Tracking Down Unknown Network Devices

This is going to be a short and sweet post, but it touches on something I had to deal with just the other day.

I was going through my router, which I do on a regular basis, to check what unknown network devices were showing up in the network list. In my case I usually do this for two reasons. The first is to name all my devices in the router itself and typically assign it a static IP. The second is for pure security. I want to know what devices are on my network, and who the device belongs to.

The particular unknown network device that I noticed, and could not identify was named “GainSpand48cb6“. I usually take pride in naming my devices, so GainSpan was not something that I had setup. I made the assumption that the d48cb6 was the last 6 digits in the mac address, which I confirmed by looking at the device info more deeply.

unknown network device gainspand

 

Now, the second issue was that the device was offline, so I could not ping it, or do any traffic sniffing on it to see what it was doing. The next step was to just start searching. I started with a reverse mac address look-up, which tells me the mac is registered to a company called GainSpan Corp. Sometimes a simple mac look up will tell you everything you need to know, but when I follow the trail further GainSpan is just the company that makes the wifi radio in the device, darn… had to dig deeper.

As I kept digging, I eventually found something that caught my eye… a post containing Fitbit in the title.

*facepalm*

fitbit-aria-gainspan

The culprit turned out to be my Fitbit Aria scale, which DOES connect over wifi, but for some reason it did not occur to me.

Oh well, at least I know for next time and can share with everyone else who might have one of these scales, that the hostname shows up as GainSpan in your network device list.

8 thoughts on “Tracking Down Unknown Network Devices”

  1. I also came across a MAC address starting with the same leading 00-1D-C9, but in my case it turned out to be my Ring video doorbell. So there’s another device to consider…

    1. Indeed, ring uses a GreenSpan wifi module which is set so it is not Pingable. ln this case you don’t want to block this from your network. I would rename it on your router for something more recognizable.

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