This is a helpful review of the fundamentals to cover. I will definitely be doing my own searches for content on the topics.

Do you have any good references for resources in the vein of teaching the fundamentals. Not like "DNS: here is how to configure a BIND server" but like "DNS: Here are the core concepts, what you will typically need to set up, common issues / confusions, and further reading."

I have tried going through RFCs for a lot of these, but they tend to be focused on implementation rather than "why". Similarly, software-specific content is "how to achieve this outcome with this implementation", but lacks context on why one would want that outcome.