What this means
The IEEE assigned the MA-S block 70B3D5B81 to Instro Precision Limited. 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:B8:1, it is Instro Precision Limited hardware.
Frequently Asked Questions
Who owns MAC prefix 70B3D5B81?
70B3D5B81 is registered to Instro Precision Limited 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. Instro Precision Limited's block covers 4,096 addresses.
What devices use 70B3D5B81?
Any network device with a MAC address starting 70:B3:D5:B8:1 was manufactured by or for Instro Precision Limited.