What this means
The IEEE assigned the MA-L block A4D1D1 to ECOtality North America. 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 A4:D1:D1, it is ECOtality North America hardware.
Frequently Asked Questions
Who owns MAC prefix A4D1D1?
A4D1D1 is registered to ECOtality North America 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. ECOtality North America's block covers 16,777,216 addresses.
What devices use A4D1D1?
Any network device with a MAC address starting A4:D1:D1 was manufactured by or for ECOtality North America.