What this means
The IEEE assigned the MA-L block 909F33 to EFM Networks. 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 90:9F:33, it is EFM Networks hardware.
Frequently Asked Questions
Who owns MAC prefix 909F33?
909F33 is registered to EFM Networks 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. EFM Networks's block covers 16,777,216 addresses.
What devices use 909F33?
Any network device with a MAC address starting 90:9F:33 was manufactured by or for EFM Networks.