What this means
The IEEE assigned the MA-S block 70B3D5CBB to Postmark Incorporated. 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:CB:B, it is Postmark Incorporated hardware.
Frequently Asked Questions
Who owns MAC prefix 70B3D5CBB?
70B3D5CBB is registered to Postmark Incorporated 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. Postmark Incorporated's block covers 4,096 addresses.
What devices use 70B3D5CBB?
Any network device with a MAC address starting 70:B3:D5:CB:B was manufactured by or for Postmark Incorporated.