Audit Your Own Wi-Fi with Kismet (Passive and Legal)
See which channels are crowded, confirm your network uses WPA2/WPA3, and spot fake access points copying your network's name.
Kismet is an open-source wireless monitor that only listens — it never transmits or connects. With a monitor-mode adapter on a Pi, you can check the health and security settings of your own Wi-Fi from a browser.
Only analyze networks you own or have written permission to test. Never try to join, crack or disrupt anyone else's Wi-Fi, and don't keep information about neighbors' devices. Laws on wireless monitoring vary by country.
Mission steps
Pick a compatible adapter
Choose a USB Wi-Fi adapter whose chipset supports monitor mode on Linux. The Pi's built-in Wi-Fi stays connected for the web interface.
Install Kismet
Install it from your OS packages or Kismet's own repository for a newer version, and add your user to the kismet group.
Start a capture
Run kismet with the adapter as the source and open the web UI on port 2501 from your laptop.
Check your network
Find your own SSID: confirm WPA2 or WPA3 (never open or WEP), note its channel and look for a second access point using your exact name.
Clean up
Keep only data about your own network, turn off packet-capture logs you don't need and delete logs when you finish.
Code
sudo apt install kismet
sudo usermod -aG kismet $USER # log out and back in
ip link # find the USB adapter, e.g. wlan1
kismet -c wlan1 # then open port 2501 on the Pi from your laptop
# when finished, remove the logs
ls ~/*.kismet && rm ~/*.kismetTip: test every script on the bench before installing it in a moving machine.
Questions
What channel should my router use?
On 2.4 GHz, pick 1, 6 or 11 — whichever has the fewest strong networks in Kismet. On 5 GHz there are many more channels and less overlap.