Currently I have a guest network available which is blocked from having access to the #LAN. I suppose I could connect the display to this network and also block access to the internet...
@syntax Routers cannot see DNS requests (maybe some can, mine cant) which your smartmeter may request, but you can set your smartmeter to use your Linux machine as DNS proxy and log DNS queries. This can be done using dnscrypt-proxy package, you can enable logging with https://github.com/DNSCrypt/dnscrypt-proxy/wiki/Logging
and if your smartmeter sends some requests you will be able to see them by filtering logs with smartmeter IP address.
@syntax Other way is to use Wireshark and sniff traffic which your smartmeter sends or recieves. Either way you will be doing some sort of man in the middle attack
Indeed, I had a mind to install Wireshark this morning and become reacquainted with it. I have my network locked down pretty well, and the router has a traffic monitoring feature, but it doesn't seem to work.
@syntax If the MAC address is listed on the box, you might be able to block the MAC address.
Yeah I figure it's doable. May not even get the damned thing (partner wants it), but if we do I want to know I can keep an eye on what it's doing.