MAC Address OUI Vendor Lookup
Look up MAC address block assignments in a dated offline IEEE registry snapshot, normalize three formats, or generate a local unicast address.
About this mac address oui vendor lookup
Look up MAC address block assignments in a dated offline IEEE registry snapshot, normalize three formats, or generate a local unicast address Performs protocol inspection, IP calculation, and network analysis client-side without sending probes or exposing network topology.
Protocol mechanics & network logic
The execution engine processes input tokens and applies transformations in the browser sandbox. Specifically, You may also enter a 6-hex-digit OUI with the same separators; it matches only its exact MA-L prefix and does not fabricate a full MAC address or infer a longer allocation. Enter 12 hexadecimal digits with optional colons, hyphens, dots or whitespace. Run locally loads the bundled registry and matches the longest public assignment: MA-S or IAB (36 bits), MA-M (28 bits), then MA-L (24 bits). The result includes organization, prefix, registry and dataset source. The random button uses Web Crypto and updates the input and local unicast result.
Worked network diagnostic scenario
Scenario: Normalize the Apple example and find its registered block.
Sample input:
Processing: Normalize the address, keep the three formats and bit flags, then match the longest public IEEE assignment for a universal unicast address.
Illustrative output:
Addressing limits & protocol boundaries
Operational constraints and validation boundaries: The bundled IEEE public data comes from Debian ieee-data 20260625; its declared snapshot date is 2024-07-22, not a live IEEE query. A block assignment does not verify a device manufacturer. Local or group addresses have no vendor attribution. Missing, private or reassigned entries may not identify a device. Generated addresses set U/L=1 and I/G=0; uniqueness is not guaranteed, so check collisions. No interface is changed and no MAC query is sent to an external service.
Addressing calculations and subnet models in MAC Address OUI Vendor Lookup follow IETF RFC definitions. Ensure subnet masks and CIDR prefixes match your network topology.
Offline network inspection boundary
Address parsing and CIDR calculations in MAC Address OUI Vendor Lookup run entirely client-side without probing external IP networks or transmitting routing data.
IETF RFC specifications & IANA registries
IETF Request for Comments (RFC) standards and IANA registry references:
MAC Address OUI Vendor Lookup verification · Audit standards
How to use it
- Enter a 6-hex-digit OUI or a 12-hex-digit MAC address with optional supported separators.
- Compare the longest matching public IEEE prefix and inspect the source and date.
- Click the action button or observe immediate live calculations rendered by MAC Address OUI Vendor Lookup.
Frequently asked questions
How does the offline MAC lookup derive its result?+
You may also enter a 6-hex-digit OUI with the same separators; it matches only its exact MA-L prefix and does not fabricate a full MAC address or infer a longer allocation.
What controls and output does the page provide?+
Source: IEEE public MA-L, MA-M, MA-S and IAB data, mirrored in Debian ieee-data 20260625. Declared snapshot: 2024-07-22. This dated offline snapshot identifies registered address blocks, not verified devices or a current live IEEE record.
What limits apply to vendor and address classification?+
The bundled IEEE public data comes from Debian ieee-data 20260625; its declared snapshot date is 2024-07-22, not a live IEEE query.
What result should the documented example produce?+
Security isolation for "What result should the documented example produce?" ensures zero transmission beyond your local workstation.