IAB: an Individual Address Block, a /36 covering 4,096 addresses. IEEE's predecessor to MA-S; no longer issued, but existing assignments remain valid.
Prefix40:D8:55:11:30:00 /36
Vendor address7 Midshires Business Park Alyesbury Bucks GB HP19 8HL
Country🇬🇧 United Kingdom
RegisteredJun 9, 2013
Block range40:D8:55:11:30:00– 40:D8:55:11:3F:FF
Address capacity4,096
AdministrationUniversally administered: its prefix comes from a block registered through the IEEE Registration Authority
TransmissionUnicast: addressed to a single device
SourceIEEE Registration Authority
Address capacity is the size of this registered block, not a count of devices actually manufactured or online. Registration identifies the organization holding the block, not a specific device model or unit.
Curious how a prefix like this turns into a full address? See how MAC addresses are structured →
Example addresses in this block
Where this block sits
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40:D8:55:11:20:00 /36
Halliburton - Sperry Drilling Service
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40:D8:55:11:40:00 /36
GD Mission Systems
The nearest registered blocks of the same size on either side of this one in IEEE's address space.
Testbook Ltd holds 1 registered blocks in the IEEE registry, ranking #29,822 of 33,427 organizations by block count.