3D, it is Adtran Inc hardware.
Frequently Asked Questions
Who owns MAC prefix 205F3D?
205F3D is registered to Adtran 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. Adtran Inc's block covers 16,777,216 addresses.
What devices use 205F3D?
Any network device with a MAC address starting 20:5F:3D was manufactured by or for Adtran Inc.