I started a networking class once, found it unutterably boring, dropped it.
I would say read all of the chapters once without worrying about memorizing every fact. Just read to see what's there, what the context is, the flow of the information.
Then go back and instead of making notes, make a study guide. What are the 7 (or 11) layers, what goes in each one, etc. Do this for each chapter without worrying about mastering one before moving to the next.
Next round, you study. Get with someone in the class or a group of people to go over it. Maybe someone else has devised a system to help with the learning.
This sounds like the kind of densely detailed info it's hard to memorize unless you use it. So if you can find use cases to demonstrate the info or relate it to, you might do much better than just by reading alone. The Internet may have things like this.