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mac oui lookup: how to identify device manufacturers on your network

mac oui lookup: how to identify device manufacturers on your network

Network management often feels like detective work. You log into your UniFi Controller, and there it is—a long list of MAC addresses that look more like license plates than devices you recognize. Tracking down which device belongs to whom can be a puzzle. That’s where MAC OUI lookup comes in handy. It helps you match those hexadecimal addresses to familiar names like “Apple,” “Samsung,” or “Intel.”

In this post, I’ll explain what MAC OUIs are, how to use them to identify device manufacturers, and ways to build that knowledge into your UniFi workflow. You’ll learn practical methods, online, CLI, and automated, for revealing who’s behind each MAC address. Plus, I'll walk you through using that info to tighten security, improve organization, and take greater control of your network.

what is a mac address—and what’s an oui?

A MAC (Media Access Control) address is a permanent, unique identifier assigned to every network interface. Think of it as the hardware-level serial number for devices that talk over Ethernet or Wi‑Fi:

DC:A6:32:BE:1F:21

That’s six pairs of hexadecimal (base‑16) digits. The first half, DC:A6:32 in this example, is called the Organizationally Unique Identifier (OUI). It corresponds to the manufacturer of that network interface. The remaining three pairs (BE:1F:21) are assigned by that manufacturer to make each address unique.

Because OUIs are globally unique and registered with the IEEE, you can use them to trace a device back to its maker. That’s what a MAC OUI lookup does: it converts the first half of a MAC into a company name.

why mac oui lookup matters

Here's what OUI lookups enable you to do:

  • spot rogue or unexpected devices Imagine seeing a MAC you don’t recognize in UniFi. Does it belong to your guest’s iPhone or a neighbor’s IoT gadget? OUI tells you the brand, so you can identify or remove it.
  • map devices to owners Label “Samsung” and you can guess it’s someone’s phone or TV. Label “Dell” or “Intel” and you might be looking at a PC. This makes it easy to match devices with users.
  • segment traffic intelligently Once you know which devices belong in guest, IoT, or work VLANs, you can enforce policies at scale. OUI info gives you the insight to create those rules.
  • streamline troubleshooting If you’re looking into signal, speeds, or IP conflicts, knowing the vendor helps you tailor your fixes—whether it's updating printer firmware or adjusting phone roaming settings.
  • automate alerts You can script daily scans to watch for OUIs that don’t match your known list. Once triggered, your system can email you or drop a Slack message.

All of this makes your network easier to manage and more secure—especially when you’ve got dozens or even hundreds of devices.

easy ways to do mac oui lookup

1. online lookup tools

There are free websites that do this work for you:

  • macvendors.com
  • wireshark.org’s OUI lookup

You type in something like DC:A6:32 or the full MAC DC:A6:32:BE:1F:21, and it returns the vendor.

Pros: no install required, fast and easy.

Cons: manual process, one at a time, depends on remote server being up.

2. command‑line lookup

On Linux or macOS you can do lookups directly in the terminal.

method a: use a CLI tool

mac‑lookup is a simple utility:

bash
brew install mac-lookup
mac-lookup DC:A6:32

This returns the vendor name.

method b: use a local OUI file

Want self‑contained offline lookup? Download the IEEE OUI file and grep through it:

bash
curl -O http://standards-oui.ieee.org/oui/oui.txt
grep "DC-A6-32" oui.txt

You’ll get a line like:

DC-A6-32   (hex)  Apple, Inc.

Pros: fast, can batch script, works offline.

Cons: requires maintenance of OUI file.

3. via UniFi Controller

UniFi shows MAC addresses in the Clients list. Sometimes it picks up hostnames or device type, but not always. If vendor info isn’t obvious, you can:

  1. Export the client list from your controller (JSON or CSV).
  2. Parse it in a script to extract OUIs.
  3. Lookup each one using an API or local file.
  4. Append vendor info to names or tags in UniFi.

This takes advantage of UniFi features and lets you use labels and groups based on vendors.

automating oui lookup in unifi

Automating OUI lookups with UniFi gives you a consistent, hands‑off approach. Here’s a simple end‑to‑end recipe:

step 1: export client data

Use the UniFi API or Controller UI to get your devices:

  • In the GUI: go to Clients → Export.
  • Via API: call /api/s/default/stat/sta to fetch client MACs.

step 2: extract and normalize OUIs

Write a script in Python or Bash:

python
mac = "DC:A6:32:BE:1F:21"
oui = mac.upper().split(":")[0:3]
key = "-".join(oui)

step 3: lookup vendors

Decide where your OUI data lives. You can:

  • Use an online API (like macvendors.co) with a curl or requests call.
  • Keep a local copy of the IEEE OUI file and build a dictionary for lookups.

