I’m planning to buy a router and modem and put OpenWrt on it for maximum control and privacy. While I could get a router with an integrated DSL modem, the previous tenants had cable internet so I’m not sure if the DSL connection even works and DSL internet is also more expensive (at least where I live). Fiber optic is not available. The problem is, there is apparently no open firmware for cable modems so I would have to buy a standalone router and a standalone cable modem. I would put OpenWrt on the router and use whatever proprietary firmware came with the modem.

So my question is:
Can a standalone modem that doesn’t do routing, spy on you?
If yes a rough explanation how would be appreciated.

It seems that modem and router are used interchangeably on the internet (probably because they are mostly combined) so it is really hard to find any information on modems. Here are both Wikipedia articles for reference:
https://en.wikipedia.org/wiki/Modem
https://en.wikipedia.org/wiki/Router_(computing)

  • electricprism
    2·
    3 months ago

    Block the ISP DNS and use your own on the router level.

    You could look into wireguard or VPN on the router level.

    Probably OpenSense.

    As long ad your device has a IMEI though not like it matters.

    There’s probably a million other things you would need too. Make sure your browser doesn’t use its own DNS, eg, Firefox + CloudFlare by default.

    I assume you could theoretically split traffic up over multiple ISP’s making it a PITA to try to make sense of.

    Also obviously separate trusted & untrusted devices, WiFi and wired into separate networks.

    • zitrone 🍋@lemmings.worldOP
      1·
      3 months ago

      That’s exactly why I want OpenWrt on my router. To have that kind of control.

      Anyway your answer is completely unrelated to my question.

      • electricprism
        1·
        3 months ago

        I think your best bet is to assume that everything you don’t control is a vector.

        The modems run binary blobs you don’t control.

        A standard modem with a singular hookup to a router is as good as it gets. Maybe you are contemplating the modem as a combo – if it is also a router and wifi, you can bet the ISP sees that as “Their Network” and not “Your Network” and any WiFi capabilities could be used to reverse hack insecure devices theoretically like smart TV or IoT.

        You could put the modem router combo in a Faraday cage to dampen the signal theoretically.

        That may not be answers to the query but I think the smart short answer is: yes, unless verified no.

        Edit: to go further, theoretically they can capture any traffic and if they get the encryption key decrypt the traffic.

        Or maybe with a quantum computer decrypt with ease. And if you have any leaks or there are backdoors then who knows what the consequences could be, cough cough xz