I have been exploring the world of home servers/self-hosting for a little over a year now, and feel like I have at a decent understanding of a lot of things that go into this. The one thing I am not remotely comfortable with yet is networking. It's like a foreign language to me.
What are some good resources or projects that I could work on to help me develop a better understanding of this? Or, what helped you advance your networking knowledge? I have an UnRaid machine and a Raspberry Pi 4 (8gb) at my disposal (for any project recommendations). Current router is ISP provided, so nothing fancy.
For a full open-source hardware and software experience you need a more exotic brand like this https://www.banana-pi.org/en/bananapi-router/. The BananaPi BPi R3 and here is a very good option with a 4 core CPU, 2GB of RAM Wifi6 and two 2.5G SFP ports besides the 4 ethernet ports. There’s also an upcoming board the BPI-R4 with optional Wifi 7 and 10G SPF.
Side note: while there are things like OPNsense and pfSense that may make sense in some cases you most likely don't require that. You've a small network and OpenWRT will provide you with a much cleaner open-source experience and also allow for all the customization you would like. Another great advantage of OpenWRT is that with a great router like the BananaPi BPi R3 you've the ability to install 3rd party stuff in your router, you may even use qemu to virtualize stuff like your Pi-Hole on it or simply run docker containers.