What this means
The IEEE assigned the MA-L block 0040FB to CASCADE COMMUNICATIONS. 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:FB, it is CASCADE COMMUNICATIONS hardware.
Frequently Asked Questions
Who owns MAC prefix 0040FB?
0040FB is registered to CASCADE COMMUNICATIONS 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. CASCADE COMMUNICATIONS's block covers 16,777,216 addresses.
What devices use 0040FB?
Any network device with a MAC address starting 00:40:FB was manufactured by or for CASCADE COMMUNICATIONS.