MA-M: a /28 block, one IEEE assigns within a larger OUI when a full /24 isn't needed, covering 1,048,576 addresses.
Prefix64:FB:81:50:00:00 /28
Vendor addressHeinrich-Hertz-Strasse 121 Hamburg Hamburg DE 22083
Country🇩🇪 Germany
RegisteredOct 16, 2015
Block range64:FB:81:50:00:00– 64:FB:81:5F:FF:FF
Address capacity1,048,576
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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64:FB:81:40:00:00 /28
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64:FB:81:60:00:00 /28
XIMO Communication Technology Co., Ltd
The nearest registered blocks of the same size on either side of this one in IEEE's address space.
Kay Schulze & Karsten Pohle GbR holds 1 registered blocks in the IEEE registry, ranking #17,503 of 33,427 organizations by block count.