step 4: tag devices in UniFi

Once you know vendor names, use the UniFi API to update the client record with a note, tag, or custom name—e.g., "Apple iPhone (Apple)".

step 5: add alerts

Scheduling your script daily or hourly keeps your list fresh. Just include logic like:

python
if vendor not in known_list:
    send_email_or_slack("New vendor found: %s at %s" % (vendor, mac))

That way, you get a heads‑up whenever a device from a new vendor appears.

dealing with odd cases

random mac addresses

Modern smartphones use randomized MACs when scanning or joining public Wi‑Fi. These OUIs won’t match your local database. To handle this:

  • Note the OUI is random and skip, flag as “random.”
  • Correlate with DHCP lease history, IP usage, or hostname to tell who it really is.

new hardware / new OUIs

Manufacturers are assigned new OUIs all the time. If your OUI list is outdated, you may get “unknown” responses. To fix that:

  • Regularly update your OUI file from IEEE (frequency depends on how often you run scripts).
  • Use online APIs that auto‑sync current data.

virtual or container MACs

Containers or VMs can use locally administered MACs or VMware OUIs. Recognize them as “virtual device” and cross‑check with your hypervisor’s host list.

network management use cases

segmenting traffic by vendor

Say you’ve tagged devices:

  • Apple
  • Google
  • Sonos

You can make firewall rules or VLAN rules in UniFi to treat Alexa/Sonos/Google smart devices differently from your work devices. This reduces risk and keeps media traffic off your secure network.

blocking unknown vendors

If a MAC shows up with a vendor you don’t know, you can automatically isolate it until investigated.

Example logic in your automation script:

python
if vendor not in allowed_vendors:
    tag device as “quarantine”

Then firewall rules block those devices until you clear them.

bandwidth policies

Want to limit streaming to certain devices? With vendor labels, you can apply bandwidth caps or priority to categories like:

  • Gaming
  • IoT
  • Business

That frees bandwidth for what matters most.

step‑by‑step: a unifi script example

Here’s a simple Python pseudocode example. You can adapt it to your environment:

python
import requests

# load your list of known vendors
with open("oui.txt") as f:
    vendor_map = { line[:8].replace('-',':'): line[18:].strip() for line in f if "(hex)" in line }

def lookup_vendor(mac):
    oui = mac.upper()[0:8]
    return vendor_map.get(oui, "Unknown")

# fetch clients via UniFi API
results = requests.get("https://unifi/api/...").json()
for client in results["data"]:
    mac = client["mac"]
    vendor = lookup_vendor(mac)
    name = client["hostname"] or "unknown"
    print(f"{mac} → {vendor} ({name})")

    if vendor == "Unknown":
        # update UniFi tag or note
        requests.post("https://unifi/api/update_client", json={
            "mac": mac,
            "note": "Unknown vendor"
        })

That script prints vendor info and updates a note in UniFi for any unknown vendor—it’s a start. From here, you could:

  • Auto‑tag by vendor,
  • Quarantine new vendors,
  • Alert you via email or Slack.

And because it uses saved OUI data, it works even if your API access is spotty.

securing your network with oui data

Here are some practical ways to use OUI lookup for real‑world security:

  1. device inventory: Audit your devices regularly to ensure every MAC matches a known name or user.
  2. guest visibility: Seeing “Huawei” or “Xiaomi” pop up unexpectedly might trigger a check if the guest later leaves.
  3. smart home isolation: Tag all IoT brands and move them to a guest or IoT VLAN for safe segmentation.
  4. BYOD management: Let personal devices get internet only but keep corporate PCs in a separate VLAN with more restrictions.
  5. policy tracking: Use labels like “Work laptop”, “Streaming TV”, or “Printer” to apply correct firewall and QoS rules.

wrap‑up

MAC OUI lookups are a low‑effort, high‑value tool for any network admin. You can use them casually with a website, or build full automation into your UniFi workflow.

Once you start tagging devices with vendor names and then move them into logical groups or VLANs accordingly, your network becomes simpler, safer, and smarter.

If you manage multiple sites or just want to reduce repetitive work, you should consider managed UniFi hosting. At UniHosted, we provide cloud‑hosted UniFi controllers with custom scripts and templates that include OUI‑based tagging, device automation, and VLAN segmentation. You get the reliability of cloud infrastructure with workflows prebuilt for your needs—including automated MAC OUI lookups.

conclusion

MAC addresses may seem like random hex, but OUIs expose the brands and types behind those numbers. With a little effort, or a bit of automation, you can transform your UniFi network into something you truly understand. You’ll know which device belongs to whom, where it should live in your setup, and whether it’s allowed to be there at all.

Investing in automated OUI lookups pays off by saving you time, reducing guesswork, and boosting security. If you'd rather focus on your network than building automation yourself, Unihosted has turnkey scripts and managed controller hosting designed for professionals who want precisely this level of insight without the upkeep.