What is "Locally administered address"?

What is "Locally administered address"? What does it mean?

It is basically a MAC address set by a network administrator.

MAC address can be either:

• Universally administered address (UAA), which is a unique address assigned to each physical device by the manufacturer.
• Locally administered address (LAA), which can be assigned to the device by a network administrator or by special software and override the UAA for that device.
• Universal address administered locally, which is a hybrid situation used for virtual machines.

I have a device on my home network that I don't know. It has a LAA and no info comes up from my internet provider. I also have a creepy ex who lived here until recently and now I'm a little freaked out. Xfinity says they are investigating but it's been a week. How do I find out what kind of device it is if not the specifics?

The simplest way to identify the device would be to think of what in your place has access to the Internet.

If a device is hard to identify from its detected name, turning various devices off and on one by one and repeating the scan in-between can help to find out what is what.

If you still have no idea what some devices are, it makes sense to change your WiFi password in your router to stop them from using your network.