With the growing number of network-enabled devices in your home, meaningful security becomes elusive. The first step to addressing the situation is knowing what you have. A few examples below use the nmap utility to scan your local network and detect active devices and services.

Install nmap-to-CSV conversion utility

In my experience, the nmaptocsv.py worked only with Python 2.7, so you may need to install this version as an alternative and update the script to use it.

Define scan parameters

Run the scan

Cleanup the output file

Converted to spreadsheet the end result may look something like this

Running this scan on a regular basis and generating a diff report should help you detect new and suspicious devices on your home network.