MA-M: a /28 block, one IEEE assigns within a larger OUI when a full /24 isn't needed, covering 1,048,576 addresses.
PrefixB4:DF:43:20:00:00 /28
Vendor address1835 Kramer Ln, Ste A100 Austin TX US 78758
Country🇺🇸 United States
RegisteredJul 30, 2026
Block rangeB4:DF:43:20:00:00– B4:DF:43:2F: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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B4:DF:43:10:00:00 /28
UTA WIRELESS S.R.L.
Next
B4:DF:43:30:00:00 /28
Hangzhou Huasu Technology CO., LTD.
The nearest registered blocks of the same size on either side of this one in IEEE's address space.
Wenzel Associates holds 1 registered blocks in the IEEE registry, ranking #32,082 of 33,427 organizations by block count.