What is an Individual Address Block (IAB)?
An Individual Address Block is for people who need less than 4097 unique 48-bit numbers (EUI-48) and thus find it hard to justify buying their own OUI. The IAB is a particular OUI belonging to the IEEE Registration Authority, concatenated with 12 additional IEEE-provided bits, leaving only 12 bits for the owner to assign to his (up to 4096) individual devices.
An Individual Address Block is for people who need less than 4097 unique 48-bit numbers (EUI-48) and thus find it hard to justify buying their own OUI. The IAB is a particular OUI belonging to the IEEE Registration Authority, concatenated with 12 additional IEEE-provided bits, leaving only 12 bits for the owners to assign to their (up to 4096) individual devices. Unlike an OUI, which allows the assignee to assign values in various different number spaces (for example, EUI-48, EUI-64, and the various CDI number spaces), the Individual Address Block can only be used to assign EUI-48 identifiers. All other potential uses based on the OUI from which the IABs are allocated are reserved, and remain the property of the IEEE Registration Authority. It should also be noted that, although to this date all Individual Address Blocks have been allocated under a single OUI, at some point in the future that OUI will be exhausted and the IEEE Registration Authority will choose a new OUI value for subs
