I am still very much a novice in the self-hosting space, Linux etc. having fairly recently switched from using macOS as my daily driver and not tinkering much at all.
One of the things that often confuses me is networking and making sure my setup is secure. This is currently holding me back from hosting more stuff locally that I would require access to from outside my home, as I am afraid I am doing something that could severely compromise my data. It can sometimes be difficult to follow explanations from more advanced users due to the many different components of networking and security, and different layers of abstraction, which prevents me from following completely. I might understand one particular case, but then be unable to make connections to another one. So I would want to research this more intensively, and ideally I would end up being able to easily understand the data flows - the paths the data takes (e.g. I make a HTTPS request to some server from my laptop, how is that traffic routed correctly through my local area network and later the wide area network), in what forms (i.e. different protocols, encryption layers etc.).
In communities like this, I see there are a lot of very knowledgeable people who maybe could recommended any resources that cover this from the basics and onto more advanced stuff? Maybe a textbook from a university course on ICT that is considered particularly good? A YouTube channel with great explanations and visualizations? I am looking both at home LAN and internet in general. Enterprise level networks are not very interesting to me (at the moment).
From what I've understood from previously looking up this with my ISP, is that I connect my own device to the WiFi router they gave me. In that case I have four boxes... :) But I will naturally double check this before going forward with it, and then I might also get some clarification on what the two different boxes in my cabinet are. Bridge mode can be activated through a switch in that online portal though.
I've closed them and everything still works the same way. So I guess the ports have just been open for anyone to say hello. A good example of one of the many areas where I get confused because I don't truly understand all this stuff very well. I learn more every day, and I've gotten plenty of tips in this thread, but it makes me a bit sad that self-hosting safely requires spending a lot of time learning about this stuff, and requires continued vigilance to keep things updated. This excludes a lot of people from enjoying the freedom that comes with data ownership and control. My issue is of course not with the self-hosted solutions - the developers have done excellent work to make these tools available to people including myself, who is not an IT professional. My issue is rather that the society at large has given the major tech players carte blanche to do whatever they want for such a long time, that true privacy is so distant for most people. Some good things going on in Europe to combat this (at least against corporate malpractices), but still not nearly good enough.
Thanks again for all your answers. I really appreciate you taking the time to educate me on this stuff. It's time for me to log off the computer now, and stare at a large screen in my living room instead. The season finale of Stargate SG-1 season 6 awaits :)
Oh, before I go, I just realized that the boxes in the cabinet also handles fiber TV signals.