What this means
The IEEE assigned the MA-L block 00407D to EXTENSION TECHNOLOGY CORP.. 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 00:40:7D, it is EXTENSION TECHNOLOGY CORP. hardware.
Frequently Asked Questions
Who owns MAC prefix 00407D?
00407D is registered to EXTENSION TECHNOLOGY CORP. 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. EXTENSION TECHNOLOGY CORP.'s block covers 16,777,216 addresses.
What devices use 00407D?
Any network device with a MAC address starting 00:40:7D was manufactured by or for EXTENSION TECHNOLOGY CORP..