I'm curious to see what information I'm blasting out to the various services I depend on for internet (ISP, DNS, probably Cloudflare, etc.).
Are there any easy to setup, entirely self-hosted tools I can run on my home network that would allow me to snoop on my own traffic.
I want more than just DNS, so I'm not just looking for pihole and its ilk. I want to see things like SNI and any non-protected traffic that any of the devices on my network might be sending that I just don't know about.
Ideally, it would be something I could leave on without affecting my speed/latency, but something to turn on occasionally and spot check would be better than nothing.
My router runs VyOS, so I should have quite a bit of flexibility in what I do with my traffic, though I never have figured out if/how to deploy custom software to it…
AdGuard home is quite a nice thing to have a look at what phones home in the network.
I have a few devices that don’t show up in Adguard Home because they ignore the DNS that they’re told to use.
They have hard coded DNS that can’t be changed, ensuring they can reach the outside world (unless completely blocked).
Some Google devices and some Amcrest cameras I have are guilty of this.
You can redirect all DNS traffic to your own DNS server to get around this.
Unless it’s DNS encrypted over HTTPS in which case it just looks like HTTPS traffic and the most you can do is block known DNS IPs.