MA-L: a full /24 OUI block, IEEE's largest, covering 16,777,216 addresses.
Prefix00:12:3C:00:00:00 /24
Vendor address4119 Walnut Street Philadelphia PA US 19104
Country🇺🇸 United States
RegisteredSep 2, 2004
Block range00:12:3C:00:00:00– 00:12:3C:FF:FF:FF
Address capacity16,777,216
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 →
Ownership timeline
- Sep 2, 2004 – Apr 9, 2007 IP3 Networks, Inc. name changed
- Apr 9, 2007 – present Second Rule LLC
Example addresses in this block
Where this block sits
The nearest registered blocks of the same size on either side of this one in IEEE's address space.
Second Rule LLC holds 1 registered blocks in the IEEE registry, ranking #25,485 of 33,427 organizations by block count.