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)

  • Ebby
    7•2 months ago

    First of all, the ISP controls cable modem firmware. They have all the settings and manage the device. You don’t get much control there.

    As for your question, I’d say no, for 2 reasons. First, designing that capability is expensive and modems are built for cheap reliability. Second, any hardware to spy is more useful installed in a data center accessible to their user base. There is not much point installing unnecessary tech to one endpoint.

    As for router, they are beefier CPU-wise. AT&T has in the past prevented users from changing DNS settings and that could lead to lots of tasty data. Deep packet inspection is becoming more prevalent in home routers as is integration with other technologies. (EERO devices for example).

    Make sure to fire up a VPN or something when you need.

    • zitrone 🍋OP
      2•2 months ago

      Thank you!

      After posting this yesterday when lying in bed trying to sleep (i posted directly before going to bed) I thought of a similar reason:

      Since (as far as i understood it) a modem is just a device that converts between 2 different types of internet signals, the ISP also needs one on their end to connect me to their data center. So it would be way easier for them to spy on their end of the cable (or signal, or whatever type of modem is used) than on my end, since there isn’t really much happening in between.

      • a Kendrick fan
        1•2 months ago

        thanks for this, I was also in this situation, I got a xiaomi router and flashed OpenWRT on it, I then turned off the Wifi switch on the ISP router making it a modem only but I was still concerned about my internet data as it moves between my modem and their servers. your comment made it clearer

        i should probably invest in that mullvad vpn now