What this means
The IEEE assigned the MA-S block 70B3D5B51 to Critical Link LLC. 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 70:B3:D5:B5:1, it is Critical Link LLC hardware.
Frequently Asked Questions
Who owns MAC prefix 70B3D5B51?
70B3D5B51 is registered to Critical Link LLC in the IEEE MA-S registry.
What does the MA-S registry type mean?
An MA-S assignment, formerly called OUI-36, covers 36 bits, giving the vendor 4,096 device addresses, the smallest block the IEEE issues. Critical Link LLC's block covers 4,096 addresses.
What devices use 70B3D5B51?
Any network device with a MAC address starting 70:B3:D5:B5:1 was manufactured by or for Critical Link LLC.