Microsoft Corporation
CID
CID: a Company ID, not a MAC OUI. It identifies an organization for use in other IEEE 802 protocols, most commonly locally administered ELI-quadrant addresses, rather than being burned into hardware directly.
PrefixCA:12:5C:00:00:00 /24
Vendor addressOne Microsoft Way Redmond US 98052-6399
Country🇺🇸 United States
Block rangeCA:12:5C:00:00:00– CA:12:5C:FF:FF:FF
Address capacity16,777,216
AdministrationLocally administered: set by software, not burned into hardware
TransmissionUnicast: addressed to a single device
IEEE 802c quadrantELI: Extended Local Identifier
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
Other blocks registered to Microsoft Corporation
00:03:FF:00:00:00 /24
MA-L
00:12:5A:00:00:00 /24
MA-L
00:15:5D:00:00:00 /24
MA-L
00:17:FA:00:00:00 /24
MA-L
00:1D:D8:00:00:00 /24
MA-L
00:22:48:00:00:00 /24
MA-L
00:25:AE:00:00:00 /24
MA-L
04:27:28:00:00:00 /24
MA-L
08:35:7D:00:00:00 /24
MA-L
0C:1B:7B:00:00:00 /24
MA-L
0C:35:26:00:00:00 /24
MA-L
0C:41:3E:00:00:00 /24
MA-L