I have an unknown device that is connecting to my wifi router, and can't figure out what it is to save my life. I've never seen it before and haven't bought any new devices lately, it seems to have appeared out of the blue.

From my router admin page I can see the device reports as:

MAC: D4-4B-5E-FD-BF-A0

I have looked up this MAC address and it reports the maker as:


Ok fine, you can check out their website and see they make wifi/bluetooth chips that are used in various devices. Not very informative.

I also tried using nmap to scan the device, I have never used nmap before but tried a command I found in a similar answer:

nmap -v -Pn -p 1-65535

Starting Nmap 7.12 ( https://nmap.org ) at 2016-05-31 20:14 MDT
Initiating Parallel DNS resolution of 1 host. at 20:14
Completed Parallel DNS resolution of 1 host. at 20:14, 0.02s elapsed
Initiating Connect Scan at 20:14
Scanning [65535 ports]
Completed Connect Scan at 20:14, 1.85s elapsed (65535 total ports)
Nmap scan report for
Host is up (0.000017s latency).
All 65535 scanned ports on are filtered

Read data files from: /usr/local/bin/../share/nmap
Nmap done: 1 IP address (1 host up) scanned in 1.93 seconds

Which seems to indicate all ports are unreachable, so no luck determining what services or OS is running on this device.

In the statistics section of my router I can see this device is still connected and regularly transmitting a packet or two every second, but still have no idea what it is or what it's sending.

I know I can block this device by changing my WPA2 password or by filtering this MAC address, but I really need to know what it is first. What else can I do to find out what this device is or where it is physically located?

  • 1
    Could you capture the traffic and see what protocol it is using, or perhaps post it here? It might be a way to understand what this device is.
    – A. Darwin
    Jun 1, 2016 at 13:01

1 Answer 1


Rass, yes I remembered 4 years ago my network guy reported the very same problem. The accounts department went and bought a Brother wireless printer & connected it via wifi. turns out it's MAC points to a Japanese NIC maker of Brother & Toshiba printers. Man check your bomboclate print fleet first.

  • 1
    This was it. It was a Brother wireless printer that my roommate had, hasn't used in years, turned back on and literally decided to keep it in the closet so it was out of sight then forgot about it. Thanks for the lead! Jun 1, 2016 at 13:09

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