[vlovich123]

The strategy that works best for me is to just start at the simplest step & iterate from there. Do research online to find blog posts / articles describing how to solve specific problems. When doing reading, make sure to note terms of art that repeat so that you know what to look for.

So the first step I would do to start on a TCP/IP stack would be "how to open a raw socket" (granted you have to know the magic phrase here). There's also tons of "how to implement TCP stack" articles (same for ethernet etc) that probably are good starting points if I didn't know that magic phrase. The other thing is to find people to talk to who know more than you to answer those questions.

Once you have that, you can setup a real TCP socket on one end and a raw socket client on the other & then the same thing in reverse. Then look up the TCP/IP framing on Wikipedia (+ read up on the broad overview of how TCP works and the various parts). Once you have the framing implemented, try implementing the basic sequence to establish a connection. Then keep noting what features a full TCP stack has, which are required, & which are missing from my implementation (that's when I'd start reaching for the standards that everyone references).

Of course, if you want to do something novel beyond just "hey I have confidence that I can implement such a stack myself" (e.g implementing something with certain performance characteristics) that requires a deeper understanding of how things work and a good filter on possible ideas & which ones are going to likely work out the best (that is gained through expertise, creativity & intelligence)

[pipes]

If you made this into a book, I'd buy it! Especially if it was structured so that each chapter had a coding exercise that built on the previous one so that by the end I had a working stack.

My favourite programming book is structured like this "elements of computer systems" also referred to as "from nand to Tetris"