[BarbaryCoast]

Wanted to bump this. It's the book I recommend when someone asks, "How can I learn networking".

My next favorite is the Top-Down book everyone above mentions. I like that it starts with loading a web page, instead of bits on a wire. And they have pcap files so you don't even need a lab.

The Stevens book is the standard text for programmers writing network code.

Beej's Guide (https://beej.us/guide/bgnet/) Is how I learned.

By the time you get here, you'll know enough to know which book to read next.