Most low level network programming

I am trying to begin learning of network programming with C++ and I want to go to very low level, to be more specific about level I want to begin somewhere above the drivers and under the sockets I want to be able to create my own sockets, the goal is not to create socket but the idea is that I want to be able to understand the code of socket or how it's code is done same goes to protocols. I am not asking to search for any resources just tell me the resources that you used to learn on such low level.

I found similar question to this on stackoverflow but they are useless. so please don't post those questions under this question.

also I know the stuff in C++ I mean fundamentals and maybe more and I want to know how much should I know to begin learning such low level network programming.

thank to everybody in advance.