Guides
Learn.
What a MAC address is and how it works, plus how to load the data behind this site into the tools that already expect it.
Fundamentals
Fundamentals
What is a MAC address?
Every network interface, Wi-Fi, Ethernet, Bluetooth, has one. Here's what it is, in plain terms, before the deeper dive into how it's structured.
Read the guide →Fundamentals
How MAC addresses work
Forty-eight bits, six bytes, and two of those bits mean something you can read off directly. Here's how the whole address is put together.
Read the guide →Fundamentals
Find your MAC address
The menu names shift a little between OS versions; the command-line methods below don't, so they're the ones worth remembering.
Read the guide →Fundamentals
MAC vs. IP address
Both identify a device on a network. Neither does the other one's job, and mixing them up is the source of a lot of confused troubleshooting.
Read the guide →Fundamentals
MAC randomization
Your phone almost certainly isn't broadcasting its real MAC address anymore. Here's why that started, and how to tell the difference.
Read the guide →Guide · Docker networking
Recognise a Docker container
The 02:42 pattern is a useful clue, not proof. Here is what Docker's generated MAC address reveals, how to verify it, and where the shortcut breaks down.
Read the guide →Guide · Docks and laptops
MAC address pass-through
Plug the same dock into two laptops and the network sees two different MAC addresses. Boot one laptop into Windows, then Linux, and it can happen again. Here is the firmware feature behind it, and how to tell which address is which.
Read the guide →Fundamentals
History of the MAC address
The 48-bit format on every network interface today traces back to a lab at Xerox PARC in 1973, and it's been extended, not replaced, ever since.
Read the guide →Downloads & tools
Guide · Cisco ISE
Cisco ISE
ISE's profiler leans on the MAC vendor to fingerprint endpoints. When the Feed Service can't reach Cisco, or its cache just hasn't kept up with IEEE, here's how to load a current OUI file by hand.
Read the guide →Guide · Wireshark & tshark
Wireshark
Current Wireshark versions compile their default IEEE manufacturer database into the application. A personal manuf file still lets you add or override vendor mappings without waiting for the next release.
Read the guide →Guide · Nmap
Nmap
Every "MAC Address: ... (Vendor Name)" line nmap prints during a scan comes from nmap-mac-prefixes, a file that only updates when nmap itself does.
Read the guide →Guide · CSV
CSV
Six columns, one row per registered block, every OUI size IEEE assigns, not just the 24-bit ones. No account, no rate limit, just a file.
Read the guide →Guide · JSON
JSON
The same data as the CSV, as one JSON array, for anything that would rather Marshal than split on commas.
Read the guide →Guide · Self-hosted
Self-hosted
A single OUI file is a weekend project. A lookup engine that holds up under real production traffic, and stays correct as IEEE's data changes under it, is not.
Read the guide →Guide · Tools compared
Tools compared
Every MAC vendor lookup option traces back to the same five IEEE registries. Where they differ is how current the data is, what shape it comes in, and what happens once you're doing more than one lookup by hand.
Read the guide →Guide · Homebrew
Homebrew install
Macadress Scanner is distributed through its own Homebrew tap rather than Homebrew's core cask registry. Here's the install command, what to do about the tap trust prompt, and how to upgrade or remove it later.
Read the guide →Manufacturing & provisioning
Guide · Manufacturing & provisioning
Batch provisioning
Registering a block, defining a serial number scheme, and generating your first batch, plus the scenarios that come up once real devices are moving: a partial shipment, an unused batch, a mistake caught early.
Read the guide →Guide · Manufacturing & provisioning
Allocating MAC addresses in manufacturing
From owning an IEEE block to a programmed, verified unit: how manufacturers assign a unique MAC address to every network interface they ship, and the decisions that keep two units from ever sharing one.
Read the guide →Guide · Manufacturing & provisioning
MAC address pool management
One block, several production sites, concurrent runs: the point where a shared CSV file stops being a safe way to hand out MAC addresses, and what to replace it with.
Read the guide →Guide · Manufacturing & provisioning
Manufacturing serial numbers
What makes a serial-number scheme safe for production inventory rather than just a random string: structure, a check digit, guaranteed uniqueness, and a fixed link to the unit's MAC address.
Read the guide →Guide · Manufacturing & provisioning
MAC addresses at a contract manufacturer
You own the IEEE block; someone else builds the units. How to hand out addresses so a contract manufacturer can program every unit without ever being able to collide with your other production.
Read the guide →Guide · Manufacturing & provisioning
Multiple MAC addresses per device
A device with Ethernet, Wi-Fi and Bluetooth needs three MAC addresses, not one. How to count the interfaces on a unit and reserve a block of addresses for each unit in a run.
Read the guide →Guide · Manufacturing & provisioning
Allocation spreadsheet template
A starting-point CSV for tracking what you programmed into each unit, with notes on the point where a shared spreadsheet stops being a safe way to allocate addresses.
Read the guide →No guides match that search. Browse the raw downloads instead, or try a MAC lookup.
Looking for the raw data?
Every guide above links to the exact file it covers, or grab all five formats at once from the downloads page.